United States General Accounting Office

GAO Report to Congressional Committees

April 1995 CRUISE MISSILES

Proven Capability

Should Affect Aircraft

and Force Structure

Requirements

GAO/NSIAD-95-116

GAO United States

General Accounting Office

Washington, D.C. 20548

National Security and

International Affairs Division

B-256664 

April 20, 1995

The Honorable Strom Thurmond

Chairman, Committee on Armed Services

United States Senate

The Honorable Ted Stevens

Chairman, Subcommittee on Defense

Committee on Appropriations

United States Senate

The Honorable Floyd Spence

Chairman, Committee on National Security

House of Representatives

The Honorable C.W. Bill Young

Chairman, Subcommittee on National Security

Committee on Appropriations

House of Representatives

This report, an unclassified version of our August 1994 classified report, discusses the results of

our self-initiated review of cruise missiles’ wartime performance and potential impact on future

aircraft capabilities and forward presence requirements. It contains recommendations to the

Secretary of Defense to ensure that the services take cruise missile capabilities into account

when determining aircraft requirements and the forces needed for forward presence.

We are sending copies of this report to the Secretaries of Defense, the Air Force, and the Navy

and the Director of the Office of Management and Budget.

Please contact me at (202) 512-3504 if you or your staff have any questions concerning this

report. Major contributors to this report are listed in appendix II.

Richard Davis

Director, National Security

 Analysis
Executive Summary

Purpose Operation Desert Storm marked the first time that U.S. forces employed

the Navy’s Tomahawk missile and the Air Force’s Conventional Air

Launched Cruise Missile (CALCM) in combat. GAO initiated this review to

determine the missiles’ performance during Desert Storm, including any

limitations. GAO also addressed the advantages of these missiles over

tactical aircraft and the missiles’ potential impact on the requirements for

future tactical weapon systems and forward presence.

Background The Tomahawk is a highly accurate subsonic missile powered by a jet

engine and is launched from Navy surface ships and submarines. It flies

more than 500 miles, navigating along a pre-programmed route that

follows specific terrain features to the target. Tomahawk land attack

missiles can carry a 1,000-pound class high-explosive or a submunitions

warhead. The CALCM is also powered by a jet engine but is launched from

B-52 bombers. It flies a pre-programmed route using signals from the

Global Positioning Satellite system and carries a conventional blast

warhead. The CALCM’s accuracy is roughly half that of the Tomahawk. Both

weapons are capable of attacking land targets that are fixed or not easily

relocatable. A separate variant of the Tomahawk is designed to attack

ships at sea.

On January 17, 1991, forces of the U.N.-sponsored coalition initiated a

massive aerial campaign against Iraq in response to its August 1990

invasion of Kuwait. U.S. Navy ships and submarines launched 288

Tomahawk missiles and Air Force B-52 bombers launched 35 CALCMs

during the campaign, all against targets in Iraq.1

 During the campaign,

coalition aircraft launched more than 40,000 individual attacks against

targets in Iraq and Kuwait. The targets ranged from strategic facilities,

such as electrical generation plants and command and control facilities in

Baghdad, to tactical targets, such as deployed Iraqi Army combat units.

Tomahawk missiles have subsequently struck two Iraqi facilities in the

Baghdad area. On January 17, 1993, 42 missiles were successfully launched

against the Zafraniyah Nuclear Fabrication Facility, and 23 missiles were

successfully launched against Iraqi Intelligence Service headquarters on

June 26, 1993.

Results in Brief Military service officials and analysts stated that both the Navy’s

Tomahawk land attack missile and the Air Force’s CALCM contributed to

1

Of the 288 Tomahawks launched, 282 successfully transitioned to cruise flight.

Page 2 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

the success of U.S. combat operations during Operation Desert Storm.

According to studies conducted by the Center for Naval Analyses and the

Defense Intelligence Agency and GAO’s analysis of Gulf War Air Power

Survey data, Tomahawk missiles and CALCMs hit their intended aim points

with success rates approaching those of manned precision strike aircraft,

such as the F-117A Stealth Fighter. However, several problems were

noted. The Tomahawk demonstrated limitations in its range, mission

planning time, and lethality, and the desert terrain made it difficult to

employ the Tomahawks. The CALCM’s warhead and guidance limited the

types of targets it could successfully attack. The Tomahawk’s performance

improved in subsequent raids on the Zafraniyah nuclear facility and Iraqi

intelligence headquarters.2

 The success rate was about 26 to 35 percent

higher for the Zafraniyah raid, and 20 to 29 percent higher for the raid on

Iraqi Intelligence Headquarters, than the success rate during Desert Storm.

The Navy has funded programs to address the Tomahawk’s limitations.

The Air Force is studying a proposal to produce two improved variants of

the CALCM but, because of competing priorities, has not requested any

funds.

As demonstrated during Operation Desert Storm and the two Iraqi raids,

cruise missiles have advantages over tactical aircraft systems and provide

military commanders additional options for precision strike operations.

Cruise missiles can strike many types of targets and can be used in many

conditions, such as at night, in a variety of weather conditions, or in heavy

air defenses. Cruise missiles can also be used without the additional

resources—electronic warfare aircraft, fighter escort, and refueling

aircraft—required for manned aircraft strikes. Additionally, as the raid on

Iraqi intelligence headquarters demonstrated, such strikes do not require

the presence of an aircraft carrier battle group. Employing cruise missiles

can also avoid possible political constraints, such as obtaining host nation

permission to use U.S. aircraft from forward deployed bases or fly through

a third nation’s airspace. Most importantly, cruise missiles provide the

ability to strike targets without risking the loss of aircraft and the death or

capture of U.S. aircrew members. However, tactical aircraft systems have

some advantages over cruise missiles, including their ability to attack

mobile or relocatable targets and penetrate more hardened targets, and

will therefore retain a key role in offensive air operations. Also,

aircraft-delivered munitions are better suited for conducting large-scale or

extended campaigns because of their relatively lower costs.

2

CALCMs were not used in these strikes.

Page 3 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

Since the Tomahawk and CALCM have broadened the options available to

commanders and can be used against many categories of targets struck by

manned aircraft, the characteristics (such as range and degree of stealth)

of most aircraft and the number of aircraft required for future precision

strike weapon systems should be affected. In addition, since Navy

warships carrying cruise missiles have shown that they can conduct

forward presence missions and crisis response without the presence of

carrier-based air forces, they are a viable option for performing those

missions. As a result, fewer aircraft carriers may be required, which could

result in budgetary savings.

Principal Findings

Tomahawk and CALCM

Contributed to Success of

Desert Storm

Both the Tomahawk and the CALCM contributed to the success of recent

U.S. combat operations. According to studies conducted by the Center for

Naval Analyses and the Defense Intelligence Agency and GAO’s analysis of

Gulf War Air Power Survey data, the percentage of Tomahawks and

CALCMs fired during Operation Desert Storm that struck their intended aim

points approached the rate at which bombs carried aboard F-117As on

strike missions hit their intended targets. The Tomahawk missiles were

able to strike heavily defended targets that, if attacked by aircraft, could

have resulted in the unacceptable loss of aircraft and aircrews. For

example, Tomahawk missiles were the only weapons used against targets

in the downtown Baghdad area during daylight for most of the campaign.

In addition, cruise missiles were used in attacks against 8 of the 12

categories of targets struck by manned aircraft.

Desert Storm also demonstrated several limitations in the design and

employment of both missiles. Tomahawk operations were hampered by

the lengthy mission planning process and the stringent geographic

information requirements to support the missile’s navigation systems.

Also, the desert terrain made it difficult to employ the Tomahawks.

Improvements already incorporated into the Tomahawk weapon system

since the Persian Gulf War address many of the limitations noted during

Operation Desert Storm. Table 1 summarizes the Tomahawk limitations

that were noted during Desert Storm and subsequent improvements

incorporated into the missile.

Page 4 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

Table 1: Tomahawk Limitations and

Improvements Limitation Improvement Result

Tomahawk was not

responsive to the tactical

commander’s needs, since

route selections were limited,

mission planning times were

lengthy, and its arrival with

tactical aircraft was difficult to

coordinate accurately.

Global Positioning System

guidance was added,

mission planning hardware

and software were

upgraded and automated,

Afloat Planning System was

introduced, and Time of

Arrival software was

incorporated.

Route selections are

expanded. Mission

planning time is reduced by

about 90 percent. Theater

commanders will have an

in-theater mission planning

capability. The Time of

Arrival software allows strike

times to be coordinated

much more accurately.

Unitary warhead’s

penetrating ability was

limited.

Warhead was redesigned

and programmable delay

fuse was incorporated.

Lethality is increased

because the missile can

penetrate further into

targets before the warhead

detonates.

Some targets were at the

extreme limit of the missiles’

range.

Warhead and engine were

redesigned.

The new, lighter warhead

allows the missile to carry

more fuel, extending the

range. The redesigned

engine provides more thrust

and is more fuel efficient.

Stream raids alerted Iraqi

defenses.

Global Positioning System

guidance was added.

Since more routes to the

targets will be available,

defenders will not be

alerted by the repetitive use

of a few routes.

Additional improvements to the missile are under consideration that if

incorporated, would further extend the Tomahawk’s capability. The

missile’s accuracy would be increased by about 60 percent, the warhead’s

penetration ability would be increased by about 100 percent, and the same

missile variant would be able to attack both surface ships and land targets.

Additionally, both the time required for the mission planning process and

the information required to support that process would be reduced to

levels commensurate to that required for manned aircraft strikes.

The Tomahawk was also employed subsequent to Operation Desert Storm

in strikes against two targets in the Baghdad area. The Tomahawks were

used for both strikes instead of manned aircraft because the National

Command Authorities (i.e., the President and the Secretary of Defense)

were unwilling to risk the loss of aircraft or aircrews. In January 1993,

Navy ships in the Red Sea and the Persian Gulf launched 42 missiles

against the Zafraniyah nuclear facility, and in June 1993, 23 missiles were

launched against Iraqi Intelligence Service headquarters. The Tomahawk’s

success in striking its intended aimpoint increased by about 26 to

Page 5 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

35 percent, and 20 to 29 percent, respectively, from the Desert Storm

success rates. These missiles were the same model as those used in Desert

Storm.

The CALCM’s employment during Operation Desert Storm was limited due

to the nature of its warhead and guidance system. The warhead’s limited

ability to penetrate targets and the guidance system’s lower accuracy

(compared with the Tomahawk’s) restricted the types of targets that could

be successfully attacked. Even though the Air Force is studying a proposal

to upgrade the CALCM, it has not funded any improvements to the missile to

address the limitations identified in Desert Storm due to competing

funding priorities.

Cruise Missiles Broaden

Combat Options

Cruise missiles have some advantages over tactical aircraft systems. For

example, with a destructive capability generally similar to that of

aircraft-delivered munitions of the same class, Tomahawk missiles allow

U.S. forces to strike an adversary’s fixed targets with precision at long

ranges without risking the loss of aircraft or aircrews. This capability is

advantageous when responding to a crisis or in the early stages of an

extended campaign when an adversary’s air defenses would normally be

their strongest. Currently, 135 ships and submarines are equipped to

launch Tomahawk missiles, which significantly expands the U.S. ability to

respond to an adversary. Also, as demonstrated by the June 1993 strike

against Iraq, the Tomahawk allows U.S. forces to take offensive action

without the presence of an aircraft carrier battle group or the tasking of

conventional air forces. The CALCM can also be launched for attack with no

U.S. forces present in theater. For example, the B-52 bombers that

launched CALCMs during Desert Storm took off from an air base in the

United States. In addition, the submarine-launched Tomahawk introduces

an element of surprise.

Cruise missiles do not require the support of as many assets as are needed

for manned air strikes. The missiles are only dependent on the platforms

from which they are launched, whereas manned aircraft require support

from tanker aircraft, electronic jammer, or fighter aircraft. In addition,

some political constraints may be avoided by employing the Tomahawk

rather than tactical aircraft. For example, since the Tomahawk is a

seaborne weapon system, the need to obtain prior base access or

overflight agreements is minimized.

Page 6 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

Tactical aircraft systems have some advantages over cruise missiles and

will therefore retain a key role in air operations against enemy targets.

Tactical aircraft are better suited for conducting large-scale or extended

campaigns. Because of aircraft-carried munitions relatively lower cost

(e.g., a 2,000-pound laser-guided bomb, can cost about $60,000 compared

with $1.1 million for a Tomahawk missile) and greater inventory, the

numerous targets in such campaigns would be more effectively attacked

by aircraft-carried munitions. Furthermore, cruise missiles must be

programmed with the target’s location before being launched. Therefore,

only manned aircraft currently have the flexibility to successfully attack

mobile or easily relocatable targets, such as tanks and other ground

forces.

Cruise Missile Capabilities

Should Affect Future

Aircraft and Carrier

Requirements

Cruise missile capabilities should affect the requirements for most future

precision strike weapon systems, since the missiles have broadened the

combat options available and can strike heavily defended and longer range

targets with results, in many cases, similar to those of manned aircraft

attacks. Therefore, most future strike aircraft, if employed in conjunction

with cruise missiles and a limited number of highly capable aircraft, may

not require as long a range or as high a degree of stealth as originally

planned. In addition, fewer strike, tanker, command and control, and

electronic warfare aircraft may be required if cruise missiles are used to

strike a larger portion of enemy targets.

According to Department of Defense (DOD) directives, an important

objective of the defense acquisition system should be to minimize the

overlap and duplication among weapon systems. However, GAO has

previously reported that the services justify acquisitions of new systems

on narrowly defined tasks or on a unique weapon system capability

because the services believe they have specific, but complementary,

requirements for engaging similar targets. As a result, alternative systems

are not always considered. For example, in July 1993, GAO reported that an

analysis of theater air interdiction by the Chairman of the Joint Chiefs of

Staff considered only fixed-wing aircraft and did not consider options for

using land- or sea-based missiles and long-range artillery.3

 Also, in

April 1992, GAO reported that the Air Force and the Army limited their

analyses of close air support requirements to the types of weapons

3

Roles and Functions: Assessment of the Chairman of the Joint Chiefs of Staff (GAO/NSIAD-92-200,

July 15, 1993).

Page 7 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

currently under their respective purview and gave little, if any,

consideration to the contributions of other close support weapons.4

Both the Navy and the Air Force have tactical aircraft upgrade programs

underway that will require major expenditures. These programs will result

in modifying existing aircraft to enhance their strike capabilities,

developing new aircraft, and retiring some aircraft types. For example, the

Navy is developing the F/A-18 E/F, which it expects will be its primary

carrier-based attack aircraft, at an estimated total cost of about $85 billion

for 1,000 aircraft. The Navy is also modifying the F-14 to provide it with a

strike capability and is planning to retire all its A-6 medium strike

bombers, its only carrier-based, long-range, all-weather strike aircraft.

Additionally, the Air Force plans to incorporate a ground attack capability

into the F-22.

As demonstrated by the June 1993 raid on Iraq, cruise missiles provide the

United States with a viable strike capability in the absence of aircraft

carrier-based strike aircraft. DOD’s Bottom-Up Review stated that only 

10 carriers were required for conducting two nearly simultaneous major

regional contingencies but that 11 were required to meet forward presence

requirements in three worldwide regions. The review noted that the

planned aircraft carrier force level of 11 active carriers and 1 training

carrier would support regional forward presence 12 months per year in

one region but would result in an average 4-month gap in carrier presence

per year for the two remaining regions. The review also stated that 

10 carriers would increase the average gap in carrier presence in the two

regions to 6 months. The review depicted a 4-month gap as an acceptable

risk and a 6-month gap as unacceptable.

If the Tomahawk-capable warships were judged to be an acceptable

alternative for conducting presence operations, the Navy could achieve

considerable budgetary savings. GAO previously reported that the average

annualized cost of a notional aircraft carrier battle group was $1.5 billion.5

Recommendations GAO recommends that the Secretary of Defense assess the extent to which

cruise missiles could affect the requirements for manned strike aircraft

and aircraft carriers. This assessment should examine the (1) effect that

4

Major Acquisition: DOD’s Process Does Not Ensure Proper Weapons Mix for Close Support Mission

(GAO/NSIAD-92-180, Apr. 17, 1992).

5

Navy Carrier Battle Groups: The Structure and Affordabilitiy of the Future Force (GAO/NSIAD-93-74,

Feb. 25, 1993).

Page 8 GAO/NSIAD-95-116 Cruise Missiles
Executive Summary

existing cruise missiles and potential upgrades have on the design

characteristics, such as the range, payload, and stealth characteristics, of

planned future aircraft; (2) potential effect of the resulting alternative

aircraft designs on future aircraft affordability; and (3) degree to which

increased cruise missile inventories could affect the number of aircraft to

be procured. GAO also recommends that the Secretary of Defense reassess

the degree to which cruise missile-equipped platforms could fulfill

peacetime presence requirements and the effect that increased reliance on

those platforms would have on the Bottom-Up Review’s justification for an

additional aircraft carrier for presence missions.

Agency Comments DOD provided written classified comments on the classified draft of this

report. DOD partially concurred with the major findings of that report, but

it disagreed with GAO’s recommendations. GAO has incorporated

unclassified summaries of DOD’s comments in this report where

appropriate.

DOD agreed that cruise missiles provided many useful capabilities and that

new generations should be more flexible and versatile than existing

missiles. However, DOD said that cruise missiles had inherent limitations

that precluded them from successfully performing some strike missions;

therefore, even though cruise missiles represent an important supplement

to U.S. air power, they cannot replace manned aircraft. It also said that the

Bottom-Up Review process took into account the capabilities of cruise

missiles and other advanced munitions when it set its force goals and

modernization priorities.

Although DOD said it considered cruise missile capabilities as part of the

Bottom-Up Review process, GAO found no analysis that specifically made

the assessments it recommended. DOD did not provide any documentation

to support its statement that cruise missile contributions were considered.

GAO agrees that cruise missiles do not provide the full range of capabilities

inherent in an aircraft carrier battle group, either from the standpoint of

providing peacetime presence or responding to a crisis. However, GAO

believes that not all situations require the full capability of an aircraft

carrier battle group to show U.S. resolve and commitment or forestall

actions by other nations. Therefore, although cruise missiles may not

address all peacetime presence situations, GAO still believes that cruise

missiles provide useful options for conducting some peacetime presence

missions and that its recommendation is valid.

Page 9 GAO/NSIAD-95-116 Cruise Missiles
Contents

Executive Summary 2

Chapter 1 

Introduction

12

The Tomahawk Weapon System 12

CALCM 17

Objectives, Scope, and Methodology 18

Chapter 2 

Cruise Missiles’

Capabilities Have

Been Proven in

Recent Conflicts

21

The Desert Storm Air Campaign 22

Cruise Missiles’ Performance in Desert Storm 24

Tomahawk Performance Since Desert Storm 27

Tomahawk Improvements to Address Shortfalls and Expand

Capabilities

28

Agency Comments and Our Evaluation 30

Chapter 3 

Cruise Missiles

Broaden Options

33

Cruise Missiles Offer Additional Options for Attacking Targets 33

Tactical Aircraft Systems Retain Key Roles 39

Agency Comments and Our Evaluation 41

Chapter 4 

Cruise Missiles’

Proven Capabilities

Should Affect Strike

Aircraft Requirements

and Force Structure

Choices

43

Cruise Missiles Can Affect Strike Aircraft Requirements 43

Services Do Not Always Consider Alternatives 45

Cruise Missile-Equipped Platforms Can Provide Forward

Presence and Crisis Response

46

Recommendations 47

Agency Comments and Our Evaluation 47

Appendixes Appendix I: Tomahawk Improvements Address Limitations 50

Appendix II: Major Contributors to This Report 60

Tables Table 1: Tomahawk Limitations and Improvements 5

Table 1.1: Tomahawk-Capable Naval Forces Projected for 1999 16

Table 2.1: Block III Tomahawk Improvements That Address

Desert Storm Limitations

29

Table 2.2: Tomahawk Block IV Improvements Over Block III 30

Table 3.1: Comparison of Tomahawk and Manned Aircraft 34

Page 10 GAO/NSIAD-95-116 Cruise Missiles
Contents

Table 3.2: Representative Navy Strike Packages in Desert Storm 37

Figures Figure 1.1: Tomahawk Missile Variants 13

Figure 1.2: Block II Tomahawk Flight Profile 15

Figure 2.1: Desert Storm Area of Operation 23

Figure I.1: Block III Navigation Modes 52

Figure I.2: World Areas Covered by the Block II and Block III

TLAM-C Missiles’ Range

55

Figure I.3: Block IV Concept of Operations 59

Abbreviations

APS Afloat Planning System

CALCM Conventional Air Launched Cruise Missile

CEP Circular Error Probable

CMSA Cruise Missile Support Activity

CNA Center for Naval Analyses

DIA Defense Intelligence Agency

DOD Department of Defense

DSMAC digital scene mapping and area correlation

GAO General Accounting Office

GPS Global Positioning System

HARM High Speed Anti-radiation Missile

TERCOM terrain contour matching

TASM Tomahawk Antiship Missile

TLAM Tomahawk Land Attack Missile

Page 11 GAO/NSIAD-95-116 Cruise Missiles
Chapter 1 

Introduction

Operation Desert Storm marked the first time that the Navy’s Tomahawk

Land Attack Missile and the Air Force’s Conventional Air Launched Cruise

Missile (CALCM) were used in combat. A total of 323 cruise missiles were

fired against a variety of Iraqi targets in the conflict’s early stages. The

missile attacks were part of a multiphase air campaign designed to

decapitate the Iraqi leadership, gain air superiority, and reduce Iraqi

combat power in preparation for the ground offensive to restore Kuwait’s

border. Tomahawk missiles have subsequently struck two Iraqi facilities in

the Baghdad area. U.S. ships launched 42 missiles against the Zafraniyah

Nuclear Fabrication Facility on January 17, 1993, and 23 missiles against

Iraqi Intelligence Service headquarters on June 26, 1993. These attacks

demonstrated that cruise missiles could play an important role in both

major conflicts and more limited engagements by allowing U.S. forces to

strike an adversary with a high degree of accuracy at long ranges and

without risking the loss of aircraft or aircrew.

The Tomahawk

Weapon System

The Tomahawk cruise missile is a long-range, unmanned subsonic missile

with both land attack and antiship capability that can be employed under a

variety of weather conditions. It is launched from a variety of Navy surface

ships and attack submarines. There are four Tomahawk variants: the

nuclear land attack missile (TLAM-N), the antiship missile (TASM), the

conventional land attack missile with a unitary warhead (TLAM-C), and the

conventional land attack missile with a submunition warhead (TLAM-D).

Each variant employs a common body and propulsion system but is

equipped with different warheads and guidance systems. The four variants

are shown in figure 1.1.

Page 12 GAO/NSIAD-95-116 Cruise Missiles
Chapter 1 

Introduction

Figure 1.1: Tomahawk Missile Variants

Common aft body

Payload/guidance


module

Radome

TASM Anti-Ship

TLAM/N Nuclear


Land Attack

TLAM/C Conventional


Land Attack


(unitary warhead)

TLAM/D Conventional


Land Attack


(submunitions warhead)

Submunitions


payload

Source: Navy.

Page 13 GAO/NSIAD-95-116 Cruise Missiles
Chapter 1 

Introduction

Navy ships and submarines currently deploy predominantly with TLAM-Cs

and TLAM-Ds. The TLAM-Ns were removed from the vessels as the Cold War

was ending. Navy officials said that the TASM’s mission has been reduced

because this variant is not particularly suited to warfare in littoral waters

that may be crowded with both combatant and noncombatant ships. The

TASM was originally intended as an over-the-horizon, open ocean, antiship

weapon to be employed against ships in a battle group.

The TLAM-Cs and -Ds employed during Operation Desert Storm and the

subsequent strikes were Block II missiles, which make up the majority of

the current inventory.1

 All Tomahawks delivered to the Navy since

April 1993 have been improved Block III models. The Navy plans

production of a Block IV variant by the end of this decade. The

improvements incorporated in the Block III missile and those planned for

Block IV are discussed in appendix I.

The Block II Missile The principal difference between the Block II TLAM-C and TLAM-D is the

warhead. The TLAM-C carries a 1,000-pound-class unitary warhead, and the

TLAM-D carries a submunitions payload consisting of 166 bomblets. The

TLAM-C is employed against a single fixed target, such as a specific point on

a building, whereas the TLAM-D is designed to attack area-type targets, such

as aircraft parked on a ramp. A single TLAM-D missile can dispense its

submunitions payload over as many as three separate targets.

The Block II TLAM-C and TLAM-D ranges equal or exceed the unrefueled

combat radius of most U.S. manned tactical strike aircraft. However, those

missiles that are launched from a submarine torpedo tube have a range

about 30 percent less than surface ship-launched missiles. The

submarine-launched Tomahawk has a booster rocket that propels the

missile to the surface after it leaves the torpedo tube. The missile is

partially de-fueled to compensate for the booster’s added weight, which

decreases its range. However, the Navy has begun procuring an improved

booster that allows submarines to launch fully fueled missiles.

The Tomahawk missile follows a pre-programmed route over specific

terrain features to its target using a combination of terrain contour

matching (TERCOM) and digital scene matching and area correlation

(DSMAC). The Tomahawk’s flight profile is illustrated in figure 1.2.

1

A block represents an overall baseline for the missile system’s configuration.

Page 14 GAO/NSIAD-95-116 Cruise Missiles
Chapter 1 

Introduction

Figure 1.2: Block II Tomahawk Flight Profile

Mission


planning

Weapon


control

All up


round

Preplanned


missions

Ashore


planning

Cruise phase

• Terrain following


• Very low altitude


• Terrain masking


• Defense avoidance TWCS

CCS MK1

First


preplanned


way point

SAM


site

DSMAC


maps

Terminal phase

• Refine accuracy


• Terminal


 maneuver

Conventional


target

Nuclear


target

TERCOM


Maps

Fighter


base

Note: CCS MK1, Combat Control System Mark 1; SAM, surface-to-air missile; TWCS, Tomahawk

Weapon Control System. An all up round is a complete missile assembly.

Source: Navy.

During the initial portion of its flight, the missile navigates by TERCOM. A

radar altimeter aboard the missile periodically scans the terrain over

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Chapter 1 

Introduction

which the missile is flying. The on-board computer then compares the

resulting terrain elevation profile to its profile of the predicted route to the

target, which was stored in the computer before the missile’s launch. The

computer then adjusts the missile’s course so that it is following the

planned route to the target.

The Tomahawk navigates by DSMAC during the terminal leg of its flight to

the target. The DSMAC process uses an optical sensor in the missile that

scans the ground over which the missile is flying. The on-board computer

converts the scanned image of the ground features into an image of black

and white contrasts. The computer then compares that image to its stored

DSMAC black and white images of the selected sites along the route. As with

TERCOM, the missile’s computer then adjusts the missile’s course so it is

following the preplanned route. The Block II missile uses inertial

navigation between TERCOM and DSMAC update points.

Currently, 60 surface ships and 75 submarines are capable of launching

Tomahawk missiles. The Navy projects that by 1999 the

Tomahawk-capable force will consist of 82 ships and 55 submarines.

Table 1.1 shows the projected Tomahawk platform force.

Table 1.1: Tomahawk-Capable Naval Forces Projected for 1999

Ship Submarine class

Class CG DD-963 DD-963 DDG-51 SSN-688 SSN-688 SSN-637 SSN-21 Total

Launch system VLSa VLS ABLb VLS CLSc TTLd TTL TTL

Number of assets 22 24 6 30 31 20 1 3 137

Note: All Tomahawk-capable platforms are equipped to launch both Block II and Block III

missiles, and the Block IV missile is planned to be compatible with any Tomahawk-capable ship

or submarine.

aVLS stands for vertical launch system. It is the missile launch system carried aboard many

surface combatants and is capable of launching antiair missiles in addition to the Tomahawk. VLS

can hold either 61, 90, or 122 missiles, depending on ship type.

bABL stands for armored box launcher. It is a Tomahawk launch system installed aboard some

surface ships not equipped with VLS and can hold up to four Tomahawks.

cCLS stands for capsule launch system. It is a submarine-based version of VLS.

dTTL is the torpedo tube launch system. All SSN-688, –637, and –21 class submarines can launch

the Tomahawk from their torpedo tubes.

The planned wartime loads of TLAM-C and TLAM-D missiles vary for surface

ships and submarines. Navy officials said that notional missile loads are

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Introduction

used for planning purposes; actual loads could vary depending on the

specific mission assigned by the operational commander.

The Tomahawks share launcher space with other missiles on several ship

classes. Arleigh Burke class destroyers and Ticonderoga class cruisers are

predominantly loaded with standard surface-to-air missiles. Because

attack submarines have limited weapon storage space, all TTL Tomahawks

carried displace an equal number of torpedoes.

Tomahawk Procurement The Navy plans to continue procuring Block III TLAM-C missiles until fiscal

year 1998. It plans to procure 216 missiles in fiscal year 1994 at a cost of

about $1.2 million per missile and 217 missiles per year from fiscal years

1995 to 1998. The Navy currently plans to begin production of the Block IV

missile through the remanufacture of existing Block II missiles and TASMs

after fiscal year 1998.

CALCM The Air Force’s CALCM was the other U.S. cruise missile used in the Gulf

War. The CALCM is a modification of the nuclear-armed Air Launched

Cruise Missile, which is a subsonic, all-weather cruise missile. During the

modification process, certain components are removed, and a

conventional warhead is installed. A Global Positioning System navigation

capability is also added. The resulting weapon has a circular error

probable (CEP) roughly twice that of the Block III TLAM-C.

2

The CALCM is carried by B-52 bombers and is launched within range of the

target. After launch, CALCM follows a preplanned route to its target, using

inertial navigation with Global Positioning System updates. The missile’s

mission can be changed or updated by the flight crew while the B-52 is

airborne. New or updated missions can be transmitted to the aircraft from

the air base and then loaded into the missile’s computer. This process

allows CALCM missions to be changed or updated any number of times

before launch. However, once launched, no communications with the

missile are possible. The Air Force’s current inventory of CALCM’s includes

missiles authorized to replace those used in Desert Storm.

Mission planning for the CALCM is performed at Offutt Air Force Base,

Nebraska. The average mission planning time for a new target for CALCM is

comparable to the planning time for a Block II Tomahawk mission. The

completed missions are transmitted to a U.S. air base from which the B-52

2

CEP denotes the radius around the target in which 50 percent of the missiles can be expected to land.

Page 17 GAO/NSIAD-95-116 Cruise Missiles
Chapter 1 

Introduction

CALCM flight will be launched. Bomber preparation and loading can take an

average of 24 hours but can be done concurrently with mission planning.

Flight times to Iraq during Desert Storm averaged 16 hours. Total response

time for CALCM for an unplanned target in Iraq is similar to that of the

Block II Tomahawk.

Objectives, Scope,

and Methodology

We initiated this review because Desert Storm and subsequent Iraqi strikes

showed that the Tomahawk and CALCM added a new dimension to

offensive air operations. We determined the missiles’ performance during

Desert Storm, including any limitations. We also addressed the advantages

of these missiles over tactical aircraft and the missiles’ potential impact on

the requirements for future tactical weapon systems and forward

presence.

We met with agency officials responsible for program management and

obtained pertinent documents concerning the characteristics, missions,

and employment concepts of the Tomahawk cruise missile system and

several tactical aircraft systems capable of striking the same types of

targets as the Tomahawk. We also obtained information on future planned

aircraft and missile systems and planned modifications to existing

systems.

To gain the operators’ perspective on the Tomahawk, CALCM, other

unmanned standoff weapons, and manned aircraft, we met with officials of

two unified commands and various Navy and Air Force commands. During

those visits, we discussed the commands’ policies and procedures for

employing Tomahawk and various precision strike systems. We also

visited two Tomahawk-capable ships—the U.S.S. Stump, a Spruance class

destroyer, and the U.S.S. Key West, a Los Angeles class attack

submarine—and discussed Tomahawk operations with the officers and

crews of those vessels. Additionally, we visited the Navy’s Strike Warfare

Center and discussed the planning and conduct of carrier strike operations

with officials of the Center.

To gain insights into the roles and experiences of the various weapons

systems in the Gulf War, we interviewed Navy and Air Force officers who

participated in Tomahawk and CALCM planning and employment during the

Gulf War and the two subsequent Tomahawk strikes on Iraq. We also met

with officials who had analyzed the planning and preparation that

preceded the air campaign and the campaign’s results. Additionally, we

reviewed various studies and reports concerning the campaign, including

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Chapter 1 

Introduction

the major reports directed by the Navy and the Joint Chiefs of Staff on the

performance of Tomahawk in Desert Storm and the two 1993 raids on Iraq.

We analyzed data from the Air Force-sponsored Gulf War Air Power

Survey and met with officials who performed this survey to develop

information concerning the number and types of targets attacked and the

aircraft and missile systems used to conduct those attacks. We limited our

analysis to the Tomahawk and CALCM missiles and precision strike systems

and the targets they attacked. At our request, Navy and Air Force officials

performed several analyses that compared the effectiveness of various

weapon systems against a selected group of targets.

We performed our work at the following locations:

In the Washington D.C., area

• Office of the Secretary of Defense

• Office of the Chairman, Joint Chiefs of Staff

• Office of the Chief of Naval Operations

• Headquarters, U.S. Air Force

• Cruise Missile Project Office

• Defense Intelligence Agency

• Naval Research Laboratory

• Advanced Research Project Agency

• Naval Maritime Intelligence Center

• Center for Naval Analysis

• Institute for Defense Analysis

• Center for Air Force History

In the Norfolk, Virginia, area

• Headquarters, U.S. Atlantic Fleet

• Cruise Missile Support Activity, Atlantic

• Operational Test and Evaluation Force

• U.S.S. Stump

• U.S.S. Key West

• Air Combat Command

In the Honolulu, Hawaii, area

• Headquarters, U.S. Pacific Command

• Headquarters, U.S. Pacific Air Forces

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Introduction

• Headquarters, U.S. Pacific Fleet

• Cruise Missile Support Activity, Pacific

At MacDill Air Force Base, Florida

• Headquarters, U.S. Central Command

• Headquarters, Navy Central Command

Other U.S. Locations

• Naval Strike Warfare Center, Naval Air Station, Fallon, Nevada

• Headquarters, Central Air Forces, Shaw Air Force Base, Sumter,

South Carolina

We performed our work from August 1992 to December 1993 in

accordance with generally accepted government auditing standards. The

Department of Defense (DOD) provided written classified comments on a

classified draft of this report. DOD partially concurred with the major

findings of the report, but it disagreed with our recommendations.

Unclassified summaries of DOD’s comments have been included in the

report where appropriate.

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Cruise Missiles’ Capabilities Have Been

Proven in Recent Conflicts

Both the Tomahawk and the CALCM contributed to the success of U.S.

combat operations during Desert Storm and the 1993 strikes on Iraq.

During Desert Storm, U.S. Navy ships and submarines launched 288

Tomahawk missiles, and Air Force B-52 bombers launched 35 CALCMs, all

against targets in Iraq. The missiles were used against a wide range of

targets that included predominately electrical production facilities; Scud

missile facilities; command, control, and communications facilities; and

leadership targets. Many of these targets were similar to those attacked by

manned aircraft. Cruise missiles struck fixed, heavily defended strategic

targets that if attacked by manned aircraft—particularly non-stealth

aircraft—could have resulted in the unacceptable loss of aircrews and

aircraft. The cruise missiles also struck targets at ranges that would have

required manned strike aircraft to refuel.

According to studies conducted by the Center for Naval Analyses and the

Defense Intelligence Agency, Tomahawk missiles and CALCMs hit their

intended aim points with success rates approaching those of manned

precision-strike aircraft, such as the F-117A stealth fighter. The

Tomahawk’s performance improved in the 1993 raids on the Zafraniyah

nuclear facility and Iraqi intelligence headquarters. The success rate was

about 26 to 35 percent higher for the Zafraniyah raid, and 20 to 29 percent

higher for the raid on Iraqi Intelligence Headquarters, than the

Tomahawk’s success rate during Desert Storm.

Desert Storm also demonstrated several limitations in the design and

employment of both missiles. Tomahawk operations were hampered by

the stringent geographic information requirements to support the missile’s

navigation systems and the lengthy mission planning process. The

Tomahawk also demonstrated limitations in its range and lethality. The

limited ability of the CALCM’s warhead and its guidance system’s lower

accuracy (compared with the Tomahawk’s) restricted the types of targets

that the CALCM could successfully attack.

Improvements have already been incorporated into the Block III

Tomahawk variant currently in production and address many of the

limitations noted during Operation Desert Storm. The proposed Block IV

Tomahawk would further expand the missile’s capabilities. The Air Force

is studying a proposal to produce two improved variants of the CALCM that

would address limitations observed during Desert Storm, but it has not

requested any funds.

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Proven in Recent Conflicts

The Desert Storm Air

Campaign

When Iraq invaded Kuwait on August 2, 1990, U.S. military commanders

began drafting plans for an air war against Iraqi targets in the event that

Iraq attacked Saudi Arabia before sufficient U.S. ground forces were in

theater. The commanders also began developing a four-phase plan to eject

Iraqi forces from Kuwait. The first phase was for a strategic air campaign

focused initially on decapitating Iraqi military and civilian command and

control by a series of attacks against strategically vital targets, followed by

attacks against fielded military forces. Five basic categories of

targets—command and control, industrial production, infrastructure,

population will, and fielded forces—were encompassed in the plan.

The most important targets were command, control, and communications

targets, which were to be struck forcefully to incapacitate Saddam

Hussein’s ability to control his nation, disrupt the Iraqi forces, and induce

the Iraqis to withdrawal from Kuwait. Attacks on key production and

infrastructure targets would follow to further fracture the country and

degrade Iraq’s ability to replenish its forces. Attacks on targets such as

television and radio stations and electrical power generation and

distribution facilities, would degrade the will of the civilian population.

Finally, in preparation for a coalition ground assault, Iraqi forces in the

field would be struck.

Three other phases were to follow. The intent of the second phase was to

gain air superiority, and the third phase was to reduce the capability of the

Iraqi ground forces before the coalition ground attack. The fourth and final

phase was the coalition ground attack into Kuwait. Figure 2.1 shows the

Desert Storm area of operation and distances to target sites.

Page 22 GAO/NSIAD-95-116 Cruise Missiles
Chapter 2 

Cruise Missiles’ Capabilities Have Been

Proven in Recent Conflicts

Figure 2.1: Desert Storm Area of Operation

DJIBOUTI

ETHIOPIA

Legend

US Airfield

City

SUDAN

EGYPT

TURKEY

Taif

JORDAN

SYRIA

IRAQ

OMAN

IRAN

500 Miles

ISRAEL

Al Kharj

Khamis Mushait

SOMALIA

YEMEN

Mosul

KUWAIT

Al Basrab

Baghdad

OMAN

BAHRAIN

QATAR

SAUDI ARABIA

UAE

Shaikh Isa

1,000 Miles

Page 23 GAO/NSIAD-95-116 Cruise Missiles
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Proven in Recent Conflicts

Source: Our analysis of Gulf War Air Power Survey data.

Even though the size and duration of the air plan changed before the start

of the air campaign on January 17, 1991, its basic premise remained

unchanged. Phase I attacks on Iraqi air defense facilities, the electrical

power system, and command and control targets were carried out

predominately by the F-117A, F-111F, F-15E, and A-6E aircraft, all of which

carried precision munitions such as laser-guided bombs, and by

Tomahawk cruise missiles and CALCMs. In total, coalition fixed-wing

aircraft launched more than 40,000 individual attacks against targets in

Iraq and occupied Kuwait during the campaign.

Cruise Missiles’

Performance in

Desert Storm

Tomahawks and CALCMs struck heavily defended targets deep in Iraq

whose destruction was vital to the success of the Desert Storm air plan

and that, if attacked by aircraft, could have led to unacceptable losses of

aircraft and aircrews. Most cruise missiles were fired early in the

campaign. Navy ships attempted to launch a total of 297 Tomahawk

missiles. Of the 288 that were launched, 282 (95 percent) achieved cruise

flight and proceeded toward their target.1

 Of the 39 CALCMs carried to

launch points by B-52s, 35 (90 percent) were launched and proceeded

toward their target.

According to data in studies conducted by the Center for Naval Analyses

(CNA) and the Defense Intelligence Agency (DIA) and our analysis of Gulf

War Air Power Survey data, both missiles achieved results approaching

those of manned aircraft, such as the F-117A, during Desert Storm.

DOD and Navy officials said that multiple weapon strikes on many of the

aim points and a lack of timely battle damage assessment during Desert

Storm made it very difficult to determine the effectiveness of the

Tomahawk and the CALCM. Target analysts were unable to obtain damage

assessments for each aim point after each attack. Since many targets were

attacked more than once by both aircraft and cruise missiles, it was an

arduous task to determine which attack caused the observed damage in

those cases. Additionally, since many aim points were also targeted by

multiple missiles, it was difficult for the analysts to determine how many

weapons caused the resulting damage.

1

Of the 297 attempted launches the 9 missiles that did not launch suffered various launch and

system-related failures. Of the six missiles that launched but did not achieve cruise flight, five had

problems deploying their wings, and the booster engine of one failed to separate from the missile.

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DOD officials said that the missiles’ mission objectives must be taken into

account when measuring the missiles’ success. Even if intended targets

are not destroyed, a military objective can be met if the targets are

rendered unusable or damaged as a result of being struck by some of

several missiles targeted against it.

Tomahawk missiles struck targets in 8 of the 12 overall target categories.2

The emphasis placed on the categories changed between the first 2 days

and the remainder of the conflict. However, over the course of the

campaign, the majority of the Tomahawks that were fired were launched

against targets in four specific strategic target categories.

According to Navy officials, the 38 target complexes that Tomahawks

attacked were all heavily defended and lent themselves to attack by an

accurate, unmanned weapon such as the Tomahawk. Many of these targets

were similar to those struck by manned aircraft. In many cases, the

Tomahawk and manned aircraft not only struck the same categories of

targets but also the same complexes. For example, Air Force aircraft

launched 355 strikes—239 by the F-117A—against complexes that were

also struck by the Tomahawk. Navy aircraft launched 185 strikes against

complexes that were also struck by Tomahawk.

The Tomahawk’s geographic reach equaled or exceeded that of manned

aircraft. Many of the targets the Tomahawk and manned aircraft attacked

were located in the same areas of Iraq. The Tomahawk’s range allowed it

to strike its targets flying from launch points in the Mediterranean and the

Red Seas, and the Persian Gulf. The F-117As, flying from bases in southern

Saudi Arabia (see fig. 2.1), were refueled on all missions. In addition,

Tomahawk missiles were the only weapons that struck targets in the

downtown Baghdad area during daylight for most of the campaign. Even

though the Air Force’s F-117As attacked Baghdad-area targets at night

throughout the campaign, attacks by other aircraft were stopped after

Iraqi ground defenses shot down two F-16s on the second day of the

conflict.3

 Thus, the Tomahawk’s use had the added benefit of maintaining

psychological pressure on the Iraqis in and around Baghdad.

Navy officials believe that some Tomahawks may have been shot down by

Iraqi ground-based antiaircraft artillery. However, there appears to be no

evidence that surface-to-air missiles contributed to Tomahawk kills. These

officials also said that Tomahawk’s flight profile made it difficult for

2

Of the selected weapons, only the F-117A struck targets in all 12 categories.

3

The F-117A was only employed at night, since it was visible to the naked eye during daylight.

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surface-to-air missile systems to successfully identify and attack

Tomahawks.

The limited number of routes used by Tomahawks to approach Iraqi

targets and the tactics employed to ensure coordination with tactical

aircraft missions may have contributed to missile losses. Because the

usable routes into Iraq were so limited, multiple Tomahawks were

launched along the same route. Thus, Iraqi gunners might have come to

expect that, once a Tomahawk was sighted, others would soon follow

along the same path. As a result, it would have been much easier to

identify and engage the missiles that followed. According to a CNA study,

the success rate for Tomahawks fired within the first 2 days of the air war

was much higher than for those fired later, indicating that the Iraqi

gunners might have become accustomed to seeing the missiles using

certain routes and flying in stream raids.

Despite its limitations, Navy officials said that the Tomahawk’s use

provided a clear view of the missile’s performance under arduous

conditions. The flat, featureless terrain gave mission planners perhaps the

most difficult task possible in creating the TERCOM and DSMAC scenes

needed. The hot Middle East climate meant that the Tomahawk’s engine

was operating under the harshest possible conditions as well. Officials

assert that the conditions under which the Tomahawk operated had to be

considered when assessing the system’s performance.

As with the Tomahawk, the CALCM contributed to the success of Operation

Desert Storm but also demonstrated some limitations. On the first day of

the conflict, seven B-52Gs carrying AGM-86C CALCMs took off from

Barksdale Air Force Base, Louisiana, on a 35-hour, 14,000-mile round trip.

All targets that the CALCMs attacked were in 2 of the 12 categories and

consisted of 5 military communications sites and 3 electrical power

stations. DIA’s assessment of CALCM’s damage to Iraqi targets concluded

mission objectives were achieved against the majority of targets.

The cruise missiles were not the only systems that demonstrated

limitations during Operation Desert Storm. Not all manned aircraft struck

their intended targets. For example, as stated earlier, our analysis of Gulf

War Air Power Survey data showed that the percent of the weapons

carried aboard the F-117As that took off during the conflict and struck

their intended targets was similar to the success rate achieved by the

cruise missiles. The F-117As carried munitions on about 1,300 sorties, but

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Proven in Recent Conflicts

they released only about 79 percent of the weapons against their targets.4

Of those released, a high percentage struck their intended aim points. Poor

visibility (overcast, fog, and smoke) limited the F-117A’s ability to use its

laser targeting and bomb guidance system. Almost 350 strikes were

aborted after takeoff due to bad weather conditions alone. For example,

more than half of the F-117A flights were unsuccessful on days two and

three of the air campaign because of low clouds.5

 In addition, bad weather

halted operations for 2 consecutive nights during the later stage of the air

campaign and during the final 2 days of the war. Another 76 strikes were

aborted because the pilots had problems identifying the targets.

Other aircraft were also affected by various problems. For example, about

780, or 33 percent, of the 2,310 F-111F sorties were aborted before striking

their targets because of mechanical and other problems and poor weather.

Mechanical problems with various aircraft components, such as inertial

navigation systems, air refueling systems, and digital computer complexes,

caused nearly 45 percent of the aborts. Poor weather restricted the

aircraft’s ability to launch laser-guided bombs and caused nearly

25 percent of the aborts.

Tomahawk

Performance Since

Desert Storm

Since Desert Storm, U.S. forces used the Tomahawk to strike Iraq in two

punitive raids. On January 17, 1993, U.S. forces struck the Zafraniyah

Nuclear Fabrication Facility, located just outside Baghdad, in response to

Iraq’s refusal to cooperate with U.N. inspectors. Even though tactical

aircraft were available, the National Command Authorities (i.e., the

President and the Secretary of Defense) chose the Tomahawk for the

strike because they wanted to avoid the potential loss of pilots or aircraft

and unacceptable damage to nonmilitary targets. U.S. forces targeted 

8 buildings and fired 46 Block II TLAM-C missiles, 42 of which (91 percent)

were successfully launched and transitioned to cruise flight.

On June 26, 1993, Tomahawk missiles were used to strike the Iraqi

Intelligence Service headquarters complex in the Baghdad area in

retaliation for the plot to assassinate former President Bush. U.S. Central

Command officials said that the Tomahawk was also chosen for this

mission because it could strike the target without risking the loss of

aircraft or aircrews. Additionally, an aircraft carrier was not present in

theater at the time. U.S. forces targeted 6 buildings in the complex and

4

A sortie is one aircraft taking off on one flight.

5

Because it flies at a very low altitude, the Tomahawk is not as affected by bad weather in the target

area as much as manned aircraft.

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attempted to launch 25 Block II TLAM-C missiles, 23 of which (92 percent)

were successfully launched and transitioned to cruise flight.

The Tomahawk’s performance improved during the two strikes. The

success rate was about 26 to 35 percent higher for the Zafraniyah raid, and

20 to 29 percent higher for the raid on Iraqi intelligence headquarters, than

the success rate during Desert Storm.6

Tomahawk

Improvements to

Address Shortfalls

and Expand

Capabilities

Improvements already incorporated into the Block III Tomahawk cruise

missile system, which is in production, address many limitations that were

noted during Desert Storm. Table 2.1 illustrates the principal

improvements incorporated into the Block III system.

6

Navy officials said that 3 of the 23 missiles that successfully launched missed their aim points in the

Iraqi intelligence headquarters raid because they were incorrectly programmed due to a mission

planning software error. The missiles struck the aim points for which they were programmed. If these

missiles were counted, the success rate for the raid would be 12 percent higher.

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Table 2.1: Block III Tomahawk

Improvements That Address

Desert Storm Limitations

Limitation Improvement Result

Tomahawk was not

responsive to the tactical

commander’s needs, since

route selections were limited,

mission planning times were

lengthy, and its arrival with

tactical aircraft was difficult to

coordinate accurately.

Global Positioning System

guidance was added,

mission planning hardware

and software were

upgraded and automated,

Afloat Planning System was

introduced, and Time of

Arrival software was

incorporated.

Route selections are

expanded. Mission

planning time is reduced by

90 percent. Theater

commanders will have an

in-theater mission planning

capability. The Time of

Arrival software allows strike

times to be coordinated

much more accurately.

Unitary warhead’s

penetrating ability was limited.

Warhead was redesigned,

and programmable delay

fuse was incorporated.

Lethality is increased

because the missile can

penetrate further into

targets before the warhead

detonates.

Some targets were at the

extreme limit of the missiles’

range.

Warhead and engine were

redesigned.

The new, lighter warhead

allows the missile to carry

more fuel, extending the

range. The redesigned

engine provides more thrust

and is more fuel efficient.

Stream raids alerted Iraqi

defenses.

Global Positioning System

guidance was added.

Since more routes to the

targets will be available,

defenders will not be

alerted by the repetitive use

of a few routes.

The Navy is also considering further evolutionary enhancements to the

missile system through the Tomahawk Baseline Improvement Program, or

Block IV. These enhancements would improve the system’s capabilities

over those of the Block III system, as shown in table 2.2.

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Table 2.2: Tomahawk Block IV

Improvements Over Block III Capability Block III Block IV

Accuracy CEP same as Block II CEP 60 percent more

accurate than Blocks II and

III

Penetration Greater than the Block II Greater than the Block III

Mission planning time Up to 90 percent shorter

than Block II

Up to 50 percent shorter

than Block III

DSMAC/TERCOM required 

for full accuracy

Yes No

Data link—missile status No Yes

Data link—third party control No Yes

Antiship No Yes

aThe Block III missile can fly missions using only the Global Positioning System for navigation, but

the missile’s CEP is greater than that of a Block II missile.

Because of the Block IV system’s planned improvements, program officials

estimated that attaining these requirements could reduce the number of

missiles needed to defeat a group of targets by 40 percent. The Navy’s

fiscal year 1994 budget included funding to initiate the Block IV program.

Production would begin at the conclusion of the Block III program, and

the first Block IV missiles would be delivered about fiscal year 2000.

Although the Air Force is studying a proposal to upgrade the CALCM, it has

not funded any improvements to the missile to address the limitations

identified in Desert Storm due to competing funding priorities.

Agency Comments

and Our Evaluation

DOD partially concurred with our assessment of the cruise missiles’

performance during Desert Storm. However, DOD said that the data we

presented for Tomahawk’s performance was the result of a preliminary

CNA study and did not represent the context in which the missiles were

employed. Pointing out that about 80 percent of the weapons the F-117As

released struck their targets, DOD said that the 63-percent success rate we

stated for the F-117A was misleading because we considered more than

only the weapons that were released against targets. It also said that

refueling operations depend on the geography of the conflict and that

refueling is often conducted to enhance flight safety.

CNA completed its study of the Tomahawk’s Desert Storm performance

after we submitted a draft of our classified report to DOD for comment. The

study included an analysis of the number of missiles that struck their aim

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points and the number of targets in which Tomahawk strikes achieved the

intended military objectives. The final results were basically unchanged

from the preliminary results we included in our draft report. We have

incorporated the study’s final results into this report.

We recognize that the Gulf War Air Power Survey data shows that about

80 percent of the weapons the F-117As released struck their target, but we

believe that a success rate based only on the number of weapons released

after the aircraft reached the target areas and successfully identified the

targets is not comparable to the percentage of cruise missiles launched

that struck their targets. We believe the number of weapons the F-117As

carried from the airfields compares most directly with the number of

cruise missiles that were launched from the ships and B-52s; therefore, we

based our analysis on that number.

The success rate of the Tomahawk missiles that arrived in their target

areas was much higher than the success rate of all missiles launched. Our

analysis of data in CNA’s final Tomahawk study shows that more than

75 percent of the TLAM-Cs programmed for a terminal dive maneuver that

arrived in their target area struck their intended aim point.

We agree with DOD’s comment that aircraft are frequently refueled to

enhance flight safety. However, as the Gulf War Air Power Survey points

out, aircraft (including the F-117A) were frequently refueled during Desert

Storm because the distance to the targets from their bases exceeded their

unrefueled combat radius. Even though all future conflicts may not involve

the ranges encountered during Desert Storm, the cruise missiles’ range is

an advantage.

DOD said that, even though our report implied that cruise missiles could be

used interchangeably with manned aircraft, the Tomahawk’s current

capabilities restricted its use to fixed, nonhardened targets. DOD believed a

range of weapons would be required to defeat many targets and that cruise

missiles would be especially valuable early in an air campaign when used

to create conditions more favorable to the large-scale employment of

manned aircraft. DOD also said that the Air Force was considering

improvements to the CALCM.

We agree that cruise missiles are best employed against fixed,

nonhardened targets. We also agree, as discussed in chapter 4, that cruise

missiles can be used to attack heavily defended targets in preparation for

large-scale attacks by manned aircraft. However, we also believe, as

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Proven in Recent Conflicts

Desert Storm showed, cruise missiles can be employed successfully

against a wide range of the targets to be encountered in a conflict.

DOD also said that, even though our report stated that the Air Force had no

plans to improve the CALCM, the Air Force is studying a proposal to

improve the missile. We have modified our report to so indicate.

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Chapter 3 

Cruise Missiles Broaden Options

The cruise missiles’ performance in Desert Storm and the two subsequent

Iraqi raids demonstrated that military commanders have a new option for

highly accurate strike operations under a variety of conditions. During

those conflicts, cruise missiles struck targets at night, in bad weather, or in

the face of heavy air defenses without risking the loss of aircraft and the

death or capture of U.S. aircrew members. In many cases, the cruise

missile attacks achieved results similar to those of manned aircraft

attacks.

Cruise missiles have other advantages over manned aircraft. For example,

Tomahawk strikes do not require the additional resources—electronic

warfare aircraft, fighter escort, and refueling aircraft—required for

manned aircraft strikes. Additionally, as the raid on Iraqi intelligence

headquarters demonstrated, cruise missile strikes can be launched without

the presence of an aircraft carrier battle group. Employing cruise missiles

can also avoid possible political constraints, such as obtaining host nation

permission to use U.S. aircraft from forward deployed bases or fly through

a third nation’s airspace. Currently, 135 ships and submarines are

equipped to launch Tomahawk missiles, which significantly expands the

U.S. ability to conduct forward presence operations or respond to an

adversary without the presence of an aircraft carrier battle group or

conventional air forces. CALCM attacks can also be launched from U.S.

bases, which allows the United States to attack an adversary without

necessarily having forces nearby or risking the loss of U.S. aircrews.

Reductions in mission planning times and other planned improvements

could make the Tomahawk as responsive for strike missions as manned

aircraft attacks.

Tactical aircraft systems have some advantages over cruise missiles and

will therefore continue to play a key role in offensive strike operations.

For example, aircraft-launched munitions can successfully attack a wider

spectrum of targets than cruise missiles, such as those that are mobile,

relocatable, or more hardened. Additionally, tactical aircraft systems are

better suited for conducting large-scale or extended campaigns that

encompass a large number of targets because of the greater amount of

munitions needed and the munitions’ relatively lower cost compared with

that of cruise missiles.

Cruise Missiles Offer

Additional Options for

Attacking Targets

Both the Tomahawk and the CALCM broaden commanders’ options by

providing highly accurate strike weapons they can employ against a

variety of targets at long ranges, under a variety of conditions, and without

risking the loss of aircraft or aircrew. Cruise missiles also have other

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advantages. For example, the Tomahawk uses fewer supporting resources

to launch a strike, and planning times for the Tomahawk are equal to or

better than aircraft in many cases. Additionally, the sea-launched

Tomahawk and the U.S.-based CALCM are not subject to the same airspace

and host nation basing restraints that can hamper employment of

ground-based tactical aircraft. Table 3.1 summarizes and compares the

advantages of cruise missiles and manned aircraft.

Table 3.1: Comparison of Tomahawk

and Manned Aircraft Factor Cruise missiles Manned aircraft

Risk to U.S. forces No risk of loss of aircraft

and aircrews

Potential loss of aircraft and

aircrews

Target types

Mobile Cannot attack Can attack

Fixed Can attack Can attack

Hardened Not as effective Effective

Support requirements Launch vessela Aircraft carriers are

supported by ships of battle

group; Navy and Air Force

strike aircraft require

supporting aircraft (fighter,

electronic warfare,

command and control, and

tankers)

Mission planning time Block II has lengthy

process; Block III and Block

IV will have a relatively short

process

Relatively short process

Access/basing rights Launch from international

waters

May require access to

non-U.S. bases or airspace

Availability 135 launch vessels Limited to aircraft carriers

and air bases

Cost High cost per missile Very high acquisition cost

for aircraft; relatively low

cost for munitions

aCruise missiles require extensive support to plan the mission. However, the launch vessel

requires no external support after it receives the mission data.

Reduced Risk to U.S.

Forces

Both Tomahawk and CALCM allow U.S. forces to strike an adversary with

precision at long ranges without risking the loss of aircraft or aircrew,

which is a significant factor in any decision to use military force.

According to Air Force and Navy officials, the unwillingness to risk any

losses was a factor in the National Command Authorities’ decision to use

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Tomahawks for the two 1993 strikes against Iraq. According to the

officials, the public’s reaction to the loss of any aircraft or aircrew during

those raids would have diminished the raid’s intended effect. Desert Storm

illustrated that risk reduction was also important during an extended

conflict.

Similar Effectiveness to

That of Manned Aircraft

Weapons

The destructive capabilities of the Tomahawk and the CALCM are generally

similar to those of aircraft-delivered munitions of the same class. Thus,

when used to attack targets that are susceptible to damage by their

warheads, the Tomahawk’s and CALCM’s effectiveness is comparable to

manned aircraft and the munitions they deliver. At our request, Air Force

officials computed the expected probability of damage for the cruise

missiles and guided bombs against a selection of common target elements.

They considered factors such as construction of the target, weapon

delivery accuracy, reliability, fuse, impact angle, and the targeted

element’s vulnerability to damage from the weapon. On the basis of a

70-percent probability of kill to the target, the Air Force’s analysis showed

that the numbers of cruise missiles required to destroy the target, when

differences in warhead weights were considered, was comparable in most

cases.1

As its mission planning process is improved, the Tomahawk system is

becoming as responsive, and in some case more responsive, to an

operational commander as tactical aircraft.2

 Currently, if a preplanned

Tomahawk mission for the target is aboard, a launch platform needs about

1 hour of preparation time to fire a missile. With the advent of the Block III

system, missions will be able to be planned 90 percent faster than Block II

missions, depending on the availability of imagery and the priority of the

missions.

Strikes by manned aircraft also require extensive planning and preparation

time. Navy officials said that the average strike by carrier-based aircraft

can take 24 hours or more to plan and launch. During this period, the

target imagery and surrounding defenses are analyzed, and the plan for all

aircraft involved in the strike is prepared. The plan encompasses all the

aircraft involved in the strike—the strike planes, electronic warfare

support aircraft, fighter escort, and tankers. Meanwhile, other personnel

1

According to Navy officials, a 70-percent probability of kill results in a very high level of physical

damage to the target. Depending on the objective of the strike, a lower probability of kill causes a

lower level of physical damage but can achieve a useful military objective and require fewer weapons.

2

The mission planning process is discussed in detail in appendix I.

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prepare the aircraft for the strike. The weapons to be carried by the planes

are taken from the ship’s ammunition magazines, assembled, and moved to

the flight deck. The ordnance and fuel are loaded aboard the aircraft, and

the aircraft are aligned on the deck for launch. Once the mission plan is

prepared and approved, the aircrews briefed, and the planes readied, the

process of launching a 35-plane mission can take almost 1 hour.

Fewer Supporting

Resources

Even though the Tomahawk requires extensive support in the mission

planning process, the ships and submarines launching a Tomahawk strike

require no additional resources after the strike has been ordered and the

mission data provided. The crew executes the launch procedure, which

can be done while the vessel is conducting other missions, such as

antisubmarine or antiair warfare. When launched, the Tomahawk is

autonomous and requires no further support.

When both Air Force land-based and Navy carrier-based manned strike

aircraft carry out their attacks, they are generally supported by several

other types of aircraft. The supporting aircraft protect the strike aircraft

from enemy defenses, provide command and control, and refuel the

aircraft taking part in the attack. These groups of strike and support

aircraft are commonly called “strike packages.” Table 3.2 shows the

aircraft that made up some typical Navy strike packages during Operation

Desert Storm and the weapons they carried. Air Force strike packages

were similarly constituted.

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Table 3.2: Representative Navy Strike

Packages in Desert Storm Aircraft

Target Quantity Type Ordnance

Aircraft maintenance and

repair facility

4

6

6

2

F/A-18

F/A-18

A-6

EA-6B

4 HARMa and AAb missiles

AA missiles

6 MK 83 bombs

3-4 ECMc pods

Communications sites 2

11

2

2

F/A-18

F/A-18

A-6

EA-6B

2 HARM and AA missiles

3 MK 83 bombs and AA missiles

2 TALDd and 1 Shrike missile

3 ECM pods

Air defense sector operations

center

2

2

9

2

8

F/A-18

F/A-18

F/A-18

EA-6B

F-1 4

2 Walleye missiles

4 TALD and AA missiles

3-4 MK 84 bombs and AA

missiles

4 ECM pods and 1 HARM

AA missiles

Note: These strike packages do not include the airborne tankers, command and control, and

protective fighter cover over the aircraft carrier.

aHigh-Speed Anti-radiation Missile.

bAir-to-air missiles.

cElectronic countermeasures.

dTactical Air-Launched Decoy.

Source: Navy data.

In those packages, the A-6 and F/A-18—depending on its configuration and

weapon load—constituted the offensive strike aircraft. EA-6B electronic

warfare support aircraft electronically jammed enemy defenses and

attacked Iraqi radars with HARMs. F/A-18s, armed with HARMs and other

weapons, also attacked Iraqi radar sites. To protect the other aircraft in

the package from attacks by Iraqi fighter/ interceptors, a fighter escort was

generally provided by F-14s or F/A-18s. Because of the distances between

the aircraft carriers and Iraqi targets, extensive air refueling operations,

both enroute to the target and during the return to home base, were

required and were conducted by KA-6 or S-3 aircraft. Navy aircraft were

also refueled by Air Force tanker aircraft.

Air Force aircraft also required extensive refueling support during Desert

Storm. The distances from the airfields on the Saudi peninsula and from

the aircraft carrier operating areas to the targets generally exceeded the

operating range of the aircraft. For example, F-117As, with a combat

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radius of 550-nautical miles, struck targets 905-nautical miles from their

home base.

The January 1993 Tomahawk strike on the Zafraniyah nuclear facility

illustrated the difference in resource requirements between the Tomahawk

and manned aircraft. That raid was accomplished with 42 Tomahawk

missiles launched from 4 ships. Navy officials said that a strike package of

about 40 planes would probably have been used to conduct the same

strike using carrier-based aircraft. A composite force of similar size

composed of Navy carrier-based and Air Force land-based strike aircraft

could also have been used.

Fewer Foreign Constraints Because of foreign political constraints, the only forces the United States

can employ unilaterally, in many cases, are carrier-based aircraft,

U.S.-based bombers, and missiles aboard vessels operating in international

waters. In a conflict, the United States may have to obtain a host nation’s

permission to launch strikes by U.S. aircraft from that nation’s bases. For

example, the U.S. government had to obtain specific authorization from

the British government to utilize the F-111s based in England in the

April 1986 strike against Libya.

Manned aircraft strikes may also be hampered if a third nation denies U.S.

forces access to its airspace. In the 1986 Libyan raid, for example, the

F-111s that took off from bases in England flew through the Straits of

Gibraltar to reach Libya because the French government would not allow

them to traverse French airspace. Cruise missiles launched from vessels

operating in international waters off an adversary’s coast or from

U.S.-based bombers would not face such constraints.

Potentially More Available

in a Crisis

As force levels decline and U.S. forces withdraw from overseas bases,

cruise missiles may be the most immediately available weapons with

which the National Command Authorities can respond in a crisis. The

Navy projects that, by 1999, 137 surface ships and submarines will be

Tomahawk equipped, and the number of deployable aircraft carriers will

have decreased to 11. The Navy would then be unable to maintain a

full-time aircraft carrier presence in the Mediterranean Sea, the Indian

Ocean, and the western Pacific Ocean, as it has in the past.

Even though Tomahawk-capable ships and submarines operate as part of

aircraft carrier battle groups, they also are capable of operating

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independently or as part of surface action groups. The two vessels that

launched the 1993 attack on the Iraqi intelligence headquarters operated

independently. No U.S. aircraft carrier was within striking distance of Iraq

at the time.

The ability to utilize overseas air bases and the time needed to deploy

tactical aircraft could also slow the Air Force’s response. Under those

conditions, CALCM-armed B-52s, flying refueled missions from their U.S. air

base, may be the most responsive Air Force weapon.

Tactical Aircraft

Systems Retain Key

Roles

Notwithstanding the capabilities of cruise missiles, tactical aircraft

systems have significant advantages under many conditions and will

therefore continue to retain a key role in offensive strike operations. For

example, hardened targets generally can only be successfully attacked by

aircraft-deployed munitions because of the Tomahawk’s limited ability to

penetrate these targets. In at least one instance in Operation Desert Storm,

the Tomahawk was unable to penetrate the roof of a target it struck; a

later attack by F-117As successfully penetrated the structure.

Only manned aircraft currently have the flexibility to successfully attack

mobile or imprecisely located targets, such as tanks and other ground

forces. The process of the pilot visually identifying the target before

releasing the aircraft’s weapons compensates for any target movement

after the strike was planned or prestrike errors in location. Current cruise

missile guidance systems, on the other hand, must be programmed before

launch to guide the missiles to a geographic point that coincides with the

targets’ location. If such targets were programmed and then moved before

the missile’s arrival, the missile’s path could not be corrected.

In addition, manned aircraft are better suited for striking the large number

and variety of targets in a protracted conflict. For example, during the

Desert Storm air campaign, over 1,000 strike aircraft flew more than 40,000

strikes against about 5,500 targets during the campaign.3

 Large quantities

of high-cost munitions, such as cruise missiles, are not available for use in

such conflicts.

The comparative costs of the weapons also affect cruise missiles’

suitability for extended campaigns. For example, the cost of attacking a

target with a Tomahawk is higher than the cost of attacking it with

manned aircraft because of the expected attrition rates for the aircraft. At

3

These targets were fixed installations and not targets such as deployed troops and equipment.

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our request, the Air Force analyzed the comparative costs of attacks by

cruise missiles and F-15E, F-111, and F-117A manned aircraft against six

common generic targets for a Southwest Asia 1999 scenario. The targets

included a military command headquarters bunker, a petroleum refinery

distillation unit, a control van for an SA-5 surface-to-air missile complex,

an aircraft in a revetment, a thermal power plant generator hall, and a

hardened aircraft shelter. The aircraft employed MK-84 unguided bombs,

GBU-24 or GBU-27 laser-guided bombs, and the Joint Direct Attack

Munition I.

The analysis determined the number of weapons and the associated cost

to damage a target to a 0.8 probability of destruction throughout the

duration of a campaign. The analysis’ results were derived from weapon

effectiveness reflected in the Joint Munitions Effectiveness Manuals and

the weapon loads in the aircraft operating manuals. The costs per kill were

derived from the individual costs of the sorties’ weapon costs (e.g., $2,000

for the MK-84 unguided bomb, $60,000 for a GBU-24/27, $392,000 for a

CALCM,

4

 and $1.8 million for the Tomahawk cruise missile); attrition; and

direct support costs of threat suppression, tanker support, and electronic

warfare obtained from Desert Storm historical data.5

 Weather attrition

factors were also included in the analysis, but the operating cost for the

platform launching a Tomahawk, command and control aircraft for

manned aircraft attacks, or the relative importance of manned versus

unmanned systems were not considered. The analysis also did not

consider or place any value on factors such as American aircrew members

killed in action or captured as prisoners of war or collateral damage.

The analysis found that comparable numbers of laser-guided bombs,

Tomahawks, and CALCM were needed to destroy some of the targets.

However, because of the Tomahawk’s and CALCM’s higher unit costs,

manned overflight systems would be more cost-effective against a wide

variety of targets. For example, the cost to attack a petroleum refinery

with F-117As employing a combination of GBU-27s and Joint Direct Attack

Munition Is was about 96 percent less than the cost of attacking the

refinery with the Tomahawk. Although the cost differential was less,

Tomahawk and CALCM costs were also higher for attacking the thermal

power plant because of the weapons’ higher unit costs. The CALCM’s cost

was about 48 percent less than the Tomahawk’s cost, and the F-117A’s and

4

This figure does not include the original acquisition cost of the Air Launched Cruise Missile that was

converted into the CALCM.

5

The Air Force’s analysis used a cost of $1.8 million for the Tomahawk, which is higher than the fiscal

year 1984 unit cost of $1.1 million per missile.

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F-15’s costs were about 88 and about 80 percent less, respectively, than the

Tomahawk’s.6

Agency Comments

and Our Evaluation

DOD concurred with our assessment that manned aircraft would continue

to play a key role in strike operations and provided several examples of

what it considers to be the advantages of manned aircraft, such as the

ability to attack mobile and hardened targets and the minimization of

collateral damage. Although it concurred that cruise missiles provided

commanders with additional options for strike operations, it said that the

cost of using cruise missiles versus manned aircraft to reach an acceptable

level of damage was very different. DOD also believed that our statement

that cruise missiles do not require additional support resources was

misleading because of the extensive requirements of the Tomahawk’s

mission planning process.

We agree that the munitions cost of an attack is less if manned aircraft are

used considering the cost of the munitions and attrition rates of the

manned aircraft. However, cost is only one measure of a weapon’s

suitability.

DOD’s cost comparison of the F-117A strike on Iraqi Air Force headquarters

and the 1993 Tomahawk strike on Iraqi intelligence headquarters does not

portray the differing environments in which those two attacks were made.

Although both weapons were suitable for attacking the targets, the F-117A

strike on the Iraqi Air Force headquarters involved two aim points on one

building and took place when the full array of coalition forces had already

been deployed to Iraq and were conducting combat operations during the

Desert Storm campaign. The 1993 Tomahawk strike was against a large

target complex with multiple aim points located six separate buildings

throughout the complex. A strike by manned aircraft would have required

the time and resources of either deploying a carrier battle group to the

area, since an aircraft carrier battle group was not in the area at the time,

or obtaining host country authorization for the use of Air Force tactical

assets based in the area. Employing the Tomahawk also responded to the

National Command Authorities’ desire to conduct the strike without

risking the loss of aircraft and aircrew.

We also agree that the Tomahawk mission planning process requires

considerable resources. A goal of the Block IV program is to reduce the

6

The cost for the F-15E using the same weapons were higher than the costs for the F-117A throughout

the analysis. Air Force officials attributed the cost difference to the lower attrition for the F-117A.

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time and resources required for mission planning. However, we believe

that the extensive support requirements of manned aircraft strikes must be

taken into account when comparing the various systems. The 1993

Tomahawk strike on Iraqi intelligence headquarters is a clear illustration

of this point. Extensive intelligence and target data would have been

required to plan both a manned aircraft strike and a Tomahawk strike.

However, after the Tomahawk mission data was prepared and transmitted

to the ships, the launch vessels that were already operating in the area

required no external support to launch the strike. On the other hand, all of

the aircraft we discussed as making up a strike package would have been

required to support a manned aircraft strike. We asked Navy strike

planners how large a strike package would have been required if Navy

manned aircraft had been used for the strike, and they said that as many as

40 to 45 aircraft could have been required.

We disagree with DOD’s comment that one of the advantages of manned

aircraft is the minimization of collateral damage. Even though the risk of

collateral damage may be relatively low in attacks by aircraft employing

precision munitions such as the F-117A, it can be a significant factor for

other aircraft/weapon combinations. For example, the Gulf War Air Power

Survey report notes that aircraft employing nonprecision munitions were

not used to strike targets in urban areas because of the high risk of causing

politically unacceptable collateral damage to civilian targets. Conversely,

Navy officials told us that the Tomahawk was chosen to strike targets in

several instances during Desert Storm because U.S. commanders believed

the targets were too close to sensitive civilian targets to risk the collateral

damage that could have resulted from manned aircraft strikes. Thus, even

though collateral damage occurred during the 1993 Tomahawk strikes, we

believe that an advantage of the Tomahawk is its low overall risk of

collateral damage compared with manned aircraft.

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Affect Strike Aircraft Requirements and

Force Structure Choices

Cruise missile capabilities should affect the design characteristics and

quantity required for most future manned precision strike weapons

systems as well as aircraft carrier force levels. Even though their

capabilities overlap those of other strike weapon systems, cruise missiles

have broadened the options available to commanders and have

demonstrated that they are a viable strike capability in the absence of

theater- or aircraft carrier-based strike aircraft. Therefore, most future

strike aircraft may not require as long a range or as high a degree of stealth

as originally planned. Also, fewer tanker, command and control, and

electronic warfare aircraft may be required if cruise missiles are used to

strike a larger portion of the targets.

According to DOD policies, an important objective of the defense

acquisition system should be to minimize the overlap and duplication

among weapon systems that perform the same or similar missions.

However, we have previously reported that the military services justify

such duplication on the basis of having complementary requirements to

engage similar targets and, as a result, do not always consider alternative

solutions.

The 135 ships and submarines currently equipped to launch the

Tomahawk significantly expand the U.S. ability to conduct forward

presence operations. If the warships were judged to be an acceptable

alternative to an aircraft carrier battle group, considerable budgetary

savings could result.

Cruise Missiles Can

Affect Strike Aircraft

Requirements

Cruise missiles’ proven capabilities give U.S. decisionmakers viable

alternatives to manned aircraft in several situations, such as the attack of

heavily defended or long-range fixed targets. Those capabilities, used in

collaboration with selected high-performance, manned strike aircraft,

could affect the characteristics of most future manned aircraft. The

resulting force of strike weapon systems would include both manned

aircraft and cruise missiles and would have a range of capabilities.

Because its range allows it to attack fixed targets at distances that require

manned strike aircraft to refuel, the Tomahawk could mitigate range

requirements in most types of future manned strike aircraft. For example,

the unrefueled range of the Navy’s F/A-18E/F is expected to be 390 to 450

miles, and the unrefueled range of the F-117A is about 550 miles. As shown

in a recent CNA study, a majority of the targets in many countries are

within those ranges. The study analyzed strike range requirements for the

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Affect Strike Aircraft Requirements and

Force Structure Choices

AF/X and found that, for the countries studied, a majority of the potential

targets were relatively close to the countries’ coast lines.1

Longer range targets generally lend themselves to attack by weapons such

as Tomahawk. Navy and Air Force officials noted that most long-range

targets are fixed, high-value strategic targets, whereas mobile targets and

ground forces are generally attacked at shorter ranges. Therefore,

Tomahawks or aircraft such as the B-1, B-2, or B-52 could be used to

attack most long-range targets, and, as a result, manned strike aircraft

could be optimized for shorter range targets. According to Navy officials,

not all targets are currently suitable for attack by cruise missiles, but most

fixed targets will be susceptible to cruise missile attack with the advent of

the Block IV Tomahawk.

Refueling remains an option when the range of manned strike aircraft

must be extended to attack specific hardened targets. As pointed out in

chapter 3, the F-117As were refueled for all their strikes during Desert

Storm. Configuring most future Navy strike aircraft to conduct unrefueled

strikes at ranges greater than those of current-generation strike aircraft

may be unnecessary. Therefore, most future aircraft could be optimized to

conduct attacks at shorter ranges, potentially resulting in procurement

savings. Longer range targets could be attacked by, and would be

vulnerable to, long-range bombers, Tomahawks, other cruise missiles, and

refueled strike aircraft, when necessary.

Cruise missiles’ ability to attack heavily defended targets without placing

aircraft or aircrews at risk could also affect stealth requirements for most

future aircraft and result in more affordable aircraft designs. Desert Storm

demonstrated that the majority of U.S. aircraft can operate effectively

without stealth technology. According to DOD officials, in the first days of

the air campaign, cruise missiles acting with a limited number of F-117A

and nonstealth defense suppression aircraft, such as the F-4G and EA-6B,

effectively incapacitated the Iraqi air defense system and rendered it

largely ineffective after day 3. This created a relatively benign environment

in which nonstealth aircraft operated with near impunity for the remainder

of the conflict. As a result, Air Force officials said that, once the air

defense system was degraded, the F-117A was valued more in many cases

for its precision bomb dropping capability than for its stealth

characteristics. These officials also said that the degradation of enemy air

defenses is likely to be a top priority in any future conflict, as it was during

Desert Storm. However, as both Desert Storm and the 1993 strikes

1

The Navy had subsequently canceled the AF/X program.

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Affect Strike Aircraft Requirements and

Force Structure Choices

demonstrated, Tomahawks can be used instead of manned aircraft when a

high level of defenses remain or a defense suppression campaign may not

be practicable.

Configuring most future strike aircraft with stealth capabilities may be

unnecessary. A small force of stealth strike aircraft, such as the F-117A or

its successors, could be maintained to attack well-defended targets along

with cruise missiles such as the Tomahawk, and the majority of these

aircraft could have a more conventional configuration, resulting in

procurement savings.

Other existing and planned standoff weapons, such as the Joint Standoff

Weapon, and the Standoff Land Attack Missile, will also permit strike

aircraft to remain outside of the range of a target’s defenses while

conducting an attack, further reducing the need for stealth characteristics.

Services Do Not

Always Consider

Alternatives

DOD acquisition policies require analysis of mission needs, costs, and

alternatives to ensure that cost-effective solutions are matched to valid

requirements before substantial resources are committed to a particular

program. According to those policies, an important objective of DOD’s

acquisition system should be to minimize the overlap and duplication

among weapon systems that perform the same or similar missions,

including when more than one service participates in similar missions

areas. However, we previously reported that the services justify

acquisitions of new systems on narrowly defined tasks or on a unique

weapon system capability because they believe they have complementary

requirements to engage similar targets.2

 As a result, alternative systems are

not always considered. For example, in July 1993, we reported that the

analysis of theater air interdiction in the Chairman of the Joint Chiefs of

Staff’s report on the roles, missions, and functions of the armed forces

considered only fixed-wing aircraft and did not consider options for using

land- or sea-based missiles and long-range artillery.3

 Also, in April 1992, we

reported that the Air Force and the Army gave little, if any, consideration

to the contributions of other close support weapons when determining

close air support requirements.4

 In both reports, we said that actions

should be taken to minimize the overlap among weapon capabilities.

2

Weapons Acquisition: A Rare Opportunity for Lasting Change (GAO/NSIAD-93-15, Dec. 1992).

3

Roles and Functions: Assessment of the Chairman of the Joint Chiefs of Staff Report

(GAO/NSIAD-92-200, July 15, 1993).

4

Major Acquisitions: DOD’s Process Does Not Ensure Proper Weapons Mix for Close Support Mission

(GAO/NSIAD-92-180, Apr. 17, 1992).

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Force Structure Choices

Both the Navy and the Air Force have tactical aircraft upgrade programs

underway that will require major expenditures. These programs will result

in retiring some aircraft types, modifying existing aircraft to enhance their

strike capabilities, and developing new aircraft. The Navy is developing

the F/A-18E/F, which it expects to be its primary short- to medium-range

carrier-based attack aircraft. It estimates the total cost of the F/A-18E/F

program to be about $85 billion for 1,000 aircraft. The Navy is also

modifying the F-14 to provide it with a strike capability and plans to retire

all its A-6 medium strike bombers, its only carrier-based, long-range,

all-weather strike aircraft. Additionally, the Air Force plans to incorporate

a precision ground attack capability into the F-22.

Cruise

Missile-Equipped

Platforms Can

Provide Forward

Presence and Crisis

Response

As the June 1993 raid on Iraq demonstrated, cruise missiles provide the

United States with a viable strike capability in the absence of aircraft

carrier-based strike aircraft. DOD’s Bottom-Up Review stated that only 10

carriers were required for waging two nearly simultaneous major regional

conflicts but that 11 were required to meet peacetime forward presence

requirements in three worldwide regions. The review noted that the

planned aircraft carrier force level of 11 active carriers and 1 training

carrier would support regional forward presence 12 months per year in

one region but would result in an average 4-month gap in carrier presence

per year for the two remaining regions. The review also stated that a force

of 10 carriers would increase the average gap in carrier presence in the

two regions to 6 months. The review depicted a 4-month gap as an

acceptable risk and a 6-month gap as unacceptable.

The 135 ships and submarines currently equipped to launch Tomahawk

missiles significantly expand the U.S. ability to conduct forward presence

operations, and the Tomahawk’s capabilities may lessen the risk

associated with the additional 2-month gap in presence. Those ships and

submarines also expand the U.S. ability respond to an adversary in a crisis

without the presence of an aircraft carrier battle group or conventional air

forces. In addition, CALCM attacks can also be launched from U.S. bases,

eliminating the need for any U.S. forces present in theater.

If the Tomahawk-capable warships were judged to be an acceptable

alternative for conducting presence operations, the Navy could achieve

considerable budgetary savings. As we previously reported, the average

annualized cost of an aircraft carrier battle group was about $1.5 billion.5

5

Navy Carrier Battle Groups: The Structure and Affordability of the Future Force (GAO/NSIAD-93-74,

Feb. 25, 1993).

Page 46 GAO/NSIAD-95-116 Cruise Missiles
Chapter 4 

Cruise Missiles’ Proven Capabilities Should

Affect Strike Aircraft Requirements and

Force Structure Choices

Recommendations We recommend that the Secretary of Defense assess the extent to which

cruise missiles could affect the requirements for manned strike aircraft

and aircraft carriers. This assessment should examine the (1) effect that

existing cruise missiles and potential upgrades have on the design

characteristics, such as the range, payload, and stealth characteristics, of

planned future aircraft; (2) potential effect of the resulting alternative

aircraft designs on future aircraft affordability; and (3) degree to which

increased cruise missile inventories could affect the number of aircraft to

be procured. We also recommend that the Secretary of Defense reassess

the degree to which cruise missile-equipped platforms could fulfill

peacetime presence requirements and the effect that increased reliance on

those platforms would have on the Bottom-Up Review’s justification for an

additional aircraft carrier for presence missions.

Agency Comments

and Our Evaluation

DOD partially concurred with our assessment of cruise missile’s potential

effect on the design characteristics of future aircraft, but it disagreed with

our recommendations. It believes that cruise missiles and manned aircraft

must be viewed as complementary systems and that cruise missiles are

best suited to small, punitive operations and manned aircraft can better

meet the overall requirements of supporting two major regional conflicts.

We agree that cruise missiles and manned aircraft are complementary

systems, but we continue to believe that cruise missiles should affect

design characteristics of future aircraft. The range issue illustrates our

point. Officials that prepared the F/A-18 E/F and the AF/X cost and

operational effectiveness analyses said, in the campaign summaries

supporting these analyses, that systems such as Tomahawk missiles and

long-range bombers were used to attack many of the longer range targets,

which tended to be more fixed than shorter range targets. Therefore, they

said that both aircraft, although not excluded from attacking the longer

range targets, were generally used to attack shorter range, more mobile

targets. The officials also said that a shorter range—combined with other

tradeoffs—was adequate for both aircraft, particularly the AF/X. We

believe that such analysis should be applied to all future aircraft designs to

ensure that cruise missile capabilities are fully exploited.

DOD believes that the range and stealth characteristics of manned aircraft

must be viewed in the total context of the myriad competing

priorities—such as range, payload, and survivability—in an aircraft’s

design and that these requirements in an aircraft’s design are independent

of cruise missile capabilities. DOD also said the campaign analysis

supporting the F/A-18E/F cost and operational effectiveness analysis

Page 47 GAO/NSIAD-95-116 Cruise Missiles
Chapter 4 

Cruise Missiles’ Proven Capabilities Should

Affect Strike Aircraft Requirements and

Force Structure Choices

summary addressed the employment of Tomahawk. It also said that it

considered the Tomahawk’s contributions, on a limited basis, in other

strike aircraft tradeoffs.

We agree with DOD’s comment that an aircraft’s stealth requirement is

driven by the missions it will fly and that all aircraft would benefit from

the various signature reductions that are part of stealth. However, we

continue to believe that if cruise missile capabilities are fully considered,

tradeoffs may be possible. If, as DOD said, cruise missiles are especially

useful in the early stages of an air campaign to create more favorable

conditions for the large-scale employment of manned aircraft, manned

aircraft can be employed in a more survivable environment. As a result,

the design of most strike aircraft could include a less costly, though still

adequate, stealth capability. Therefore, a less costly overall mix of aircraft

could be employed. As Desert Storm demonstrated, heavily defended

targets can be successfully attacked by cruise missiles and a limited

number of highly capable and survivable aircraft, leaving other targets to

be attacked by less survivable aircraft.

A recent CNA study reinforced this point. In an analysis of the Tomahawk’s

effect on modernizing naval aviation, CNA found that planned Tomahawk

forces were suitable for attacking a modest number of heavily defended

and deep targets early in a campaign and that capability reduced the need

for naval aircraft to carry out those missions.

Although it agreed that aircraft carrier presence has been reduced as the

Navy’s force structure declined, DOD said that cruise missiles were only

partial substitutes for the ability of an aircraft carrier and its associated

battle group elements to provide forward presence. Cruise missiles cannot

conduct the variety of missions the elements of an aircraft carrier battle

group are capable of conducting, and cruise missiles do not provide the

visibility—a key tenet of forward presence—that a carrier battle group

provides. DOD believed that, although cruise missiles are an excellent

addition to the U.S. conventional arsenal, the forces identified during the

Bottom-Up Review were needed to win two nearly simultaneous major

regional conflicts while providing forward presence.

We agree with DOD that cruise missiles do not provide the full range of

capabilities inherent in an aircraft carrier battle group, either from the

standpoint of providing peacetime presence or responding to a crisis.

However, we believe that the full capability of an aircraft carrier battle

group is not required in every situation to show U.S. resolve and

Page 48 GAO/NSIAD-95-116 Cruise Missiles
Chapter 4 

Cruise Missiles’ Proven Capabilities Should

Affect Strike Aircraft Requirements and

Force Structure Choices

commitment or forestall actions by other nations. The July 1993 strike

against the Iraqi intelligence headquarters provided potential adversaries

with a very tangible demonstration of U.S. capability that they cannot

safely disregard. Additionally, as one Pacific Command official pointed

out, potential adversaries cannot discount the possibility of the presence

of Tomahawk-equipped submarines, even though the submarines are not

visible. Furthermore, the July 1993 strike’s effect was not tempered by U.S.

losses, as were the strikes in Lebanon and Libya. Therefore, even though a

system such as Tomahawk may not address all peacetime presence

situations, we still believe that cruise missiles provide useful options for

conducting peacetime presence missions and that our recommendation is

valid.

Page 49 GAO/NSIAD-95-116 Cruise Missiles
Appendix I 

Tomahawk Improvements Address

Limitations

An upgraded Block III Tomahawk variant is in production. The resulting

changes to the missile address many of the system limitations noted

during Operation Desert Storm and expand the system’s capabilities for

future conflicts. A follow-on Block IV upgrade, which is under

consideration, would further expand the missile’s capabilities.

Tomahawk Block II

Mission Planning

Limitations

During Desert Storm, Tomahawk operations were hampered by the

lengthy mission planning process and the stringent geographic information

requirements of the Block II system. According to a Navy official, mission

planning times took as long as 72 hours during the conflict. Also, it was

difficult to find routes leading to targets that were usable by the

Tomahawk’s navigation system because of the relatively flat, featureless,

desert terrain in the area.

Planning a Block II Tomahawk mission is an extensive process. All

Block II Tomahawk missions are currently planned at two land-based

facilities or Cruise Missile Support Activities (CMSA), located at

Headquarters, U.S. Pacific and Atlantic Commands. During the mission

planning process, planners must identify a route extending from a fixed

starting point to the target. The route must be within the missiles’ range,

must not contain any obstacles to its flight such as steep mountains or

concentrations of enemy air defenses, and must pass over terrain that

would allow planners to prepare usable Terrain Contour Matching

(TERCOM) maps and Digital Scene Mapping and Area Correlation (DSMAC)

images. Planners must also identify specific aim points on the target

whose destruction will achieve the desired military effect. Finally,

planners must select a terminal maneuver—the manner in which the

missile impacts the aim point—and the number of missiles needed to

achieve the desired level of destruction.

The Block II missiles’ need for TERCOM maps and DSMAC images

significantly affects the planning process. The preparation of a TERCOM

map requires high-quality geographic data of specific terrain features that

meet stringent requirements for changes in elevation. The DSMAC process

requires imagery of the intended scene that provides a specified range of

contrast. Since the contrast of a ground scene can vary between night and

day or with the changing seasons, the imagery must be specific to those

conditions. The scene’s precise geographic location must also be known.

CMSAs obtain the TERCOM data from the Defense Mapping Agency, and a

variety of intelligence activities provide the images CMSAs use to prepare

the DSMAC scenes. The entire planning process for the Block II system, if

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Appendix I 

Tomahawk Improvements Address

Limitations

the TERCOM and DSMAC data is readily available, takes from 24 to 80 hours. If

the required imagery is not readily available, Tomahawk mission planning

can be delayed until the imagery is procured. Navy officials noted that this

delay occurred during Desert Storm.

Planned missions are transferred to the Tomahawk-capable ship or

submarine either through delivery of a data transport device (which is a

large computer disk) or through radio communications channels. Once a

ship or submarine is tasked to launch a Tomahawk, the process on board

the launching vessel involves powering up the missile, aligning its inertial

navigation equipment, transferring the mission into the missile’s computer,

and then launching the missile.

Navy and Air Force officials said that, after Desert Storm started, it was

difficult to incorporate Tomahawk strikes into the evolving air campaign

because of the Tomahawk’s long planning times. That difficulty

contributed to the missiles’ heavy use early in the air war: about 75 percent

of the missiles were fired during the first 3 days.

Tomahawk Block III

Upgrade Program

The Tomahawk cruise missile Block III upgrade program is intended to

increase the system’s capability and its responsiveness to the needs of the

tactical commander. The program encompasses improvements in all

aspects of the weapon system—the missile, mission planning, and the fire

control system. Block III development began before the Persian Gulf War,

and the first missiles were delivered in April 1993. The improvements

address many limitations in the system that were noted during Desert

Storm.

Expanded Route

Selections

One of the most significant improvements to the Block III missile is its

added ability to navigate to targets using the Global Positioning System

(GPS). GPS navigation frees the Tomahawk from having to fly over terrain

that is suitable for and has been mapped for TERCOM navigation. Guiding

from the signals of GPS satellites, a Block III missile can approach the

target area from any direction and needs only to fly over one terminal

DSMAC scene to achieve its full accuracy. The missile retains its ability to

navigate to the target area with the TERCOM/DSMAC system. It can also

navigate using only the GPS system; however the missile is three times less

accurate in this mode. Figure I.1 illustrates the navigation modes of the

Block III missile.

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Tomahawk Improvements Address

Limitations

Figure I.1: Block III Navigation Modes

Mission


Planning

Preplanned


missions

Ashore


planning

TWCS

CCS 

First


preplanned


way point

SAM


site

Conventional


target

TERCOM


maps

Satellite


updates

Afloat planning

TOA

GPS TOA

GPS

TACAIR

DSMAC IIA

maps

Tailored


missions

Note: CCS, Combat Control System; SAM, surface-to-air missile; TOA, time of arrival; TACAIR,

tactical aircraft; TWCS, Tomahawk Weapon Control System.

Source: Navy.

The expanded selection of routes from which mission planners can choose

should enhance the missiles’ survivability. Navy officials believe that

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Appendix I 

Tomahawk Improvements Address

Limitations

mission planning limitations may have contributed to some Tomahawks

being shot down during Desert Storm. The Block III missile’s ability to

approach the target area from any direction using GPS should reduce that

vulnerability.

Reduced Mission Planning

Time

Mission planning improvements will shorten the planning process. The

improvements, which are in place and operational at CMSAs, include new

software and workstations that automate many of the Tomahawk’s

mission planning tasks. As a result, according to Navy officials, missions

using TERCOM maps and DSMAC scenes can be planned in 90 percent less

time, with potentially fewer human errors. The flexibility to configure

missions using only GPS to navigate to the target area and one terminal

DSMAC scene, if the DSMAC imagery is available, will further reduce mission

planning time by more than 60 percent. Additionally, Navy officials said

that missions using only GPS to navigate could be planned in even shorter

periods.

Navy officials said that the Block III upgrades were compatible with the

Block II missile. Block III missiles can utilize Block II TERCOM/DSMAC

missions and retain such benefits as the Block III’s increased range and

more lethal warhead. Both CMSAs will continue to plan Block II missions to

support the Block II missiles that will remain in the inventory.

Enhanced Integration With

Tactical Aircraft

The Time of Arrival control incorporated within the Block III missile’s

on-board computer adjusts the missile’s speed and course so that it arrives

at its target at a more precisely defined time. This control helps avoid

airspace conflicts and weapon fratricide problems and can allow the

aircraft to take advantage of disruptions of enemy defenses caused by

cruise missile attacks.

Improved Warhead

Lethality

During Desert Storm, the Tomahawk’s inability to penetrate more heavily

constructed targets limited its effectiveness. The Block II missile and its

warhead can penetrate only about half the amount of concrete of the

Block III missile, which incorporates a redesigned warhead that is lighter

in weight than the Block II warhead—700 compared with 1,000

pounds—yet stronger.

The Block III’s new warhead is equipped with a programmable delay fuse

that increases the warhead’s lethality. The new fuse can be programmed to

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Appendix I 

Tomahawk Improvements Address

Limitations

detonate at varying lengths of time after the warhead contacts the target,

giving it additional time to penetrate into the target before exploding. This

allows more of the warhead’s explosive power to be spent damaging vital

components inside the target. The Block II fuse has a single delay setting.

Longer Range Many of the targets attacked during Desert Storm were near the

Tomahawk’s maximum range. Incorporating the new smaller, lighter

warhead allows the missile body to carry more fuel, therefore increasing

the range of the Block III TLAM-C. Additionally, Block III missiles are

equipped with a more fuel-efficient engine that provides greater thrust.

Since its warhead was not modified, the TLAM-D’s range was not

significantly changed.

More potential targets are within reach of the Block III TLAM-C because of

its greater range, as shown in figure I.2. The additional range also allows

the Tomahawk-equipped ships or submarines to remain further out from

shore, thus increasing the distance from potential shore-based threats.

Page 54 GAO/NSIAD-95-116 Cruise Missiles
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Tomahawk Improvements Address

Limitations

Figure I.2: World Areas Covered by the Block II and Block III TLAM-C Missiles’ Range

Block II coverage from outside 12-nautical mile territorial waters

Block III coverage from outside 12-nautical mile territorial waters

No coverage

Source: Navy.

Mission Planning in

Theater

The Block III program also introduces the Afloat Planning System (APS),

which will provide Tomahawk mission planning capability to carrier battle

groups and theater commands. According to Navy officials, this capability

will make the Tomahawk more tactically responsive by reducing the need

for CMSAs to plan all missions. Additionally, APS will allow the tactical

commander to modify existing Tomahawk missions to meet the needs of

the changing battlefield. APS suites will be deployed on aircraft carriers,

and mobile vans containing APS suites will be deployable to theater

command headquarters when needed. An APS suite consists of a single set

of Tomahawk mission planning workstations that are identical in function

to those located at CMSAs. The shipboard suites will be staffed by five

personnel assigned to detachments located with CMSAs and four shipboard

Page 55 GAO/NSIAD-95-116 Cruise Missiles
Appendix I 

Tomahawk Improvements Address

Limitations

personnel. The van-mounted suites will be staffed by nine personnel

assigned to the detachments.

Tomahawk Baseline

Improvement

Program (Block IV)

The Navy is also considering further evolutionary enhancements to the

missile system through the Tomahawk Baseline Improvement Program, or

Block IV. According to program officials and documents, the upgrades

under consideration would improve the system’s capabilities over those of

the Block III system. Program officials estimate that the Block IV system’s

planned improvements would reduce the number of missiles needed to

defeat a target set by 40 percent.

Funding to initiate the Block IV missile system’s development was

included in the Navy’s fiscal year 1994 budget. Under the program,

production would begin at the conclusion of the Block III production

program, and the first Block IV missiles would be delivered about fiscal

year 2000. Navy officials estimate that research and development costs

should total about $600 million through fiscal year 1999. According to

current plans, all missiles produced under the program would be

remanufactured from earlier Block II and TASM Tomahawks beginning

about 1999. The Tomahawk inventory would then proceed toward a force

consisting of Block III and IV missiles.

Modern Seeker Technology One of the improvements being considered for the missile is incorporating

an imaging seeker for terminal guidance, which would make the Block IV

Tomahawk’s guidance system significantly better than that of previous

versions of the missile.1

 The Tomahawk currently flies a pre-programmed

route to a specific geographic coordinate that coincides with the desired

aim point on the target. If any errors are made during the planning process

that instruct the missile to fly to a different point, or if an erroneous

location is used for the target, the missile will miss its aim point. An

imaging seeker is capable of target recognition, which would enable the

Block IV missile to compensate, to some degree, for such errors. The

Block IV missile would be programmed to fly to its target area using GPS

and inertial navigation. When it arrives in that area, its seeker would

search for the target. When the missile recognizes the target, it would

home in and strike it. Because the new seeker could compensate for minor

errors in mission planning or target location, Block IV should have an

accuracy 60 percent greater than Blocks II and III.

1

The Navy is considering an imaging infrared seeker.

Page 56 GAO/NSIAD-95-116 Cruise Missiles
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Tomahawk Improvements Address

Limitations

Simplified Mission

Planning

Block IV mission planning would be simplified if the missile was equipped

with an imaging seeker. The TERCOM/DSMAC data gathering and planning

process would be eliminated, since the missile would navigate using GPS.

The Block IV’s imaging infrared seeker would be capable of using target

images from any source normally used for aircraft mission planning

purposes, thereby eliminating the need for special intelligence imagery

support for the Tomahawk. If target imagery is available, land strike

missions should require about one-half the time to plan as do Block III

missions.

Greater Target Penetration Currently, the Navy is considering equipping the Block IV with a warhead

capable of penetrating about twice the reinforced concrete than the 

Block III missile’s warhead. Navy officials said that analysis showed that 

Block IV’s penetration would allow it to defeat a high percentage of

potential targets.

Anti-Surface Ship Capable Navy officials said that the Block IV missile, with its imaging seeker, would

give the Navy a long-range, antiship missile with target recognition

capability and would reduce the number of missile variants ships must

carry.2

 The imaging capability would be particularly useful in the crowded

littoral waters where the officials expect most future surface ship

engagements to occur. Current antiship missiles, such as TASM and

Harpoon, use radar-based seekers that cannot discriminate among several

returns and attack only the intended target. As a result, these weapons are

of limited use in crowded waterways where potential target ships may be

intermingled with neutral vessels. Navy officials said that the Harpoon was

not used during Desert Storm for this reason.

Navy officials said that Block IV’s imaging infrared seeker technology

would be capable of carrying images of various surface ship types in its

on-board computer. Thus, the seeker would be able to scan a target area

containing several ships and would only attack a ship it recognized as

matching the image of its intended target.

Added Data Links The Navy is considering adding two data links to the Block IV missile. The

links would increase the missile’s effectiveness because fewer missiles

would be used to strike previously damaged or improperly planned aim

points. One link would transmit an optical image from the Block IV missile

2

With a dual-capable missile, the vessels would only need to load one type of missile, rather than two.

Page 57 GAO/NSIAD-95-116 Cruise Missiles
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Tomahawk Improvements Address

Limitations

while it is in flight to a third-party aircraft. The other would be a satellite

data link.

The first data link would allow a controller on board an aircraft to adjust

the missile’s aim point for tactical or other reasons, for example, if the

missile was slightly off course or the predesignated aim point had already

been damaged and the controller wanted to designate another aim point.

The data link would also allow an airborne controller to direct the missile

to another target for tactical reasons, such as if the original target had

already been destroyed.3

Even though the satellite data link’s exact nature has not been determined,

program officials note that, at a minimum, it would allow the missile to

transmit a health status signal while in flight. That signal would apprise the

launch platform of the missile’s condition until impact. If the missile

developed mechanical trouble during the flight, began to navigate

incorrectly, or stopped broadcasting altogether (possibly indicating that a

fatal malfunction had occurred or that it had been shot down), a back-up

missile could be launched. The signal would also provide strike planners

an initial battle damage assessment, since it would indicate if the missile

impacted in the target area.

Block IV officials said that the satellite data link could also enable 

Block IV to receive signals. Command authorities could therefore abort a

missile from its mission if success was in doubt, lessening the chance for

unintended collateral damage. The satellite data link would also allow

commanders to divert the missile to an alternate target, if tactical reasons

dictated. Figure I.3 illustrates how the data links could function.

3

Block IV is expected to be able to carry two to three missions in its on-board computer.

Page 58 GAO/NSIAD-95-116 Cruise Missiles
Appendix I 

Tomahawk Improvements Address

Limitations

Figure I.3: Block IV Concept of Operations

UHF-FO

Mission planning

CMSA

APS

Two-way data link

TMMM launch

Dual-mission


missile

Autonomous


anti-jam GPS


navigation to


target area

GPS Third party


real-time


targeting


(AWW-13)

Target

Target

Note: TMMM, Tomahawk Multi-Mission Missile; UHF-FO, ultrahigh frequency follow-on.

Source: Navy.

Page 59 GAO/NSIAD-95-116 Cruise Missiles
Appendix II 

Major Contributors to This Report

National Security and

International Affairs

Division, Washington,

D.C.

Richard J. Price, Assistant Director

Tim F. Stone, Evaluator-in-Charge

Shawn M. Bates, Evaluator

Norfolk Regional

Office

Edward W. States, Regional Assignment Manager

Vincent Truett, Evaluator

(701050) Page 60 GAO/NSIAD-95-116 Cruise Missiles
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