Potential for Reducing Costs by Using More JT3D Engines in the KC-135 Reengining Program

NSIAD-83-47: Published: Sep 23, 1983. Publicly Released: Sep 23, 1983.

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Henry W. Connor
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GAO reviewed two Air Force KC-135 reengining programs to determine whether the Air Force selected the more cost effective mix of the programs which it undertook to fulfill its needs for additional aerial-refueling capability for KC-135 airplanes.

One KC-135 reengining program uses new, current-technology CFM56 engines to replace J57 engines on KC-135 airplanes while the other uses JT3D engines from used Boeing 707 series airplanes. GAO found that the Air Force did not use appropriate methodology to determine which engine was the more cost effective. By properly discounting costs for alternative mixes of JT3D- and CFM56-equipped KC-135's, GAO estimates that the Air Force would save about $283 million of life-cycle costs totaling about $28 billion. GAO suggests that the Air Force reengine more KC-135's with JT3D engines. GAO noted that a KC-135 fleet mix that includes 200 KC-135 reengined aircraft provides the same capability as the Air Force's planned mix that includes 88 KC-135 reengined aircraft. While neither mix may meet the Air Force's forecasts of future tanker aircraft requirements, GAO believes that the uncertainties warrant expanding the JT3D program to achieve the life-cycle cost savings.

Recommendation for Executive Action

  1. Status: Closed - Not Implemented

    Comments: DOD does not agree with the recommendation and, therefore, does not plan to take any action. While nothing in the DOD comments causes GAO to change its position, it has gained little congressional or agency support. Accordingly, further followup is not warranted.

    Recommendation: The Secretary of the Air Force should expand the JT3D program--to the extent that the used Boeing 707's are available at reasonable prices--to cover reengining 200 KC-135's and make offsetting reductions in the CFM56 program.

    Agency Affected: Department of Defense: Department of the Air Force


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