United States General Accounting Office

GAO Report to the Secretary of Defense

March 1995 UNMANNED AERIAL

VEHICLES

No More Hunter

Systems Should Be

Bought Until Problems

Are Fixed

GAO/NSIAD-95-52

GAO United States

General Accounting Office

Washington, D.C. 20548

National Security and

International Affairs Division

B-259256 

March 1, 1995

The Honorable William J. Perry

The Secretary of Defense

Dear Mr. Secretary:

The Department of Defense (DOD) is acquiring the Hunter Short-Range

Unmanned Aerial Vehicle (UAV) for use by the Army, the Navy, and the

Marine Corps at an estimated cost of over $4 billion. We reviewed the

Hunter program to determine (1) whether it has been demonstrated to be

logistically supportable, (2) whether its performance deficiencies found in

prior testing have been resolved, and (3) whether it represents a valid

joint-service effort as mandated by Congress.

Background The Hunter is a pilotless aircraft resembling a small airplane that is

controlled from a ground station. (See fig. 1.) It is intended to perform

reconnaissance, target acquisition, and other military missions by flying

over enemy territory and transmitting video imagery back to ground

stations for use by military commanders.

The Hunter program (formerly called the Short-Range UAV program) began

in 1989 as a joint-service effort in response to congressional concern over

the proliferation of UAVs by the different services and the need to acquire

UAVs that could meet the requirements of more than one service. DOD

started the program by procuring two candidate systems for competitive

testing. In early 1993, after the Hunter was selected as the winning system,

DOD approved its low-rate initial production of seven systems and awarded

a $171-million contract.

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Figure 1: Hunter UAV: Wingspan 29’ Length 23’

Each system includes eight UAVs with payloads, a launch and recovery

station, ground stations for controlling flight and processing information

from the UAVs, and other related equipment. (See fig. 2.) DOD plans to buy

24 systems for the Army, 18 for the Navy, 5 for the Marine Corps, and 3 for

training, for a total of 50 systems.

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Figure 2: Hunter UAV System

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Results in Brief To date, the Hunter UAV system has shown itself to be logistically

unsupportable, and tests have identified serious performance problems

that adversely impact the system’s effectiveness. Based on its performance

to date, the system may prove unsuitable for use by operational forces

and, contrary to DOD plans, could require costly contractor maintenance

and support to keep it operating. Furthermore, after several crashes

during testing, the Hunter UAV system was ordered grounded by DOD and

has remained grounded. Nevertheless, DOD plans to commit to full-rate

production for the land-based configuration before determining whether

the Hunter UAV can meet Navy requirements, thus putting a single

joint-service system, as called for by Congress, at risk.

DOD has recently restructured the Hunter program in an effort to address

the system’s problems. However, the restructured program would further

delay and curtail critical testing while allowing for additional procurement

of systems whose performance is so far unproven and possibly defective.

According to DOD, award of a second low-rate production contract is

needed to avoid a prolonged production break. However, award of a

second low-rate production contract would not eliminate the production

break. In view of this and because of the risks in further committing to an

unproven system, we believe that further production should be deferred

until the system demonstrates satisfactory performance.

Hunter System Is Not

Supportable

DOD Instruction 5000.2 requires that efforts to develop a system’s logistical

supportability begin early in the acquisition process to assure that it can

be successfully operated and maintained when deployed. These efforts

include developing the proper procedures for maintaining the system and

for training military personnel to operate and repair the system.

Accordingly, the contract for the Hunter UAV system required that the

contractor develop logistic support information and deliver it when the

low-rate production contract option was awarded in February 1993.

Such logistic support information is supposed to identify and document

(1) functions that personnel must perform to operate and maintain a

system in its operational environment; (2) the types of military personnel,

such as air vehicle pilots and maintenance technicians, best suited to

perform the operations and maintenance functions; (3) all training,

including training curriculums and training materials, required to prepare

personnel to operate and maintain the system; (4) all equipment required

to maintain the system, such as mechanical tools used to repair trucks,

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and computer hardware and software used to test and repair faulty

electronic equipment; and (5) the system maintenance schedule.1

As of December 1994, the contractor had not delivered adequate logistic

support information. In 1993, the Joint Tactical UAV Project Office

conducted a logistics demonstration to evaluate the adequacy of the

logistic support information provided by the contractor. For the logistics

demonstration, the contractor trained military personnel to conduct

system maintenance and developed system manuals describing 3,107

maintenance tasks. The trained military personnel attempted all of the

maintenance tasks, but they completed only 56 maintenance tasks on the

first attempt. After government analysis, and extensive revisions by the

contractor, military personnel were able to complete 1,526 more tasks.

Government testers informed us that 1,347 of the 3,107 maintenance tasks

were so ill-defined in the contractor-supplied manuals that revisions were

not practical.

In a letter dated January 1994 to the contractor, the Hunter contracting

officer stated that the results of the logistic demonstration reflected a

system that was not yet sustainable and did not have a support structure in

place. The contracting officer identified logistic support information as the

primary area of deficiency. He informed the contractor that the system

manuals were grossly inadequate to either operate or maintain the system

and that the training curriculum was insufficiently defined. According to

the logistics demonstration final report, the system manuals contained

insufficient references, incorrect or vague cautions and warnings, and

conflicting equipment terminology. The testers concluded that these

deficiencies caused the manuals to be difficult to use and error prone and

that the system manuals could lead to equipment damage and injury to

personnel.

The Joint Tactical UAV Project Office revised the contract delivery

schedule to allow additional time for the contractor to deliver adequate

logistic support information. The revised schedule delayed the delivery of

logistic support information from February 1993 until October 1994 for

unit maintenance and until June 1995 for depot maintenance. Analysts at

the U.S. Army Missile Command, the Hunter program’s lead logistics

agency, reviewed all available logistic support information in May 1994.

They concluded that, based on the contractor’s past history of not

developing logistic support information in accordance with DOD policy and

1

The maintenance schedule should point out how often items such as air filters, oil filters, and spark

plugs should be replaced in all the air vehicle engines.

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the sheer magnitude of the work remaining, the contractor would not be

able to provide complete logistic support information before June 1995.

Missile Command logistics analysts said that without adequate logistic

support information, DOD would have to rely on the contractor for logistic

support. Based on DOD’s experience with other programs, Missile

Command officials expect contractor logistic support to be more

expensive than the support originally planned to be provided by the

services. For example, government cost estimates of service-provided

operations and maintenance for a Hunter system was set at $2.9 million a

year for peace-time operations. However, the contractor has already

proposed billing the government about $1.7 million to provide logistic

support for one system for 300 flight hours in a 3-month operational

exercise. This equates to about $5,666 per flight hour and $6.8 million a

year for one system.

As we have seen on other systems such as the Pioneer UAV and the SLQ-32

shipboard electronic warfare system, insufficient logistic support

information can also lower system readiness. For example, the Pioneer’s

readiness has been degraded because faulty maintenance manuals caused

maintenance personnel to order the wrong replacement parts, and

logistics assessment reports on the SLQ-32 show that inadequate technical

manuals increased operations costs and lowered readiness levels.2

Hunter’s Performance

Problems Have Not

Been Resolved

DOD policy requires that operational test and evaluation be structured to

determine (1) the operational effectiveness and suitability of a system

under realistic combat conditions and (2) whether the minimum

acceptable operational performance requirements have been satisfied.

As stated in our December 1993 report,3

 results of the limited user testing

conducted during 1992 revealed significant performance deficiencies in

the Hunter system. While some actions have been taken or are planned

that are designed to correct problems, our review indicates that serious

deficiencies remain unresolved. We also found that none of the fixes had

been operationally tested to ensure that the system meets minimum

acceptable operational requirements. In addition, acceptance testing on

the first low-rate production system, which began in May 1994, disclosed

2

Electronic Warfare: Inadequate Testing Led to Faulty SLQ-32s on Ships (GAO/NSIAD-93-272, Aug. 19,

1993).

3

Unmanned Aerial Vehicles: Performance of Short-Range System Still in Question (GAO/NSIAD-94-65,

Dec. 15, 1993).

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B-259256 

new problems. As of October 1994, the delivered system had not been

accepted. Furthermore, during acceptance testing in late October 1994, an

air vehicle was almost totally destroyed when it went out of control.

Consequently, DOD grounded the Hunter system.

Hunter System’s Reliability

Has Not Been

Demonstrated

Limited user testing conducted in 1992 showed that the Hunter system was

unreliable in several critical areas. The system required frequent

unanticipated repairs, the air vehicle engine performance was

unsatisfactory, and the built-in-test equipment was inadequate. These

problems have yet to be resolved.

Unanticipated Repairs To ensure that the Hunter is reliable and does not create an excessive

maintenance burden, system requirements specify that it require no more

than one unanticipated repair every 4 hours. However, limited user tests

showed that the Hunter required unanticipated repairs every 1.2 hours.

DOD acknowledges that the system failed to meet this requirement but has

taken no further action to demonstrate that the system can perform as

required. Instead, DOD has relied on contractor estimates, which state that

the requirement for unanticipated repairs is achievable.

The importance of system reliability was demonstrated during Operation

Desert Storm. According to DOD’s lessons learned, the frequent failure of

the Pioneer showed that UAV systems must be reliable to adequately

support combat operations.

Air Vehicle Engine Limited user tests conducted in June 1992 disclosed that the two engines

used in each air vehicle, which were designed for a motorcycle, were

particularly unreliable and had a short life. The engines experienced

recurring problems with valve seizures. Because of the repeated engine

failures during testing, the project manager directed the contractor to

replace all engines with modified versions. Although the purchase price of

the motorcycle is under $8,000, DOD has contracted not-to-exceed prices as

high as $53,000 each for the engines. The replacements showed some

improvements, however, failures continued. Army test officials concluded

that each UAV unit equipped with 2 Hunter systems could be required to

replace from 3 to 10 engines a week. Furthermore, the frequent engine

replacements could overburden the services’ logistics systems.

According to program officials, these engine problems have been

corrected and the original systems procured have been retrofitted with the

changes. Program officials also plan to incorporate the modifications in

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the systems being produced. Program officials also said the air vehicle

engines demonstrated acceptable performance during subsequent

verification testing. However, valve seizures reappeared during more

recent testing. In fact, during July 1994, while testing the first low-rate

production system delivered, the problems with push rods and valve

seizures continued. Test officials have refused to accept delivery of this

system until these problems are resolved. In addition, at least two earlier

crashes, which resulted in significant damage to the air vehicles, have

been partially attributed to other engine-related failures.

Built-in-Test Equipment Hunter’s built-in-test is supposed to identify system faults needing repair.

However, following limited user testing, test officials concluded that the

built-in-test equipment consistently failed to meet requirements and

required redesign to correct the deficiencies. The built-in-test detected

only 11 of 154 problems during the tests and isolated the cause of only 2 of

the 11 faults detected. The test agency concluded that the inadequate

built-in-test design significantly hampered system maintenance and

increased the time to correct problems.

In 1993, logistics demonstration testing disclosed that while some software

modifications had been made, Hunter’s built-in-test equipment still did not

meet requirements. Currently, DOD plans no further testing of the Hunter

built-in-test equipment until February 1995.

System Ability to Meet

Relay Requirements

Remains Questionable

Most Army and Marine Corps units planning to use the Hunter need UAVs

that operate at ranges greater than that at which the ground station can

directly control the Hunter. DOD plans to extend the range of the Hunter

through a process called “relay operations.” Relay operations involve

controlling one UAV at long range through a second UAV operating at a

closer range, as shown in figure 3. Establishing a relay is to be

accomplished by the ground station transmitting commands to and

receiving video imagery from the air vehicle operating at long ranges

through relay equipment on the UAV operating at a closer range.

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Figure 3: Hunter UAV Relay Operations

Most of the limited user tests planned to demonstrate this capability failed

because of engine failures or other problems with the air vehicle and relay

component. The test agency concluded that the system’s ability to transmit

Page 9 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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video imagery during relay operations was unacceptable for a fielded

system. DOD has incorporated some modifications intended to improve the

system’s relay capability and overcome past poor video quality. However,

according to an official of the Defense Contract Management Command,

subsequent testing has determined that the quality of the video imagery

from the low-rate production system that has been delivered, but not

accepted, is worse than that demonstrated during the limited user tests.

The contractor has replaced system components in an attempt to solve the

problem. However, the adequacy of the changes has not been verified in

flight testing because the system has remained grounded.

System Ability to Support

Artillery Operations Has

Not Been Met

The Hunter system is supposed to locate and identify targets so that they

can be engaged by artillery fire. The system is also expected to detect

where artillery lands in relation to the target so that the artillery can be

adjusted. To be effective, these tasks must be done quickly so that the

targets can be hit before they are able to take cover or move.

During the limited user tests conducted in 1992, the Hunter failed to meet

requirements. Army testers concluded that the system was not sufficiently

timely and may never meet Army standards. Even though the system

demonstrated unsatisfactory performance during the 1992 testing, DOD’s

current plans do not include any corrective action to resolve this

deficiency. DOD officials stated that this is because the system operational

requirements documents do not establish specific time frames in which

the Hunter must be able to support artillery operations.

However, the mission needs statement that justified procurement of the

Hunter states that the system is intended to acquire targets that would

then be engaged by artillery or other means. We believe that a requirement

to adjust artillery fire in a timely fashion is inherent in missions whose

objective is to engage targets.

Acceptance Testing

Reveals New Deficiencies

The Defense Contract Management Command is responsible for accepting

delivery of the system hardware and began acceptance testing of the first

low-rate production system in May 1994. On June 14, 1994, the Command

recommended that the UAV program office terminate acceptance testing

because extensive software changes were needed and the air vehicle flew

in a circle even when programmed for straight and level flight. Acceptance

testers also noted that air vehicle engines continue to have valve seizures.

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However, the Joint Tactical UAV Project Office ignored the

recommendation and acceptance testing continued.

In July 1994, the Command reported to the UAV program office that several

problems needed to be resolved prior to system acceptance. The

Command identified software as the most critical problem with the system

and pointed out that the existing software was not acceptable for field use.

In addition, test results continued to show that the air vehicles pulled to

the left during takeoff and flight. On some air vehicles, this condition was

severe and could affect safety of flight. Therefore, tests of the system’s

speed and altitude capability were performed by flying the air vehicle in a

circle; the air vehicle could not meet contractual requirements when it was

flying straight and level. DOD officials believe that subsequent system

modifications have resolved this problem. However, the adequacy of the

modifications has not been fully tested because the system remains

grounded. The acceptance testing of the first low-rate production system

delivered also showed a significant increase in the loss of data link

connections between the ground station and the air vehicle when

compared to the results of the 1992 limited user test.

Goal of Joint-Service

System Is at Risk

DOD currently plans to begin full-rate production of the Hunter system for

the Army and the Marine Corps before verifying that the system will meet

the Navy’s needs. If subsequent testing of a Navy version of the Hunter

were to show the system to be unsuitable for naval use, DOD would already

be fully committed to a system that did not meet the need of all services,

as called for by Congress. As a result, the congressional call for DOD to

develop a joint-service system is at risk.

Although DOD plans call for operational testing before full-rate production,

the testing will not include an evaluation of the system’s ability to meet the

Navy’s operational requirements. Operational testing of the Navy

requirements is not scheduled until after DOD plans to commit to full-rate

production of the land-based Hunter. According to the Commanding

General of U.S. Army Operational Test and Evaluation Command, the DOD

Director of Operational Test and Evaluation has expressed concern that

the operational testing of the Navy variant will not occur until after the

full-rate production decision for the land-based system.

Hunter program officials maintain that the contractor showed that the

Hunter can be operated from a ship during a maritime demonstration.

However, according to a Navy official, this demonstration did not reflect

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B-259256 

realistic operational conditions. For example, during the shipboard

demonstration, the contractor removed all aircraft from the flight deck.

According to the Navy official, under realistic conditions, other aircraft

would remain on the deck of the ship during operation of the Hunter

system. In addition, there have been at least five air vehicle crashes

involving the tail hook recovery system that would be used to land the

Hunter aboard ship.

Restructured Program

Increases Risk

Under the Defense Acquisition Board (DAB) approved program schedule

(see fig. 4), DOD has seven systems under contract with deliveries

scheduled through April 1995 and operational testing from November 1994

to May 1995. This schedule allows a 23-month break, from April 1995 to

March 1997, in the delivery of UAV systems. The UAV Joint Project Office

asserts that it must award a second low-rate production contract for four

additional systems to reduce the 23-month break in production deliveries

and keep skilled contractor employees on the job.

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Figure 4: DAB Approved Program Schedule

Employees

Low-Rate Production Deliveries

1st Full-Rate Production Delivery

Replacement Hardware

10/94

Operational


Testing

12/94 2/95 4/95 6/95 8/95 10/95 12/95 2/96 4/96 6/96 8/96 10/96 12/96 2/97 4/97 6/97

550


500


450


400


350


300


250


200


150


100


 50


 	0

Page 13 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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However, as indicated in figure 5, the level of contractor employees will

still be significantly reduced even with the additional production because

the second production contract award is not anticipated to be made before

June 1995. Furthermore, a sizable break in production deliveries of over

one year would still exist. Therefore, the impact of a second procurement

on labor force stability would be marginal at best because at that point in

time less than 50 employees would be retained. In addition, not awarding

the second production contract reduces the risk from further commitment

to a potentially unsuitable system.

Page 14 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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Figure 5: UAV Joint Projects Office Proposed Program Schedule With Second Low-Rate Production Contract

10/94 12/94 2/95 4/95 6/95 8/95 10/95 12/95 2/96 4/96 6/96 8/96 10/96 12/96 2/97 4/97 6/97

0

100

200

300

400

500

50

250

350

450

550 Employees

Operational


Testing

Low-Rate Production Deliveries

1st Full-Rate Production Delivery

2nd Low-Rate Production Deliveries

Replacement Hardware

150

Page 15 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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Recommendation We recommend that the Secretary of Defense prohibit award of a second

low-rate production contract until the Hunter system satisfactorily

demonstrates that it is operationally effective and operationally suitable

and will satisfactorily meet the requirements of the Army, the Marine

Corps, and the Navy.

Agency Comments

and Our Evaluation

We did not obtain written agency comments on this report. However, we

discussed its contents with officials from the Office of the Secretary of

Defense, the Assistant Secretary of the Navy, the Defense Airborne

Reconnaissance Office, the UAV Joint Project Office, and the Joint Tactical

UAV Program Office and incorporated their comments as appropriate. The

officials maintained that award of a second low-rate production contract is

warranted to prevent a prolonged break in production deliveries and

retain skilled contractor employees.

Our review indicated that even with a second production contract, a

significant break in production deliveries and a significant reduction in

contractor employees would still occur. Because of the risks involved in

further committing to an unproven system, we believe that further

production should be deferred until the system demonstrates that its

problems are solved and its performance is satisfactory.

The officials pointed out that operational testing of the Navy variant is to

be done before a commitment is made to its production. By that time,

however, DOD will have already made the full-rate production decision on

the Army and the Marine Corps version jeopardizing the goal of a

common-service system.

Scope and

Methodology

To accomplish our objectives, we focused primarily on the results of

system testing, including logistics and shipboard demonstrations and

limited user testing. We also examined the results of technical tests that

assessed some other aspects of the system’s performance. In addition, we

reviewed (1) test plans and schedules, (2) performance requirements

documents, (3) acquisition plans, (4) the original contract and all

modifications, and (5) other records bearing on the Hunter UAV status and

potential suitability and effectiveness.

We obtained information from officials of the Program Executive Office

for Cruise Missiles and UAV Joint Project Office, Naval Air Systems

Command, Arlington, Va.; Hunter Joint Tactical UAV Program Office and

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Integrated Material Management Center, U.S. Army Missile Command,

Huntsville, Ala.; U.S. Army Training and Doctrine Command, Fort

Huachuca, Ariz.; DOD Contract Management Command, Sierra Vista, Ariz.;

Marine Corps Combat Development Command, Quantico, Va., and 1st

Remotely Piloted Vehicle Company, Twenty-Nine Palms, Calif.; Aviation

Requirements Branch, Commander, Naval Surface Forces Atlantic,

Norfolk, Va.; and Weapons Support Improvement Group, Assistant

Secretary of Defense for Production and Logistics, Office of the Secretary

of Defense, Washington, D.C.

We performed our work from October 1993 to November 1994 in

accordance with generally accepted government auditing standards.

As you know, 31 U.S.C. 720 requires the head of a federal agency to submit

a written statement on actions taken on our recommendations to the

Senate Committee on Governmental Affairs and the House Committee on

Government Reform and Oversight not later than 60 days after the date of

the report. A written statement must also be submitted to the Senate and

House Committees on Appropriations with an agency’s first request for

appropriations made more than 60 days after the date of the report.

We are sending copies of this report to appropriate congressional

committees; the Secretaries of the Army and the Navy; and the Director,

Office of Management and Budget. We will make copies available to others

upon request.

Page 17 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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Please contact me at (202) 512-4841 if you or your staff have any questions

concerning this report. Major contributors to this report were Jack Guin,

Assistant Director; Pam Greenleaf, Evaluator-in-Charge; John S. Warren,

Evaluator; and Charles A. Ward, Evaluator.

Sincerely yours,

Louis J. Rodrigues

Director, Systems Development

 and Production Issues

(707041) Page 18 GAO/NSIAD-95-52 Unmanned Aerial Vehicles
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