SELF-PROTECTIVE MEASURES

TO ENHANCE AIRLIFT

OPERATIONS IN

HOSTILE ENVIRONMENTS

by

JOHN A. SKORUPA, Lt Col, USAF

Research Fellow

Airpower Research Institute

Winner oftheAir Force Historical Foundation's

1988 Colonel James Cannell MemorialAward

Air University Press

Maxwell Air Force Base, Alabama 36112-5532

September 1989
Skorupa, John A.

Self-protective measures to enhance airlift operations in hostile environments/by

John A. Skorupa.

p. cm.

Includes bibliographical references.

1. Airlift Mllitary-United States . 2. Air warfare. 3. United States Air Force.

I. Title.

UC333.S56 1989 89-15156

358.4'4'0973-dc20 CIP

ISBN 1-58566-028-0

First Printing September 1989

Second Printing September 1993

Third Printing August 2000

Fourth Printing September 2001

Disclaimer

This publication was produced in the Department of Defense school environment and in the

interest of academic freedom and the advancement of national defense-related concepts . The

views expressed in this publication are those of the author and do not reflect the official policy or

position of the Department of Defense, or the United States government.

This publication has been reviewed by security and policy review authorities and is cleared for

public release.

11
FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . ix

ABOUT THE AUTHOR . . . . . . . . . . . . . . . . . . id

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . xiii

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . xv

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi

Part I

OPERATIONAL NEED

1 AIRLIFT DOCTRINE AND FORCES . . . . . . . . . . 3

Current Airlift Doctrine . . . . . . . . . . . . . . . . . . 3

Formal Doctrine . . . . . . . . . . . . . . . . . . . . 4

Joint Doctrine . . . . . . . . . . . . . . . . . . . . . . 7

Informal Doctrine . . . . . . . . . . . . . . . . . . . 8

Force Structure . . . . . . . . . . . . . . . . . . . . . . . 11

Strategic Airlift . . . . . . . . . . . . . . . . . . . . . 11

Tactical Airlift . . . . . . . . . . . . . . . . . . . . . . 16

Airlift Operations . . . . . . . . . . . . . . . . . . . . 17

Other Operations . . . . . . . . . . . . . . . . . . . . 19

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 19

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2 THE THREAT . .

. . .

. . . . . . . .

. . .

. . . . . . . . 23

Mission Scenarios . . . . . . . . . . . . . . . . . . . . . 23

Deployment . . . . . . . . . . . . . . . . . . . . . . . 24

Employment and Sustainment . . . . . . . . . . . . . 25

Threat Intensity . . . . . . . . . . . . . . . . . . . . . . 26

Near Main Operating Bases . . . . . . . . . . . . . . 28

En Route between Theaters . . . . . . . . .

.

. . . . . 28

En Route within Theater . . . . . . . . . . . . . . . . 31

Near Forward Operating Locations . . . . . . . . . . 34

Peacetime-versus-Wartime Threats . . . . . . . . . . . 34

Threat Trends . . . . . . . . . . . . . . . . . . . . . . . 35

History . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Future . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 43

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . 44

iii
Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Waveform Types . . . . . . . . . . . . . . . . . . . . 55

Other Design Considerations . . . . . . . . . . . . . 58

Radar Usage . . . . . . . . . . . . . . . . . . . . . . 59

Electronic Warfare Practice . . . . . . . . . . . . . . . 63

Offensive and Defensive Tasks . . . . . . . . . . . . 64

Electronic Warfare Tasks . . . . . . . . . . . . . . . 65

Electro-optical Countermeasures . . . . . . . . . . . . 79

Infrared Homing Missiles . . . . . . . . . . . . . . . 80

Antivision Lasers . . . . . . . . . . . . . . . . . . . . 81

Laser Beam-Riding Missiles . . . . . . . . . . . . . . 82

Directed-Energy Weapons . . . . . . . . . . . . . . . 82

System Countermeasures . . . . . . . . . . . . . . . . . 83

Time . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Countering Humans . . . . . . . . . . . . . . . . . . 83

Missile Guidance Countermeasures . . . . . . . . . 84

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 86

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

4 TECHNOLOGICAL SOLUTIONS . . . . . . . . . . . . 91

Design Philosophy . . . . . . . . . . . . . . . . . . . . . 91

Benefits of LowAltitude . . . . . . . . . . . . . . . . . 94

Countering Radar Systems . . . . . . . . . . . . . . . . 99

Avoiding Detection and Acquisition . . . . . . . . . 99

Defeating Radar Systems . . . . . . . . . . . . . . . 105

Countering Airborne Interceptors . . . . . . . . . . . . 108

Avoiding Airborne Interceptors . . . . . . . . . . . . 109

Defeating Airborne Interceptors . . . . . . . . . . . 110

Defeating Radar Missiles . . . . . . . . . . . . . . . . . 115

Countering Electro-optical Weapons . . . . . . . . . . 117

Avoiding Infrared Detection and Acquisition . . . . 117

Defeating Infrared Tracking . . . . . . . . . . . . . . 120

Defeating Infrared Missiles . . . . . . . . . . . . . . 121

Avoiding Optical Detection . . . . . . . . . . . . . . 124

Defeating Optical Tracking . . . . . . . . . . . . . . 125

Countering Directed-Energy Threats . . . . . . . . . . 125

Countering Antivision Lasers . . . . . . . . . . . . . 126

Countering Laser Beam-Riding Weapons . . . . . . 127

Countering Directed-Energy Weapons . . . . . . . . 128

iv
5 ECONOMIC AFFORDABILITY . . . . . . . . . . . . . 135

Linking Missions, Aircraft, Threats, and Solutions . . . 135

System Requirements for Category 1 Threats . . . . 136

System Requirements for Category2 Threats . . . . 137

Weapon System Costs . . . . . . . . . . . . . . . . . . . 139

Cost of Doing Nothing . . . . . . . . . . . . . . . . . . . 142

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 147

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

6 BUDGETARY REALISM . . . . . . . . . . . . . . . . . 151

Peacetime-versus-Wartime Considerations . . . . . . . 151

Core Systems versus Augmentation and

Future Requirements . . . . . . . . . . . . . . . . . . 157

Strap-On and Partial Fleet Capabilities . . . . . . . . . 163

Aircraft-Unique Considerations . . . . . . . . . . . . . 168

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 170

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

7 SUMMARY AND RECOMMENDATIONS . . . . . . . 173

Lessons Learned . . . . . . . . . . . . . . . . . . . . . . 173

Operational Need . . . . . . . . . . . . . . . . . . . . 174

Technical Feasibility . . . . . . . . . . . . . . . . . . 175

Economic Realism . . . . . . . . . . . . . . . . . . . 178

Recommendations . . . . . . . . . . . . . . . . . . . . . 181

Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Doctrinal Debate . . . . . . . . . . . . . . . . . . . . 183

Organizational Machinery . . . . . . . . . . . . . . . 184

ILLUSTRATIONS

Figure

1 Radio Frequency Absorption . . . . . . . . . . . . . . . . 53

2 Visible and Infrared Absorption . . . . . . . . . . . . . . . 53

3 Radar Burnthrough . . . . . . . . . . . . . . . . . . . . . . 69

4 Ghosting Problem with Netted Radars . . . . . . . . . . . 70

5 Knife-Edge Diffraction . . . . . . . . . . . . . . . . . . . . 109

v
pyp

6 Deployment Mission Air-to-Air Missile Threats . . . . . . 31

7 Employment and Sustainment Mission

Surface-to-Air Missile Threats . . . . . . . . . . . . . . . . 32

8 Electromagnetic Spectrum . . . . . . . . . . . . . . . . . . 50

9 Atmospheric Particle Sizes (Diameter) . . . . . . . . . . . 51

10 Land and Airborne Radars . . . . . . . . . . . . . . . . . . 60

11 Soviet Naval Radars . . . . . . . . . . . . . . . . . . . . . . 61

12 Early Warning and Tracking Radar ECMand

ECCM Techniques . . . . . . . . . . . . . . . . . . . . . . 78

13 Infrared Sensitive Photoconductors . . . . . . . . . . . . . 80

14 Mission, Aircraft, and Threat Linkage . . . . . . . . . . . 136

15 Self-Protective Systems for Deployment Mission . . . . . 137

16 Self-Protective Systems for Employment and

Sustainment Missions . . . . . . . . . . . . . . . . . . . . . 138

17 Weapon System Acquisition Costs . . . . . . . . . . . . . . 140

18 Acquisition and Installation Costs of Fully Capable

Self-Protective Systems . . . . . . . . . . . . . . . . . . . . 141

19 Acquisition and Installation Costs of Fully Capable

Self-Protection for MACInventory . . . . . . . . . . . . . 142

20 Cost of Doing Nothing to Defend the C-17 Fleet . . . . . . 143

21 Affordability ofDefending Airlift Aircraft . . . . . . . . . 143

22 Cost of Doing Nothing to Defend the C-130 Fleet . . . . . 144

23 Affordability of Defending C-130 Aircraft . . . . . . . . . 144

24 Cost of Doing Nothing to Defend the Airdrop

C-141 Fleet . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

25 Affordability of Defending Airdrop C-141 Aircraft . . . . 146

26 Category 1 Threats and Solutions versus Normal

Peacetime Need . . . . . . . . . . . . . . . . . . . . . . . . 153

vl
Installation Costs for the MACInventory . . . . . . . . . . 156

30 Rank Order of Protective Systems . . . . . . . . . . . . . . 157

31 Incremental Buildup of Protective Systems . . . . . . . . . 160

32 Incremental Buildup: Short-, Intermediate-, and

Long-Term Acquisition and Installation Costs . . . . . . . 161

33 Incremental Buildup: Acquisition and Installation

Costs for the MAC Inventory . . . . . . . . . . . . . . . . 162

34 C-130 Strap-On Candidate System Costs . . . . . . . . . . 166

35 Savings Potential of Not Equipping Certain C-130s . . . . 167

36 Impact of Partial C-130 Equipage on Costs . . . . . . . . . 167

37 Incremental Buildup: Acquisition and Installation

Costs for C-5s, C-17s, and Airdrop C-141s . . . . . . . . . 169

Vii

North America as possible has elevated airlift's importance in

national security to a critical level. Air Force support of this

strategy has led to the acquisition of new airlift aircraft and an

emerging doctrine of global forward delivery that exposes

airlifters to awide range of threats across the conflict spectrum.

Such a doctrine and our plans for global projection maynot be

supportable unless airlift aircraft are equipped with selfprotective systems. Alack of airlift survivability is a potential

Achilles' heel in the US global defense posture. This is an

ominous and compelling reason for studying how to protect

airlift aircraft in hostile environments.

Self-Protective Measures to Enhance Airlift Operations in

Hostile Environments is a worthy response to this national crisis

for its timeliness, comprehensive approach, and authority. The

report is timely not only in addressing an issue of national

strategic significance but also in doing so at a time when the

Military Airlift Command is beginning its search for solutions.

The report is comprehensive in its examination of strategy,

doctrine, forces, threat, and technological solutions while also

considering cost and fiscal issues. Thereport is authoritative in

its blending of military art with industrial science, and only a

person with the author's experience and insight could have

produced it.

The author's unique perspective on this topic comes from

having spent 19 years as a pilot in transports, as an aeronautical

engineer developing and acquiring combat aircraft, as a staff

officer at the Military Airlift Command dealing with daily

operational issues, and as aresearch fellow studying the subject

at great length. He has done a masterful job of explaining

complex problems and potential solutions in easily understood

terms. The study will undoubtedly stand as a landmark effort

AUTHOR

Lt Col John A. Skorupa is a graduate of the United States

Air Force Academy, the Air Force Institute ofTechnology, and

the Air War College. He holds bachelor of science andmaster

of science degrees in aeronautical engineering.

His assignments have included tours of duty as an aeroperformance engineer, chief engineer on a solid-rocket motor

development program, acquisition source selection evaluator,

branch chief at Headquarters Military Airlift Command

(MAC) responsible for C-5 and C-17 aircraft acquisitions,

director of command presentations at Headquarters MAC,

and MAC-sponsored research fellow.

As a command pilot, he has accumulated more than 3,000

flying hours, primarily in C-130s, ofwhich 190 were in combat

in Southeast Asia. His decorations include four Meritorious

Service Medals, two Air Medals, and two Air Force

Commendation Medals.

He is married to the former Barbara Ann Seabright of

Phoenix, Arizona. They have one child, a son, Scott.

W. Klingaman, a senior research fellow and my adviser at the

Air University Center for Aerospace Doctrine, Research, and

Education (AUCADRE), and John E. Jordan, Jr., my editor.

Both ofthese gentlemenwere thereat the beginning, teaching,

counseling, andlistening through every step and draft along the

way. Their help was invaluable.

Credit also belongs to Col Dennis M. Drew, director of the

Airpower Research Institute (ARI), and members of his staff,

DrDavid Maclsaac andCol Keith W. Geiger,whohelped focus

the research . Their help was also invaluable in producing the

briefing taken to Headquarters Military Airlift Command,

which concluded the year-long effort .

Contributors who helped make this study authoritative by

contributing information on their efforts in the field are:

Kelton Farris and J. R. Meese, Boeing Military Airplane

Company; John Hughes, British Aerospace; Louis Manz,

Eaton-AIL; Neal Socha, General Dynamics; Tom O'Brien,

Jack Ingold, and Joe Stump, Grumman; Pete Reggie, Dave

Sjolund, and Don Dabney, Hughes Radar Systems Group;

Frank Romanelli andJimSawicki, IBM; Bill MacInnis and Bob

Dudley, Lockheed; Bill O'Hare, Vern Binion, andDickHeath,

Raytheon; Ed Hanna, Sanders Associates ; Gerald MacKay,

Singer; Charles Chopoton, Bob Tidwell, Jeff Hoffman, and

Warren Hatcher, Texas Instruments; Gary Barr, Tracor; and

Dwight Hunsicker and Bob Venkus, Westinghouse.

Aspecial thanks goes to Maj Ray A. Yagher, Aeronautical

Systems Division, Air Force Logistics Command, WrightPatterson Air Force Base, Ohio, for advice and counseling

along the way. His efforts saved me many hours in pursuit of

what would have been unproductive leads.

Finally and most important, I want to express my gratitude

to my wife, Barb, and son, Scott, who patiently endured the

many hours this effort kept me from them. Their support made

it worthwhile and possible .

threat require that we be prepared. to defend our interests as

far from North America as possible ."' That strategy "relies

heavily on forward deployment of combat-ready forces,

reinforced by strong alliance relationships.

,2 It is unlikely,

however, that the United States could station sufficiently sized

and configured forces to support a sustained allied defense

against a full-scale attack by a major foreign power in any

theater of war. Since it is equally unrealistic to expect that our

friends and allies will be able to absorb the full brunt of such

an attack by themselves, success of US national security

strategy maywell depend on the strategic and tactical mobility

of our military forces .

Given ample warning, mobility requirements could be met

by sea and land transportation, but warning time is rarely

ample. In Europe, for example, US forces would have to hang

on three to four weeks before receiving their first resupply and

reinforcement by sea. In three weeks, the outcome of the

conflict could be decided. In Africa, the Middle East, and the

southern Pacific basin, there are no US ground forces in place

to augment or replace the defense capabilities of our friends

and allies . Moreover, as anticipated in the National Security

Strategy of the United States, US security interests may be

threatened by conflicts short of general war, andsome of those

mayrequire immediate and direct intervention by the United

States . In all of these circumstances, the role of airlift is

paramount.

To support US global strategy, airlift doctrine and force

modernization initiatives are structured to provide direct

delivery of forces to terminal locations adjacent to the battle

area. Direct delivery to and sustainment of US forces at

forward locations is a key aspect of AirLand Battle planning,

but there are reasons to suspect that this doctrine will be

difficult to apply in a modern conflict using airlift assets that
economically realistic to equip airlift aircraft with selfprotective systems?

Part I of this study is devoted to examining the question of

operational need. This is done by comparing doctrine, force

structure, and the threat . Part II addresses technical feasibility

by examining the requirements of electronic warfare and the

solutions offered by technology. Part III addresses economic

realism by evaluating system costs, budgetary impacts, and

acquisition strategies . In conclusion it summarizes findings and

makes recommendations for assisting MACin transitioning to

a force structure capable of electronic combat.

Howis this study different from previous or ongoing efforts?

First, it addresses the significance of doctrine in shaping the

inventory; it shows how aspects of inherited doctrine have

slowed the evolutionary process offorce modernization; and it

indicates where those aspects have created disparities in favor

of the enemy. Second, it investigates the nature of the

interaction between aircraft penetrating enemy defenses and

the defenses as they respond. Third, it addresses acquisition

strategy for countermeasures from a major command's

perspective. Fourth, it goes beyond most current efforts by

looking at unconventional defense opportunities that exploit

emerging technology in cockpit presentations, precision

navigation systems, lethal defense options, laser-guided

weapon defense, directed-energy weapon defense, and stealth

technology. And finally, it offers an approach by which

Headquarters MAC could sponsor the development,

integration, and acquisition of mission-enhancing technology .

NOTES

1. National Security Strategy of the United States, The White House,

January 1987, 19.

2. Ibid .

xvi
OPERATIONALNEED

Establishing an operational need for a weapon system or a

military capability requires an iterative, or cyclical, process of

balancing strategy, doctrine, forces, and missions against the

threat. Since national security strategy defines the task and

doctrine provides the architecture for fleshing out forces and

assigning missions, a comparison of the capability of US forces

to carry out their mission against the threat's ability to deny

mission accomplishment is an appropriate departure point for

establishing operational need.

Accordingly, chapter 1 accepts, as given, the national

security strategy of defending US interests as far from North

America as possible and begins with a discussion of doctrine

and current airlift force structure. When the two are compared,

a mismatch becomes apparent. The doctrine prescribes a

capability for forward delivery and operations into overlapping

threat regions in support ofthe AirLand Battle, but the current

airlift force structure only reflects capability in a no-threat

environment. The threat, in effect, becomes a discriminant in

determining force structure shortfalls .

Chapter 2 is a general assessment of the threat to the airlift

mission. That assessment makes it apparent that airlift force

structure has not kept pace with the threat and is severely

limited in its ability to carry out current doctrine.

The importance of chapters 1 and 2 is in establishing the

operational need to equip airlift forces with self-protective

devices. Establishing this need provides a logical lead-in to

discussions of technical feasibility in part 11 and economic

reality in part 111.

1

AIRLIFTDOCTRINE AND FORCES

The environment in which airlift aircraft must operate is

becoming increasingly hostile. Man-portable, shoulder-fired,

heat-seeking missiles have been supplied to armies and

insurgent groups around the world and must be considered

commonplace. In addition, the nature of the battlefield is

changing such that airlift aircraft will be increasingly exposed

to pockets of conventionally armed military units.' Given that

MACairlift aircraft currently carry no defensive systems, must

transports accept a diminished role in future US military

strategy or can they be defended? If they can be defended,

should they rely on supporting forces or should they be

equipped to defend themselves?

These are weighty questions whose solutions will have

repercussions beyond the airlift community. In fact, they bring

into question the ability of airlift forces to support national

security strategy. To answer these questions, one must examine

what national security strategy currently requires and howAir

Force doctrine supports that strategy.

CurrentAirlift Doctrine

As mentioned in the introduction, the United States must

"be prepared to defend our interests as far from North America

as possible.

,2 When economic realities, alliance limitations,

and geopolitical requirements are considered, the necessity for

a survivable airlift force becomes evident. National security

strategy is quite clear on this point. How doctrine works to

support the strategy, however, is not so clear.

3
military action."3Since Air Force doctrine is forged from "the

study and analysis of experience," its basis is "what has usually

worked best."4While "it is authoritative," it "requires

judgment in application" to future circumstances5 To make

doctrine relevant, the Air Force organizes it into three levels

of application: basic, operational, and tactical.

Basic Doctrine. "Basic doctrine states the most fundamental

and enduring beliefs which describe and guide the proper use

of aerospace forces in military action.

,6 Undoubtedly, the most

sacred Air Force belief is the need to gain air superiority

quickly. Without air superiority, US forces will lose freedom of

action and tactical flexibility. Addressing this issue, Air Force

Manual (AFM) 1-1, Basic Aerospace Doctrine of the United

States Air Force, states :

As a primary consideration, aerospace forces must neutralize

opposing aerospace forces, including both aerospace and

surface threats; otherwise, they cannot fully exploit their striking

power to assist friendly surface forces . Aerospace superiority,

therefore is prerequisite to the success of land and naval forces

in battle . ?

The strong implication of AFM 1-1 is that without air

superiority, all else is in jeopardy. So, how does one fight until

air superiority is gained? What if gaining air superiority takes

longer than the surface battle will permit? If the lowly Afghan

insurgent could deny the Soviets air superiority, what makes

the Air Force think it can achieve air superiority against the

Soviets, or even an insurgent?

Basic doctrine also specifies primary roles and missions .

Airlift is oneof these, and its objectives are "to deploy, employ

and sustain militaryforces through the medium ofaerospace."s

Butno specific mention is made of howto defend airlift forces.

4
Also, defensive counterair (DCA) whose mission is to detect,

identify, intercept, anddestroy enemyaerospace forces that are

attempting to attack friendly forces or penetrate friendly

airspace," would presumably help.10

The doctrinal question is not as clear-cut as AFM1-1 would

lead one to believe, however. For example, how do SEAD and

DCA forces protect airlift aircraft targeted by a terrorist's

shoulder-fired, heat-seeking missile? Or if the US concept of

future war is the AirLand Battle, inwhich rapidly maneuvering

forces penetrate to each other's rear areas, how do airlift

aircraft avoid coming within lethal range of penetrating or

bypassed enemy forces while keeping the friendly forces

resupplied?

Operational Doctrine. Basic doctrine is too general in

nature to answer these types of questions. Instead one must

inquire at the operational level of doctrine .

Operational doctrine applies the principles of basic doctrine to

military actions by describing the proper use of aerospace forces

in the context of distinct objectives, force capabilities, broad

mission areas, and operational environments . Operational

doctrine describes the organization of aerospace forces, and it

anticipates changes and influences which may affect military

operations, such as technological advances. The Air Force

publishes operational doctrine in the Air Force 2-series manuals

to provide detailed mission descriptions and methods for

preparing and employing aerospace forces ."

On review of AFM 2-1, Tactical Air Operations-Counter

Air, Close Air Support, and Air Interdiction, and AFM 2-4,

Tactical Air Force Operations- TacticalAirlift, one is struckby

how old they are (2 May 1969 and 10 August 1966,

respectively). Conceptually, they fall short on several scores :

they predate AirLand Battle doctrine (circa 1982); they contain

5
airlifters will be operating in areas that impose no requirement

for self-protection.

Recently released AFM 2-8, Electronic Combat (EC)

Operations, dated 30June 1987, addresses the electronic aspect

of self-protection by stating:

Enemy threat systems most likely to impact airlift operations

outside of the forward areas are enemy naval SAMs, mobile

SAMs, and hostile electronic warfare against communications,

navigation, and IFF [identification, friend or foe] systems. In

addition to these threats, airlift forces operating in the forward

combat area are susceptible to early warning and acquisition

radars, antiaircraft gunlaying systems, selected SAMs, and

fighter interceptor aircraft. While most airlift operations are

normally conducted in relatively permissive environments, threat

warnings, countermeasures, and exendables are required to

protect the force from these threats."

For the first time, modern wartime conditions are described

and a solution is suggested, although it does not mention the

role of SEAD and DCA.

The Military Airlift Command is currently in the process of

drafting United StatesAir Force Operational Doctrine -Airlift,

wherein it proposes:

The relatively lame size, slow speed, and poor inflight

maneuverability of airlift aircraft make them vulnerable to many

ground and air threats. Survivability against these threats

depends on combinations of accurate intelligence assessments,

combat tactics, onboard defensive systems, supporting tactical

air operations, and joint suppression of enemy air defense

systems. 13

The key change promulgated by AFM2-8 and the draft MAC

manual is the concept of "onboard defensive systems."

However, until the draft manual is formalized and the concepts

of AFM2-8 and AFM 1-1 are integrated in a coherent plan,

Air Force operational doctrine will be lacking.

Tactical Doctrine. At the tactical level ofAir Force doctrine,

the gaps remain. First, tactical doctrine is intended to guide

6
, y oftactical doctrine is suspect. Indeed,

review of AFM3-4, Tactical Air Operations- Tactical Airlift,

dated 22 September 1971, illustrates the point. For instance,

tactical airlift doctrine addresses capabilities and tactics that

no longer apply because of the present nature of enemy

defensive systems . Formal Air Force doctrine (basic,

operational, and tactical), therefore, falls short of answering

the questions concerning howto protect airlift aircraft.

At this point it maybe instructive to point out that not all Air

Force doctrine is the exclusive domain of the Air Force, nor is

it all formal. Frequently, joint doctrine, in resolving joint roles

and missions, obligates the Air Force to a particular course of

action.

Joint Doctrine

To illustrate the influence of joint doctrine on airlift,

consider the joint AirLand Battle doctrine . This doctrine

requires US forces, including ground forces, to attack potential

adversaries indepth. When ground forces proceed into the rear

area of enemy formations, they will require periodic resupply

that will expose the logistics stream to bypassed enemy forces .

This constitutes a threat . Of course, not all resupply in AirLand

Battle will go by air; most will probably go by truck. Still, airlift

is responsible for a critical portion.

The airlift community is just now starting to address these

issues. In December 1987 the joint Army-Air Force Airlift

Concepts and Requirements Agency (ACRA) at

Headquarters MACsubmitted a draft ofjoint pamphlet, Joint

Airlift for Combat Operations (MACP 55-XX and TRADOC

PAM 525-XX), which strives to resolve the doctrinal

requirements for deep operations . Many previously

7
systems."

Although thisjoint doctrine helps considerably in addressing

airlift doctrine for the AirLand Battle, it brings one back to the

starting point of this search, because it does not address, for

example, the shoulder-fired missile threat. In addition, it

suggests that the presence of US forces deep in the enemy's

rear area will attract a strong enemy air response in the form

ofairborne interceptors andarmedattack helicopters, creating

additional threats. 6 Also it ignores the surface-to-air threat

posed by enemy forces operating deep in the US rear area, a

traditional "safe haven" for airlift aircraft. In fairness to the

pamphlet, it recognizes the limitations of SEAD forces and

only requires that corridors be "relatively" free of enemy air

defense systems . Nevertheless, the pamphlet states,

"Defensive systems and electronic countermeasures capability

are necessary [for transports] to limit attrition and ensure

mission success.

1'

Informal Doctrine

Occasionally, when formal Air Force and joint doctrines are

neglected, informal doctrine fills the void. A sequence of

events in the development of the C-17 aircraft illustrates this

point. When the C-X Request for Proposal (from whence the

C-17 came) was sent to potential builders, technology and

operational efficiency had combined to make it possible for a

strategic airlift aircraft to deliver cargo into the forward area's

3,000-foot runways. Consequently, the proposals spawned the

concept of "direct delivery," or delivery from main staging

bases to forward operating bases (FOBs) . Subsequent

testimony, during congressional budget hearings, advertised

this capability as an important distinguishing advantage over

8
study that validated the mission, threat, and need for specific

types ofdefensive systems. This study was then endorsed by the

secretary of defense and submitted to Congress. Inthe process,

several doctrinal issues were decided. Although formal

doctrine did not guide the development of the C-17, as formal

doctrine is supposed to do, doctrine in other forms did.

To further illustrate the influence of informal doctrine, a

discussion of the evolution of US airlift forces and the role they

have inherited should be helpful. In addition, a review of the

types of airlift aircraft currently in the force should be

particularly illuminating.

To begin, the US form of airlift evolved from the early days

of World War II when the Air Corps Ferrying Command was

formed to move Lend-Lease materiel from the United States

to Great Britain. 18 As the war expanded to the Pacific theater,

airlift forces were combined under the Air Transport

Command (ATC).19 Troop carrier squadrons, however,

remained with the tactical air forces.

The legacy of Air Transport Command was quickly

established as it provided regular flights where no service had

flown before. In addition to ferrying aircraft to the Soviet

Union by way of Alaska, the command delivered aircraft to

North Africa, India, and China. Of all the routes, the "Hump"

to China was the most inspiring, instilling the "you call, we

haul" informal doctrine . Aircraft used were primarily such

military adaptations of commercial aircraft as the C-47 (DC-3).

With the formation of the Department of Defense and the

creation of the Air Force as a separate organization under the

National Security Actof 1947, the NavalAir Transport Service,

the Air Weather Service, and the Airways and

Communications Service were consolidated with the Air

Transport Command to form the Military Air Transport

9
of airlift : anytime, anywhere.Militaryvariants ofcommercial

aircraft, such as the C-54 (DC-6), still predominated.

Airlift continued to gain in stature through the Korean and

Vietnam conflicts so that Congress elevated it on 1 January

1966 to the status of a major command, the Military Airlift

Command. Initially, MAC controlled strategic airlift assets

that operated between theaters of operations (for example, the

continental United States, or CONUS, and Europe). Tactical

airlift assets, which evolved from the earlier troop carrier

squadrons of World War II fame, remained under the tactical

air forces until 1 December 1974, when MACassumed control

of them.22 During this period a transition from a military

airline-type operation, flying commercial equipment, to

combat airlift began and uniquely military aircraft (C-97,

C-119, C-123, C-124, C-130, C-133, C-141, and C-5)

increasingly displaced the civilian aircraft.

In recognition of MAC's growing importance to US strategy,

it was designated a specified command on 1 February 1977,

effectively streamlining command and control procedures

during periods of hostilities as On 1 March 1983 MAC took

control of all Air Force special operations activities, and on 1

October 1987 it was integrated into the newly formed unified

command, US Transportation Command (USTRANSCOM) . 24

Currently MAC operates at several levels . During

peacetime, its primary task is deterrence, as is reflected in its

motto, The Backbone of Deterrence. To fulfill this peacetime

role, it must train and maintain a credible capability to deploy

and employ militarily significant forces quickly to points where

vital US interests are at stake. During hostilities MACwould

continue the deployment and employment functions while

10
versa, is not significant here. The important point is that

informal doctrine encompassing "can do," "you call, we haul,"

and "airlift: anytime, anywhere" grew regardless of the

potential threat. Informal doctrine is as much apart of MAC's

culture as formal andjoint doctrine, and it has had as significant

an influence in shaping the present airlift force structure.

Force Structure

In peacetime and in wartime MACperforms both strategic

and tactical missions . Although there is a tendency to think of

specific aircraft as being strategic or tactical, it is really the

mission that determines the designation of a particular aircraft.

Nevertheless, it is helpful to examine the various airlift aircraft

in the context of their usual missions to evaluate shortfalls in

doctrine or forces when compared against the threat described

in chapter 2.

Strategic Airlift

The airlift forces MAC uses on strategic, or intertheater,

missions include the C-5AB Galaxy, the C-141B Starlifter, the

KC-10A Extender, and aircraft of the Civil Reserve Air Fleet

(CRAF). All these aircraft have considerable capability, but

until recently there was no agreement on numbers required .

Quantification of Requirement. Since 1974, 18 major

mobility studies have attempted to quantify airlift

requirements25 The most widely respected was the 1981

"Congressionally Mandated Mobility Study." It evaluated US

strategic airlift requirements for four European and Southwest

Asian scenarios and determined that afiscally achievable level

of airlift would be 66 million ton-miles per day (mtm/d) ab Note

11
figure has become sacrosanct even though it is not based on

national security requirements.

Confusing budgetary limits with national security

requirements is only part of the problem. Since 1981 the size

of Army units has growndramatically. For example, anotional

1981 mechanized infantry divisionweighed in at approximately

50,000 tons; presently such a division weighs more than 79,000

tons. Although the Army has attempted to rectify this

situation by creating light infantry divisions, the overall airlift

requirement has increased above that considered in the 1981

study.

To date MAC has increased its airlift capability to

approximately 45 mtm/d. Representative numbers of current

aircraft are shownin table 1.

TABLE1

Strategic Airlift Aircraft

Million Ton-Miles

Aircraft Number perDay

C-5A 64 11.0

C-5B 44' 7.5'

C-141B 215 14.2

KC-10A 41 4.5

CRAP 330 11.3

TOTAL 694 48.5

*To be reached in July 1989.

The C-17 aircraft will join the service in 1992 and should

build overall capability to the desired 66 mtm/dlevel by 1998. 29

The main point of this discussion is the criticality of airlift

resources. Since the real airlift requirement is greater than the

66 mtm/d goal, the loss of even small numbers of airlift aircraft

would have serious consequences in meeting mobility

requirements .

12
y ppg qp

(cargo too large for C-130s or C-141s) as the Army's main

battle tank. Although it could carry up to 340 troops, its real

militaryvalue is its ability to carry Army equipment that cannot

fit in smaller aircraft3° For example, 26 percent of a

mechanized infantry division's equipment is too big for other

current aircraft. TheC-5's ability to "kneel" on the ground and

offload and onload through front and rear cargo doors

enhances its utility over civilian systems. Operational

experience with this aircraft, however, has resulted in

restricting its operations to runways longer than 5,000 feet.

Furthermore, its size frequently confines it to airfields built to

jumbo jet specifications, effectively eliminating many forward

area fields and fighter bases.

C-141B. The C-141B is also an air-refuelable aircraft. It is of

narrow-body configuration but is otherwise similar to the C-5.

Its flexible interior configuration allows it to carry 103 litter

patients, 13 463L system pallets, or oversize rolling stock

(equipment too large for commercial cargo aircraft) up to 45

tons in weight.In an airdrop mode, it can precisely deliver up

to 35 tons or 155 paratroops . It, too, is limited to airfields of

5,000 feet or longer.

KC-10A. TheKC-10A is a militaryversion ofthe commercial

DC-10 cargo plane. Its primary function is as a tanker, but it

can serve as a transport. Because its cargo floor is 17 feet above

the ground, the KC-10A requires specialized ground-handling

equipment. Furthermore, its cargo compartment is designed

for palletized loads (no unpalletized rolling stock) that must

conform to one of five contour limits and four weight limits . It

is capable of carrying 27 463L system pallets or 84.5 tons of

cargo. When pallets are not in place, extensive use of shoring

13
widebody capable airports.

C-17. The C-17 has a wide-body fuselage of the same

approximate exterior dimensions as the C-141B and KC-10A,

but it has superior ground-handling characteristics. It is

designed for outsized rolling stock, short runways, and small

parking areas. Because it will be air refuelable, it will be able

to carry 102 passengers, 48 litter patients, 18 463L system

pallets, or 86 tons of equipment to any place in the world that

has 3,000 feet of runway. In an airdrop mode, it will precisely

deliver 102 paratroops, 13 pallets, or 55 tons. As an additional

feature, it will be able to deliver outsized equipment using

low-altitude parachute extraction system (LAPES)

procedures . Retirement of 54 older C-141s, placement of

another 80 C-141s in the reserves, and purchase of 180 C-17s

will bring strategic airlift capability up to 66 mtm/d by the year

2000. 32

An interesting development in the acquisition of the C-17

has been the recent addition by Congress of the requirement

to include defensive system costs in the funding profile. As a

result of this requirement, the C-17 Defensive Systems Study

was completed and submitted to the secretary of defense in

September 1987. The study recommended inclusion of

onboard defensive systems in the C-17's design. This sets an

informal doctrinal precedent for defending other transports on

similar missions or in similar threat environments with

onboard systems.

Civil Reserve Air Fleet. CRAF aircraft make a significant

contribution to MAC's total strategic lift capability, but they

bring equally significant operating limitations . In a

mobilization scenario, they would contribute 144.9 million

passenger-miles per day, which is approximately 95 percent of

14
palletized cargo and to use of commercial-class airports. They

can carry all but the largest oversize vehicles, but they cannot

carry them in combat-ready configurations because of the

various degrees of disassembly required 3`' Because of the

voluntary nature of the CRAF program, its contribution could

change significantly from month to month. In general, the

long-range CRAF consists of the' Boeing 747, Lockheed

L-1011, McDonnell Douglas DC-10, Boeing 707, McDonnell

Douglas DC-8, and Boeing 757. The Boeing 767 will also

participate under a special medical evacuation program.

The Boeing 747 comes in numerous variants, but in general

provides wide-body cargo capability along with a large

passenger capability. The cargo configuration can carry up to

45 pallets or 99.1 tons, while the passenger configuration can

carry up to 419 people. 35

The Lockheed L-1011 was not designed as a cargo carrier.

However, it can carry up to 274 passengers36

The McDonnell Douglas DC-10 is a wide-body transport

with both cargo and passenger variants . The cargo

configuration can carry 27 pallets or 69.9 tons and the

passenger configuration can carry up to 359 people.

The Boeing 707 is a narrow-body airframe that offers both

cargo and passenger variants . The cargo version carries 13

pallets or 29.9 tons . The passenger version carries up to 149

people. 38

The McDonnell Douglas DC-8 is a narrow-body airframe

with both cargo and passenger variants . The cargo version can

carry up to 18 pallets or 41 .4 tons, while the passenger version

can carry up to 264 people.

The Boeing 757 comes in only a passenger version. As such

it can carry up to 185 people ao

15
and 47 cargo aircraft are identified by tail number and are made

available at any location in the CONUSwithin 24 hours. 1

Stage LI of the CRAF, Airlift Emergency, offers an

additional 24 passenger aircraft over stage I within the same

24-hour period. Stage II can be declared at the discretion ofthe

secretary of defense. s

Stage III activation of the CRAF, National Emergency,

offers approximately 188 passenger aircraft and 68 cargo

aircraft over stage II. It can be activated at the discretion ofthe

president or by declaration of Congress, but it allows

participants up to 48 hours to respond. 3

In the event of a NATO contingency, MAChas agreements

with various European governments to gain the use of an

additional 265 passenger aircraft, 88 cargo aircraft, and 34

combination variants . In addition, 14 supersonic Concorde

aircraft would become available

Tactical Airlift

MAC's tactical airlift forces are intratheater assets dedicated

to specific theaters . They are under the operational control of

the theater commanders.

Qualification of Requirement. These aircraft have

intertheater range, but they do not have the capacity to carry

significant tonnage over that range. As a result, the significant

measure of merit for tactical airlift aircraft is generally

accepted to be in terms of tons per day45 Despite this

convention, no acceptable criteria have been developed to

quantify how much tactical airlift is required. Every attempt to

do so has resulted in "scenario-dependent" values that lack the

universality of the 66 mtm/dvalue that determines sufficiency

(albeit fiscal) for strategic airlift. Table 2 reflects current fleet

16
C-130. Thevarious models ofthe C-130 are all characterized

by a four-engine, turboprop design that allows routine

operations into austere landing fields of3,000-foot length. The

C-130A model has a maximum gross weight at takeoff of

122,900 pounds, the C-130B has a gross weight at takeoff of

133,000 pounds, and the E andHmodels can go up to 155,000

pounds. Maximumcargo load over a 1,000-nautical-mile range

is 26,000 pounds for the C-130A, 40,400 pounds for the C-130B,

46,600 pounds for the C-130E, and 47,000 pounds for the

C-130H. Each model can carry either 90 passengers or 64

paratroopers 47

Airlift Operations

Strategic airlift is responsible for intertheater deployment

operations, moving troops and equipment from a CONUS

main operating base (MOB) to a theater MOB or from one

theater MOB to another a8 Occasionally, such deployments

could be airdrops using the C-141B. When the C-17 enters the

inventory, it will be capable of airdrop or airland operations at

forward operating locations (FOLs). Such a capability,

CONUS MOBto theater FOL, is referred to as direct delivery.

Once troops and equipment reach the theater MOB, they

are then moved forward via the most expeditious means, be it

ground, sea, or air transportation. Such air transportation is

17

Aircraft Number Tons/Day

C-130A 104 1868

C-130B 80 1437

C-130E 237 4257

C-130H 83 1491

TOTAL 504 9053
intertheater or intratheater in nature . Airlanding is the

preferred mode, if an airfield is convenient, because of speed,

minimization of losses, and unit integrity considerations49 If

landing is not practical, or where surprise is a consideration,

airdrop is an option. Strategic assets (C-141s and C-17s) and

tactical assets (C-130s) are available for airdrop. The size of

the forces to be employed, field congestion during airland

operations, weather, the threat, terrain, anduser requirements

determine whether single-ship or formation tactics are used.

In the past, if the enemy threat imperiled the mission,

supporting forces wouldbe included to suppress the defense.

An important distinction between intertheater and

intratheater aircraft is their beddown location . Intertheater

aircraft receive support at the various theater MOBS, but they

rely on their CONUS MOB for scheduled maintenance.

Intratheater aircraft usually cannot get maintenance support in

forward areas so aircrews must carefully assess the likelihood

of safely departing from a destination before they arrive to

avoid stranding the aircraft at an FOL. Intertheater aircrews

are changed at appropriate intervals en route, while the aircraft

keep moving. Intratheater aircraft, by contrast, keep the same

crew throughout a mission.

Once US troops are in place they will be sustained using the

same concept of operations used in intertheater and

intratheater deployment. In addition to airland and airdrop

modes of resupply, LADES is an option for heavy pieces of

equipment. The C-130 has, and the C-17 will have, this

capability .

Redeployment operations are merely a reverse of

deployment . If the redeploying forces remain in-theater,

intratheater assets may do thejob entirely. If the redeployment

returns to the CONUS, intertheater assets would be used.

18
ppp

p

Air Weather Service, and the Aerospace Audiovisual Service.

For the purpose of discussing self-protective measures for

airlift aircraft, however, this study is limited to those forces

discussed at length in the previous sections .

Conclusions

Two doctrinal lessons can be drawn from the discussion of

the evolution of US airlift. First, the early days ofmilitary airlift

were not much different from airline operations . As a result,

historical precedent undoubtedly influenced early Air Force

doctrine to leave defense of transports to other forces So

Second, acquisition of the C-17 adds direct-delivery doctrine

to Air Force airlift doctrine. Implicit in direct-delivery doctrine

is the risk associated with flying otherwise undefended aircraft

near combat zones. The C-17 Defensive Systems Study, the

Military Airlift Survivability Study, and the MAC Electronic

Warfare Study acknowledge this threat and providejustification

for equipping transport aircraft with defensive systems.

In summingup the doctrinal issues, one can say that formal

Air Force airlift doctrine, particularly at the operational and

tactical levels, is dated and offers inconsistent guidance.

Although electronic combat doctrine unequivocally requires

self-protective systems on transports, airlift, electronic combat,

SEAR, and DCAdoctrines do not. They should be revised and

standardized to acknowledge the requirement for onboard

defensive systems for transports and to provide an integrated

approach to operations . Joint doctrine, at least in the form of

the draft pamphlet, JointAirlift for Combat Operations, recommends equipping transports with defensive and electronic

countermeasure systems. Informal doctrine, driven by direct

19
aircraft . Depending on the nature of the threat facing

intertheater aircraft, as opposed to the intratheater and

direct-delivery aircraft, a distinction might be made in the type

of defense required. To determine such options, however, one

must consider the threat arrayed against these forces as they

perform their missions.

NOTES

1. MACP 55-XX, JointAirlift for Combat Operations, draft, 14 December

1987, A-3.

2. National Security Strategy of the United States, The White House,

January 1987, 19.

3. AFM 1-1, Basic Aerospace Doctrine of the United StatesAirForce, 16

March 1984, v.

4. Ibid.

5. Ibid.

6. Ibid.

7. Ibid., 2-12.

8. Ibid., 3-5 .

9. Ibid., 3-3 .

10. Ibid.

11. Ibid., vi .

12. AFM 2-8, Electronic Combat (EC) Operations, 30 June 1987, 30, 31.

13. AFM 2-XD, United States Air Force Aerospace Operational

Doctrine-Airlift, draft, 1 February 1987,7.

14. AFM 1-1, vi.

15. MACP 55-XX, E-4,5.

16. Ibid., 4.

17. Ibid., 5, 6, F-6.

18. Roger D. Launius, "MAC Airlift : ABrief History,"AirliftAssociation

Convention Decisions, Scott AFB, Ill ., October 1983, extracted fromAirlift

Operations School Supplemental Reading Text, 503-1.

19. Ibid.

20. Ibid., 503-2.

21. Ibid.

22. Ibid., 503-3.

23. Ibid.

24. Ibid.

25. Headquarters MAC/CSR (Command Presentations), briefing,

"Airlift in Support of National Objectives," May 1986, N-12.

26. USAirForce Airlift Master Plan, 29 September 1983, III-5 .

20
31. Ibid.

32. Ibid ., V-4. The USAF TotalForce Plan, 17 September 1984, keeps 100

C-141s in the active inventory but operates them at a 2.0-crew-per-airplane

ratio, as would the Reserves. The capability and airframe service life are the

same either way. The 180 C-17s represent primary aircraft authorized

PAA). An additional 30 C-17s would be built as backup aircraft inventory

(BAI) and trainers to keep units at full strength while aircraft were in depot

overhaul andwere,being used to train crews.

33. Ibid., III-9.

34. Ibid., II-6 .

35. Ibid.

36. Ibid.

37. Ibid.

38. Ibid., II-7 .

39. Ibid.

40. Headquarters MAC/XPW (Assistant for Civil Air), point paper

presented to the MAC Briefing Team, Scott AFB, M.,15 April 1985 .

41. US AirForceAirlift Master Plan, II-5.

42. Ibid.

43.Ibid.

44. Headquarters MAC/XPW (Assistant for Civil Air), point paper

presented to the MAC Briefing Team, Scott AFB, Ill., 28 November 1984.

45. USAirForceAirlift Master Plan, III-8.

46. Ibid ., III-16. The C-130D is no longer in the inventory and has been

omitted from the table.

47. Military Airlift CommandData Book, Scott AFB, Ill., October 1987,

10.

48. USAirForceAirlift Master Plan, II-7, 8.

49. Ibid ., II-9.

50. William H.Tunner, Over the Hump (Washington, D.C. : Government

Printing Office, 1964), 79. Capt John E. "Blackie" Porter armed two C-47s

with two Bren .30-caliber machine guns each. Onegun was operated by the

copilot firing through his open cockpit window while he other was manned

by a crewmember firing tough the open cargo door. For backup they

carried .45-caliber Thompson submachine guns and hand grenades. On one

occasion they happened across a Japanese Zero sitting in a meadow while

its pilot was repairing the engine. After seven passes they finally killed the

pilot and riddled the Zero.

21

Emerging airlift doctrine supporting national defense

strategy exposes airlifters'to a variety of threats across the

conflict spectrum in both peace and war. Excluding threats to

parked airlifters as being outside the scope of this study,

weapons that can engage airlifters fall into one of two

categories-surface-to-air or air-to-air . Because MACaircraft

currently carry no defensive equipment, they are vulnerable to

all such threats that can acquire, track, and intercept them.

By sorting out and assessing these threats in terms of airlift

employment modes,peacetime-versus-wartime requirements,

threat intensities, and threat trends, this chapter verifies the

operational need for defensive systems . Additionally,

organizing the chapter in these terms is helpful because the

discussion of mission scenarios and lethality eliminates several

types ofthreat from considerationand consequently minimizes

the countermeasures required . Thepeacetime-versus-wartime

discussion helps to distinguish between what equipment is

needed now and what could be added later. The discussion of

trends identifies threats that are not usually considered . This

chapter thus lays the groundwork that enables later chapters to

identify appropriate solutions and to establish priorities for

developing and installing defensive systems.

Mission Scenarios

As can be seen from the discussion of strategic and tactical

airlift in chapter 1, MAC mission scenarios can be organized

in several ways. In a 1982 Summer Study, the US Air Force

Scientific Advisory Board examined MAC operations and

23
Electronic Warfare Study, performed by Hughes Aircraft

Company and Tracor Corporation, chose to group MAC

missions as follows: intratheater airlift, intratheater landing,

intratheater airdrop, and a catchall group including combat

search and rescue and aerial refueling.2 Similarly, the C-17

Defensive Systems Study, performed by Headquarters MAC,

chose this organization: deployment (CONUS to theater),

employment (to battle area or around the theater), and

sustainment, including routine (from major ports to the

brigade support area), resupply forward of the brigade support

area, resupply of deep operations, andredistribution of critical

supplies 3

From these efforts, one can begin to appreciate the nature

of current MAC missions . However, to reach this study's

ultimate goal of specifying alternatives for defending airlift

aircraft, the most productive organization appears to be along

the following lines : deployment (MOB to MOB) and

employment/sustainment (MOB or FOLto FOL).

Note that no distinction is made in this study between a

forward operating base and aforward operating location. Also

note that for the purposes of this paper, sustainment missions

are somewhat narrowly defined to mean forward sustainment

of engaged forces . For reasons that should become clear in

chapter 5, this definition will help MACmake decisions about

equipping categories of aircraft with self-protective systems. In

that chapter a distinction will be made between the aircraft

required for employment and those required for sustainment.

Deployment

Characteristically, the deployment mission will be

performed by C-5, C-141, C-17, KC-10, and CRAF aircraft.

Within the deployment scenario the first opportunity for

24
theater MOBS,where security 

ypy,

the potential for terrorist, insurgent, or Spetsnaz (Soviet

special forces) intrusion is greater. Once an airlift aircraft

reaches moderate to high altitude, however, the threat from

such forces is negligible .

Continuing on a deployment mission, the next opportunity

for the threat to intrude is over international waters. Operating

beyond the protective umbrella of friendly land and naval air

patrol, a deployment mission is vulnerable to enemy airborne

interceptors (AIs) and naval SAMS5' 6

Upon descent into the theater MOB traffic pattern, the

deployment mission reenters the threat envelope of the

terrorist, insurgent, and Spetsnaz. In addition, confusion

created by enemy communications jamming and random

attacks, traffic congestion, and US operations security

precautions will complicate tactical options and create

distractions from defensive tasks. The return or backhaul leg

of this mission wouldreexpose aircraft to the same threats.

Employment and Sustainment

The aircraft used on this missionwill be the C-17, C-141, and

C-130. The C-17 and C-130 will perform airland missions,

while all three will perform airdrop missions . The C-141

airdrop mission will most likely be in conjunction with a

brigade-size airdrop.

Employment missions occasionally originate from CONUS

staging bases (Operation Bright Star '82, a brigade airdrop in

Egypt, and Operation Urgent Fury, the 1983 invasion of

Grenada), but more frequently they are intratheater

operations . Nevertheless, both employment and sustainment

missions are subject to Spetsnaz-type threats including

25
missions will be subject to random AI intrusion, using either

missile or gun attack. If US air superiority has not been

achieved, the AI threat could be severe. As the flight

approaches the battle area, the transports (especially those at

medium and high altitudes) will come within range of mobile

and fixed-base SAMS of conventional forces. If pockets of

bypassed or advancing enemy troops are overflown or if the

FOL is close to an unsanitized battle area, the threat could

include radar and electro-optically guided SAMS, hand-held

SAMS, radar and electro-optically aimed antiaircraft artillery

(AAA), and small arms fires Under these circumstances, the

threat would extend from ground level up through the

maximum altitude of the transport.

The C-17 Defensive Systems Study estimates that

sustainment missions will routinely go as far forward as the

brigade rear area (BRA) andwill be 90 percent airland and 10

percent airdrop.9 The BRA will be approximately 20 to 40

kilometers from the forward line of owntroops (FLOT).1° This

study also estimates that 50 percent of the airdrop missions will

be massed. On occasion, it will be necessary to take supplies as

far forward as the battalion and company level."

Threat Intensity

To assess the intensity of the threat, the C-17 Defensive

Systems Study and the draft joint pamphlet, Joint Airlift for

Combat Operations, suggest comparable definitions (table

3)

.12, 13

26
The C-17 Defensive Systems Study applied these

definitions totheRerceived threat and reached the assessments

shown in table 4.

4

27

Category 1 Small arms, optical antiaircraft artillery (up to .50 caliber),

hand-held surface-to-air missiles.

Characterized by small numbers and lack of integrated

defense. Evasive action maybe required .

Category 2 Category 1 threat plus early generation radar surface-to-air

missiles, radar antiaircraft artillery heavier than SO caliber,

airborne interceptors (no look-down/shoot-down or allweather).

Characterized by moderately integrated defenses, butlimited

numbers or poor deployment . Evasive action, electronic

countermeasures, and/or defense suppression may be

required .

Category 3 Category 2 threat plus advanced-generation surface-to-air

missiles, airborne interceptors (look-down/shoot-down and

all-weather), helicopters with air-to-air missiles, directedenergyweapons.

Characterizedby dense or highly integrated network. Evasive

action, electronic countermeasures, anddefense suppression

must be employed.

TABLE 4

C-17 Study Threat Assessments

Mission Assessment

CONUSMOB to Theater MOB NoThreat to Category 1Threat for C-5, C-141,

C-17, KC-10, and CRAF.

CONUSMOBto FOL Category 1 to Category 2 Threat for C-141 and

C-17.

Theater MOBto FOL Category 1 to Category 2Threat forC-130 and

C-17.

FOL to FOL Category 2 Threat for C-130and C-17.
category 3 weapons may pose significant threats to all MAC

airlift aircraft, including C-5s and airland C-141s. While the

most likely threats to transports fall in categories 1 and 2 and

these categories are used in this research as discriminators for

computations and recommendations, discussion throughout

this study recognizes the possibility that MAC aircraft will

encounter category 3 threats.

Near Main Operating Bases

In the vicinity of MOBS, the most threatening weapon

available to terrorists, insurgents, and Spetsnaz is the

hand-held SAM of the SA-7, SA-14, Redeye, Stinger,

Blowpipe, or Rayrider variety. Characteristically, such missiles

home on their target using asingle or dual-band infrared (heat)

seeker, withvarying degrees offalse-target rejection capability.

The Blowpipe differs in being optically tracked but manually

steered by way of a thumb controller .

15 The Swedish Bofors

Rayrider missile, as its name suggests, tracks a laser beam that

illuminates the target. 16 All these missiles are man-portable,

have a range ofup to five kilometers, and have small warheads

without proximity fusing .

En Route between Theaters

On the overwater leg of the deployment, long-range

interceptors and naval SAMS are potential threats. If such

forces are to detect, acquire, and track airlift aircraft transiting

their airspace, the airlifter must give away its position or the

enemy must use a search-and-tracking device. The most

common type of search-and-tracking device is radar, but radar

has a serious drawback in this role -it gives away the presence

of the tracking party.

28
air defense purposes, airlift aircraft could have a relatively easy

time staying beyond effective SAM range, provided they were

equipped{ with threat-avoidance receivers. However, current

MACaircraft do not have such equipment.

In mutually passive operations, where the enemy employs

bistatic radar techniques (a system consisting of as few as one

transmitter and one or more listen-only tracking sets), and in

situations of imperfect military intelligence, airlift aircraft

might blunder into lethal encounters. For example, naval

surface forces employing emission control procedures, but

passively linked to an over-the-horizon radar, could trap an

unsuspecting transport.

Some deployment missions may expose transports to

short-range AI threats. On deployment legs to Southwest Asia,

for example, MAC aircraft could come under attack from

land-based interceptors belonging to countries along the coast

of Africa andthe Persian Gulf. Undersuch circumstances, the

threat-avoidance option maybe the only solution that can react

fast enough to keep the relatively near fighter from closing and

achieving a "kill." Specific equipment available to potential

enemies could include that listed in tables 5 and 6.

29
Fighters NATO Code Remarks

MG-23 Flogger-G/K (2xAA-7, 4xAA-8, AA-11),

Soviet Union, Libya.

MiG-29 Foxbat-A 700-NM range, 4 AAMs (AA-6,

AA-7, AA-8), Soviet Union,

Libya, Iraq, and Syria.

MiG-29 Fulcrum 350-NM range, 6 AAMs (AA-8,

AA-9, AA-10, AA-11), LD/SD,

track-while-scan, 60-NM search,

45-NMtrack, Soviet Union.

MiG-31 Foxhound-A LD/SD, track-while-scan (same

as MiG-25 plus AA-9), Soviet

Union.

Su-27 Flanker 400-NM radius, LD/SD, 130-

NM search, 100-NM track, 8

AAMs (AA-8, AA-10, AA-11),

Soviet Union.

Tu-28 Fiddler Works with Tu-126 Mainstay, 4

AAMs (AA-5), Soviet Union.

F-4 Phantom II 8 AAMs (Sidewinder and

Sparrow), Iran.

F-14A Tomcat 8 AAMs (Sidewinder, Sparrow,

and Phoenix), Iran, Libya, and

Iraq.

Mirage III Magic 530/550, Iraq, Libya.

Legend

AA-Air-to-Air

AAM-Air-to-Air Missile

LD/SD-Look-Down/Shoot-Down

NM-Nautical Mile

30
En Route within Theater

En route to theater FOLs, airlifters could easily be

ambushed by bypassed or penetrating enemy forces . Because

of the emphasis on maneuverability in this type of warfare

(AirLand Battle), surface-to-air threats will be primarily

restricted to mobile SAMS and AAA. Fixed-base threats will

be well knownand vigorously attacked or deliberately avoided.

Accordingly, the weapons of potentially hostile forces include

those in table 7.

31

AAMs NATOCode Remarks

AA-2 Atoll AIM-9B equivalent, IR guided,

3- to 4-NM rangef Soviet Union.

AA-5 Ash Semiactive radar guided (I/J

band), 16-NM range, Soviet

Union.

AA-6 Acrid Semiactive radar homing,

25-NM range, 220-lb warhead,

Soviet Union.

AA-7 Apex IR or semiactive radar homing,

17-NM range, Soviet Union.

AA-8 Aphid IR or semiactive radar homing,

3- to 4-NM range, all-aspect,

Soviet Union.

AA-9 Amos Radar guided, LD/SD missile,

25-NM range, high altitude,

Soviet Union.

AA-10 Alamo Radar guided, LD/SD missile,

19-NMrange, Soviet Union.

AA-11 Archer 38-NM range, active terminal

radar, Soviet Union.

Magic R-530 18-km range, semiactive homing

or IR seeker, Iraq, Libya, and

Syria .

Magic R-550 6-NM range, IR seeker, Iraq,

Libya, and Syria .
SAMS NATO Code Remarks

SA-4A/B Ganef 1,000 to 80,000 ft, 5- to 45-mile

range, command guidance and

semiactive radar homing, salvo

and guide2 missiles per target,

E-band surveillance, H-band

acquisition, Soviet Union.

SA-6A/B Gainful 50 to 30,000 ft, 2- to 12-mile

range, command guidance and

semiactive radar homing, Eband acquisition, Soviet Union

plus 22 othernations.

SA-7 Grail 50 to 10,000 ft,

0.5- to 3-mile

range, IR homing (SA-N-5),

Soviet Union.

SA-8 Gecko 150 to 30,000 ft,7.4-mile range,

command guidance, semiactive

radar and IR homing (SA-N-4),

Soviet Union, Iraq, Syria, Libya,

Nicaragua, and Angola.

SA-9 Gaskin 50 to 15,000 ft,0.4- to 4-mile

range, passive radar and IR

homing, Soviet Union plus 20

other nations.

SA-10B Grumble Low to high altitude, 50-NM

range, Mach 6, 200-lb warhead

(SA-N-6), Soviet Union.

SA-11 Gadfly 100 to 45,000 ft,

1.6- to 15-NM

range, commandguidance, semiactive monopulse radar and IR

homing, SA-6 replacement

(SA-N-7), Soviet Union and

Syria.

SA-12A Gladiator Low to high altitude, 80-km

range, 330-lb warhead, Mach 3,

SA-4 replacement, Soviet

Union.

SA-13 Gopher 30 to 32,000 ft, 5-mile range,

passive radar and IR homing,

SA-9 replacement, Soviet

Union.

SA-14 Gremlin SA-7 replacement, Soviet

Union.

SA-16 SA-7 replacement, Soviet

Union.

32
range, monopulse radar

guidance, Libya .

Hawk Lowto medium altitude, 22-NM

range, semiactive radar homing,

Iran .

Rapier Low to medium altitude, 4-NM

range, command to line-of-sight

guidance, Iran.

Roland Lowto mediumaltitude, 3.4-NM

range, command guidance and

IRhoming, Iraq.

In mature theaters, such as Europe, near- and cross-FLOT

operations by transports will require substantial joint

suppression of enemyair defenses (J-SEAD) to avoid category

3 threat weapons. Fortunately, in such theaters an extensive

transportation infrastructure exists. This should reduce the

frequency with which aerial transport will be required and the

volume of supplies such transport should have to carry.

In such lesser-developed theaters as Africa or Southwest

Asia, the threat will likely be different in density andexposure.

Less-developed regions are likely to contain fewer modem

weapons, but there is likely to be an increased need for airlift

because of the poorly developed transportation infrastructure

characteristic of such regions. Partially because of lower

numbers ofthreatening weapons, the possibility exists that the

FLOT may not be well defined and because of the increased

reliance on airlift, the number of near- and cross-FLOT airlift

operations may actually be greater than in a European

scenario 23

Comparing the two types of theaters reveals two

generalizations that can be made regarding the threat to airlift

aircraft. First, the mature theater threat, while potentially high

in lethality, maybe restricted to relatively well-defined areas.

When airlift operations are required within those areas,

33
defined and maybe found throughout the area. It is ironic that

in such an environment, airlift aircraft may be more exposed

to threats and may be more at risk than in a theater that is

usually acknowledged as a higher-threat region.

Near ForwardOperating Locations

The proximity of the battle area to the FOIJs will increase

the possibility of airborne and mobile surface threats

influencing airlift operations, especially as airlifters support

units below the brigade level. In addition to the threats

experienced near MOBS, FOI-s could have limited exposure to

the weapon systems listed in tables 5, 6, and7. Self-protection

countermeasures, evasive action, and J-SEAD operations may

be required.24

Peacetime-versus-Wartime Threats

This paper assumes three categories of conflict: normal

peacetime, operations short of war (most notably peacetime

contingencies and foreign internal defense), and war. This

categorization of conflict is important because of the

perspective it offers on several threats airlift aircraft will face .

In peacetime contingencies and war, MAC aircraft must

anticipate all threats, including air-to-air weaponry. Under

normal peacetime conditions, the probability of hostile

airborne interception is very low. However, during all

categories some level of threat exists. For example, during

normal peacetime, operations short of war, and war, nonstatesponsored terrorism poses a significant threat to MAC

operations. When states get involved-for instance, in

state-sponsored terrorism and cross-border operations34
As the intensity of conflict escalates, threat systems are

added to the enemyorder of battle. This is not surprising, but

what is significant is the quantum leap that occurs when

sovereign states or groups ofsovereign states enter the conflict.

At this point, one begins to find categories 2 and 3 threat

conditions. The Afghanistan conflict is an example of this

phenomenon. By itself, the Afghan resistance presented only

alow threat to Soviet airlift. Once the United States made the

decision in 1986 to supply Stinger missiles to the resistance, the

lethality of the conflict rose dramatically for Soviet airlift. Thus,

with minimal effort, a third-party state supporting aresistance

movement was able to severely curtail an unprepared

superpower's airlift operation.

Three points in this discussion ofpeacetime-versug-wartime

threats deserve emphasis. First, air-to-air threats exist during

operations short of war even though they are usually not

considered during normal peacetime conditions. Second, a

terrorist threat exists at all times. Andthird, state involvement

in a conflict raises the ante for airlift, including US airlift, to

significant levels .

Threat Trends

Theradio frequency (RF) spectrum has been much used for

military measures and countermeasures since WorldWarII. In

fact, thewhole concept ofelectronic warfare took on its present

character during the Battle of Britain when the Germans

attempted to establish navigation aids that would permit

all-weather bombing of England.

35
series ofshortwave transmitters (200

KHz to 900 MHz)25 Based in northernFrance, the transmitters

beamed their broadcasts over London. German aircraft

needed onlyto tune aloop antenna to ride these beams to their

targets. Eventually the British caught on to Lorenz and

countered with Meaconing. After picking up the German

broadcast, the British sent the signal by land line to a

transmitter situated off course, of course. As the German

bombers flew toward the increasing signal strength of the

British transmitter, they were increasingly misled.

As results from Lorenz soured, the Germans turned to

Knickbein, a dual-transmitter system that broadcast parallel

beams. One beam produced a series of aural "dots," while the

other produced a series of aural "dashes."a6 If German pilots

flew on the centerline of the two beams, they heard a steady

tone. If they strayed from course, they picked up dots or dashes

depending on which side they strayed to. The British dubbed

this system Headache and countered it with a system called

Aspirin. Based on the Meaconing system principle, the British

merely duplicated the transmissions with transmitters located

suitably off course.

By September 1940 the Germans had devised Ruffian, a

navigation aid cleverly disguised as apropaganda broadcast. In

normal operation the transmission was broadcast

omnidirectionally, but before a raid the beam was narrowed

down to 3 degrees and aimedat a timing point. The Germans

then aimed a second 3-degree beam at the timing point, and

their aircrews needed only to turnto the bomb-run heading and

begin timing when they crossed the intersection. The British

counter, Bromide, aimed crossing beams to produce

intersections that the German crews passed before the

designated timing points. With considerable frequency the

British were successful in getting the Germans to drop their

36
from British Spitfires.

After the debacle of Ruffian, the Germans devised Benito,

an interactive system using German ground controllers in

France. By sending out a frequency modulated beam and

having the bombers retransmit it to the ground station, the

ground controllers could measure the phase difference and

determine the range from London. The bombers periodically

received range update radio calls from the ground controllers.

To counter this the British developed Domino. Domino had

several variations . In one variation, the German directional

beam was rebroadcast omnidirectionally, which led to

confusing and unreliable range readings . In asecond variation,

aBritish controller spoke in German to "guide" the bombers.

On several occasions the British were successful in guiding

German bombers to safe landings at British bases28

As a final act of frustration, the Germans equipped one

squadron of bombers with all of their navigation aids to act as

a check on British interference. If all aids gave the same

reading, it was assumed the British had not interfered. To

interfere without being detected, the British would have had

to coordinate all their countermeasures to provide a coherent

wrong solution . Since this was not thought to be likely, the

German plan was to use the consensus solution to allow the

specially equipped squadron to drop incendiary bombsto mark

targets for the rest of their bombers. The British counter was a

plan called Starfish, wherebythey set false bonfires in isolated

areas after the German incendiaries were released. By placing

these fires so that the rest of the bombers reached them prior

to the real targets, the Britishwere initially successful in getting

the Germansto drop 95 percent oftheir bombs onfalse targets.

The German counter-countermeasure was to tell their crews

to drop on the second burning target. Of course, the British

then set their second fire beyond the target. Ultimately, the

37
the electronic warwith Germany, but this was not entirely the

case. In February 1942 the Germans executed a brilliant plan

to sneak theirwarships Schamhorst and Gneisenau through the

English Channel despite the watchful eye of British radar. By

introducing a daily period of jamming at dawn that appeared

to be normal atmospheric static, the Germanswere able to lull

the radar operators. Of course, the jamming decreased the

sensitivity of British radar; and by gradually increasing the

period of jamming, the Germans were able to provide

sufficient time for the warships to pass unnoticed on the

required date. 3o

As a further illustration of the insidious effects of being

unprepared to engage in electronic combat, consider the case

ofthe German Wurzburg radars. As acountermeasure to these

radars, British and American aircrews began dropping

precisely cut aluminum foil strips in voluminous quantities.

Dubbed Window by the British, its code name was the

innocuous sounding chaff. 31 Instead of acting as awindow, the

chaff acted on radar as if it were an opaque cloud, disguising

bomber formations and intentions . In an attempt to correct

what the Germans thoughtwasaproblemwith their radar, they

ordered approximately 4,000 of their best electronic engineers

to work on the project.32 Because this number represented

approximately 90 percent of their electronic engineers, they

were distracted from work on microwave radars, which the

Allies had already fielded. As a measure of comparison, the

United States only dedicated about 400 engineers to develop

radar countermeasures -a satisfactory exchange ratio.

Because the Germans did not realize the Allies were operating

in the microwave band, the Allies had a free ride there,

compounding German befuddlement.

34

In Korea the electronic air war closely resembled World

War II . Not until Vietnam, when SAMS appeared, did the

38
EB-66 aircraft were equipped with radar homing andwarning

(RHAW) gear andjammers to counter the missiles. SAM sites

became priority US targets, prompting North Vietnam to

integrate its air defense as a countermeasure. In addition to

SA-2s, AAA and ground-controlled intercept fighters were

combined to form the world's first integrated air defense

network. Because this network forced the EB-66s to stand off

from the defenses, attacking US aircraft were equipped with

self-screening jammers. During an 11-day period in December

1972, more than 1,000 SAMs were fired over Hanoi and

Haiphong in an attempt to stop massive B-52 raids. By the end

of the eleventh day, North Vietnam's air defense system had

been destroyed and B-52s bombed unopposed. Despite dire

predictions and faulty initial tactics, only 15 B-52s out of 729

sorties were shot down.

In the 1973 Arab-Israeli War (Yom Kippur War), Arab

defenses achieved technological surprise with mobile SA-6

missile and ZSU-23-4 AAAsystems. Lacking effective ECM

against the continuous wave guidance system of the SA-6,

Israeli aircraft were driven to low-altitude attacks only to be

decimated by the ZSU and SA-7. By acquiring ECM pods

effective against the SA-6, employing chaff and flares against

the ZSU and SA-7 respectively, and using helicopters in a

standoff jamming role, the Israelis were able to gain the upper

hand 36 Ultimately, the Israelis were successful in clearing

every SAM site from their path while losing less than one

aircraft per 100 sorties. Still, of the 103 Israeli aircraft lost, 100

were destroyed by surface systems.' The Arabs, on the other

hand, lost 334 aircraft in air-to-air duels, mostly to heatseeking Shafrir and Sidewinder missiles

In the Falklands campaign, both Argentina and Great

Britain suffered from a lack of airborne early warning

capability . While British Harriers employed the AIM-9L

39
countermeasures against the AIM-9L,the Argentineans could

have turned the campaign in their favor. 39

TheBekaaValley, Lebanon, saw three airbattles in 1982 and

1983 that"offer additional insight into electronic warfare. In

1982 the Israelis shot down79 Syrian aircraft while losing only

one of their own. When Syria initiated the air battle with an

attack of approximately 60 aircraft, Israel countered by

jamming their communication links, isolating the attackers

from their ground controllers. Then using E-2C Hawkeye

airborne early warning aircraft to vector their own fighters

behind the Syrians, they achieved tactical surprise . Without

infrared countermeasures (IRCM), the Arab aircraft were

again easy prey for Israeli Shafrirs and Sidewinders.

Against Syrian ground defenses, the Israelis were successful

in destroying 19 of 20 SAM sites through expert use of ECM

pods, remotely piloted vehicles (RPVs), flares, and chaff. A

typical Israeli air defense suppression mission began with a

series of RPVs making television surveillance passes on

suspected SAM sites. When a site was discovered, two more

RPVs were sent out as a team. One RPV imitated a hostile

fighter to decoy the SAM radar to turn on. The partner RPV

would then relay the radar signals back to Israeli forces for

analysis . Armed with perfect knowledge of the Syrian

electronic order of battle, Israeli fighters, defended by

appropriately tuned ECM pods, antiradiation missiles

(ARMS), chaff, and flares, then proceeded to destroy the site ao

After the Israeli success, France andthe United States each

took on the Syrians. In November 1983 eight Super Etendards,

supported by two FrenchF-8E Crusaders for MiG- cap and two

American-operated EA-6B Prowlers for standoff jamming,

attacked Islamic terrorist barracks in Baalbek. Achieving

surprise, six of the eight Super ttendards were able to drop

bombs before the AAAdefenses were alerted. Despite having

40
1983, using 16 A

6E Intruders, 12 A

7E Corsair Hs, an 

Hawkeye, several F-14 Tomcats for. MiG-cap, andtwo EA-6B

Prowlers for standoff jamming. Unfortunately, the Soviets

tipped the Syrians off to the raid and all defenses were up. The

subsequent loss of two aircraft highlighted a recent hardware

change in the SA-7 and SA-9 missile-seeker heads from

uncooled sensors to cooled sensors. These newsensors proved

invulnerable to existing Navy flares . In addition, because of

carrier landing and takeoff restrictions, the tailpipe exhaust

fairings on Navy aircraft had not been extended to shield

against the heat-seeking missiles as were those on Israeli

aircraft. Such subtle modifications were enough to tip the

balance.2

This limited historical review shows clearly that electronic

warfare has played an increasing important role in aerial

combat. It should also point up the undeniable lesson that

electronic warfare will be vital in determining the victor of the

next conflict.

Future

Introductionof the SA-7 SAM into Vietnam and Stinger and

Blowpipe SAMs into Afghanistan were disastrous events for

opposing airlift aircraft. Potentiallyjust as disastrous is the fact

that these weapons are coming into the possession of

governments hostile to the United States . For example, Stinger

missiles meantfor the Afghan resistance have been diverted to

Iran and have shown up on an Iranian craft in the Persian

Gulf.43 Given the strong Iranian support for such terrorist

groups as Hezbollah, it should come as no surprise if US

aircraft are attacked by a terrorist group using such missiles.

Furthermore, as these weapons are copied and reproduced,

they will find ready markets with terrorist groups around the

41
One must also consider the intentions of the Soviet Union

in building its first full-sized aircraft carriers, the Leonid

Brezhnev and a second as yet unnamed:44 Expected to be

operational within two years and outfitted with currentgeneration interceptors of comparable capability to the Su-27

Flanker, these carriers will greatly improve Soviet ability to

intercept airlift aircraft over international waters, especially if

they are complementedbyKrov-class nuclear-powered cruiser

groups and are protected by nuclear-powered attack

submarines . They could create a formidable barrier to

transiting airlift aircraft4s

In intratheater developments, total US J-SEAD forces have

leveled off and consist of only 42 EF-111 standoff jammers and

72 F-4G Wild Weasel SAM-site killers. Since these aircraft

must cover all theaters and will be heavily tasked to support air

interdiction, battlefield air interdiction, and close-air-support

missions, their numbers will not be adequate to support airlift

operations.6

Surviving in the future intratheater environment will require

more than passive, low-altitude flying by transports . TheMAC

Electronic Warfare Study estimates that a MAC transport at

500-foot altitude approaching an airfield 20 kilometers from

the battle area in Europe will be painted by more than 50 radar

emitters and tracked by at least 154' Perhaps the most

persistent of the radar threats, because of its resistance to

SEAD targeting, will be Mainstay, the new Soviet airborne

warning and control system. Exploiting a true overland,

look-down capability, Mainstay could vectorinterceptors or tip

off artillery to the presence of transport aircraft48

Accidental encounters with isolated enemy ground forces

promise to be more injurious in the future. In addition to

expected upgrades in current units and weapons (for example,

the ZSU-X mobile AAAunit), laser systems are likely to be

42
Second, even at their current relatively lowpower levels, they

have temporarilyblinded flight crews whohave looked directly

at them. Third, when viewed through heads-up displays

(HUDs), the intense laser light "will almost certainly blind the

pilot."si

Looking further into the future, two trends will put airlift

under even greater stress. First, the Army 21 operational

concept foresees opposing units operating in a "swarm, strike,

and scatter" mode.

a

Under this concept, surface lines of

communication will be subjected to sudden andunpredictable

attack. To compensate, airliftwill have to be the primary means

of resupply

.

3 Second, freedom of operation for airlift in rear

areas will decrease as the enemy gains greater capability to

target those areas

.

54 Of particular concern to airlifters will be

such Soviet helicopters as the Hokum, which will have a

credible air-to-air capability55 In short, the air defense

environment will become much more lethal.

Conclusions

From the preceding discussion of mission scenarios, types of

threat encounters, threat intensity, and trends, the reader can

appreciate the vulnerability of unprotected airlift aircraft.

Given the doctrinal requirement that airlift aircraft carry out

missions in hostile environments, the mismatch between

doctrine, the available force capability, and the threat becomes

apparent. Clearly, an operational need for self-protective

systems exists on deployment, employment, and sustainment

missions . Having established the need, the discussion can turn

in part II to consideration of technical feasibility.

43
Study)(U), Washington, D.C., December 1982,26. (SECRET) (Information

extracted from this source is unclassified.)

2. Hughes Aircraft Company and Tracor Corporation, "Military Airlift

Command Electronic Warfare Study Briefing" (U), presented to

Headquarters MAC, January 1988, slide 3. (SECRET) (Information

extracted from this source is unclassified.)

3. Headquarters Military Airlift Command, C-17Defensive Systems Study

(U), ScottAFB, M.,17 July 1987,6 . (SECRET) (Information extracted from

this source is unclassified.)

4. Scientific Advisory Board, Report oftheAd Hoc Committee, 1. 5. Ibid., 28.

6. Hughes and Tracor, "Military Airlift Command Electronic Warfare

Study Briefing," slide 3.

7. Scientific Advisory Board, Report ofthe Ad Hoc Committee, 29.

8. Ibid.

9. Headquarters MAC, C17Defensive SystemsStudy, ii . 10. Ibid.

11. MACP 55-XX, Joint Airlift for Combat Operations, draft, 14

December 1987,10a.

12. Ibid., 5-6. This source refers to the threat levels as category 1, 2, and

3, respectively, to avoid the subjective "low," "medium," and "high" threat

labels .

13. Headquarters MAC, C-17Defensive Systems Study, 12.

14. Ibid., 13.

15. Charles H. Wiseman, "Soviet Weapons and Electronics-Radar

Systems," in Intemational CountermeasuresHandbook: 1986, 11th ed. (Palo

Alto, Calif. : EWCommunications, Inc., 1986),183.

16. Richard S. Friedman, Advanced Technology Warfare (New York:

Harmony Books, 1985), 29.

17. Wiseman, "Radar Systems," 177-78,235-37,242.

18. "Specifications,"Aviation Week & Space Technology, 9 March 1987,

139,174.

19. Wiseman, "Radar Systems," 177-78,235-37,242.

20. "Specifications," Aviation Week & Space Technology, 139,174.

21. Ibid ., 170-75.

22. Wiseman, "Radar Systems," 184-88, 246-48 .

23. MACP 55-XX, A-3.

24. Headquarters MAC, C17Defensive Systems Study, 12,13.

44
25. D. B. Harris et al., 

History of Electronic Countermeasures, in

Electronic Countermeasures (Los Altos, Calif.: Peninsula Publishing, 1978),

2-2.

26. Ibid.

27. Ibid., 2-3.

28.Ibid.

29. Ibid., 2-3,2-4.

30. Ibid., 2-7.

31. Ibid., 2-11.

32. Ibid., 2-12.

33. Ibid.

34. Ibid.

35. W. D. Meskill, "WhyECCM? The Need for ECCM,"RadarElectronic

Counter-Countermeasures (Dedham, Mass.: Artech House, Inc., 1979),

28-29.

36. Ibid., 29.

37. Charles W. Corddry, "The Yom Kippur War, 1973- Lessons New and

Old," National Defense, May-June 1974, 508.

38. Robert Hotz, "The Israeli Air Force Faces New Arab Arms,"Aviation

Week & Space Technology, 10 March 1975, 16.

39. Mario de Arcangelis, Electronic Warfare (Poole, Dorcet, UK:

Blandford Press, 1985), 282-83.

40. Ibid., 265-70.

41. Ibid., 272-73.

42. Ibid., 275-76.

43. "The Alchemy of Turning Guns into Luxury Villas," U.S. News and

World Report, 30 November 1987, 36.

44. Department of Defense, Soviet Military Power (Washington, D.C.:

Government Printing Office, March 1987), 66, 86.

45. Ibid., 86.

46. Ray A. Yagher, Jr., "An Immediate Imperative," Journal of Electronic

Defense, November 1987, 46.

47. Hughes and Tracor, "Military Airlift Command Electronic Warfare

Study Briefing," 8A.

48. Department of Defense, Soviet Military Power, 106.

49. Ibid., 112.

50. Friedman, Advanced Technology Warfare, 29.

51. F. Clifton Berry, Jr., "The British Are Coming," Air Force Magazine,

June 1987, 75.

52. Headquarters MAC, C-17Defensive Systems Study, 97.

53. Ibid., 98.

54. Ibid., 97.

55. Department of Defense, Soviet Military Power, 80.

45

Despite the tenor inspired by modem antiaircraft weapons,

those weapons operate on well-known physical principles and

have limitations that are readily exploitable. The intent of

chapter 3 is to explore the operating principles of the primary

threats to airlift aircraft and to point out realistic avenues of

counterattack. The chapter explores limitations in using the

electromagnetic spectrum; discusses the tasks required of the

offense and defense; examines the operating principles of

systems devised to exploit the electromagnetic spectrum to

include radar, infrared, electro-optical, and laser systems; and

discusses system weaknesses .

Chapter 4 brings the discussion of technical feasibility to a

conclusion by showing howemerging technology is presenting

a unique opportunity to allow relatively large and slow aircraft

to counter threats, including those launched by airborne

interceptors, in all portions of the electromagnetic spectrum.

Provided with such options for technically feasible weapons,

the discussion can then turn to affordability in part III.

47

ELECTRONIC WARFARE:

HOWIT FUNCTIONS

The principal adversary of the United States has developed

and exported antiaircraft weapon systems of amazing variety,

sophistication, and lethality. When combined in an integrated

air defense system, they present a formidable array.

Superficially they would even appear to be impregnable. In

reality they have subtle weaknesses that are not usually

advertised, but that are well worth studying and exploiting.

Once revealed, these weaknesses suggest technological

possibilities for increasing the survivability of airlift aircraft.

The starting point in the search for weaknesses is the

electromagnetic spectrum, which defines the domain of

electronic warfare.

Electromagnetic Spectrum

The electromagnetic spectrum groups electromagnetic

energy bywavelength andfrequency and serves as the basis for

describing such energy. From lowest to highest frequency, it

includes radio waves, microwaves, millimeter waves, infrared

radiation, visible light, ultraviolet radiation, X rays, gamma

rays, andcosmic rays . By emitting from orreflecting offmatter,

electromagnetic energy serves as a conduit for information. It

is this relationship with matter that makes it particularly useful

in warfare.

The enemy exploits electromagnetic energy, in this case

waveforms, to seek and obtain necessary information to detect,

acquire, track, and identify the airlifter. To understand the

weaknesses in detecting, acquiring, tracking, and identifying

49
o udestad eectoagetcaes, oe ust 

the interaction of wavelength, frequency, and the speed with

which the waves operate. This relationship is described by the

formula,'v = f x wl, wherev_ is the velocity of propagation, f is

the frequency of the radiation, and wl is the wavelength.

Simplifying this equation is the fact that the velocity, v is a

constant equal to the speed of light for any particular medium.

(In air the speed of light is approximately 300,000 kilometers

per second.) Thus frequency and wavelength are inversely

related (as one increases, the other must decrease) and,

because velocity is aconstant, they are paired. That is, only one

wavelength can occur at a given frequency and vice versa (table

8).

TABLE 8

Electromagnetic Spectrums

Frequency Wavelength Type ofRadiation

0 to approx Infinitely long Radio Waves

300 MHz to 1 meter

300 MHz to 1 meter to Microwaves

1360 GHz .022 cm

1360 GHz to .022 cm to Infrared

4.0 X 105 Hz 7.5 X 10"5cm

4.0 X 105 Hz 73 X 10'5 cm Visible Light

to 7.5 X 105 GHz to 4 X 10-5 cm

7.5 X 105 GM 4 X 10"5cm Ultraviolet

to 18.8 X 10 5 GHz to 1 .6 X 10-5 cm

18.8 X 105 GHz 1 .6 X 10"5cm X Rays

to 24 X 109 GHz to 1.25 X 10'9cm

24 X 109 GHz 1 .25 X 10-9 cm Gamma Rays

to 5.5 X 1011 GM to 5.5 X 10-11 cm

5.5 X 1011 GHz 5.5 X 10-11 cm Cosmic Rays

and higher and shorter

Legend

cm-Centimeter

GHz-Gigahertz

MHz-Megahertz

50
see objects only to the extent that wavelengths of visible light

are neither scattered nor absorbed by particles, water vapor,

and other components of the atmosphere . In the case of

particles, the rule ofphysics holds that as they approach the size

of waves, scattering occurs. Particles much smaller than a

wavelength produce little scattering, while those much larger

than a wavelength scatter waves according to the nature of the

particle's composition, independently of the wavelength?

Thus, as particulate size approaches the wavelengths ofvisible

light (0.4 to 0.75 microns -one micron is one one-thousandths

of a millimeter), scattering occurs and vision is obscured. For

this reason haze, mist, fog, smog, clouds, rain, and other

atmospheric conditions limit the usefulness of systems that

operate in the visible light portion of the electromagnetic

spectrum (table 9).

One way around this hinttation is the use of systems that

operate with longer wavelengths. For example, haze is

"transparent" to infrared (IR) radiation because IR

wavelengths (0.75 to 2,200 microns) are larger than the particle

sizes (0 to 0.5 microns) that produce haze. If scattering were

the only limiting factor, one might assume that IR and longer

waves have overwhelming advantages compared to visible

light. Indeed, they have unique advantages, but they also have

limitations caused by weather conditions and atmospheric

absorption.

51

TABLE 9

Atmospheric Particle Sizes (Diameter)3

Haze 0 to 0.5 microns

Mist, Fog, Clouds OS to 80 microns

Rain 250to 3,000 microns
that account for most absorption under 300 gigahertz (GHz)

(300 x 109 cycles per second -microwave andradio bands) are

water vapor andoxygen.4 Each gas produces several absorption

bands. Water vapor's absorption bands are centered on 22

GHzand 183 GHz, while oxygen's are centered on60 GHzand

119 GHz5 (fig. 1). Above 300 GHz and below 10 terahertz

(THz) (10 x 1012 cycles per second-infrared band),

absorption due to water vapor is very high, effectively

restrictinguse of the microwave region to 300 GHzandbelow. 6

Above 10 THz (infrared region) water vapor and carbon

dioxide are the limiting gases. Watervapor's absorption bands

reappear in the infrared range at 46 THz (6 micron), 158 THz

(1.9 micron) and 210 THz (1.4 micron).* Carbon dioxide's

absorption bands occur at 21 THz (14.3 micron) and 70 THz

(4.2 micron). In addition, water vapor and carbon dioxide

combine to absorb radiation centered on 110 THz (2.7 micron)

(fig. 2). Other effects-such as ionospheric absorption,

tropospheric and ionospheric dispersion, refraction,

polarization, and free-space propagation limits-also act to

restrict use of the electromagnetic spectrum, but they are

beyond the scope of this discussion.

Thepreceding discussion shows that scattering, absorption,

and other phenomena render large portions of the

electromagnetic spectrum useless for electronic warfare. Only

asmall number of "windows" are available to be exploited: 300

GHzandbelow (microwave andradio bands), twobands in the

infrared region corresponding to wavelengths of 2to 5 microns

and 8 to 14 microns, and most of the visible portion of the

spectrum. Enemy threats that operate in these bands tend to

take the form of radar; radio frequency homing devices ;

infrared search, track, and homing devices; and lasers .

"When dealingwith very high frequencies the practice is to refer to them in terms of the associated wavelengths.

52

operates by sending out radio waves and 

listeningfor

returning echoes. Azimuth and elevation of a target echo are

determined by pointing an antenna, unless fan-shaped search

beamsare used. In this case, an extra elevation antenna maybe

required . By measuring the time delay of the echo, radar can

determine range. Since radio waves travel at the speed oflight,

a target one nautical mile away will produce an echo in 12.35

microseconds (12.35 x 10"6seconds). This interval is known as

the radar mile. A target two miles away will take 24.70

microseconds, twice as long, to produce an echo.

In addition to atmospheric propagation limitations, the

maximum range of radar is dependent on the returning echo

being stronger than the ambient "noise." This relationship is

called the signal-to-noise (S/N) ratio and should be greater

than 1.0 . If it is not, the signal will not be detected. What makes

this such an interesting problem andfundamental to electronic

warfare is that the 'signal strength and noise level are

simultaneously affected by both the searching radar and the

target. For example, echo powerreceived can be expressed by

the equation

Echo Powerlo = _P x _G x Sigma x A_

16XPi X R4

where _P is the transmitted pulse power,

Gis the gain or multiplying effect ofthe transmitting antenna,

Sigma is the radar cross section or reflecting area ofthe target,

_A is the effective capture area of the receiving antenna,

Pi is the universal constant equal to the ratio ofcircumferenceto

diameter of a circle, and

Ris the distance between the radar and the target.

From this equation it is clear that the radar controls P G

and A (R too if the radar is moving) while the target controls

Sigma and _R. But this only accounts for the signal portion of

the S/N ratio. Noise is just as big a factor.

54
opeatooud e to ae te S/ato, t s ceay 

the interest of the target to minimize the ratio. This is the

essence of electronic warfare.

Waveform Types

In order for a radar to "hear" an echo, it must make some

provisionfor picking up the echo while the radar is transmitting

or, failing this, it must stop transmitting. For pulse-type radars

this means that they must operate on a cycle of alternating

transmitting and listening. Continuous wave (CW) radars

transmit continuously by constantly varying the frequency of

their transmission . An echo is detected off-frequency from the

ongoing transmission .

Pulse Radars. When a pulse radar transmits, it sends out a

pulse oflimited duration orpulse width. If the pulse is too long,

short-range target echoes will return and be lost in the

continuing pulse transmission . Hence, pulse width determines

the minimum range of a pulse radar. Maximum range is

determined by the length of time spent listening for echoes. If

the radar does not listen long enough, long-range echoes will

be lost in the secondpulse transmission. Therefore, radars that

have a high pulse repetition frequency (PRF) have relatively

short range. Conversely, radars that wait for long-range echoes

send out fewer pulses and update their tracking data relatively

infrequently. Herein lies an essential compromise made by

every pulse radar designer. A practical limit does exist,

however, for how short the pulse can be. Short pulses create

problems regarding how much energy can be packed into a

pulse during the transmit time. Very short pulse widths with

relatively low energy have difficulty producing an echo that can

be "heard" above the background noise level because of

55
and elevation the same way that pulse radars do, by pointing

an antenna in aparticular direction. Determining range is not

so easy. Thesimplest form of a CWradar would operate on one

frequency. Such a radar would not be very useful because the

returning pulse would be obscured in the transmission.

Consequently, CWradars continuously change their frequency

in a warbling fashion. As echoes return, the transmitter has

moved to other frequencies to create a clear channel for

listening. This leads to another problem. If aCW radar merely

timed until a particular frequency echo returned, it could not

"know" if that particular returning frequency was caused by

range delay or by avelocity induced Doppler shift of a slightly

different frequencythat had been transmitted alittle earlier or

later.*

To get around this ambiguity, CW radars use frequency

modulation schemes to code the wave, which allows range

determination. Frequency shift in the coded echo can then be

used to determine velocity according to the Doppler principle.

As a result, CW radars are also referred to as Doppler radars.

Because CW radars continuously transmit, their energy is

diluted over a longer period of time than that of pulse radars.

Consequently, for a given transmitter power level, CW radars

have shorter range than pulse radars.

Pulse Compression Radars. Pulse compression radars

extend the pulse duration while varying frequency. This

technique is used to pack more energy into each pulse than can

a simple pulse radar, typically up to 10 times as much, to

improve the detection ability of the radar." Sacrificed in the

process of extending the pulse duration are echoes from close

'boppler shift is caused by the transference of target velocity to a radar echo. An oncoming target raises the frequency of

the echo, a retreating target lowers the frequency. Aneveryday example of Doppler shift is the shift in sound a train whistle

makes as it approaches, passes, and retreats from a listener.

56
Pulsed Doppler Radars. A fourth class of radar is a

combination of the first two and is called a pulsed Doppler

radar. By interleaving pulse and Doppler functions in a

coherent fashion, the radar is able to eliminate spurious echoes

and discriminate nonmoving targets. As a penalty this radar

retains either "blind" speeds or "blind" ranges depending on

the designer's emphasis2 By using a staggered or variable

pulse repetition frequency these "blind" speeds or ranges can

be moved into regions where they are less of a nuisance .

Pseudorandom Pulse. A fifth class of radar is the

pseudorandom pulse, identified with theoretical lowprobability-of-intercept (LPI) radars. By spreading

transmissions over awide frequency band, using acoded pulse

repetition frequency, and not using any more power than

necessary, such a radar's signature can be made to resemble

random noise. From this characteristic comes the lowprobability-of-intercept nomenclature . 13

All radars are derived from these five classes of radar

waveforms. Discussion of some of their more common design

features requires an understanding of mainlobe versus

sidelobe effects, phased-array radars, synthetic aperture

radars, conical-scan techniques, and monopulse techniques.

57
gy 

Several schemes exist for doing this, but a common failing is

the transmission of side beams in addition to the main beam.

In the parlance of radar technicians, these are called sidelobes

and mainlobe, respectively.

Sidelobes are inconvenient because if they rival the

mainlobe in magnitude the radar will yield ambiguous azimuth

readings on targets it is tracking . In an electronic warfare

environment, an adversary could seek to confuse the radar by

injecting false targets or noise into the sidelobes, particularly

if the sidelobes are prominent. In an effort to minimize

sidelobes, radar designers developed the phased-array

antenna.

The phased-array radar, instead of diverting a stream of

electromagnetic energy, builds a beam incrementally using

hundreds or thousands of individual transmitters. By also

shifting the phase of each transmitter appropriately, the

phased-array antenna can cancel unwanted beam effects or

enhance desired effects. In addition, such an antenna can steer

the beam via the same phase-shifting effects, instead of using

a rotating antenna for scanning. An additional feature is the

antenna's ability to form and control multiple, independent

beams, all steered electronically . Unfortunately, such

high-technology antennae are very expensive.

To take advantage of less-expensive scanning techniques,

many modern tracking antennae still employ a conical-scan

technique to keep the mainlobe centered on the target. By

forming a pencil-shaped mainlobe and rotating it around the

centerline to the target, a conical-scan radar reads the strength

of the returning echo to measure its pointing accuracy . If the

radar detects that the target is beginning to move outside the

swept area, it expands the circular sweep. If the target signal is

decreasing in strength toward the center of the swept area, it

58
inherent instabilities associated with mechanical scan rates,

monopulse radars were developed.

Monopulse radars employ multiple beams to bracket a

target. Instead ofwaiting for several scan adjustments to detect

target movement, monopulse radars get position updates on a

pulse-to-pulse basis. Since monopulse radars can operate at

upward of2,000 pulses per second compared to approximately

a 30 Hz scan frequency for conical-scan radars, the

improvement is impressive.ia

Not all mechanical movement is a disadvantage, however.

Synthetic aperture radars use movement to increase their

resolution . By constructing alinear array ofphase shifters, like

those used in a phased-array antenna, and by moving this array

along the axis ofits construction, onecan increase the resolving

power of the antenna, severalfold. For example, if a 10-foot

antenna looking over a range of 10 miles has a resolution of

500 feet (the ability to distinguish objects that are at least 500

feet long), moving asimilar radiating element in a straight line

at the speed of a jet aircraft "constructs" a "synthesized"

antenna of 1,000 feet. Proper processing of the sinals received

by such an antenna yields a resolution of 5 feet. The utility of

such aradar in ground mapping is obvious.

Radar Usage

Exploiting radar for military purposes is quite logical in view

of its potential to perform detection, acquisition, tracking, and

identification tasks. As aresult of conflicting requirements for

long-range search and target tracking for missile guidance,

military systems have evolved into basically two types: early

warning (EW) andtarget-tracking (IT) radars.

Early warning (surveillance) radars, whether airborne or

surface based, emphasize long-range performance and tend to

59
g 

p

radars, which operate in the very high frequency (VHF) radio

band, and the US PAVEPAWS and ballistic missile early

warning system (BMEWS) radars, which operate in the

ultrahigh frequency (UHF) radio band.16 Ground-controlled

intercept (GCI) radars are EW radars that also have a

height-finder radar (tables 10 and 11).

TABLE 10

Land and Airborne Radarst'

Radio Radar

Frequency Band Band Radar 7yp

10-30 MHz HF Over-the-Horizon

30-150 MHz VHF A Spoon Rest-EWRadar; SA-2

Knife Rest-EW Radar; SA-2

150-400 MHz UHF B Tall Iisag-EW Radar

UHF C Flat Pam-ITRadar; SA-3, -6, -8

Squint EreIT Radar, SA-3

Hen House-EW Radar, ABM

1-2 GHz SHF D SA3Command Link

FPS-117 (US)-EWRadar

Martello (UK)-EWRadar

2-3 GHz SHF E Back Net-EW Radar

BarlockTT&EW Radar

BigBar/Mesh-EW Radar

Crotak (France)-ITRadar

LongTrack-EW Radar; SA4, -8

LongTrough-EW Radar

Odd W-EW Radar

Token-EW Radar

WhiffAAARadar, 100-mm Gun

24 GHz SHF E/F FanSong-EW &TT Radar, SA-2

Fire Can-AAA Radar, 57-mm,

85-mm,100-mm Guns

3-4 GHz SHF F AWACS(US &NATO)-AEW Radar

Aegis (US)-Naval EW &TT Radar

Rapier (UK &US).EW Radar

60
4-8 GHz SHF G/H Land Roll-EW Radar, SA-8

Straight Flush-IT Radar; SA-6

6-8 GM SHF H Pat Hand-TTRadar, SA-4

Skip Spin-AI Radar,,Su-15

Flagon Yak-28 Fires barP

Square Pair IT Radar; SAS

8-10 GHz SHF I ClamShell-IT Radar, SA-11

Crotale (France) Command Link

LowBlowITRadar; SA-3

Spin Scan-AI Radar, MG-21

Fishhbed, Su-9 Fishhpot

APG-66 (US &NATO)-AI Radar,

F-16

8-20 GM SHF I/J Flap Wheel-AAA Radar, 57-mm,

130-mm Guns

High Lark-AI Radar, MG-23

Flogger B/G

Fox Fire AI Radar, MG-25 Foxbat

10-20 GM SHF J Gun Dish-TrRadar, SA-9, ZSU-23

Rapier (UK)-Command Link

Legend

ABM-Antiballistic Missile

HF-High Frequency

SHF-SuperHigh Frequency

TABLE11

Soviet Naval Radarsta

Radar

Frequency Band RadarSystem

OS-1 .0 GHz C Big Net-EW Radar; Cruisers, Destroyers and Pickets;

SA-N-1, -2

Head NetA-EWRadar, Cruisers and Destroyers

Top-Sail-EWRadar, Carriers and Cruisers

Top Trough-EWRadar, Cruisers and Destroyers

1-2 GHz D Head light-IT Radar, Carriers and Cruisers; SA-N-3, -14

1-3 GHz D/E Flat Spin-EW Radar; Destroyers and Smaller Ships

2-3 GHz E Hair Net-EW Radar, Older Frigates

Slim Net-EW Radar, NewerDestroyers and Frigates

61
Target-tracking radars, conversely, operate over relatively

short ranges and thus can operate at higher frequencies.

Several advantages make higher frequencies attractive . First,

the higher the frequency, the smaller the antenna can be. Since

radar antennae must be several times the size of the

transmitted wavelength to sufficiently focus the beam for

precision guidance, the higher the radar frequency is, the

shorter the wavelength and, hence, the narrower the antenna.

This tends to become critical for missiles that carry their own

radar. Second, the higher the frequency, the lower the tracking

beam's elevation can be without incurring multipath

ambiguities. Third, the higher the frequency, the wider the

transmission band will be because a radar usually exhibits a

bandwidth of 10 percent of its nominal operating frequency.

62

2-4 GHz E/F Head Net C-EVE Radar, Carriers, Cruisers, Destroyers,

and Frigates

3-4 GHz F HeadLight-TT Radar, Carriers and Cruisers ; SA-N-3, -14

Pop Group-IT Radar, Carriers, Cruisers,

Frigates and Smaller, SA-N-4

Strut Curve-EW Radar, Frigates and Smaller

4-6 GHz G Fan Song E-TTRadar, Cruisers, Destroyers, and Smaller,

SA-N-2

Head Light-TT Radar, Carriers and Cruisers; SA-N-3, -14

6-8 GHz H Bass Tilt-AAA Radar, 30-mm, 57-mm, 76-mm Guns

Head Light-TT Radar; Carriers and Cruisers; SA-N-3, -14

6-10 GHz H/I FrontDome-TTRadar, Destroyers; SA-N-7

Pop Group-TT Radar; Carriers, Cruisers, Frigates and

Smaller; SA-N-4

8-10 GHz I Hawk Screech-AAA Radar; 45-mm, 57-mm, 76-mm,

100-mm Guns

High Sieve-EW Radar, Cruisers and Destroyers

Owl Screech-AAARadar, Carriers, Cruisers, Destroyers,

and Frigates; 76-mm

8-20 GI-1z I/J Kite Screech-AAA Radar, Cruisers, Destroyers, and

Frigates; 100-mm, 130-mm

Top Dome-IT Radar, Cruisers; SA-N-6
presence of an aircraft within the range of the sensor system.

Once alerted, the enemy will attempt to acquire, or localize,

the aircraft with appropriate sensors. After localizing the

aircraft, the enemy must track and identify it . Tracking is the

process of building aposition (azimuth, elevation, and range)

history and velocity derivation of the target. Identifying the

target usually meansdetermining friend or foe status, but it can

also mean classification as to the degree of threat . Modern,

sophisticated weapon systems routinely detect, acquire, track,

and identify virtually simultaneously . Intercepting the aircraft

is the process of engaging it with the various types ofweapons

at the enemy's disposal. Forexample, to afighter, interception

means closing to within attack range. To SAMS, it means

launching and guiding a missile to the transport. Intimidating

the transport is to cause it to abort its mission under threat of

destruction. And, of course, disablement and destruction are

self-explanatory. Note that damage and destruction may be

dependent not on direct impact but on warhead effects

controlled by a fuse mechanism.

For the transport, avoiding the threat can mean avoiding

detection, acquisition, tracking, and identification as well as

avoiding the lethal envelope of the weapon. Deceiving the

enemythreat is diluting it with real orimagined targets andcan

occur through massing of aircraft, deceptive jamming of

sensors, or employment of decoys. Degrading meansreducing

enemy capability by confusing and overloading sensors and

command and control networks. Intimidating the threat is a

form of degradation that causes the enemy to operate

inefficiently or not at all because of the threat of destruction.

Damaging and destroying means using lethal force against

sensors and weapons to eliminate components ofthe system or

the weapon itself.

64
unbroken chain to defeat the airlifter; only one of the airlifter

s

tasks need be accomplished to defeat the threat . Despite the

fact that most of the tasks facing the airlifter are difficult, they

are possible . Furthermore, if an airlifter only achieves partial

success in several of the tasks, the net effect may sufficiently

degrade the threat to defeat it . With this background the next

undertaking is to examine electronic warfare tasks in detail.

Electronic Warfare Tasks

Nations conduct electronic warfare for three reasons: to

exploit the electromagnetic spectrumfor their ownuse, to deny

use of the spectrum by the enemy, and to counter attempts by

the enemy to deny use. Accordingly, the classical divisions of

electronic warfare are electronic support measures (ESM),

electronic countermeasures (ECM), and electronic countercountermeasures (ECCM) .

Electronic Support Measures. As defined by the

Department of Defense, ESM is

that division ofelectronicwarfare involving actions taken to search for,

intercept, locate, and identify immediately radiated electromagnetic

energy for the purpose of immediate threat recognition. Thus,

electronic warfare support measures provide a source of information

required for immediate action involving electronic countermeasures,

electronic counter-countermeasures, avoidance, targeting, and other

tactical employment of forces .'

Thekey words for airlifters are immediate threat recognition,

source ofinformationfor immediate action involving electronic

countermeasures, avoidance, and targeting. Because it

broadcasts electromagnetic energy, a radar reveals the location

of the transmitter and much about its purpose. With diligent

military intelligence and appropriate ESM onboard, an airlift

65
countermeasures. Under such a scenario, it is clear that the

threat has weaknesses that ESM could address. The question

should be "Is there a requirement for ESM on airlift aircraft

and what form should it take?"

The requirement for ESM is fairly easy to establish.

According to the US Air Force Scientific Advisory Board's

1982 Summer Study recommendations,

Despiteall attempts to avoid threats, however, MACaircraft maycome

under attack both en route and in combat areas. We recommend they

be equipped with appropriate survivability packages

including . . . radarwarning receivers . . . to reduce the effectiveness of

missile attacks from surface and air."

A radar warning receiver (sometimes referred to as a radar

homing and warning or RHAWreceiver), as earlier suggested,

detects threatening radars and displays them to the aircrew as

a strobe line or a position on a scope. For example, if the

transport were heading north and a threat was displayed at the

3 o'clock position on the scope, the crew would know that a

threatening radar was due east of the airplane . Such a scheme

works well with alimited number of threats, but as the number

increases, the crew can become quickly saturated. As noted

earlier, a Hughes and Tracor study suggests that a transport

aircraft approaching an airstrip in the brigade rear area at

500-foot altitude in aEuropeanwarscenario would be scanned

by at least 50 threatening radars andtracked by at least 15'4A

radar warning receiver presentation under such circumstances

would be of limited value. It would warn the crew of the threat,

but it would not indicate how to proceed.

Instead, what the aircrew would need is some form of a

threat-avoidance receiver (TAR) that not only displays threats

that also analyzes them to predict a "no-detection" path, if one

is possible ; activate appropriate ECM devices; and predict a

66
sequential task hierarchy of avoiding detection t

e, 

detected, jamming the threat, avoiding lethal threat envelopes,

or damaging or destroying the threat.

To count=er foreseeable threats, a TAR should include a

frequency range that protects against existing and predicted

threats, while coping with the anticipated pulse density. For

example, the current radar threat to an aircraft at 40,000-foot

altitude consists of emitters operating from VHF-band

through J-band (70 MHz to 20 GHz) with pulse densities that

can reach one million pulses per second. The threat in the year

2000 will extend the frequency range to at least 40 GHz and

the pulse density to 10 million pulses per second25 At 500-foot

altitude a TAR will have a slightly easier time since it is

estimated that only 25 percent of the threat emitters will be

able to illuminate the airlifter. In addition the TARshould rank

threats for ECMto negate and should control the ejection of

expendable countermeasures.

Electronic Countermeasures. The second major classical

division in electronic warfare, ECM, is

that division ofelectronic warfare involvingactions taken to prevent or

reduce an enemy's use of the electromagnetic spectrum. Electronic

countermeasures include electronic jamming and electronic

deception.'b

The key concepts are jamming, deceiving, and degrading the

enemy's use of the medium. To cover the subject in the context

of an airlifter's mission, it is helpful to organize the topic in

terms of active (observable) measures, passive (unobservable)

measures, stealth techniques, and passive-active techniques. In

reading the following discussion, the reader should remember

that the enemyis attempting to increase the S/Nratio while the

airlifter is attempting to decrease it.

67
acat, active ECM need not be supplied by the transport

itself. When it is, it is called self-screening jamming. When

active ECMis provided by a nearby aircraft, it is called escort

jamming, and when it is provided by a distant platform, it is

standoff jamming. Self-screening and escort jamming give

away the location of the airlift aircraft while standoff jamming

only gives away the location of the jammer. Thus, standoff

jamming maybe thought of as passive from the perspective of

the transport.

As implied, the jammer need only accomplish one of two

functions : deceive the radar or degrade its capability.

Deceptionjamming mimics the radar's waveform to gain entry

to its range, velocity, and angle tracking loops where it induces

the radar to track false targets. Degrading occurs through noise

jamming that strives to lower the S/N ratio to less than 1.0.

While less sophisticated than deception jammers, a powerful

noise jammer can be more widely employed.

Thejammer's pulses act on the radar receiver in one of two

ways, through the radar mainlobe or through the sidelobes.

Mainlobe jamming must be timed to occur during the brief

interval the mainlobe is sweeping past the target aircraft and is

only effective if performed by the target aircraft or a jammer

on the same azimuth from the radar. If the separation between

the jammer and the airlift aircraft is greater than the mainlobe

beam width, both the jammer and the airlift aircraft will be

visible to the radar.

Recall fromthe echo powerequation that the strength ofthe

echo will be attenuated as a function of the distance between

the radar and airlifter/jammer to the fourth power. Ajamming

signal originating at the airlifter will only be attenuated as a

function ofthe distance squared, since the signal is not making

a round-trip. This conveys an advantage to thejammingaircraft

(in striving to make the signal-to-noise ratio less than 1.0) .

68
pot ee te oe poeuadabutougte

jamming (making the S/Nratio greater than 1.0) (fig. 3). At this

range the advantage swings back to the ground radar.

Whenthe mainlobe is jammedby a noise generator such that

the S/N ratio is less than 1 .0, the ground radar "sees" a strobe

line passing through the jamming platform's position. If there

is only one radar, or other radars are not "netted," and the

penetrating aircraft does not intrude to the point of

burnthrough, the radar cannot produce range data. Without

range data, it is difficult to engage targets with any form of

weaponry because operators cannot know if or when the

jammer is in range of their weapons.

If more than one radar is operating and they are integrated

in a defense network, noise jamming of each radar's main]obe ,
technique of producing a network solution breaks down,

however, when increasing numbers ofjammers are introduced.

To illustrate this breakdown, consider the case of two

separated` jammers and two separated radars. When two

jamming strobes are produced against each radar,_ four

intersections appear on the master scope. Two of these

intersections contain target jammers; the other two are empty

and are called "ghosts"28 (fig. 4). Since the ghosts are identical

to the target intersections, the enemymust use other means to

sort out the targets. As more jammers are introduced the

"ghosting" problem increases as a factor of the number of
the sidelobes of the radar, instead of seeing

one strobe, the

radar "sees" multiple strobes originating from virtually every

compass position. The net effect is to blank out the scope. Such

antijamm ng hardware as coherent sidelobe cancelers and

sidelobe blankers, employing auxiliary antennae and signalprocessing techniques, significantly reduce vulnerability, but

they cannot completely defeat sidelobe jamming.3°

Frequency agility (the ability of a radar to change its

operating frequency) requires an additional level of jamming

sophistication. To this point, discussion of mainlobe and

sidelobe effects has been based on a radar operating on one

frequency. Even nonagile radars can be tuned to operate

anywhere within 10 percent oftheirnominal design frequency.

This increases the difficulty of jamming them and naturally

favors radars designed to operate at higher frequencies since

10 percent of a larger number produces a wider margin for

operation. Once such aradar is successfully jammed, however,

there is an incentive to change frequency to get away from the

jamming. To assure continued jamming of a radar that has

frequency agility, thejammer must periodically "look through"

thejammingto make sure the radar has not changed frequency

or shut down. 31 To do so, the jammer must either isolate its

jamming and receiving antennae or cease jamming briefly to

sample the radar's output.

Noisejammers come in three basic forms: barrage, spot, and

swept. When a jammer has enough power and can cover awide

band of frequencies, it is called a barrage jammer. The test is

thejammer's ability to produce enough noise at all frequencies

in the barrage band to reduce the S/N ratio to less than 1 .0 for

any radar operating within the band. To illustrate this point,

consider a jammer producing 1,000 watts of power while

covering a band of 1,000 MHz. Such a jammer produces a

spectral power density of one watt per megahertz. In a

71
capability . Acting as a standoffjammer at arange of 50 nautical

miles against the same radar's sidelobes, such output might

only be effective in reducing the range to 92 percent of the

unjammed value. Against the same radar with sidelobe

reduction techniques, the output may only be effective in

reducing the range detection capability to 98 percent31

Spot noise jamming concentrates the jamming energy over

a much narrower frequency band. Compared to barrage

jamming, it is much more efficient, but it requires either agood

automatic lookthrough capability to detect a radar frequency

shift or it requires ahuman in the control loop33

To get around the control requirements associated with spot

jamming, designers developed swept jamming. Such jammers

produce spotjamming density levels, but sweeg through the

frequency band of interest on a repetitive basis.

Against early warning radars, self-screening noise jamming

appears to offer the most screening potential. Against tracking

radars,which are associated with missile and AAAsystems, this

is not necessarily the case.

Whereas early warning radars tend to be pulse radars,

target-tracking radars tend to be monopulse, conical scan, or

Doppler. In the case of missile systems, if the tracking radar is

assured that the target is withinthe range ofthe missile, precise

range information is not needed. All the missile need do is

home on the jamming or ride thejamming strobe to the target.

Because of these characteristics, deceptive techniques are

usually used against target-tracking radars.

The aim of a deceptive technique is to stop the radar from

tracking the target. Numerous techniques are used depending

on the type of radar. Since tracking radars usually feature

narrow mainlobe beams, they must be fed precise target

coordinates to acquire the target. Such information usually

comes from asurveillance radar or amissile acquisition radar.
coordinates to the tracking radar. In an automatic control

mode, this process can take up to 10 seconds35 With a skilled

human operator in a manual control mode, this time can be

reduced considerably, but missile accuracyusually suffers from

the less-smooth human control.

To understand how tracking radars are induced to break

track requires some knowledge of their operating

characteristics. For example, pulse radars track by "building"

range gates around their targets. Range gates specify a period

in time during which the radar will accept signals as valid

echoes. Recall from the radar mile discussion that range and

echo time delays are analogous. Signals falling outside the near

and far gates are rejected as being too early and too late,

respectively, to be echoes from the target. To get pulse radars

to accept a jamming pulse instead of the echo from the target

requires a deceptive technique called range gate pull-off

(RGPO)36 The RGPO jammer analyzes the radar pulse

arriving at the aircraft and constructs ajamming pulse to mimic

the echo. Ensuring overlap of the echo by the jamming pulse,

the jammer raises the power of the jamming signal until it is

much stronger than the echo. Since radars must have an

automatic gain control to keep from being overwhelmed by

echoes from nearby targets, the gain (sensitivity) is lowered. As

the strength ofthe jamming pulse increases, the jammer delays

the pulse so that the radar is made to "think" the target is

pulling away. Theradar then adjusts its range gates accordingly.

This is called capturing the gate . Once the gate is captured the

radar can no longer "see" the real target (because ofthe radar's

lowered gain) as long as the jamming continues. When the

range gate has been pulled off to the extent that the real echo

will be rejected, the jammer shuts off. The tracking radar must

then cycle through the acquisition process to reacquire the

target. Such a process can be employed repetitively to defeat

73
Doppler radars build velocity gates instead of range gates.

Against such radars, velocity gate pull-off (VGPO) must be

substituted for RGPO. 37 Velocity gates are constructed by

setting certain frequency limits on returning echoes once the

target has been acquired. Any echo with a frequency outside

thesevelocity gates is rejected . To institute VGPO, thejammer

must first capture the gate by mimicking the echo while raising

the jamming signal strength. By gradually shifting the

frequency (to simulate a change in velocity of the target), the

jammer causes the radar to adjust its velocity gate to the

dictates of thejammer. When the velocity gate has beenpulled

off sufficiently to reject the real target, the jammer shuts off.

As a check against such techniques, some Doppler radars test

the frequency shift of echoes to make sure they conform to

accepted acceleration limits . Asmart jammer can compensate

for these checks, however, and keep false target acceleration

within bounds.

Pulse compression radars are called coherent radars because

of their ability to process radar signals and remove unwanted

noise. Noise jamming against these types of radars is usually

counterproductive, so deceptive jamming is recommended.

Against pulse compression radars, the jammer need only have

the ability to decompress the pulse, analyze it, and reproduce

it to accomplish VGPO. Use of repeater jamming is effective

against pulse compression radars because of their inherent

inability to perform leading-edge pulse tracking . Leading-edge

pulse tracking derives from the phenomenon in which delayed

echoes are seen as longer-range targets, with the first echo, or

leading edge, being the real target.

Pulse Doppler radars are also considered coherent because

of the pulse phase correlation used in establishing velocity

gates. Jamming only the Doppler velocity gate is not effective

because the pulse aspect of the radar still provides

74
Against low

probabilityofintercept radars the trick is to

know they are operating in the first place. If intelligence can

establish the parameters of the waveform, filters can be

programmed into the jammer to screen for these signals.

Otherwise, sophisticated techniques involving channelized

receivers, instantaneous frequency measurement techniques,

spectrum analysis, or Bragg-cell type receivers will be required

to ferret out the signal. Once it is known that an LPI radar is

operating, however, repeater jamming would appear to be

sufficient4°

Jamming phased-array radars is more difficult because of

their low sidelobes, concentrated mainlobe energy, and

track-while-scan (TWS) capability. Otherwise, noise and the

RGPO and VGPO techniques previously described are

applicable .

Conical-scan radars are particularly vulnerable to ECM

attacks against the tracking antenna. Against a plain conicalscan radar, inverse gain jamming (echoes are reinforced

inversely proportional to the strength of the radar pulse at the

target) produces a tracking error signal that tends to drive the

antenna away from the target to the point of breaking lock.

Later versions of conical-scan radars employatechnique called

lobe-on-receive-only (LORO), which uses a nonscanning

beam that is received by the conically scanning antenna. Since

thejammer cannot discern the scan rate from the beam, it must

search for it by sweeping the frequency range with energy and

by monitoring the tracking radar beam for a reaction. When

the jammer sweeps inverse gain signals through the receiving

antenna's scan-rate frequency, the conical-scan transmitting

antenna will temporarily go unstable . By detecting this

instability in the signal and sweeping back to this frequency, the

jammercan drive the conical-scan transmitting antenna offthe

target41

75
pqy qgy

are usually quite small. Instead, the more successful techniques

attempt to exploit multipath signals through crosspolarization, cross-eye, or terrain-bounce techniques42

Cross-polarization works on the principle that the tracking

error sensing circuit in the radar has a positive feedback for

cross-polarized signals (rotated 90 degrees), as opposed to the

required negative feedback for tracking . This technique is

easier to use against parabolic antennae than planar-array

antennae.

43

Cross-eye jamming is the simultaneous repeating of the

transmitted monopulse signal from two separated antennae

operating 180 degrees in phase shift. By producing arelatively

powerful jamming signal and keeping the separation of the

jamming sources a beam width apart, maximum error is

induced

Terrain bounce is a technique that is more appropriate for

decoying missiles than for deceiving ground-based radars. It

relies on abistatic jamming principle whereby the monopulse

signal is repeated and bounced off the nearby surface of the

earth in the direction of the radar. To be effective the jammer

should employ afan-shaped signal, wide in azimuth but narrow

in elevation, with low sidelobes. When jamming is successful

the SAM or air-to-air missile impacts the ground on the spot

illuminated.4s' 41

Passive Techniques. Passive ECM techniques are those that

can be employed without giving away the location of the

initiating platform. The most obvious is chaff (precisely sized

strips of foil), which when introduced into the airstream

produce a radar echo many times the size of the aircraft. To be

effective, chaff must be cut to a length equal to one-half the

wavelength of the victim radar 47 The frequency diversity of

threat radars listed in tables 10 and 11 suggests that aircraft

76
effective againstearlywarning and search radars. Notonly does

it act to screen targets, but it also causes automatic gain control

problems for susceptible radars so that detection range is

reduced.'

Stealth Techniques. The most effective ECMtechnique is to

reduce an aircraft's radar cross section. Lumped under abroad

category called stealth technology, radar cross-section

reduction techniques can be very effective. In the evolution of

the B- 1B aircraft, stealth technology wassuccessful in reducing

the A-modelreflection by an order ofmagnitude. For example,

if aB-1Awere first detectable by a radar 35 nautical miles away,

the B-1B would not be detected until it came within

approximately 20 nautical miles48 Radar cross-section

reduction techniques fall into one of three subcategories:

vehicle shape, skin design, and radar absorbent coatings and

material .

The "stealthy" vehicle shape should emphasize surfaces that

reflect radar waves away from the source, a blended fuselage

and wing, hidden inlets and engine compressor face, and the

elimination of such obvious radiating elements as antennae.

When the direction from which threat radars will be radiating

can be determined (i .e ., always from above), steps can be taken

to deflect radar echoes away from that direction. Skin design

should emphasize absorbing incident waves and canceling

interior waves for the range of threat frequencies that are

critical .49 Radar absorbent coatings and material are used in

circumstances where the first two techniques are impractical

or unsuccessful .

PassiveActive Techniques. This category includes the use of

towed decoys and expendable jammers. Atowed decoy is an

antenna towed at some distance from an aircraft and is only

caused to radiate after the aircraft is detected . The principles

77
place. Adisadvantage with the towed decoy is its influence on

aircraft performance.

An expendable jammer is not deployed until it is needed. It

is then ejected and activated and operates while descending

either in free-fall or on a parachute. A disadvantage with an

expendable decoy on a parachute is that it will quickly slow

while descending and, thus, is theoretically subject to amoving

target filter . Additionally, expendable decoys are limited in

power output compared to the towed variety.

Electronic Counter-Countermeasures. So far, this

discussion has shown that the five radar classes in their many

forms can be countered with ECM. However, each

countermeasure has counter-countermeasures that act to

restore dominance of the threat radar. Despite ongoing efforts

to come up with the perfect radar and the perfect jammer, the

fact remains that no radar is unjammable and no jammer is

perfect. Aquick review of table 12 should illustrate the nature

of this continuous action and reaction cycle in electronic

warfare.

TABLE 12

Early Warning and Tracking Radar

ECM and ECCM Techniquesst

Radar Type ECM ECCM

Range Obscuration

EW & TT Spot Noise More Power, Frequency Agile

Pulse Compression.

EW Barrage Noise Same, Constant False Alarm

Rate.

EW Swept Noise Same, Variable Intermediate

FrequencyProcessing.

78
Electro-optical Countermeasures

Electro-optical (EO) systems exploiting visible and infrared

radiation have been used in warfare ever since World War II

when the Germans used IR signal lamps and the Italians used

IR-sensitive mirror systems to locate ships. Modern systems

exploit IR radiation for such uses as seeker heads in missiles,

search and track systems, night-vision devices, photographic

sensors, and navigation systems. In addition, visible and IR

portions of the spectrum are exploited in laser (light

amplification by stimulated emission of radiation) systems.

79

EW &TT CoverPulse Pulse Compression.

Network Solution .

Frequency Agility.

EW &Tr False Targets Pulse Repetition.

Frequency Jitter.

Frequency Agility.

Sidelobe Reduction .

TT Range-gated Noise Frequency Agility.

Home on Jam.

IT Range-gate Pull-in Pulse Repetition .

Frequency Jitter.

TT Chaff Moving Target .

Indicator.

Angle Obscuration

TT Inverse Gain Lobe-on-receive-only.

EW & TT BuddyMode Noise Monopulse .

Pulse Compression.

Angle Deception

EW & IT Inverse Gain Lobe-on-receive-only.

TT Jog Detector Anticipation Circuit.

Plus Frequency Agility

Velocity Deception

TT Velocity Gate Pulse, Pulse Doppler.

Pull-off Acceleration Checker.
missiles, antivision lasers, laser beam

riding missiles, and

directed-energy weapons (DEWs).

Infrared Homing Missiles

In addition to IR's earlier-mentioned usefulness in

penetrating haze, IR guidance systems make use ofthe fact that

all matter warmer than absolute zero (-459.69° Fahrenheit)

produces infrared radiation. Because IR homing devices do not

have to supply the IR energy for their guidance system, they

can operate passively . IR homing missiles rely on

photoconductive (table 13) or photovoltaic sensors that are

responsive to certain wavelengths of IR radiation.

The warmer matter becomes, the shorter the wavelength of

radiation given off. For example, room temperature objects

primarily radiate in the 6-to-10 micron region. Objects at 400

degrees Fahrenheit primarily radiate in the 3-to-10 micron

region, and objects at 900 degrees Fahrenheit primarily radiate

in the 2-to-10 micron region. Because of the atmospheric

absorption band between 5 and 8 microns, a heat-seeker

80

TABLE 13

Infrared Sensitive Photoconductors 52

Photoconductor Wavelength Sensitivity

Lead Sulfide, -60°F 1 to 3.5 microns

Lead Sulfide, Room

Temperature 1 to 2.8 microns

Telluride, -320°F i to 5 microns

Indium Antimonide, -320°F 1 to 6 microns

Germanium, Doped, Room

Temperature 1 to 9 microns
8-to-10 micron region.

Early heat-seeking missile designers, in fact, used room

temperature lead sulfide sensors, but they found that their

missiles went astray whenever their sensors scanned past the

sun, sunlit clouds, or brightspots of illuminated earth reflecting

in the 2.5-micron range. To achieve better false-target

rejection capability, rotating reticles were used to "chop"

incoming radiation. Chopping periodically blocked the sensor

from view, thereby setting up an alternating signal current. By

amplifyinE the alternating signal, better noise rejection was

achieved.

Infrared countermeasures (IRCM) in the form of

pyrotechnic flares and IR-strobe jammers were then

developed to offset the improved performance of the reticles.

Flares are used to flood the IR sensor with so much energy that

the target (for example, jet exhaust) becomes insignificant and

thus "invisible ." The IR-strobe jammer attempts to

synchronize its flashes with the openings of the chopper. If

synchronization is achieved, the missile has two targets within

its sensor's field of view and its homing becomes erratic.

To keep missiles from homing on decoys, IR seeker

designers developed dual-band sensor systems that can

recognize the signature of real targets and reject poor

imitators. Such techniques would appear to be vulnerable to

IR decoys more effectively tuned to mimic jet-exhaust

characteristics.

Antivision Lasers

Lasers can transmit sufficient energy to temporarily or

permanently blind personnel. Incidents cited by US Navy and

Norwegian aircrews, which involved flying past Soviet ships,

serve to emphasize the serious nature of this threat. In each

A,
(HUDs), or if beams emanating from higherpowered devices

were used against the unaided eye, permanent blindness could

result55 If a high-powered beam happened to pass through a

HUD, explosive delamination of the HUDoptics could occur.

One weakness associated with such weapons is the

monochromatic nature of the light they produce .

Countermeasures might exploit that characteristic by filtering

or reflecting the frequency of the laser's energy.

Laser Beam-Riding Missiles

Such weapons as the Swedish Bofors Rayrider man-portable

SAMpose aunique threat to airlift aircraft. To date, effective

countermeasures have not been demonstrated although

possibilities include attacking the illuminating laser operator

with another laser, attacking the missile directly, and

back-lighting reflective (optical) chaff.

Directed-Energy Weapons

Use of lasers as directed-energy weapons is being pursued

with greatvigor as part ofantiballistic missile defense. An early

and certain application ofsuch weapons will be against aircraft.

Since numerous sources have projected the mid-1990s to the

year 2000 as a feasible time frame for producing suchweapons,

the threat appears imminent. Because such a weapon would

probably be aimed in an analogous fashion to radar and

optically aimed SAMs, antiradar and antioptics (laser) tactics

would appear to be feasible.

82
weaknesses, the focus has been on internal operation and

exploitation of electromagnetic phenomena. Such weapons

also have weaknesses inherent in their functions: they are

subject to time constraints, human operator limitations, and

guidance and control problems.

Time

To avoid being destroyed by a missile, an airlifter need only

frustrate a targeting solution long enough to escape the

missile's envelope. By causing the tracking radar to break track

periodically, a jamming aircraft buys time and comes closer to

escaping . Accordingly, speed is an ally of the transport along

with delayed detection. Since low-altitude penetration delays

detection, speed and low altitude have synergistic effects.

Countering Humans

Many tracking radars employ a human backup to automatic

tracking circuitry to allow countering of ECM techniques.

Whenever a human manually controls a radar, however, its

accuracy suffers, resulting in as much as a 30-percent reduction

56 in probability of kill . Furthermore, humans have saturation

limits and resonant frequencies that can be attacked as well .

For example, astrobe lamp cycled at approximately five cycles

per second will eventually incapacitate a person viewing it.

Another way to attack humans is psychologically by placing

them at risk, as use of an antiradiation missile would do. If a

threat radar appears and is not deterred by ECM, airlift aircraft

could wield the ultimate countermeasure: destruction of the

radar. Such a threat might cause operators to be more selective

in using their radars, creating greater opportunity for

transports to avoid the threat .

83
defeating amissile. Basically there are three types of guidance

techniques: homing, beam riding, and command guidance.

Homing is the process of proceeding to a source of radiation

and, in turn, is divided into three paths: a pursuit course, a

collision course, and a proportional navigation course. Pursuit

guidance is characterized by constant turning to place the

target in the center of the seeker. Turn rate is proportional to

the line-of-sight (LOS) angle fromthe missile centerline . Since

this path results in continuously turning flight, a drag penalty

is incurred that decreases range. Acollision course is aconstant

bearing course that requires instantaneous course corrections.

In theory this is the most efficient path, but in practice it is not

realistic, and any attempt to turn instantaneously usually

results in a suboptimum range capability . The optimum range

path is aproportional navigation course, in which the missile

turns with a rate proportional to the rate of change of the

bearing to the target.

When flying any of the homing paths, a missile operates in

one of three modes: passive, active, or semiactive. Passive

operation does not require that either the launching platform

or the missile radiate. An example of a system that operates

passively is a heat-seeking missile. Active guidance requires

the missile to illuminate the target, usually with radar. An

example of a system that uses active guidance is the advanced

medium-range air-to-air missile (AMRAAM) in its terminal

phase. Regardless of the relative positions of the launch

platform and the target, a missile relying on passive or active

homing guidance becomes more accurate the closer it gets to

its target. Avariation of the two homing modesjust discussed

is semiactive guidance. In this mode the launch platform must

illuminate the target for the missile. Thefarther the target gets

from the launch platform, the less accurate the guidance. Most

modern radar missiles are semiactive s', ss

84
p

y g y

inefficient flight path, they may have to perform severe

corrective maneuvers as they near intercept, and they suffer

accuracy degradation proportionally with distance . Because

they receive their guidance from their aft direction, ECM

directed at them usually must act through the backside of their

highly directional antennae, which is most difficult.

9

Command guidance relies on two radar beams, one tracking

the target and another tracking the missile. The missile turns

on command from the controller and relies on a proximity

fusing system, a command link, or impact for detonation. As a

result, the missile can be fired to a point ahead of the target,

efficiently using its propulsive energy. As target range from the

tracking platform increases, accuracy suffers5 °

Concepts for defeating missiles are only limited by one's

imagination, but they generally focus on the weak links in

guidance systems. Since homing missiles are guided by energy

radiating from or reflecting off the target, efforts to reduce,

suppress, conceal, or decoy this radiation can be effective.

Any missile that does not have aproximity fuse is vulnerable

to a last-minute flight path change by the target. If the target

can delay its maneuver until the missile requires more than its

maximum turning acceleration (G-limit) to follow the target,

the higher-speed missile will invariably overshoot. For

example, aMach-3 missile homing on a Mach-0.7 target would

have to "pull" more than 18 times the G-load of the target to

fly the same track. If the target maneuvers too early, however,

a missile need not fly the same track, but can "cut" the corner

to reduce the required G-load towithin its capability. Since the

lead time required to "cut" the corner is proportional to the

G-load capability of the target, a low-G capable aircraft like a

transport would have a very small margin of time, or window

85
andpersonnel during their time of flight while protecting their

rearward-facing, beam-riding antennae against ECM. The

inherent weakness of the system is in the vulnerability of the

exposed components . Since a laser system would be optically

sighted, it would be theoretically vulnerable to laser energy

aimed back through the optical components.

Command-guided weapons require a communication link,

which opens another avenue for deception. If the tracking

radar is negated, the missile is lost. If the command link is

negated, the missile is lost. Countermeasures against such

systems would undoubtedly jam both tracking and

communication links while maneuvering to exploit the

system's long-range inaccuracies .

Against fused weapons, the possibility exists that the weapon

could be deceived into detonating prematurely. Homing

weapons that rely on CWradar illumination maybe vulnerable

to a descending frequency VGPO technique to trick the

weapon into "thinking" it is passing the target 61

Conclusions

From the preceding discussion of the electromagnetic

spectrumand electronic warfare, four concepts should emerge.

First, the threat has imposed a requirement on MAC to

become proficient at electronic warfare. Second, despite its

technical nature, electronic warfare is too important to be

relegated to technicians ; all levels of leadership will have to

acquire warfighting skill in electronic warfare. Third, the

action-reaction nature ofECMand ECCMrequires persistent

command attention in developing countermeasures on a

continuous basis. And fourth, despite the myths attached to

certain antiaircraft weapons, they all can be countered, even by

airlift aircraft.

86
2. Richard E. Fitts, The Strategy ofElectromagnetic Conflict (Los Altos,

Calif. : Peninsula Publishing, 1980),159.

3. Ibid., 160.

4. M. D: Earle, "Characteristics of Infrared Radiation," Electronic

Countermeasures (Los Altos, Calif.: Peninsula Publishing, 1978), 21-4.

5. Ibid., 31-4.

6. Fitts, Strategy ofElectromagnetic Conflict, 145.

7. Earle, "Characteristics ofInfrared Radiation," 21-4.

8. Stephen L. Johnston, "Millimeter Waves Present New Opportunities

for EWTechniques," International Countermeasures Handbook: 1986, 11th

ed. (Palo Alto, Calif.: EW Communications, Inc., 1986), 323.

9. Earle, "Characteristics of Infrared Radiation," 21-4.

10. Fitts, Strategy ofElectromagnetic Conflict, 12.

11. Ibid., 116.

12. D. Curtis Schleher, Introduction to Electronic Warfare (Dedham,

Mass. : Artech House, Inc., 1986), 32.

13. Ibid.

14. ibid., 150-51.

15. Fitts, Strategy ofElectromagnetic Conflict, 25.

16. Schleher, Introduction to Electronic Warfare, 343.

17. Charles H. Wiseman, "Soviet Weapons and Electronics-Radar

Systems," International Countermeasures Handbook: 1986, 11th ed. (Palo

Alto, Calif.: EW Communications, Inc ., 1986), 270-76.

18. Ibid., 262-69.

19. Johnston, "Millimeter Waves," 324.

20. Schleher, Introduction to Electronic Warfare, 346.

21. Ibid., 344.

22. Ibid., 258.

23. US Air Force Scientific Advisory Board, Report of the Ad Hoc

Committee on the Enhancement ofAirlift in Force Projection (1982 Summer

Study) (U), executive summary, Washington, D.C., December 1982, 1.

(SECRET) (Information extracted from this source is unclassified.)

24. Hughes Aircraft Company and Tracor Corporation, "Military Airlift

Command Electronic Warfare Study Briefing" (U), presented to

Headquarters MAC, January 1988, EW-1. (SECRET) (Information

extracted from this source is unclassified.)

25. Schleher, Introduction to Electronic Warfare, 38.

26. Fitts, Strategy ofElectromagnetic Conflict, 257.

27. Ibid., 84.

87
Artech House, Inc .,1979),143.

31. Fitts, Strategy ofElectromagnetic Conflict, 85.

32. Schleher, Introduction to Electronic Warfare, 126 .

33. Fitts, Strategy ofElectromagnetic Conflict, 90.

34. Ibid.

35. Schleher, Introduction to Electronic Warfare, 115.

36. Ibid., 116.

37. Ibid.

38. Ibid., 173.

39. Ibid., 283.

40. Ibid., 173-78.

41. Ibid., 239.

42. Ibid., 152

43. Ibid., 152-55.

44. Ibid., 158-59.

45. Ibid., 249.

46. A. I. Leonov, and K. I . Fomichev, Monopulse Radar (Dedham, Mass. :

Artech House, Inc ., 1987). Reprinted in part in "Soviet Book Describes

Techniques for Jamming Monopulse Radars," Aviation Week & Space

Technology, 9 February 1987, 61-67.

47. G. S. Sundaram, "Expendables in Electronic Warfare-Proven

Decoys for Survival," Interavia Data, 1980, 74.

48. Richard S. Friedman, Advanced Technology Warfare (New York:

Harmony Books, 1985),19.

49. Richard N. Johnson, "Radar Absorbing Material: A Passive Role in

an Active Scenario," International Countermeasures Handbook, 11th ed.

(Palo Alto, Calif. : EW Communications, Inc ., 1986), 377.

50. "Towed Expendable RF Decoy to Defeat Classified Threats,"

Aviation Week & Space Technology, 21 September 1987, 23.

51. Stephen L. Johnston, "Guided Missile System ECM/ECCM," Radar

Electronic Counter-Countermeasures (Dedham, Mass. : Artech House, Inc .,

1979),122-23.

52. Earle, "Characteristics of Infrared Radiation," 21-7.

53. Ibid., 21-3.

54. Ibid., 21-10.

55. Department of Defense, Soviet Military Power (Washington, D.C. :

Government Printing Office, March 1987), 113 .

56. Fitts, The Strategy ofElectromagnetic Conflict, 98.

57. Johnston, "Guided Missile System ECM/ECCM," 123-24.

88
Engineering, Inc., 1978), 958-60.

60. Ivanov, "Improved Radar Designs," 457-58.

61. Schleher, Introduction to Electronic Warfare, 163.

89

Having established operating principles and weaknesses of

threat systems, this study's next task is to develop concepts for

effective countermeasure systems. Fortunately, MACcan start

with a clean slate to design self-protective systems and can

profit from the lessons of the past while exploiting new

technological opportunities .

Design Philosophy

One lesson of the past is the need to apply the correct design

philosophy. In general there are four prominent design

philosophies available to an ECM system designer : one is to

counter the current enemy electronic order of battle (EOB), a

second is to counter the current EOB and anticipated enemy

changes, a third is to counter the current enemy EOB and a

"mirror image" of one's own capability to improve the EOB,

and the fourth is to counter generic systems (radar forexample)

improved to optimum levels . Each philosophy has its own

advantages and liabilities .'

Attempts to counter only the enemy's current EOB

minimize short-term costs, but they do not protect against

change. Since some change is inevitable, the risk of battlefield

surprise is high. Also, long-term costs could be relatively high

because each change introduced by the enemy will require a

rapid countering reaction, which is usually very inefficient .

Adopting the second design philosophy (assessing the

enemy's capability to change current systems and then

countering those systems) increases short-term costs over the

first choice andpossibly reduces long-term costs, depending on

the accuracy of one's assessments. This philosophy also

91
The third design approach (countering the current EOB

while giving the enemy "mirror-image" capabilities) tends to

cost more over the short term than the second approach, but it

may save more over the long term. Of course, this approach

assumes a technological lead over the enemy. Although

protection against surprise is improved further, estimates of

one's lead over the enemy tend to be optimistic . Worse, this

designapproach condemns one to continue the action-reaction

design cycle, thus keeping long-term costs relatively high.

The fourth design approach (countering generic systems

developed to optimumcapability) requires one to continuously

improve state-of-the-art technology. Consequently, it tends to

be very expensive in the short term and relatively inexpensive

over the long term. By its very nature, it tends to overestimate

the enemy's capability. Thus this approach offers the most

protection against surprise . In new fields of technology,

however, the fourth design approach is often constrained by

the state of the art and never quite reaches the theoretical

optimum. As technology matures in a particular field, such as

radar, the fourth option becomes increasingly possible .

All four design approaches have utility depending on the

urgency of the need. For example, when the SA-2 SAM was

first used by North Vietnam, specific countermeasures were

developed on a rapid-reaction basis using the first design

approach. However, upgrades to the first-generation

countermeasure system tended to use a combination of design

approaches two and three. As second-generation systemswere

developed on a more orderly basis, the fourth design approach

wasused to a greater extent .

Currently MAChas no self-protective systems on its aircraft

and the threat has reached the level at which MACmust react.

Unfortunately, MACcannot afford to wait the 10 or more years

it takes to develop new systems. As a result, a two-stage

92
use. Many existing ECM systems trace their lineage to

rapid-reaction projects of the Vietnam era. As a result, their

designs tended to neglect reliability, maintainability, and

availability . Furthermore, these early ECM systems were

designed for use by aircraft with radar and infrared signatures

much smaller than those of current airlift aircraft. Adapting

such systems may require extensive modifications (for wiring,

antennae, cooling, power generation, etc.) that may foreclose

future options or, worse yet, only provide partial protection.

Over the long term, a prudent approach would emphasize

modular hardware, designed along the philosophy ofthe fourth

design option, with performance controlled by software. This

approach recognizes that individual hardware modules will

reflect the then current state of the art instead of theoretically

optimum performance. As significantly improved levels of

performance are obtained, newer modules can be substituted

on a preplanned product improvement (M) basis . For

instance, a long-term approach to designing a radarjamming

and -deception system might break the system into functional

subsystems : receiving antennae, signal processing, power

generation, transmitting antennae, and software . Within each

subsystem, modules could be designed to deliver state-ofthe-art performance. Then, for example, as improvements in

K-band power generation become available, the K-band

module could undergo retrofit. An added benefit ofusing this

approach is that classified operational features will tend to be

in the software, which can be changed and protected more

easily than hardware.

Adopting the fourth design approach, where feasible, has

subtle but compelling logic. When dealing with a dynamic

threat, as in electronic combat, one must assume that technical

intelligence will lagthe introduction ofnewenemycapabilities .

Consistent with this reality, ECMsystems should be designed

93
a balanced approach would exploit all feasible counter

measures, including deception. 3

An often overlooked facet of the fourth design approach is

the psychological dimension. Attacking all nonhuman links in

the enemy's EOBwhile ignoring the humanmakes little sense.

Despite significant success with "hunter-killer" tactics

employing Wild Weasel aircraft and their killer counterparts,

the United States has yet to take the next step in electronic

combat evolution, namely providing a broader base of forces

with this capability. So long as the only Air Force physical

threat specifically directed at radar transmitters is the limited

number of F-4G aircraft, enemy tactics can be relatively

simple. If a significant portion of Air Force assets could wage

such warfare, the enemy's options would be much more

constrained. Considering that large aircraft are relatively

insensitive to the size and weight penalties that hunter-killer

systems impose on fighter-size platforms, aunique opportunity

presents itself to increase US electronic combat capability .

Benefits of Low Altitude

The first rule of combat airlift operations is to avoid the

threat whenever possible . An effective way to avoid both

surface and airborne threats is to make maximum use of

low-altitude flight. The advantage of low-altitude flight in

regard to surface threats can be seen from the line-of-sight

horizon equation:

d = (2H)as

where dis the approximate distance to the horizon inmiles and

_H is altitude in feet.4 As the equation demonstrates, the higher

one is, the greater the distance one can see; the farther one can

94
Whether one can survive at any particular altitude is a

function of asequence of events in which both the attacker and

evader participate. Ultimately, the preferred altitude will be

determined by the chances of success. An expression for the

probability ofbeing killed in asingle encounter might be stated

as follows:

Pk = Pdet XPacq X Ptr X Pint X Pdes

where Pkis the probability ofbeing killed,

Pdet is the probability ofbeing detected,

Pacq is the probability of being acquired,

Ptr is the probability ofbeing tracked,

Pi nt is the probability ofbeing intercepted, and

Pd,sis the probability of being destroyed by the weapon.

The factors that an airlift aircraft can influence in such an

engagement, Pdet, Pacq, and Ptr, tend to favor low altitude (Punt

has benefits both ways, so it tends to be neutral) . In other

words, whatever tactics, ECM, or defensive steps an airlifter

can employ at high altitude can also be employed at lowaltitude

and usuallywith better effect. As aresult, the factors that would

tend to favor high altitude for the airlifter must be determined

by the enemy's circumstances.

Since the equation is for a single engagement, adding a

second engagement of equal Pk would double the chances of

being killed . Therefore the point of equal probability of being

killed between low- or high-altitude cruise occurs when the

number of engagements at high altitude drops off to the point

where it is balanced by the savings in Pdet, Pacq, and Ptr at low

altitude. If the number of engagements does not drop off as

altitude increases (it would not against conventional Soviet

forces in such regions as the Fulda gap, even at maximum

95
generated by 

multipatheffects. Multipath is the tendency of

radar beams to propagate along multiple paths as the radar

elevation angle is lowered toward horizontal and the mainlobe

interacts with the ground. In practical terms, this creates

ambiguous echoes and scope clutter. To avoid this, radar

operators increase the radar elevation angle until it is above

the region where this phenomenon occurs. The net effect of

multipath and raising the radar elevation angle is to decrease

the range at which a low-flying object can be first acquired . In

effect, multipath and ground clutter effects require the radar

to be closer than the horizon to "see" a low-altitude target

(over-the-horizon radars excepted). Under these circumstances, the line-of-sight horizon equation serves as a

worst-case estimator of the range at which an aircraft can be

acquired by radar. In addition, the equation illustrates the

opportunity to lessen exposure to hostile radars by flying close

to the ground.

Low-altitude flight also has benefits againstairborne threats,

particularly jet fighters. In any engagement, a fighter pilot

places considerable emphasis on maintaining as high an energy

level as possible for his aircraft because energy translates to

maneuverability and maneuverability translates to ability to

survive. In a one-versus-one fighter engagement, for example,

the fighter with the higher energy level usually wins, all else

being equal.

To understand howthis applies to afighter-versus-transport

engagement, recall from early physics lessons that energy

consists of two components, potential and kinetic. Potential

energy is stored energy, and an aircraft's potential energy

comes from its position and fuel supply. Position in this case

relates to altitude; the higher the altitude, the higher the

potential energy. Kinetic energy is energy of motion and can

be expressed as:

96
gg p

airspeed will have to sacrifice much of its potential energy and

a portion of its kinetic energy, particularly if it intends to make

a gunpass. To use its guns it must drop to near the altitude of

the target and if it does not slow down, the time available to

make a gunpass is so short that its chances of success are small.

This is so because an air-to-air cannonis only effective atranges

of less than 3,000 to 4,000 feet. Inside 1,000 feet the fighter

employing a cannon runs the risk of shooting itself down as it

flies through shrapnel . Therefore, the window of opportunity

is open only as long as it takes the fighter to traverse the range

from 4,000 feet to 1,000 feet. A500-knot fighter overtaking a

250-knot transport would enter and exit the window of

opportunity in about seven seconds . Against a nonmaneuvering target at moderate altitudes, this time would be

sufficient for even the least proficient of fighter pilots, but

against a maneuvering target at low altitudes, the available

time is much less .

The way a fighter's cannon is boresighted dramatically

affects alow-altitude gunpass. If the cannon were aligned with

the fighter's centerline, the cannon would point along the flight

path when the fighter was flying at a zero angle of attack.

However, fighters generally require some angle of attack to

produce lift . The slower the airspeed, the greater the angle of

attack required ; the higher the G-load (turn rate), the higher

the required angle of attack . These constraints present the

fighter designer with design compromises: At what angle does

one incline the gun? Ground attack cannons are usually aligned

close to centerline, because expected targets are relatively

immobile and the attack maneuver can be done at one G.

Air-to-air cannons are usually inclined a couple of degrees up

from centerline partially to compensate for the cut-off angle

and the maneuvering angle ofattack needed for attacking high97
fighters cannon is inclined above centerline 2 degrees and the

fighter requires 3 degrees angle of attack to maintain level

flight, its cannon will be pointed 5 degrees above horizontal.

Therefore, to aimthe cannon at aco-altitude target, the fighter

must enter a5-degree dive. (Ifthe fighter starts the gunpass at

a higher altitude than 300 feet, it must increase its dive angle

by 1 degree for every 69.8 feet above 300 feet. Since a higher

dive angle also increases the sink rate of the fighter, little is to

be gained so close to the ground.)

Assuming the fighter begins the maneuver at 500 knots, it

has about 4 seconds of aiming before it hits the ground. Since

the fighter must begin to pull out at some time before the

projected ground impact point to compensate for downward

momentum,it will have even less tracking time. Ifthe transport

maneuvers in the vertical plane (like a roller coaster), the

fighter must also . Any dipping below the 300-foot level will

increase the angle that the fighter must point its nose below the

horizon. If darkness, weather, rough terrain, turbulence, or

some combination of these factors is added, a low-altitude gun

pass becomes a risky maneuver.

Examining the complexities of a low-altitude gunpass, one

sees that a fighter must sacrifice much altitude and at least

some airspeed to be effective. Having sacrificed altitude and

airspeed, the attacking fighter becomes more vulnerable to

attack. If one arms the transport so it can fight back, one has

created a significant disincentive for interceptor attack of

transports at low altitude. Much of the same arguments would

hold true for low-altitude missile attacks if the methods for

defeating radar and IR missiles, discussed later in this chapter,

were used.

As the preceding examination has demonstrated, flying at

low altitude can have great benefits for the airlifter, but flying

low is not always practical. For instance, transoceanic flights

98
Countering Radar Systems

Having explored various design philosophies and the

benefits of low altitude, this chapter next discusses countering

radar threat systems. In keeping with the airlifter's task

hierarchy, the discussion considers avoiding and defeating

radar systems separately.

Avoiding Detection and Acquisition

Early radar threat warning systems were called radar homing

and warning (RHAW) gear. The presentation given to the

aircrew amounted to nothing more than a strobe line or an

alphanumeric symbol on a plan-position indicator, which

showed the direction (but not range) from which the emission

came. Such a presentation was appropriate for the limited

number of threat systems of those days. Also, RHAWgear was

created not to avoid radar but to allowfighters to dodge SAMs.

Use of such systems to avoid radar detection and acquisition

would be futile; they have no avoidance mode nor could they

cope with modern threat densities. Instead, what is needed for

airlift aircraft is a system that not only indicates the direction

to the threat radar but also calculates detection and acquisition

parameters andprovides steering guidance to the pilot. When

penetration of the threat radar's space is required, the

equipment should provide steering guidance to allow

minimum duration of exposure to the threat . For lack of a

better phrase, the author calls this minimum threat exposure

path the path of least resistance .

Warning-versus-Avoidance Systems. Clearly, a radaravoidance system goes beyond RHAW gear in capability and

99
determination and signal sorting5 Although this accuracy

requirement may sound severe, it is not a significant technical

problem and it is wellworth the effort . For example, a1-degree

AOAprovides 90-percent range accuracy after 10 degrees of

azimuth passage 6The better the range accuracy, the more

effective the avoidance function can be.

From this discussion of radar-warning and -avoidance

systems, it should be clear that threat avoidance is a

requirement for airlift; that early generation warning systems

are nowinadequate ; that airlift pilots will need capable cockpit

presentations to follow avoidance paths or, if penetration is

required, paths of least resistance ; and that all of this is

technologically feasible now.

Passive Navigation. A threat-avoidance system for airlift

aircraft is essential, but it can do little good if the airlifter gives

away its position by wayof careless electromagnetic emissions.

Just as a threat-avoidance system can locate athreat radar, the

enemy can locate spurious and intentional emissions from

airlift aircraft. Included in the category of spurious and

intentional emitters are ground-mapping radars, Doppler

ground-speed radars, radar altimeters, station-keeping

equipment, and unshielded electronic equipment. Although a

thorough scrub of electronic systems could eliminate spurious

emitters, elimination of the intentional emitters would, among

other difficulties, cause navigation problems. The solution to

navigational emissions is passive navigation.

Passive navigation is possible through a system that uses a

digitized map data base and a technique to position oneself

over the map. For example, a digitized map of a flying area

could be supplied by the Defense MappingAgency and placed

in an aircraft's navigation computer. "Fixing" the aircraft's

position in relation to the computer map by way of inertial

navigation equipment, the satellite-based global positioning

100
flight .

Since the strong possibility exists that the GPS would not

survive for long in a war, more reliable methods of fixing

position 'are needed, and they might include use of a

low-powered radar altimeter. To prevent radar altimeter

transmissions from revealing an aircraft's position, two

phenomena-high frequency and absorption bands-can be

used to advantage. High frequency is important because, for a

given antenna size, the higher the frequency, the narrower the

mainlobe can be. The narrower the mainlobe, the more

directional the signal can be. The more directional the radar

altimeter's signal, the lower the chance that it will be

intercepted.

Absorption bands in the electromagnetic spectrum are

important because they can be exploited as well as thewindows

(discussed in chapter 3). Recall that atmospheric oxygen

absorbs virtually all radiation at 60 GHzwithin ashort distance

of wave travel . In engineering terms, this attenuation is

measured at approximately 10 decibels (dBs) per kilometer (10

dBsreflects asignal ratio of 10 to 1, 20 dBs asignal ratio of 100

to 1, and 30 dBs a signal ratio of 1,000 to 1). Agood signalferreting system may be able to distinguish signals that are

attenuated by 50 dBs. Intentionally transmitting radar

altimeter pulses at 60 GHz from several hundred feet above

the ground would produce echoes attenuated less than 10 dBs

(excluding reflection losses), which is well within the 50 dBs

reception ability. But a ferret system beyond five kilometers

would only hear noise because at that distance the signal would

have attenuated to the background noise level. In this manner,

accurate altitude information could be obtained at low altitude

while denying the enemy detection ability beyond

approximately five kilometers . Use of the altitude data in a

101
Integrated Terrain Access/Retrieval System (ITARS) and

Tactical Flight Management Program, British Aerospace's

Terrain Profile Matching (TERPROM) system, and Texas

Instruments' Enhanced Terrain Masked Penetration (ETMP)

system. The TERPROM and ETMP systems illustrate the

advantages of these concepts . TERPROM in its present form

is a precision navigation system with terrain-following and

obstacle-avoidance features. Terrain-avoidance, threatavoidance, and terrain-masking functions would have to be

developed. The Texas Instruments' ETMP system is more

sophisticated in providing terrain following, terrain avoidance

(TF/TA), and threat avoidance by way of terrain masking. To

accomplish the terrain-avoidance function, aradar periodically

scans the terrain ahead of the aircraft. By operating only when

necessary and in an irregular fashion, such a radar takes on

characteristics of a low-probability-of-intercept radar. Power

levels for this radar are scaled down to transmit only enough

energy to see the terrain of interest. To accomplish the

threat-avoidance function, threat data are preprogrammed or

provided in real time bywayof data link with an onboard threat

warning system. Both the TERPROM and ETMP systems

would appear to offer ahigh degree of covertness in operation;

however, the ETMP system's reliance on a scanning radar

somewhat increases its probability of detection. Nevertheless,

the scanning beam offers a safety margin for avoiding digitized

mapping errors (which are not uncommon) and for avoiding

man-made obstacles.

Apossible variation ofthe Texas Instruments scheme would

employ a laser radar in place of conventional radar, thereby

shifting the emitted energy into a less-detectable portion of the

spectrum. Sfena, aFrenchavionics company, has already tested

a carbon dioxide laser, presumably operating at the 10-micron

wavelength in the midinfrared region, for just such a purpose.

102
jammed. They can see beyond nearby ridge lines that block

radar-based systems. They promise to be an order of

magnitude more reliable than radar TF/TAsystems. They can

be automated to further reduce cockpit work load. They are

not affected byweather conditions. They allow users to preview

planned flight routes on the ground or in flight as they will

actually appear. Their accuracy is on the order of 30 meters

vertically and 130 meters horizontally, which approaches GPS

performance. Fromthe foregoing, it is clearthat passiveTF/TA

systems are not only feasible but are also advisable.

For the same reason that passive navigation is required,

spurious and intentional emitters onboard airlift aircraft must

be eliminated. To do this, a screening of all airlift models will

be required, and some existing systems-such as stationkeeping equipment, Doppler ground-speed equipment, radar,

and radio altimeters-will either have to be shut off during

combat or eliminated. In addition, communications

transmissions will have to be eliminated, converted to lowprobability-of-intercept means, or shifted to higher, more

directional frequencies (laser link with a satellite) .

Stealth Technology Applications. While the overall shape of

MAC aircraft cannot be changed inexpensively, aircraft skin

treatments and coatings can be applied to achieve significant

reductions in their radar cross sections . The purpose of such

reductions is not to make the aircraft invisible to radar, since

that is probably notpossible, butrather to degrade enemyradar

performance sufficiently to allow athreat-avoidance system to

be more effective.

Stealth skin treatments and coatings, also known as radar

absorbing materials (RAM), have been available since World

War II . The Germans used a magnetically tuned rubber sheet

material to coat submarine periscopes for protection against 3

GHz radars. Unfortunately for them, the _ British used

103
A second type of RAM is a 

graded dielectric.

Graded

dielectric absorbers work by gradually tapering the impedence

(inverse of resistance) from the value of free space to a highly

"lossy" or heat-producing state . If done smoothly in

transitioning from outboard to inboard (looking at a cross

section of the aircraft skin), little radar reflection occurs at the

outboard skin layer. Moreover, such a technique can be used

to achieve broadband frequency coverage.9

Two recent advancements in graded dielectric RAM

technology are particularly exciting for their application to

ECM. The first is a discovery by Prof Robert Birge of

Carnegie-Mellon University involving retinyl Schiff base salts.

Black in color andresembling graphite, these salt crystals have

the potential for reducingradar reflectance by 80 percent. They

are tuneable to specific frequencies so that amixture of crystals

could be assembled to provide full-spectrum coverage. In

addition they offer better performance than ferrite-based

coatings for less than one-tenth the weight, can be produced

relatively cheaply, and appear to be adaptable to coatings . 10

The second promising advancement in graded dielectric

RAMtechnology is Lockheed Corporation's development of

polyaniline and polyacetylene plastic materials with varying

degrees of electrical conductivity, which are suitable for use as

aircraft skins. Skins with stealth characteristics could be built

by bonding layers of varying impedence to form the graded

dielectric properties required . Moreover, such skins could be

simultaneously tailored with phased-array antenna

characteristics to eliminate the need for protruding antennae

anywhere on the aircraft. In addition to eliminating antennae

and reducing drag, Lockheed's "smart skins" have the votential

for lower weight than that of traditional metal skins.' Both of

these technologies should be of immediate interest to MAC.

104
result, new and aggressive options become available to jam,

deceive, destroy, or intimidate the threat .

Countering Tracldng. Just as a threat-avoidance system

would work to deny detection and acquisition, it could also

work to interrupt tracking, particularly if a terrain-masking

feature were available. Since the threat-avoidance system

would "know" what the masking potential of the land is from

the digitized landmass data base and since it would sense the

direction from which the tracking signal emanates, it could

seek to maneuver the aircraft behind suitable terrain to block

the tracking signal. Also, if the acquisition envelope of the

radar were inadvertently entered, the threat-avoidance system

could direct an appropriate exit path. If avoidance is not

possible and a path of least resistance is required, ECM or

lethal defense could be used to complement the threatavoidance system.

Accomplishing either jamming or deceptive ECMfunctions

requires a system tailored to the radar cross section of the

target it is defending. Two problems come to the fore if

fighter-type ECM systems are used to defend larger aircraft.

The first problem is power output. Since transports have radar

cross sections that are typically an order of magnitude greater

than that of fighters, an order of magnitude increase in power

output would be required to afford the same level of

protection. Since this is usually not possible with off-the-shelf

systems, radarburnthrough would occur atmuch greater range,

as the B-1A versus B-1B bomber example in chapter 3

demonstrates. Another problem with using fighter systems for

large aircraft is where to put them. Putting such a system at

virtually any external location on a transport causes the

fuselage or some other structure to blank out the opposite side

of the aircraft. If one opts for an internal location, the length

105
ECM systems, every opportunity should be explored to take

advantage oflarge aircraft advantages. Forexample, should the

ECM transmitting antenna be on the aircraft if it is likely to

face home-on-jam weapons? The answer is, probably not. In

that case, an alternative solution would be to develop an

offboard, expendable antenna system in the form of a towed

decoy, or a pair of towed decoys, with onboard sensors,

processing, and powergeneration. Although such systems have

not been practical for fighter aircraft because of the

performance penalty and the fouling potential of the tether,

they are inviting options for transports .

Toweddecoys, perhaps one mounted on each wing tip, could

be reeled out when needed to trail up to 500 feet behind and

above the aircraft, and they could be reeled in for landing.

When active jamming becomes necessary, the onboard ECM

system could be activated to jam or deceive a hostile radar

through the decoy. So long as the decoy remains within the

width ofthe threat mainlobe beam from the deploying aircraft,

the decoy and aircraft would be indistinguishable. Such a

system offers airlift aircraft a defense against home-on-jam

missiles not available to fighters that must rely on onboard

ECM.

Recall from earlier discussions that radars tend to function

as either early warning or target-tracking types and that noise

jamming of early warning types and deception of targettracking types are the preferred ECM responses. Since MAC

aircraft will encounter both early warning and target-tracking

radars, the airlift ECM system should be designed to counter

both types. As can be seen from the discussion of Soviet radar

characteristics and the discussion of window regions in the

electromagnetic spectrum, any new system, including those

mentioned here, should protect against inevitable K-band

threats (20-40 GHz).

106
systems. The ALQ

131 is still in production, but the ALQ184

is only a conversion of an earlier pod. All ALQ-184s are

apparently required by the fighter community. The advanced

self-protectionjammer (ASPJ) just now entering production is

programmed for 3,000 units. This system would be able to cope

with the latest threats, but further development maybe needed

to adapt it to airlift aircraft use. Currently, the ASPJ occupies

2.4 cubic feet andweighs only 238 pounds.

The bomber systems consist of the ALQ-172 from the B-52

andthe ALQ-161 from the B-1. Both are large, expensive, and

heavy, and each requires an electronic warfare officer

operator. These are the reasons they were rejected for airlift

use by the US Air Force Scientific Advisory Board in 1982.

These reasons still tend to rule out their conversion.

Destroying and Intimidating Threats. Countering radar

systems with ECM is a tactical necessity for airlift aircraft.

Transports have a variety of means to defeat threats, but from

a strategic perspective of waging electronic combat, the most

effective means of dealing with radar threats is to destroy them

as they are encountered. The early Air Force response, when

threat densities were relatively light, was to create Wild Weasel

radar hunters and pair them with ordnance-delivering killer

aircraft for that purpose. Since the Vietnam War, threat

densities have increased so that they outstrip the capability of

the hunter-killer teams. Thus relying on those tactics in the

future could be disastrous .

Abetter solution, and one that affords the lone transport an

option, is to equip the airlifter with a radar-killing capability,

particularly if the transport is employed in airdrop and forward

sustainment missions . If a threat is encountered and cannot be

avoided, rather than run the risk of being shot down or leaving

the threat safe to surprise an unsuspecting following aircraft,

the transport (and all other transiting aircraft) should have the

107
p

actually a modified AIM-9C Sidewinder designed for shortrange use againstsuch J-band threats as the ZSU-23-4. 12 In the

midsize range are the 400-pound class AGM-45A Shrike and

the British Aerospace air-launched antiradiation missile

(ALARM). Shrike is currently out of production, but the

ALARM is a recent development that has the appealing

feature ofbeing self-contained to the point that its use does not

require modification of the carrying aircraft. At the large end

is the 800-pound AGM-88A high-speed antiradiation missile

(HARM). HARMis the only US ARMcurrently inproduction

and it is the most capable. In its prebriefed mode, it attacks

fixed sites by flying up and over the threat mainlobe beam to

home in undetected. Used during ingress to a target area, the

missile can be launched ahead ofthe assault force to attack any

radar that activates as the assault force approaches . In its

target-of-opportunity mode, it scans the spectrum for any radar

operating and alerts the pilot to possible targets. Ifthe carrying

aircraft is illuminated by a target-tracking radar, the HARM

switches automatically to its self-protection mode, providing a

rapid-reaction capability .13 All three modes of operation fit

airlift employment and sustainment missions ideally.

Countering Airborne Interceptors

A threat-avoidance system would also have to handle

airborne threats, particularly on overwater legs. Under such a

scenario, the threat could either be active or passive in

searching for airlift targets.

108
qp

operation of the airlifters. The interceptor, however, is not

constrained to either the active or passive mode. Still, airlift

aircraft can be equipped with responsive systems that could

cope with either mode of engagement .

Active Threats. The active threat, because it radiates radar

energy that tends to give away its position, would be the easier

to handle. For example, if both the airlifter and the interceptor

were at 30,000 feet and the airlift aircraft had a radar

threat-avoidance system, a radiating interceptor could be

detected approximately 490 statute miles away (twice the

distance to the horizon in accordance with the line-of-sight

horizon equation). Exploiting the "knife-edge" diffraction

phenomenon, where wave-like propagation tends to fill in

"shadow" areas, an airlifter could extend detection range into

regions bevond the horizon (fig. 5).
g p), 

before launching a missile, the resultant chase would take 73

minutes. If, instead, the interceptor acceleratedto 1.5 Mach (in

afterburner) when the airlifter turned away, the chase would

still take 20 minutes. Fuel consumption would be a limiting

factor for the interceptor, reducing the operationalpracticality

of either fighter approach. If the interceptorwere operating off

of an aircraft carrier or had tanker support, the airlifter could

extend the avoidance point to foil the tactic, presuming

intelligence knows of the threat.

Passive Threats. Ifthe interceptor could remain passive and

rely on bistatic radar operation (another platform acts as the

transmitter), the threat could increase considerably . To

counter this possibility, Hughes Radar Systems Group has

recommended a concept called "splash track" in which a

passive fighter can be detected by a passive transport via

reflected energy originating from a third party. 14 Hughes has

developed realistic design-to-cost goals forjust such asystem,

which is explored in a later chapter. In general, such a system

would reside somewhere between current radar warning

receivers and ESM systems in capability and complexity. In

other words, it would be fairly routine to build.

Defeating Airborne Interceptors

Conventional wisdom holds that transports would be easy

prey for airborne interceptors.That no longer needbe the case.

Technology can nowprovide large aircraft with sensors to warn

of interceptor approach, with countermeasures to frustrate

acquisition and tracking, and with lethal defense options to

take the fight to the interceptor if avoidance does not work.

110
discussed. The second is an infrared search and track (IRST)

system developed by Northrop that takes advantage of recent

[R sensor advances.

Instead'of relying on ascanned IR image, the advanced IRST

system uses a nonscanning (staring) mosaic focal-plane array

to build an image. Much as the humaneye focuses an image on

the retina, the lens of the IRST system focuses the image on an

[R-sensitive mosaic focal-plane array. Just as the human eye

has multiple sensors lining the retina, the IRST system has

multiple IR-sensitive "chips" forming the mosaic. Because the

[R sensors dwell on the IR-producing object, rather than

;canning it, the sensitivity of the system is greatly increased.

Tests of Northrop's IRST system have shown that the system

1as a 50-percent chance of producing arecognizable image of

i MiG-25 Foxbat at 15 nautical miles. Against such larger

iircraft as a Tu-26 Backfire there is a 50-percent chance of

°ecognition at 30 nautical miles . Both aircraft could be

letected as hot spots at more than 100 nautical miles. Range

-ould be determined using a ranging laser, such as a

eodymium-YAG at 0.265 microns, which is outside the visible

;pectrum. 1

Countermeasures. Countering an airborne interceptor's

-adar is analogous to countering a mobile target-tracking radar.

Since the interceptor usually has the speed advantage and can

-lose on the transport at will, it controls whether or not the

;ngagement proceeds inside burnthrough range. This is

;specially true in a tail-chase scenario where fuel consumption

nay become critical for the interceptor. Under those

-onditions, it is difficult for the transport to determine when to

;witch from noise jamming to deception jamming. Therefore

ieception jamming is the preferred ECM mode. Since

ieception jamming will not prevent the interceptor from

;losing to within visual range for a gun pass, even if the

111
points for solutions.

Lethal Defense. While the airlift aircraft is slower than the

interceptor, it has substantial carrying capacity for systems that

can equalize the engagement. Four concepts that offer

significant promise are an air-to-air version of the HARM for

radar threats; the AIM-9L/M/R against forward hemisphere

attacks; a tube-launched, rocket-assisted, IR-homing artillery

round for rear-hemisphere defense; and a blinding laser (and

target designator) system for all-quadrant defense.

High-Speed Antiradiation Missile. The AGM-88 HARM,

previously discussed in an air-to-surface role, also has air-to-air

capability provided by its new, single-structure, gimballed

antenna.

16 With its ability to make an immediate 180-degree

turn after launch, HARM could now pose athreat to airborne

interceptors approaching transports from any quadrant.

Interestingly enough, Boeing Military Airplane Company

indicates interest in a similar concept in their Advanced

Transport Technical Mission Analysis Study.

17 Such versatility

invites serious consideration of HARM as a self-protective

weapon for use by transports against both surface and airborne

threats.

Sidewinder. The AIM-9 will be a necessary addition to the

airlift aircraft's arsenal not just for interceptors, but also for

such helicopter threats as the Soviet Hokum, which will have

an air-to-air capability . In the case of interceptors, exercises

that simulated C-130s with tail guns have invariably resulted in

interceptors using what is called a "face shot." Thus tail

protection alone merely moves the threat to the front. The

front hemisphere, therefore, cannot be left vulnerable. In the

case of the Hokum-type helicopter threat, this point is further

reinforced. Since a helicopter would probably be using terrain

112
airlifter must be prepared to continue on while minimizing its

exposure. In such a circumstance, attacking the helicopter

directly would be an excellent wayto defeat it or to force it to

keep out of the way.

The AIM-9L, M, and R model Sidewinders are unique in

their excellent all-aspect attack capability, whichperfectly suits

airlift aircraft because they cannot outmaneuver threats to

reach a stern attack position. Weighing approximately 190

pounds each, these missiles could be easily carried by

transports . The R model is currently in development and

should be available in 1990. It features greatly improved

acquisition range over the Mmodelwhile eliminating the need

for a cooled seeker head.

18

Copperhead. Defending the rear hemisphere cannot be done

directly with a rearward-firing missile because of the forward

velocity of the aircraft. Firing a missile rearward would cause

the missile to fly backwards until its motor could cancel the

forward velocity of the aircraft. As a result of this backwards

flight and the fact that the missile would have to power itself

through a zero-velocity point, severe instabilities would be

introduced (just as in shooting an arrow, feather endfirst). An

excellent way around this phenomenon, however, is to use

rocket-assisted artillery . In this case, the projectile accelerates

through the zero-velocitypoint inside the guntube, exitingwith

flying velocity and a rocket assist . The projectile would not be

an average artillery round, however. Borrowing from the same

technology that created the Martin Marietta Copperhead

laser-homing projectile, the artillery round would contain an

air-to-air seeker head, asmall warhead, control fins, and either

laser beam-riding or IR-homing guidance. Despite the 9,000-G

launch acceleration load, the Copperhead projectile works

well, is relatively inexpensive, and is in the inventory.

113
artillery tube increases. Such devices have the potential for

firing projectiles at speeds approaching tens of kilometers per

second, which could eliminate the need for homing projectiles.

With such velocities, one need only put the aiming pipper on

the target and fire. At the ranges under discussion, the

projectile would cover the distance seemingly instantaneously

and hit with such kinetic energy as to eliminate the need for a

warhead. Unfortunately, such systems are still afewyears away.

Their potential is so great, however, that laboratory

development and continued monitoring are advisable.

Blinding Laser. The final self-protective device against an

interceptor, particularly one interested in making a gun pass,

is the blinding laser. In this scenario, the interceptor would be

making a visual intercept and probably would be using a

heads-up display. The laser could be manually controlled or

automatically aimed by the IRST system. Since a visible laser

beam would give away the position of the airlift aircraft and

might alert the interceptor to employ countermeasures,

infrared or ultraviolet lasers would offer tactical advantages .

Even though the human eye sees only visible light, damage

to the eye can be caused by laser energy outside the visible

spectrum. Damage to the eye is a function of laser power,

intervening distance, filter effects, and duration of exposure;

an effective blinding laser may require 10 or less watts of

power. If passed through a HUD, laser energy would be

amplified, increasing its effectiveness. Even at energy levels

below that at which retinal burns occur, temporary blinding or

dazzling can incapacitate vision for 20 minutes or longer. In a

high-performance jet, such incapacitation would be

devastating.

To precludefilter countermeasures, frequency agility would

be desirable. Although frequency agility may have to wait for

free-electron lasers to mature, numerous single-frequency

114
shoulder-fired missile defense and a directed-energy weapon

defense, but examination ofthese applications is deferred until

the discussion of electro-optical threat defenses .) An

advantage of a laser beam-riding weapon is its relative

invulnerability to ECM, compared to IR-homing seekers.

Defeating Radar Missiles

Defeating a radar-guided missile may require simultaneous

attackagainst the illuminating radar beam, the missile receiver,

the command guidance channel(s), the warhead fusing

mechanism, and the maneuver capability of the missile.

Coordinating these split-second operations would require a

missile (launch) warning receiver, a control system to

synchronize flight controls and ECM, an ECM system of

comparable capability to the advanced self-protectionjammer,

and such augmenting systems as towed and expendable decoys

and chaff.

During silent-running airlift operations, the key to

successfully dodging a missile may be the ability to detect

missile launch. Anot uncommon ECCM technique employed

by SAM operators is to keep the tracking radar passive (on,

warmed-up, but not transmitting) until after missile launch to

surprise the target . To allow the airlift to detect such alaunch

passively, the US Air Force Scientific Advisory Board

recommends a missile warning receiver (MWR)21 Based on

IR- and ultraviolet-sensing techniques, such a system would

recognize the hot rocket plume of the missile as a threat and

provide the cue to turn on active ECM. (Honeywell's AAR-47

passive missile detection system would appear to fulfill this

function.) The ECMsystem could then attack acquisition and

tracking functions to defeat the missile.

115
qy

missile's attention. Second, use of decoys in widely separated

pairs makes such monopulse jamming techniques as blinking,

cross-polarization, and cross-eye jamming much more

effective. If jamming is unsuccessful in breaking the missile's

tracking solution, an offboard concept has additional benefits .

As the missile approaches the aircraft and decoys, the jamming

signal will be much stronger from the decoys than the echo off

the transport. Thus the missile will be lured away from the

transport. As the missile acquires the two decoys, it faces a

dilemma "deciding" which to attack. In many cases, it will

compromise by aiming for the centroid of the jamming signal,

thereby splitting the distance between the decoys. If a decoy is

damaged or destroyed, a new decoy can be reeled out.

Although towed decoys have an advantage in transmitting

power, expendable electronic decoys have an advantage in that

they separate themselves farther from the ejecting aircraft.

Also, expendable decoys, if released in even modest numbers,

can saturate an incoming missile's target-sorting capability.

Even if they contain their own power supply, these miniature

jammers can be built to fit standard flare and chaff dispensers.

Texas Instruments' Gen-X and Brunswick's radio frequency

expendable decoy (RFED) are two of the more promising

examples already on the market.

Against certain radar missile systems, chaffremains aviable

countermeasure. Particularly susceptible to chaff are those

radars that do not have moving target indicator capability or

Doppler processing . A substantial number of older Soviet

AAA and SAM systems do not have these capabilities. When

artfully deployed, chaff can create false targets for a tracking

gun or missile and screening for massed operations.

By integrating flight maneuvers with ECM techniques, the

transport can achieve maximum effectiveness of ECM while

116
excess of its G-limit, the target can cause the missile to

overshoot. The challenge in making such a maneuverwork for

a transport rests in precise timing and execution. Given the life

or death consequences, the complexity of the calculations, and

the reaction times required, such amaneuver could only work

if it were automated.

Automating amissile "break" maneuver could be fairly easy.

What would be required is a means to track the missile, an

autopilot, a flight control computer, and software delineating

the control laws. However, against radar-guided missiles, radar

tracking could invite home-on-radiation guidance. Therefore

a passive IRST system with laser ranging would be more

appropriate. Although such IRST systems as Northrop's are

early in development, they have great potential for providing a

solution to this self-protective need of airlift aircraft.

Countering Electro-optical Weapons

In addition to the threat posed by radar-based systems, airlift

operations are severely threatened by electro-optical systems.

Included in this category are infrared search andtrack systems,

IR missiles, optically aimed weapons, and directed-energy

weapons. Although the threats include many exotic weapons,

they also include the infantryman's rifle . The following

discussion covers this wide spectrum of threats and shows that

airlift aircraft can acquire formidable defenses against each.

Avoiding Infrared Detection andAcquisition

Earlier discussion showed there are promising steps that can

be taken to avoid ground radars, SAMs, airborne interceptors,

11 7
limited. One of the best techniques for avoiding IR threats is

to fly low to the ground, as was discussed earlier in this chapter.

Two other avenues of approach appear to offer great potential

to reduce the chance of detection and acquisition. The first is

to reduce one's thermal output to blend in with the background

noise as much as possible. The second is to conceal the sources

of thermal energy.

Reducing Thermal Output. Attempting to reduce the

thermal output ofan aircraft causes one to focus on the largest

source of thermal energy-the engines. Although other

systems may produce hot spots, those hot spots are usually

insignificant until the heat of the engines is drastically reduced

or concealed. In either instance, the effort is directed at

eliminating hot metal parts from view.

One technique for reducing ajet engine's thermal output is

to exploit turboprop designs. A turboprop is, basically, a jet

engine that converts its exhaust energy to propeller motion. In

the process, successive stages of turbines reduce the energy of

the gas flow to the point where it exhausts with little residual

energy. While the internal temperatures of aturboprop maybe

just as hot as that of other types of jet engines, the exhaust is

much cooler.

Current turboprop technology development is focusing on

General Electric's unducted fan (UDF) and Pratt and

Whitney's ultrahigh bypass (UHB) designs. Using National

Aeronautics and Space Administration (NASA) counterrotating propeller technology, these designs will be adapted for

all sizes of aircraft, including the largest aircraft in the world.

These engines will permit cruising at Mach 0.8 and will be at

least 20 percent more efficient than the most efficient

turbofans flying today. If used on a C-141 carrying a

38,000-pound payload, for example, the GE-36UDFwould be

40 percent more efficient overall than the TF33-P7 engine

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Once an engine is designed, its operating cycle is determined

and little can be done to extract further energy from the core

gas flow. What can be done is to control areas where heat is

allowed to surface at the face of an inlet or on the side of a

nacelle forward of the exhaust or nozzle area. To date these

techniques have not been priority design requirements, but the

development of IRST systems and the emphasis on passive,

"stealthy" operations will force designers to give them more

consideration.

Concealing Thermal Output. Short of a design change that

makes the engine more efficient in extracting energy from the

gas flow, concealingthe hot sections is the next best alternative.

Insulating nonexhaust areas of the nacelle takes on meaning if

exhaust treatments are accomplished simultaneously . Oneway

to insulate the face of a compressor is to lengthen the inlet

while channeling the flow through an S-turn. An IR sensor

looking at the front of such an engine would not have a clear

view of any hot metal parts. Similarly, the sides of nacelles can

be shielded by using either insulation material or insulating air

flow (by feeding a cooling flow back to the exhaust area, the

nacelle IR signature can be reduced).

Another method of reducing IR signature, which appears

more feasible than insulating, is to shield it. Several excellent

examples are already in existence . The Fairchild A-10

Thunderbolt II uses the main wing, the horizontal stabilizer,

and the twin vertical stabilizers to shield the exhaust from all

but the stern and overhead aspects. The Israeli Air Force

adopted a slightly different approach with their McDonnell

Douglas A-4 Skyhawk. By lengthening the exhaust several feet

and armor plating it, the Israelis have shifted the attention of

a heat-seeking weapon away from the fragile turbine area to a

hard point farther aft where less damage is likely. 23

119
strobed-IR jammer andthe second is using an IR flare.

The strobed-IR jammer takes advantage of spatial-filtering

design features of IR missile trackers to subject the missile to

intense bursts of IR energy, momentarily creating a more

attractive target. By shutting off cyclically, the strobe forces the

missile tracker to jump back andforth from the engine exhaust

to the jammer. Ifthe jammer can manage to do so at aresonant

frequency of the missile's tracking error feedback loop, large

control errors result .

Sanders Associates and Northrop have several IR

countermeasure systems to offer, including one similar to that

used on Air Force One. The Sanders Self-Defense System

consists of one strobe transmitting unit per engine (possibly

two for large engine diameters), weighing approximately 65

pounds, an electronic control unit weighing 5 pounds, and a

cockpit control unit weighing 3 pounds. Power required for

each transmitter is 5 to 15 kilovolt-amperes, which should be

easily accommodated on any transport.

Whereas the Sanders system uses a mechanical shutter to

create the strobe effect, the Northrop AAQ-8, which is in use

on Air Force F-4, A-7, and MC-130 aircraft, electronically

modulates a cesium lamp to produce the IR strobe. Electronic

modulation has the advantage of being readily programmable

to counter newly emergent threats. Mounting either system's

transmitting unit near the engine exhaust would require some

aerodynamic refairing of the transmitter housing, but this

would be aminor effort . Activated for landing and takeoff, the

system would be deactivated in flight (to avoid giving away

aircraft position) until amissile launch was detected .

The second IR-antitracking concept is the use ofexpendable

flares . Deployed manually when operating into or out of

airfields and drop zones in hostile areas or deployed

automatically when a missile launch is detected, the flares

would serve as decoys to lure missiles away. Because they

120
Since aircraft engines emit peak IR radiation in the 3

to5

micron band and since early generation, visible flares spread

their emissions across the spectrum to include even visible

light, spectral differences exist that create ECCM

opportunities for the enemy. In fact, the loss of two Navy

aircraft over Baalbek, Lebanon, in 1983 while using flares

against Soviet-made SAMs confirms this problem. Using filters

and dual-band seekers, the newer SAMs apparently detect that

the flare's radiation peaks outside the 3-to-5 micron band and

disregard the flare. Newer flares will have to adjust for this

capability by more closely mimicking a jet engine signature.

Additionally, for routine carriage on airlift aircraft in

peacetime, next-generation flares will have to comply with the

InternationalPyrotechnicTreaty so that transports can operate

out of commercial airports.

Fortunately, Alloy Surfaces is marketing a pyrophoric flare

that meets this requirement and has a very low visible

signature. In addition, Alloy Surfaces can tailor the flare to shift

its spectral emissions as needed.

Defeating Infrared Missiles

Defeating amodern IR missile will require either or both of

the antitracking methods just discussed. During takeoff or

landing, these methods can be employed preemptively. These

active measures can also be used near drop zones and other

hostile environments where detectability of the aircraft is

secondary to accomplishing mission objectives . At other times,

the principle of passive operations will require the antitracking

systems to remain dormant until the aircraft "knows" it is being

tracked. Keyto passive operations, then, is a cueing system that

can detect a missile launch and activate the appropriate

systems.

121
falsealarm rate, but it does provide 360 degrees of launch

coverage.

Under development by the Air Force Wright Aeronautical

Laboratories Avionics Laboratory is the silent attack warning

system (SAWS) missile launch detector . Major contractors are

Honeywell, General Electric, and Texas Instruments. The

primary goals of the SAWS development program is to apply

state-of-the-art technology to improve launch-detection

probability and decrease false-alarm rate as compared to the

AAR-47.

Whatever missile warning system is used, once a missile

launch is detected, the aircraft will require accurate range data

on the missile to permit effective flare launch. To acquire this

range information, radar appears to be the best option. Two

systems are readily available: the Westinghouse AN/ALQ-153

and the Sanders AN/ALQ-156.

Both the Westinghouse and Sanders products are pulse

Doppler radars that provide 360 degrees of azimuth coverage

and canoperate independently ofthe AAR-47, if required . The

Westinghouse modelrequires approximately 2.36 cubic feet of

space, requires 53 watts and 1,800 volt-amps of power, and

weighs 138 pounds. TheSanders modelrequires approximately

1 cubic foot, requires 425 watts, and weighs 50 pounds. Both

appear suitable for an integrated threat-detection and

countermeasures system. In operation, they would activate

upon signal from a missile warning system, acquire the inbound

missile, and feed range information to a countermeasures

controller . At the appropriate range for maximum flare

effectiveness, the countermeasures controller would cue flare

ejection and possibly an evasive tactic to introduce the

maximum angular separation between the flare(s) and the

aircraft.

122
adaptive programmer that accepts information from a radar

warning receiver and a missile warning receiver to optimally

dispense the cartridges. The ALE-40 and ALE-47 were

designed far the MJU-7B flare, which is used to protect

single-engine fighter aircraft. For such smaller airlift aircraft

as the C-130, the MJU-7 flare may be adequate, but larger

aircraft, such as the C-5 and C-17, may require much larger

flares . As a result, aflare dispenserpatterned after theALE-45,

which can accommodate flares as large as the new MJU-10B

(2 inches by 2.6 inches by 8 inches) might be required.

Presently, the Tracor dispensers can carry 15 MJU-7B or 6

MJU-10/B flare cartridges and weigh approximately 27

pounds. At least one dispenserwouldbe required for each side

of the aircraft.

Under development for the MACC-130 fleet is Lockheed's

Survivability Augmentation for Transport Installation-Now

(SATIN) system. It consists of a Litton AN/AI-R-69 radar

warning receiver, an AN/ALQ-156 missile warning receiver,

and an AN/ALE-40 flare and chaff ejector. As 'a stopgap

program aimed primarily at the IR missile threat, it contains

excellent core elements of a respectable self-protective system.

What it lacks is an adequate threat-avoidance function, a

capability to detect K-band threats, a capability to operate

passively, and an ability to deal with the more modern Soviet

radar SAMs and airborne interceptors.

To operate and survive in an AirLand Battle scenario,

SATIN would have to be upgraded to overcome these

deficiencies. A true threat-avoidance system should replace

the AN/ALR-69, a system comparable to the SAWS/AAR-47

is needed to permit passive operations, a digitized landmass

navigation system would be needed to permit passive

terrain-following/terrain-avoidance, low-altitude, all-weather

flight, and a towed-decoy ECM system should be added to

123
added for rear

hemisphere missile defense, andAIM9L,/M/R

Sidewinders could be added for forward-hemisphere missile

defense. To defeat unavoidable air and surface radar threats,

the AGM-88 HARM could be added.

Avoiding Optical Detection

Avoiding optical detection is analogous to avoiding radar

and IR threats. Two tasks are critical in avoiding optical

detection: minimizing opportunities for detection and

reducing observable characteristics.

Attempts to minimize optical detection are much like those

previously discussed in regard to minimizing radar and IR

detection. Common to all three is the benefit of low-altitude

flight. Similarly, making maximum use of terrain masking to

block the enemy's view would be advantageous. Darkness and

weather may also provide sanctuary, but operating in these

environments requires precise navigation. To navigate

precisely while not giving away the aircraft's position will

require such passive navigation systems as the TERPROMand

Enhanced Terrain Masked Penetration systems previously

discussed.

The task of minimizing distinguishable characteristics of

airlift aircraft suggests the use of camouflage . In this context,

camouflage includes disguising aircraft features in visible

wavelengths as well as at other wavelengths that EO systems

operate. During daylight, the IR energy coming from an

aircraft includes self-generated radiation as well as reflected

solar radiation. Although current IR sensors have limited

capability against a daylight-earth background, future systems

will not. As high-speed integrated circuitry permits spectral

analysis on a near-real-time basis, it will become increasingly

124
Soldiers peering through the sights oftheir rifles, AAAcrews

aiming through optical devices, personnel sighting shoulderfired missiles, and individuals using laser target designators all

control devastating weaponry, but all are susceptible to

preemptive laser attack. In each case a blinding laser system,

perhaps using multiple beams to scan sectors from the aircraft

out to the horizon, could radiate enough energy to prevent

aiming of the various weapons. If aiming were attempted, the

dwell time and energy of the laser would cause blinding or

dazzling .

Two steps in employing antivision lasers could be taken to

preclude giving away aircraftposition unnecessarily. Operating

frequencies could be shifted into the ultraviolet or IR regions,

where fewer sensors (including eyeballs) operate. Second, the

scan pattern of the laser could be adjusted so that coverage

extends only to the maximum range of expected threats ;

anyone outside that range would not be scanned. Thus covert

operations could be maintained .

Countering Directed-Energy Threats

Lasers are not only useful weapons for airlift aircraft, they

are also useful against airlift aircraft. Such weapons would be

used primarily to blind pilots, to illuminate aircraft for beamriding weapons, or, in the extreme, to attack the aircraft

directly. Defeating the foreseeable directed-energy threat,

then, is a matter of effectively dealing with these three

subareas .

125
ggpg 

and glasses25 Original interest in this area arose out of concern

for industrial safety, but the advent of battlefield lasers creates

a military incentive.

Optical Filters and Dyes. Optical filters and dyes come in

the forms of coatings or sandwich material between two layers

of glass. They operate by absorbing a particular band of

radiation, visible or invisible, and by converting the radiation

to heat. Protection against laser weaponswouldrequire optical

densities as high as 18. To lend some meaning to this measure,

note that common sunglasses provide an optical density of less

than one. An optical density of one absorbs 90 percent of

incident radiation and passes 10 percent. An optical density of

two absorbs 99 percent and passes 1 percent. Adensityof three

absorbs 99.9 percent and so on. Obviously the demandsonlaser

filters and dyes are quite severe."

Until frequency-agile lasers appear, filters anddyes can offer

inexpensive protection against known threat frequencies.

Current challenges with dyes are to narrow the band of light

that specific dyes filter so as not to impair normal vision, to

preserve dye potency over time, and to overcome saturation

effects where filtering abruptly stops.

Phosphate Glass. Phosphate glass filters light by varying its

optical density, dependent on the amount of incident light. It

has been in use for many years, but it offers little protection in

the near infrared region. Since damage from an IR laser would

be just as devastating as that produced by a visible laser,

phosphate glass would have to be augmented with additional

protection.

Dielectric Coatings and Holographic Filters. Both

dielectric coatings and holographic filters provide narrowband protection, but currently their performance is degraded

126
filter or discard the offensive path, and then recombine the

light.

Frequency-Agile Laser Protection. Abroad-based military

effort exploring 15 to 20 different techniques against

frequency-agile lasers is under way. Promising technologies

include optical switches that regulate optical density of filters,

liquid crystal filters, nonlinear reactors to light, and plastics

that rapidly polarize to near opacity and just as rapidly return

to a state of normal transmissivity. Although frequency-agile

tactical lasers appear to be a few years from maturity,

countermeasures to afford eye protection inevitably will be a

feature of future cockpits27

Countering Laser Beam-Riding Weapons

Laser beam-riding weapons, like Bofors Rayrider missile

and the US Air Defense Antitank System (ADATS), operate

by homing on reflected laser light. In most cases, the laser is

controlled by the person operating the missile launcher.

Countering such asystem is possible either by the blinding laser

defense mentioned above or by providing a more reflective

target than the aircraft. For example, if a warning system

detected an illuminating laser, it could cue ejection of a

programmed sequence of optical chaff bundles. Each bundle

would contain fast-blooming reflective confetti or sequins that

would form a cloud between the aircraft and the beam source.

Being much more reflective than the aircraft, such clouds

would make a much more attractive target.

Since askilled operatorwould notbe fooledby the cloud and

would attempt to keep the laser pointed at the aircraft, other

methods of deceiving the missile are necessary. If the enemy's

laser frequency were known beforehand, the targeted aircraft

127
Two systems to alert crewmembers that their aircraft has

been illuminated by laser energy are under development: the

advanced laser warning system and the detection of laser

emitters (DOLE) system. In addition, the Coronet Prince laser

countermeasure pods being competitively developed by

Westinghouse (ALQ-179) and Martin Marietta (ALQ-180)

may have application to airlift aircraft. 29

Countering Directed-Energy Weapons

Countering directed-energy weapons will require the same

avoidance concepts already explored for radar and IR

weapons. Similarly, precautions will need to be taken against

admitting hazardous levels of laser energy into the cockpit, as

discussed previously. In addition, two steps (one defensive, one

offensive) can be taken to counter directed-energy weapons.

Defensively, critical areas of transports can be shielded

against destructive lasers by employing laser-resistant

materials. Harlamor-Schadeck, a research firm in Yuba City,

California, has developed a man-made polymer called laser

shield that is impervious to laser energy. Under development

by the Air Force andArmy at the Army's Materials Technology

Laboratory, laser shield has remained unaltered when

subjected to significant power levels 3°

Offensively, airlift aircraft can detect unconcealed directedenergy weapons by scanning for them. Scanning would employ

an aircraft-mounted laser with a reflection tracker to detect

backscatter of laser energy from the optical components of

enemylaser weapons. Once alaserweaponhadbeen detected,

precise range and bearing information could be extracted from

the laser scanner and fed to an air-to-surface weapon for

targeting. Since battlefield directed-energy weapons are not

yet on the scene, the nature of such an air-to-surface weapon

128
. Augmenting System Solutions

Up to this point, only self-protective systems have been

considered as counters to the threats that airlift aircraft face .

While this was done by design to limit the topic, in fairness, the

author must at least mention some protective systems ofgreat

potential that might be placed on other aircraft.

The discussion of radar jamming pointed out that noise

jammingcan deny range information, but that it also gives away

the azimuth of the jammer. This is true of mainlobe jamming

only. If thejammer were placed on astandoff platform, such as

another aircraft, and equipped with extremely powerful

transmitters, it could force enough jamming energy into the

sidelobes of early warning radars to completelyblank out their

scopes. One US development effort that could lend such

support to airlift operations is the Big Crow program.

TheBig Crow programwill equip aBoeing 707 testbed with

four additional Allison T-56 engines to produce approximately

four megawatts of jamming potential. Extremely accurate

Rotman lens antennae will precisely direct this jamming

energy at threat emitters . Because of its combination ofpower

and precision aiming, the system offers significant ECM

potential for airlift operations and deserves MACsupport.

31

Further in the future are electromagnetic pulse generators

that may be able to produce nuclear ECM effects through

conventional means. The Soviets have already succeeded in

generating single pulses with peak power of more than one

billion watts and repetitive pulses of more than 100

megawatts32 Such systems will have disruptive effects not only

on electronic combat assets but also on everything employing

electronics. Friendly systems of such capability deserve

129
From the discussion in this and the previous chapter, the

readershould be able to see that not only do the primary threats

to airliftoperations have exploitable weaknesses, but that there

are systems and technologies readily available as solutions.

Therefore, it is indeed technically feasible to provide airlift

aircraft with defenses against all appropriate threats.

To this point this study has only considered the operational

need for and technical feasibility of self-protective systems.

Having cleared those hurdles, it is now time to evaluate the

economic realism of equipping airlift aircraft with these

systems.

NOTES

1. D. Curtis Schleher,Introduction toElectronic Warfare (Dedham, Mass. :

Artech House, Inc. ,1986), 28, 29.

2. Ibid.

3. Richard E. Fitts, The Strategy of Electromagnetic Conflict (Los Altos,

Calif. : Peninsula Publishing, Inc., 1980), 53-54.

4. A. T. Waterman, "Propagation," Electronic Countermeasures (Los

Altos, Calif. : Peninsula Publishing, 1978), 31-5.

5. Hughes Aircraft Company and Tracor Corporation, "Military Airlift

Command Electronic Warfare Study Briefing" (U), presented to

Headquarters MAC, January 1988. (SECRET) (Information extractedfrom

this source is unclassified .)

6. Ibid.

7. "Sfena Investigates COZ Laser for Combat Aircraft Radar,"Aviation

Week& Space Technology, 23 June 1986, 124.

8. Headquarters MilitaryAirlift Command, C-17Defensive SystemsStudy

(U), Scott AFB,

Ill

., 17July 1987,138-39. (SECRET) (Information extracted

from this source is unclassified.)

9. Richard N. Johnson, "Radar-Absorbing Material: APassive Role in an

Active Scenario," International Countermeasures Handbook. 1986, 11th ed.

(Palo Alto, Calif. : EWCommunications, Inc., 1986), 375-77.

130
Missile Program Aviation Week& Space Technology,20 January 1986, 63,

65.

13. "Navy, Air Force Plan HARM Upgrade to Extend Missile Life

through 19906," Aviation Week & Space Technology, 9 February 1987, 101,

103.

14. Hughes and Tracor, "Military Airlift Command Electronic Warfare

Study Briefing ."

15. "Northrop Developing Tactical Infrared Focal Plane Array,"Aviation

Week & Space Technology, 2 November 1987,82-83.

16. "Texas Instruments Boosts Reliability of Navy High-Speed

Antiradiation Missile," Aviation Week & Space Technology, 7 April 1986,

96-98.

17. Boeing Military Airplane Company, Advanced Transport Technical

Mission Analysis (ATTMA) Study, appendix 3A, vol. 5, ASD-TR-87-5038,

October 1987.

18. "China Lake Readies Data for 1990s Sidewinder Upgrade," Aviation

Week & Space Technology, 20 January 1986, 80, 83.

19. "Martin Upgrades Copperhead Projectile to Reduce Production

Time, Costs," Aviation Week&Space Technology, 25 January 1988, 112.

20. Bruce D. Nordwall, "Laser Advances Spur Pentagon Efforts to

Protect Flight Crewmembers' Eyes,"Aviation Week & Space Technology, 22

February 1988, 73, 75, 79.

21. US Air Force Scientific Advisory Board, Report of the Ad Hoc

Committee on the Enhancement ofAirlift in Force Projection (1982 Summer

Study) (U),Washington, D.C., December 1982, 39. (SECRET) (Information

extracted from this source is unclassified .)

22. General Electric Company, "UDF Development Status," briefing

presented to Military Airlift Command, September 1986.

23. Doug Richardson, An Illustrated Guide to the Techniques and

Equipment ofElectronic Warfare (New York: ARCO Publishing, Inc ., 1985),

28.

24. "New Lure for Radar-Guided Missiles Expands Countermeasures

Role," Aviation Week & Space Technology, 7 April 1986, 87.

25. Nordwall, "Laser Advances Spur Pentagon," 75.

26. Ibid. , 79.

27. Ibid.

28. Mario de Arcangelis, Electronic Warfare (Poole, Dorset, UK:

Blandford Press, 1985), 219.

29. Richard S. Friedman, Advanced Technology Warfare (New York:

Harmony Books, 1985), 39.

131

Up to~ this point, the discussion has established the

operational need for and the technical feasibility of equipping

airlift forces with self-protective systems. The remaining

question to be addressed is : "Is it economically realistic to do

so?" To answer that question, this section focuses on

affordability and budgetary realism. Having addressed the

economic issues, this section concludes the study with a

summary and recommendations chapter.

Chapter 5 begins the discussion ofeconomic affordability by

introducing approximate costs for two alternatives available to

airlift force planners. In addition to familiarizing the reader

with the various weapon system costs, chapter 5 demonstrates

that the cost of the do-nothing alternative is not necessarily the

least expensive option. The chapter's intent is not to

accomplish a rigorous cost accounting of acquisition,

installation, operating, and other life-cycle expenses, but rather

to convey the idea that self-protection is affordable and will

create savings as transports are increasingly exposed to hostile

environments. Finally, the chapter returns to a central theme,

the importance of airlift to national security strategy, to show

that, ultimately, the cost of securing survivable airlift must be

assessed against the value of maintaining aviable US national

security strategy.

Chapter 6 acknowledges budgetary constraints andproposes

acquisition options to lessen the cost of securing survivable

airlift. By focusing on differences between peacetime and

wartime self-protection requirements, on trends affecting

self-protection technology, and on the flexibility of modular

enhancements, it shows that there are options to allow a

gradual but steady buildup of capability.

133
134
To address cost and affordability, it is necessary to tie

together missions, aircraft associated with particular missions,

threat requirements, and technologicalsolutions in acoherent

plan. Only then can costs be assigned and budgetary impacts

assessed. Determining affordability, however, implies a

comparison of alternatives, especially if one deems the cost to

be high. For example, it is insufficient to say that a particular

purchase costs too much. The query must be: "Compared to

what?" Accordingly, to address affordability, the cost of

equipping airlift aircraft with defensive systems should be

compared to the cost of not doing so.

To accomplish these objectives this chapter links MAC'S

airlift missions with aircraft, aircraft with threat requirements,

threat requirements with technological solutions, and solutions

with approximate costs. Having done so, the chapter explores

the cost of doing nothing as a counterpoint. From this

perspective, affordability is assessed .

Linking Missions, Aircraft,

Threats, and Solutions

Which defensive system goes on which aircraft should be

determined by the missions each aircraft has and the threat

encountered on each mission. The reader should recall from

chapter 2 that the deployment mission and the employment

and sustainment mission were assessed and assigned threat

categories of 1 and 2, respectively.

In that discussion, category 1 threats included small arms,

optical AAAup to .50 caliber, and hand-held SAMs. Numbers

135
shoot-down, or all-weather capability. Numbers of threats

were assessed as limited and possessing only moderate

integration or poor deployment . Evasive action, electronic

countermeasures, and defense suppression might be required.

Assuming that an airlift aircraftwill be equipped for its primary

mission, it is possible to assign threat categories to aircraft in

the MACinventory as in table 14.

TABLE 14

Mission, Aircraft, and Threat Linkage

Mission AiraaftModel Threat Category

Deployment C-5 1

Airland C-141 1

KC-10 1

CRAF 1

Employment &Sustainment C-17 2 -

Airdrop C-141 2

C-130 2

System Requirements for Category 1 Threats

It is now possible to associate particular technological

solutions with missions, aircraft, and category 1 threats by

assigning appropriate self-protective systems . The reader

should recall from chapter 2 that the deployment mission must

counter current and future threats associated with departure

and arrival at main operating bases and also must counter

intertheater en route hazards (table 15).

136
with Splash Track against airborne and

or surface threats; AN/ALR-69

AN/ALR-69 RHAW is a lower-cost, lesscapable option.

Missile Warning Receiver Detects missile launch,

(AN/ALQ-156) warns crew, and directs

(AN/ALQ-153) optimal flare launch and

missile break maneuver,

manually selected for

takeoff and landing.

Missile "Break" Maneuver Incorporates autopilot

maneuver to provide maximum

separation from the

missile.

Flare Dispenser Ejects decoy flare

(AN/ALE-40) (nonpyrotechnic) .

Laser Energy Detector Alerts crewofbeam-riding

(AN/AVR-2) weapon lock-on.

Blinding Laser Counters hand-held SAMs,

optical AAA, and small arms.

Engine-Exhaust Extension, Lessens destructive

Armor, and Shielding potential of small IR

missiles .

Legend

IR-Infrared

RHAW-Radar Homingand Warning

System Requirements for Category 2 Threats

As in the earlier discussion, it is possible to associate

technological solutions with missions, aircraft, and category 2

threats by assigning responsive self-protective systems. Since

category 2 threats include category 1 threats, the solutions

proposed apply, but more capability will be needed in the more

demanding threat environment. In addition, category 2 threats

describe the hazards associated with airland and airdrop

operations near the battle zone, operations into and out of

137
Self-Protective Systems for

Employment and Sustainment Missions

Technological Solution Rationale

RadarThreat-Avoidance System Provides SAM, AAA, and

with Splash Track airborne interceptor

or avoidance; AN/ALR-69

AN/ALR-69 offers lower-cost, lesscapable option .

Passive Terrain Following/ Permits all-weather, lowTerrain Avoidance System altitude passive

operations.

Stealth Treatment Augmentsavoidance;

Retinyl Schiff Base Salt Paint delays radaracquisition.

Towed Decoys with Associated Permits high-power, offECM Equipment board electronic countermeasures; low-cost

counter to monopulse

threat.

Silent Attack Warning System Permits passive warning

(AN/AAR47) of hostile missile

launch; cues active

countermeasures.

Missile Warning Radar Sequences expendable

(AN/ALQ-156) countermeasures and

(AN/ALQ-153) missile "break" maneuver.

Missile "Break" Maneuver Incorporates autopilot

capability to provide

maximum separation from

the missile.

Chaff, Flare, and Expendable Provides radar, IR, and

Jammer Dispenser laser expendable

(AN/ALE-40) countermeasures.

Laser Energy Detector Provides warning of beam-

(AN/AVR-2) riding weapon lock-on.

Blinding Laser/Rangefinder Counters airborne interceptor, IR, and electrooptical threats; guides

rear-firing Copperheadtype weapon.

138
Cockpit Vision Protection Negates antivision

against Laser Weapons laser.

Lethal Defense

Rear-Firing Copperhead-type Provides rear hemisphere

airborne interceptor defense .

AIM-9RSidewinder Provides forward

hemisphere Al defense .

HARM Provides AI, SAM, andAAA

radar suppression.

Weapon System Costs

Assigning costs to particular weapons is arisky procedure for

several reasons. As indicated earlier, cost can include research

and development, acquisition, installation, spares, and

operations and maintenance totals, so any effort to consider

only nonrecurring expenses has pitfalls . Costs also become

confusing when multiyear totals are considered on athen-year

dollar basis . Nevertheless, one must start somewhere.

Accordingly, the following totals reflect approximate fiscal

year 1988 acquisition costs per aircraft. In some cases, such as

the rear-firing Copperhead-type weapon, engine-exhaust

extensions, blinding laser, antilaser windscreens, and

threat-avoidance systems, the systems envisioned are still

conceptual . Thus their costs reflect truly approximate

estimates (table 17).

139
or

AN/ALR-69 RHAW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $100,0001

Passive Navigation System

Terrain Following, Terrain Avoidance . . . . . . . . . . . . . . . . . . $550,0003

or

TERPROMwith Inertial Navigation and Global Positioning Systems . . . $250,0004

Stealth Treatment

Retinyl Schiff Base Salt Paint

C-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $120,0005

C-17, C-141 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $100,000

C-130 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 60,000

Towed-DecoyECM System

Two Decoys for C-5, C-17, C-141 . . . . . . . . . . . . . . . . . . . . . . . $500,0006

Two Decoys for C-130 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $500,000

Silent Attack Warning System (AAR-47) . . . . . . . . . . . . . . . . . . . $ 90,000

Missile WarningRadar

AN/ALQ-156 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $100,000'

Chaff, Flares, and ExpendableJammers

C-5 (10 AN/ALE40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . $90,0009

C-17 (8 AN/ALE-40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 70,000

C-141(6AN/ALE-40) . . . . . . . . . '. . . . . . . . . . . . . . . . . . . $ 50,000

C-130 (4 AN/ALE-40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 30,000

Missile "Break" Automated Flight Maneuver . . . . . . . . . . . . . . . . $ 50,00010

Exhaust Extension, Armor, and Shielding

C-5 and C-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,00011

C-141 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 40,000

C-130 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 30,000

LaserEnergyDetector (AN/AVR-2) . . . . . . . . . . . . . . . . . . . . . $ 20,00011

Blinding Laser/Rangefinder . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,00013

Cockpit Vision Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 20,00014

Lethal Defense

Copperhead-type Rear Defense . . . . . . . . . . . . . . . . . . . . . . $ 50,00015

AIM-9R (two each) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $150,00016

HARM (two each) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $520,0001

Legend

AIM-Air Intercept Missile

HARM-High-Speed Antiradiation Missile

RHAW-Radar Homing and Warning

140
Acquisition and Installation Costs of

Fully Capable Self-Protective Systems

(in Thousands of Dollars)

Airtand Ainlrop

C-5 C-141 C-17 C-141 C-130

Threat Avoidance Syst $400 $ 400 $400 $ 400 $ 400

Passive Navigation Syst 550 550 550

Stealth Paint 100 100 60

Towed Decoy ECMSyst 500 500 500

Silent Attack Warning Syst 90 90 90

AN/ALQ-156-type Syst 100 100 100 100 100

Chaff, Flares,

ExpendableJam 90 50 70 50 30

Missile "Break" Syst 50 50 50 50 ~50

Exhaust Armor/Shielding 50 40 50 40 30

Laser EnergyDetector 20 20 20 20 20

Blinding Laser 50 50 50 50 50

Cockpit Vision Protection 20 20 20

Copperhead-type Syst 50 50 50

AIM-9R (2 each) 150 150 150

HARM (2 each) 520 520 520

Estimated Installationl8 500 500 500 500 S00

TOTAL $1,260 $1,210 $3,220 $3,190 $3,120

To outfit the entire MACinventory, individual aircraft costs

would be multiplied by anticipated Total Force Plan levels . To

keep this exercise simple, no consideration is given in the

accounting to the fact that acquisitions would be phased over

a number of years. Since KC-10 and CRAF aircraft do not

belong to MAC, they are not included in table 19 calculations .

141
Aircraft Aircraft Aircraft Cost

C-5 114 $1,260,000 $ 143,640,000

Airland C-141 118 1,210,000 142,180,000

C-17 180 3,220,000 579,600,000

Airdrop C-141 62 3,190,000 197,780,000

C-130 _342 3,120,000 1,067,040,000

TOTAL 816 $2,130,240,000

When confronted with the $2 billion-plus cost of defending

this nation's airlift capability, some readers may immediately

decide that the nation cannot afford the outlay. As mentioned

earlier, such an assessment is premature without consideration

of the cost of other courses of action. To allow a balanced

assessment of affordability, the next step is to consider a

baseline option, the cost of doing nothing.

Cost of Doing Nothing

The C-17 Defensive Systems Study developed six aircraft

configurations and computed simulated flights against

European and Southwest Asian theater threats over a 54-day

period. Its baseline configuration, a C-17 with a night-vision

goggle compatible cockpit and no other defenses,

approximates the do-nothing option of this study. The results

in the study averaged 59.4 aircraft lost in Europe and 37.4

aircraft lost in Southwest Asia out of 180 aircraft in the

inventory.

Another option in the C-17 Defensive Systems Study

equipped the C-17 with a threat-avoidance receiver, a missile

warning receiver, chaff and flares, a towed-decoy ECMsuite,

and an actively emitting terrain-following, terrain-avoiding

radar. Against the same threats, this option averaged 3 .5 and

5.7 losses over the same period. Such a defensive suite has

142
py 

reflect aminimum cost of doing nothing. Using the fiscal year

1988 unit flyaway cost of the C-17 (approximately $95 million)

as a basis, the dollar costs ofthe do-nothing option are reflected

in table 20.

TABLE 20

Cost of Doing Nothing

to Defend the C-17 Fleet

(in Billions of Dollars)

Fully Delta

Do-Nothing Capable Syst Aircraft Do-Nothing

Theater Losses Losses Losses Cost

Europe 59.4 3.5 55 .9 $5 .31

SW Asia 37.4 5.7 31 .7 $3 .01

Comparing the do-nothing option with the fully capable

self-protection option proposed herein produces the required

alternative cost from which it is possible to determine

affordability (table 21).

TABLE 21

Affordability of Defending Airlift Aircraft

(in Billions of Dollars)

Do-Nothing Fully Capable Net

Theater C-17Cost MACFleet Cost Savings

Europe $5 .31 $2.13 $3.18

SWAsia $3.01 $2.13 $0.88

From these data it is clear the C-17 savings alone would offset

the cost of equipping the entire MACfleet with self-protective

143
ineffective to similarly equip a relatively inexpensive aircraft,

such as the $18 million C-130, but such a contention can easily

be disproved. For example, the C-130 would experience

disproportionately greater losses than the C-17 because the

C-130 would not be flying the safer deployment mission that

the C-17 flies. Disregarding this and applying the lower C-17

loss rate to C-130 missions produces the following data (table

22).

TABLE 22

Cost of Doing Nothing

to Defend the C-130 Fleet

(in Billions of Dollars)

Fully Delta

Do-Nothing Capable Syst Aircraft Do-Nothing

Theater Losses Losses Losses Cost

Europe 112.9 6.7 106.2 $1 .912

SWAsia 71.1 10.8 60.3 $1 .085

Comparing the do-nothing option with the proposed fully

capable self-protection option produces the required

alternative cost to determine affordability (table 23).

TABLE 23

Affordability of Defending C-130 Aircraft

Do-Nothing Fully Capable Net

Theater cost cost Savings

Europe $1 .912 Billion $1 .067 Billion $845 Million

SW Asia $1 .085 Billion $1 .067 Billion $18 Million

Thus, in a European scenario, the fully capable C-130 produces

a sizable savings. Although the Southwest Asian scenario

14 4
g y

deployment missions as the C-17would. Consideration of lives

saved and other intangible savings adds weight to the

contention. 'When these factors are added, the data strongly

favor equipping C-130s.

Using the same procedure for determining the affordability

of the options for the airdrop C-141 is complicated by the fact

that the C-141 is no longer in production. Since the US Air

Force Airlift Master Plan rates a C-17 as the equivalent of 2.3

C-141s in terms of ton-miles per day, an arbitrary conversion

is possible . Proceeding on this track, the cost of doing nothing

for the C-141 is reflected in table 24.

TABLE 24

Cost of Doing Nothing

to Defend the Airdrop C-141 Fleet

(in Millions of Dollars)

Fully Delta

Do-Nothing Capable Syst Aircraft Do-Nothing

Theater Losses Losses Losses Cost

Europe 19.3 1.2 18 .1 $748

SWAsia 10.9 2.0 8 .9 $368

Comparing the do-nothing option with the fully capable

option produces the required alternative cost to determine

affordability (table 25) . Again, the data clearly demonstrate

that equipping aircraft for self-protection makes economic

sense.

145
Do-Nothing Fully Capable Net

Theater cost Syst cost Savings

Europe $748 $198 $550

SW Asia $368 $198 $170

Assessing deployment mission losses is much more difficul

since the C-17 Defensive Systems Study scenario is heavill

biased toward the employment and sustainment-type missioi

and no other authoritative, unclassified source adequatel;

models deployment mission losses. However, one can arrive a

a subjective decision that favors self-protective equipment fo:

C-5s and airland C-141s by comparing the cost of tha

equipment to the replacement value of the two aircraft.

Assuming that MACwould notreplace either aircraft in kin(

(the C-141 is not in production andthe C-5 lost to the C-17 ii

a head-to-head competition), but rather with C-17s,

conversion of C-5s and C-141s to C-17s is required. In terms o

ton-miles per day the USAirForceAirlift Master Plan indicate

that a C-5 is equivalent to 1 .125 C-17s while a C-141 i

equivalent to 0.434 C-17s. Since the cost of equipping all C-5

with self-protective equipment is $143 million and a C-5'

replacement value is approximately $107 million (1.125 time

the C-17's $95 million cost), a savings of two or more C-5

would be cost effective. Similarly, since the C-141 equipmen

would cost $142 million, and a C-141's replacement value i

approximately $41 million (0.434 times the C-17's $95 milliol

cost), a savings of four or more C-141s would be cost effective

In other words, the cost of equipping C-5s and airland C-141

is effective if two or more C-5s and four or more C-141s are

saved over the do-nothing alternative. Judging subjectively b;

Soviet aircraft losses to Stinger missiles in Afghanistan, the

fully capable self-protection system shouldproduce at least thi

level of savings in a full-scale European or Southwest Asia

conflict.

146
4. "British Aerospace Offers TERPROM Navigation System to U.S .

Military," Aviation Week & Space Technology, 4 May 1987, 85. The article

stated that TERPROM would be marketed for $50,000-$100,000 .

Combining US Air ForceScientific Advisory Board estimates of $70,000 for

a global positioning system receiver and $80,000 for a 0.5-nauticalmile-per-hour drift inertial navigation system [US Air Force Scientific

Advisory Board, Report ofthe Panel on Enhancement ofSpecial Operations

Forces (U), Washington, D.C., 30 August 1985,86 (SECRET) (information

extracted from this source is unclassified)], the total cost could reach

$250,000 .

5. "New Materials Promise Low Radar Reflectance," Aviation Week &

Space Technology, 18 May 1987, 22. Dr Birge, the discoverer of these salts,

estimates the cost ofpainting a tactical aircraft to be approximately $30,000.

Since transports are somewhat bigger than the average tactical aircraft,

conservative sizing factors are used to estimate transport costs.

6. The $500,000 figure represents approximately $200,000 for a toweddecoy system plus $300,000 for an ECM system . Both figures are MAC

Electronic Warfare Study estimates. The ECM figure is highly dependent on

thejamming techniques exploited, however.

7. Headquarters Military Airlift Command, C-17Defensive Systems Study

(U), Scott AFB, Ill., 17 July 1987, 150. (SECRET) (Information extracted

from this source is unclassified.) The AN/AAR-47 is priced at $82,000, but

$90,000 is used to indicate some upgrade under the silent attack warning

system program.

8. US Air Force Scientific Advisory Board, Report of the Ad Hoc

Committee on the Enhancement ofAirlift in Force Projection (1982 Summer

Study) (U), Washington, D.C., December 1982, 39. (SECRET) (Information

extracted from this source is unclassified.) The SAB estimated this cost to

be between $80,000 and $100,000 . With the passage of time, the higher figure

appears more likely.

9. Ibid., 41. The AN/ALE-40 is listed here because the -(V)X version has

an automatic expendable selection capability and a threat-adaptive

programmer. The SAB estimated the price range to be $7,000 to $9,000 per

dispenser. Using the SAB estimated number of dispensers for each aircraft

andthe conservative $9,000 figure, system costs were calculated and rounded

to the nearest $10,000.

10 . The missile "break" maneuver system is the author's approach to

exploit kinematic differences between the missile and the target aircraft . The

cost attached reflects a software program that would integrate sensors with

148
12. The cost is an estimate based on projected AN/AUR-2 costs.

13 . The cost is approximate for a blinding laser/rangefinder given its

conceptual nature .

14. The cost is estimated for cockpit vision protection, given the rapidly

evolving nature of development. Since most cockpit windscreens are

laminated plastics already, the alteration of existing "sandwich" material to

provide a laser filter should not create excessive costs.

15. The Copperhead-type system would consist of a shock-mounted

artillery tube, possibly an aiming system, and one or more rounds of

ammunition. Each Copperhead round is priced at about $32,000, but the

air-to-air version could be considerably smaller and lighter.

16. "Gallery ofUSAFWeapons,"AirForceMagazine, May1988,189 . The

1988 buy was $61.1 million for 956 missiles, which equates to approximately

$64,000 per missile. Afigure of $75,000 per missile was used to account for

group A-type hardware, which would permit use of the missiles .

17. "Texas Instruments Boosts Reliability of Navy High-Speed

Antiradiation Missile,"Aviation Week&Space Technology, 7April 1986, 97.

The price of the HARM is coming down from over $350,000 per copy in the

early 1980s to the 1986 quoted price of $260,000. Improved ways of making

the seeker head should continue to lower the price in the future.

18. Scientific Advisory Board, Report ofAdHoc Committee, 39. The 1982

SABreport estimatedinstallation costs forless extensive systems at $400,000

for C-5s and C-141s and $300,000 for C-130s. The figure of $500,000 was

inserted to account for the increase in complexity and the passage of time.

For C-5s and C-141s the installation cost could well be higher, but for C-17s

and C-130s the cost couldjust as easily be lower. The listed figure, therefore,

reflects a measure of uncertainty and compromise.

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