Defense Acquisitions: Testing of F-15 and F-16 Radomes

Published by the Government Accountability Office on 1999-01-28.

Below is a raw (and likely hideous) rendition of the original report. (PDF)

National Security and
International Affairs Division


January    28,1999

The Honorable William S. Cohen
The Secretary of Defense

Subject:   DEFENSE      ACQUISITIONS:    Testing   of F-15 and F-16 Radomes

Dear Mr. Secretary:

During a review completed earlier this year, we received information     concerning
the potential for shortfalls in the performance of two radomes, one for the F-15
Eagle and one for the F-16 Falcon. The radomes, part of the aircraft’s threat
warning systems, are housings to protect antennas that receive radar signals.
Air Force specifications detail what is required of the radomes so they do not
distort radar signals. At issue is whether replacement radomes, bought for
spares and supplied by vendors other than the original manufacturer,      met the
specifications for the original radomes. The purpose of this letter is to provide
you information   developed during our work and to alert you to those issues that
warrant further review.

With the cooperation of the Air Force and the Defense Logistics Agency, we
arranged for L3 Communications,       Randtron Antenna Systems to test one spare
F-15 radome and one spare F-16 radome against the Air Force specifications.
This firm is the manufacturer    of the F-15 and F-16 antennas protected by the
two radomes and is responsible for testing the radomes from the original
manufacturer    before they are installed on new aircraft. The test data, provided
to us in October 1998, showed that the spare F-15 radome met its specification,
while the spare F-16 radome did not. Specifically, the test data suggest that for
certain radar frequencies and for certain angles between the radome and the
source of the radar signal, the F-16 radome reduces the strength of the radar
signal that reaches the antenna below the limits stated in the specification.    As a
baseline, the firm also tested two radomes of original manufacture for the same
antennas and both met specifications.     Detailed information on the F-16 radome
tested and the specification used is included in appendix I. We forwarded you
the test report prepared by L-3 Communications      under separate cover on
January 6,1999.

                                              GAO/NSIAD-99-43R       F- 16 Radomes

While the test results on the F-16 radome warrant concern, they do not, by
themselves, warrant a conclusion on the seriousness of the shortcoming.       Since
only one radome was tested, the shortcoming could be an isolated incident. Even
if it is not isolated, the shortcoming could be judged to be insignificant.  On the
other hand, if the shortcoming is not isolated and is significant, the spare radome
could affect the threat warning system’s ability to detect a radar contact.
Moreover, if the shortcoming is the result of a process that is used to buy spare
radomes from vendors other than the original manufacturer,        then the concern
may apply to other radomes purchased through a similar process.

On October 16,1998, we shared this information with representatives       fr-om your
office and the Air Force. They agreed that (1) the test results had potential
safety implications that warranted further review and (2) the Department       of
Defense would accept responsibility   for such a review. We noted that if the
Department     determines the radome’s shortcoming is significant, further review
may be necessary on (1) the possible testing of additional radomes from the same
inventory, (2) the proper disposition of the remaining radome inventory, and
(3) the potential for the procedures followed in acquiring the radomes for
allowing a similar situation to occur with other spare parts bought through a
similar process. On January 12, 1999, we received official comments from the
Department,     which concurred with a draft of this letter and agreed to undertake
further review of the test data on the F-16 radome. The Department       plans to
complete this review by March 31,1999, and to take any resulting actions by
June 30, 1999 (see app. II). Accordingly, we plan no further work on this matter.

We conducted this review from October 1997 to October 1998 in accordance with
generally accepted government auditing standards. In conducting our review,
we met with officials from the office of the Deputy Under Secretary of Defense
(Logistics), Ai r F orce Headquarters,   the Defense Logistics Agency, and the Air
Force F-16 Directorate, Hill Air Force Base, Utah. We also held discussions with
officials from the Warner Robbins Air Force Base, Georgia. L3 Communications
conducted the radome tests with the laboratory facilities and equipment at its
plant in Menlo Park, California.       We obtained the radomes for testing through
contacts with Defense Logistics Agency officials located in Columbus, Ohio, and
Richmond, Virginia.      We returned the F-15 radome to the Defense District Depot
in Mechanicsburg,      Pennsylvania,   and the F-16 radome to Air Force
Headquarters     in Washington, D.C.

Page 2                                       GAO/NSlAD-99-43R        F-16 Radomes


During the course of our work, we obtained a significant amount of additional
data that we would be happy to share with the Department to assist its review.
The major contributors  to this letter were Allan Roberts, Alan Goldberg, and
Paul Francis. If you have any questions about this letter, please contact me on
Sipcerely   yours,

Katherine V. Schinasi
Associate Director
Defense Acquisitions  Issues

Page 3                                     GAO/NSLAD-99-43R       F- 16 Radomes
APPENDIX    I                                                               APPENDIX       I

                      DETAILS      ON THE F-16 R&DOME       TESTED


The radome has a tear-drop shape, measures approximately  16 inches by 5 inches, and
is made from composite materials. Both the antennas and the radome are components
of the ALR-69 Threat Warning System.


The part number is 62463/24499-K       The Defense Logistics Agency’s stock number is
1560012776738.       The radome tested is designated with cage code number 62463. The
cage code identifies the manufacturer    of the individual radome. Air Force procurement
officials at Hill Air Force Base informed us that this vendor is no longer in business.


The radome was acquired       in January 1991 by Hill Air Force Base under Air Force
contract F4260090C1543.        Under that contract, 290 radomes were bought at a unit cost
of $684.00.


The Air Force specification for testing the electrical properties of radomes from the
original aircraft manufacturer   for installation on new aircraft is number 16ZE054A,
“Critical Item Development     Specification for Radome Group, Radar Warning-ELIN
AOO8.” This is the specification used in testing the performance of the spare F-16
radome. We did not assess whether the specification used to purchase radomes for
spare parts differed from the specification that applied to the original production

  Page 4                                                GAO/NSIAD-99-43R     F-16 Radomes
          APPENDIXII                                                                        APPENDIXII
                           OFFICE     OF THE     UNDER     SECRETARY        OF DEFENSE
                                             3000 DEFENSE   PENTAGON
                                            WASHINGTON,   DC 20301-3000

  TECHNOLOGY                                                                         JAN 12 I999

               Ms. Katherine V. Schinasi
               AssociateDirector, Defense
                  Acquisition Issues
               National Security and International
                  Affairs Division
               U.S. GeneralAccounting Office
               Washington,D.C. 20548

               Dear Ms. Schinasi:

                    This is the Department of Defense(DOD) responseto the General Accounting Office
               (GAO) draft report, “Testing of F- 15 andF- 16 Radomes,”dated December 9, 1998 (GAO
               Code 707303), OSD Case 1721.

                       The DOD concurs with the draft report. The Department of the Air Force and the
               DefenseLogistics Agency will undertakefurther review of the test data on the F- 16 radome.
               We estimatethat review will be completedby March 3 1, 1999, and that any required actions
               identified as a result of that review wih be completedby June30, 1999.

                      The Department appreciatesthe opportunity to comment on the draft.


                                                                of Defense(Logistics)

         Page 5
                                                         Q           GAO/NSIAD-99-43RF-16 Radomes
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