C-17 Aircraft

The Air Force reported that the C-17 transport aircraft met or exceeded 10 of the 11 contract specification requirements during its reliability, maintainability, and availability (RM&A) evaluation. However, the evaluation was less demanding than the one called for in a draft 1992 plan. The reduced rigor stemmed primarily from changes in the number of aircraft sorties, average sortie length, and total flying hours. The evaluation was also less demanding because it had fewer airdrops and landings at small, austere airfields than originally planned and flew cargo loads that were significantly lighter than projected in the contract specifications. The RM&A evaluation was not a statistically valid test for determining C-17 wartime utilization rates and did not prove what a mature C-17 fleet would do during 45 days of wartime surge operations. It simply demonstrated that a high utilization rate could be achieved during a 48-hour period. Finally, in awarding the incentive fee, the Air Force credited the C-17 aircraft with meeting the full mission capable rate goal. During the RM&A evaluation, however, the aircraft was restricted from performing formation personnel airdrop under realistic conditions and was rated not functionally effective for aeromedical evacuation. As a result, the $5.91 million incentive fee was $750,000 higher than justified.

GAO found that: (1) the Air Force reported that the C-17 aircraft met or exceeded 10 of the 11 contract requirements during its RM&A evaluation, but the evaluation was less demanding than originally planned; (2) although the revised RM&A evaluation plan increased total flying hours, the number of sorties, and average wartime sortie duration, it decreased the ratio of sorties to flying hours, which weakened the application of RM&A measurement criteria and lessened the stress on the aircraft; (3) the RM&A evaluation also had fewer airdrops and austere airfield landings than originally planned, and the aircraft flew cargo loads that averaged less than one-half the weight projected in contract specifications; (4) three years of operational testing show that the aircraft generally met RM&A requirements with the exception of those related to built-in-test parameters; (5) the RM&A evaluation was not a statistically valid test for determining C-17 fleet wartime utilization rates because the test's duration was too short; and (6) the incentive fee should have been reduced, since the aircraft could not perform the formation personnel airdrop mission under operational conditions, or the aeromedical evacuation mission.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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