United States General Accounting Office

GAO Report to the Chairman, Committee on

Armed Services, House of

Representatives

September 1993 SUPPRESSION OF

ENEMY AIR DEFENSES

Air Force Plans

GAO/NSIAD-93-221

GAO United States

General Accounting Office

Washington, D.C. 20548

National Security and

International Affairs Division

B-253753 

September 30, 1993

The Honorable Ronald V. Dellums

Chairman, Committee on Armed Services

House of Representatives

Dear Mr. Chairman:

In response to the Committee’s interest in the Department of Defense’s

(DOD) efforts to develop and procure future Suppression of Enemy Air

Defenses (SEAD) systems, we assessed the Air Force’s plans for the SEAD

mission as one of its primary SEAD aircraft, the F-4G “Wild Weasel,” retires

toward the end of the century. Specifically, our objectives were to assess

(1) current and future enemy air defense threats and (2) the capabilities of

the alternatives the Air Force is considering for future SEAD. This report

focuses on the Air Force’s efforts to accommodate the retirement of the

F-4G SEAD aircraft.

Results in Brief U.S. conventional combat aircraft would face increased risk in future

conflicts if the Air Force proceeds with its plans for future SEAD aircraft.

By the turn of the century, the Air Force will retire the aging F-4G “Wild

Weasel” SEAD aircraft and eliminate dedicated SEAD units. The Air Force

expects to assign the SEAD mission, as an added task, to units flying F-15

and F-16 aircraft and to equip them with SEAD systems that are less capable

than current systems. In August 1992, Office of the Secretary of Defense

(OSD) officials acknowledged to congressional staff that the Air Force’s

plans for SEAD involve some risk because there will be a time gap between

the retirement of the F-4G and the fielding of the new SEAD systems in

numbers sufficient to offset decreases in the capabilities of the new

systems. Subsequently, in March 1993, the Air Force decided to field fewer

SEAD-equipped aircraft with potentially even less capability, which would

further increase risk.

The Defense Intelligence Agency (DIA) and the Air Force have identified a

continued need for SEAD. DIA recently reported that U.S. conventional

combat aircraft would continue to face significant threats that will require

suppression to minimize their losses. Air Force threat assessments

supporting the need for future SEAD equipment have reached similar

conclusions. The Air Force’s plans to accomplish SEAD are budget rather

than threat driven. According to Air Force officials, future reduced

budgets and force structure are driving the decision to eliminate single

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mission units such as the F-4G SEAD force because they compete for

funding with the Air Force’s high priority F-22 and B-2 programs.

Background The goal of SEAD is to establish an environment that allows friendly aircraft

to attack in the safest, most effective manner. SEAD entails neutralizing,

destroying, or temporarily degrading enemy integrated air defense

command, control, communications, and radar systems that are directing

surface-to-air missiles and antiair artillery against friendly aircraft. SEAD

reduces friendly aircraft losses and allows aircraft to operate effectively.

SEAD may be accomplished by lethal and nonlethal means. Lethal SEAD

physically destroys or incapacitates crucial parts of the air defense system

such as radar antennae and communications links. Nonlethal SEAD

electronically jams (or interferes with) these systems to temporarily

degrade their effectiveness.

DOD tasks all the armed services to provide SEAD using a variety of weapon

systems such as artillery, ground-to-ground missiles, cruise missiles,

helicopters, and attack aircraft using general purpose munitions. Some

weapon systems were specifically designed for SEAD, including the Air

Force’s F-4G “Wild Weasel” and EF-111 “Raven” and the Navy’s and Marine

Corps’ EA-6B “Prowler.” The F-4G provides lethal suppression, the EF-111

provides nonlethal suppression, and the EA-6B provides both. The jointly

used High Speed Antiradiation Missile (HARM), designed to attack emitting

radar, is the services’ munition of choice for lethal SEAD.

These systems were employed extensively in the Gulf War with the Air

Force using virtually all available F-4Gs. DOD and Congressional Gulf War

studies highlighted the importance of the SEAD mission. They concluded

that the services’ SEAD aircraft were effective in shutting down Iraqi radar

systems allowing coalition aircraft to attack their targets in the safest and

most effective manner while minimizing friendly aircraft casualties.

According to Air Force officials, the F-4G “Wild Weasel” continues to fly in

the Gulf region. F-4Gs are flying to protect U. N. patrols in the north and

south “no-fly” zones in Iraq. About half of the available F-4G force is

deployed to the Gulf region.

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U.S. Tactical Aircraft

Will Remain

Vulnerable to Enemy

Air Defense Threats

U.S. attack aircraft will remain vulnerable to enemy air defenses into the

next century because of (1) the increased dispersion and sophistication of

the defenses and (2) the conventional, nonstealthy characteristics of the

attack aircraft force. At DOD’s request, DIA assessed threats to U.S.

fixed-wing tactical aircraft in the 2000 to 2005 time frame. This

assessment, completed in February 1993, concluded that U.S. conventional

aircraft would face enemy air defense threats equal to or surpassing the

current threat and will require suppression to minimize losses. In

discussing the report, DIA officials noted that the United States will

continue to face systems and technologies developed by the former Soviet

Union, Western Europe, and even the United States that are sold to

potential regional adversaries.

Documentation supporting development programs for new Air Force SEAD

systems and stealthy aircraft, as well as discussions with the Joint Chiefs

of Staff, OSD and service officials support DIA’s conclusions. For example,

to justify the stealthy F-22 Advanced Tactical Fighter program before the

Congress in March 1992, the Secretary of the Air Force noted that 

“. . . Although the Soviet threat has declined, its advanced technology,

high-performance aircraft and anti-air defense systems are rapidly being

disbursed around the globe. This proliferation can challenge our presence

throughout the world . . .”

Air Force and DOD reports on the Gulf War concluded that U.S. stealthy

attack aircraft reduced vulnerability to enemy air defense. Until 2005, the

vast majority of U.S. attack aircraft will be conventional nonstealthy

aircraft. The only stealthy attack aircraft available in 2005 will be the same

number of Air Force F-117s currently available, which comprised only

about 4 percent of the Gulf War attack force. The services have no plans to

increase the number of stealthy air interdiction aircraft until about 2005.

The Air Force’s

Current Lethal SEAD

Aircraft Is Near the

End of Its Useful Life

According to DOD and Air Force officials, the F-4G force is near the end of

its useful life and needs to be retired. The aging two-seat F-4G equipped

with the APR-47 radar receiver is the Air Force’s primary lethal SEAD

weapon system. The APR-47 is key to effective lethal SEAD because it gives

the aircraft the capability (1) to detect, classify, and localize enemy air

defense radars and (2) to quickly pass target range, bearing and enemy

system information to HARM. The APR-47 is the only radar receiver

currently available that can automatically provide HARM with both bearing

and ranging information, a factor that significantly increases the HARM’s

effectiveness.

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Even though the average age of F-4G aircraft is about 24 years, the Air

Force extended F-4G’s 1993 retirement date toward the end of the century

because there will be no system available to assume the lethal SEAD

mission until that time. In fiscal year 1989, the Air Force had 72 F-4Gs in

active units and by the end of fiscal year 1993, only 42 will remain in 

2 squadrons—1 active unit and 1 Air National Guard unit. By the turn of

the century, the Air Force expects to have retired all F-4Gs from service

and will have eliminated dedicated lethal SEAD units in favor of adding SEAD

as an additional task for F-15 and F-16 units.

Air Force Alternatives

for Future SEAD

Systems Are Less

Capable

Since 1989, the Air Force has changed directions twice in considering

future lethal SEAD systems to assume the mission as the F-4G retires. The

most recent plans would result in the Air Force trying to accomplish the

SEAD mission with a less capable system than the F-4G.

Initial Plan to Replace

F-4G Considered

Unaffordable

In fiscal year 1982, the Air Force began considering the need for a

follow-on Wild Weasel aircraft to replace the aging F-4G in the SEAD role.

In 1986, the Air Force contracted with McDonnell Aircraft Company and

General Dynamics to study how SEAD capabilities could be built into the

F-15 and F-16, respectively. In July 1987, these companies proposed

modifications to the two-seat F-15E and the two-seat F-16. Both proposals

incorporated the APR-47 into the aircraft, maintaining, at a minimum,

current capabilities. In discussing these proposals, Air Force officials

noted that a single-seat aircraft could not accommodate the APR-47.

In 1988, the Air Force included these proposals in another analysis of a

potential follow-on to the Wild Weasel and suggested that fiscal year 1990

funds be made available to start such an acquisition program. For this

analysis, the Air Force required that, at a minimum, the follow on would

maintain the capabilities of the F-4G’s APR-47. The Air Force studied

modifying various aircraft and reviewed radar receiver technology and

concluded that a modified two-seat F-15 would best meet requirements.

However, on December 11, 1989, the Air Force decided to cancel the

follow-on effort even though it had plans to retire the F-4G in 1993.

According to Air Force headquarters and Air Combat Command officials

(formerly Tactical Air Command), this decision was based on expected

budgetary constraints. They stated that the Air Force could no longer

afford to develop and support single mission aircraft that would be in

Page 4 GAO/NSIAD-93-221 Suppression of Enemy Air Defenses
B-253753 

direct competition with such Air Force priorities as the F-22 stealthy

fighter and the B-2 stealthy bomber. The Wild Weasel mission would have

to be absorbed by F-15E and F-16 aircraft modified with less capable SEAD

equipment.

Current Air Force Plans

Will Not Match Current

SEAD Capabilities

In January 1990, the Air Force Chief of Staff tasked the Air Combat

Command and the Air Systems Division with developing a plan to meet

near-term (3 to 5 years) and long-term (6 to 15 years) SEAD needs.

Near-term efforts were to concentrate on developing limited SEAD

capabilities for F-15E and F-16 aircraft. Long-term efforts were to

concentrate on new approaches to SEAD that at a minimum would lead to

the development of a target location and attack system that meets

projected threats in 2005 and that exceeds current F-4G SEAD system

performance.

The Air Combat Command and the Air Systems Division responded with a

three-phased approach, but none of the systems envisioned in any phase

would be as capable as the F-4G system. In the first phase, currently

underway, the Air Force is developing and procuring an interim HARM

Targeting System that will provide limited SEAD capability for the

single-seat F-16. This phase was intended to provide limited SEAD with

these F-16s during the expected gap between the 1993 F-4G retirement and

fielding the long-term solution.

In fiscal year 1992, the Air Force began the second phase—developing an

internal HARM targeting capability for the two-seat F-15E called the

precision direction finder (PDF). The unfunded third phase was to develop

a variant of PDF for the F-16.

The cost and operational effectiveness analysis supporting milestone I

acquisition decisions for the PDF program (completed in

March 1992) established a baseline well below the capabilities of the F-4G.

SEAD options were compared to this baseline. DOD acquisition regulations

state that the baseline is generally the current capability. However, the Air

Force omitted its most capable SEAD system, the F-4G, and used instead an

F-16 firing HARMs without SEAD electronic equipment as the baseline. The

Air Force uses the F-16 to fire HARMs only when accompanied and directed

by an F-4G. The cost and operational effectiveness analysis indicated that

the F-15E PDF system was the most cost-effective option compared to the

baseline. But the analysis is misleading because it does not provide any

indication of how this system would perform in comparison to the F-4G.

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According to Air Force officials, neither the F-15E nor F-16 PDF would be

as capable as the current F-4G.

In an August 1992 briefing to congressional staff, OSD electronic warfare

officials acknowledged the Air Force position that the PDF system was not

as capable as the current system. They also noted that degradation in

technical capability would be offset by increased numbers of aircraft

available for the mission. However, they concluded that the PDF concept

would result in some risk through 2000 because there will be a time gap

between the F-4G’s retirement and the fielding of sufficient numbers of

new SEAD systems to compensate for the degraded capability.

In March 1993, the Air Force terminated the F-15E PDF program. Air Force

officials expressed concerns that the number of F-15E aircraft are not

sufficient to assume the SEAD mission. Instead, single-seat F-15Cs are to be

modified with a PDF-like system for SEAD. The Air Force also reduced the

SEAD program budget by 50 percent through the 5-year defense plan.

According to Air Force officials, the reduced budget will lead to a system

that does not meet the operational requirements established for the F-15E

PDF system and will result in the fielding of fewer aircraft than was

planned for the F-15E PDF. Also, Air Force officials have concerns about

increasing the pilot work load for the single-seat F-15C.

Recommendation We recommend that the Secretary of Defense reevaluate funding priorities

in light of the increased risk associated with reducing SEAD capabilities.

Agency Comments

and Our Evaluation

DOD generally concurred with the report but took exception to our

description of OSD’s August 1992 congressional briefing concerning risk

associated with the PDF concept. OSD stated that the risk involved with the

PDF concept is the time gap between the F-4G retirement and the initial

operational capability of the PDF equipment and not risk to the attack

force. We clarified OSD’s position concerning risk in the report.

DOD concurred with our recommendation. DOD commented that although

the recommendation was too broad in scope, DOD will specifically address

the reduction in SEAD capabilities (i.e., F-4G capability) by requesting the

Air Force to update the cost and operational effectiveness analysis using

the F-4G with the APR-47 as the baseline by the end of fiscal year 1994. We

Page 6 GAO/NSIAD-93-221 Suppression of Enemy Air Defenses
B-253753 

recognize that the recommendation is broad in scope, but we believe that

it would allow DOD maximum flexibility in addressing this issue.

Scope and

Methodology

To accomplish our objectives, we reviewed DOD’s acquisitions regulations

and the Air Force’s requirements documents to analyze the methodology

used to select the replacement for the F-4G. We interviewed Air Force

officials to determine (1) strengths and weaknesses of options considered

for F-4G replacement and (2) how the service plan to conduct SEAD in the

future versus how it is conducted today. We also interviewed intelligence

and tactical warfare personnel to identify factors relevant to future SEAD

roles and missions.

We performed our work at the Air Combat Command (formerly Tactical

Air Command), Langley Air Force Base, Virginia; DIA, Bolling Air Force

Base, Maryland; the Joint Chiefs of Staff, OSD, the Air Force and Navy

Headquarters, Washington D.C.; the Naval Strike Warfare Center, Eglin Air

Force Base, Florida; the Marine Electronic Warfare Squadron Three,

Marine Air Station, Cherry Point, North Carolina; the National Guard

Bureau, Andrews Air Force Base, Maryland; the Air National Guard, Boise,

Idaho; and the 366th Wing and the 429th Electronic Combat Squadron,

Mountain Home Air Force Base, Idaho.

We conducted our work between March 1992 and June 1993 in accordance

with generally accepted government auditing standards.

This report was prepared under the direction of Richard Davis, Director,

National Security and Analysis, who may be reached on (202) 512-3504 if

you or your staff have any questions. Major contributors to this report are

listed in appendix I.

Sincerely yours,

Frank C. Conahan

Assistant Comptroller General

Page 7 GAO/NSIAD-93-221 Suppression of Enemy Air Defenses
Appendix I 

Major Contributors to This Report

National Security and

International Affairs

Division, Washington,

D.C.

Fred Dziadek, Assistant Director

Robert L. Pelletier, Assistant Director

John K. Harper, Assistant Director

Lisa R. Shames, Assignment Manager

Norfolk Regional

Office

Richard G. Payne, Regional Management Representative

Gaines R. Hensley, Evaluator-in-Charge

Dawn R. Godfrey, Site Senior

Angela Pun, Evaluator

(392700) Page 8 GAO/NSIAD-93-221 Suppression of Enemy Air Defenses
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