Reengining of the KC-135 Aircraft with Used Commercial Engines
Abstract
We have reviewed Air Force plans for replacing engines in a portion of its fleet of KC-135 aircraft. The plans, which the Oklahoma City Air Logistics Center in Oklahoma is administering, call for purchasing 46 used 707 aircraft and 35 spare engines from commercial airlines. The JT3D-3B engines and horizontal stabilizers from the 707 aircraft are to replace the horizontal stabilizers and J-57 engines of a like number of KC-135 airplanes. The JT3D-3B engines have more thrust, greater fuel economy, and less pollution emission than the J-57 engines. The JT3D-3B engines' additional thrust accounts for the need to replace the horizontal stabilizers. Although the Air Force normally does not refurbish its airplanes engines before the end of their estimated useful lives, the Center is having the JT3D-3B engines refurbished without first determining what useful life remain. It is spending about $200,000 for refurbishing each JT3D-3B engine even though the life-limiting components of many still have years of useful life. The Center contracted for replacing life-limiting components as necessary to provide an expected engine life of 6,000 flying hours and 4,000 cycles (or takeoffs and landings). This is about 17 years of life at the expected Air Force use rate. Such components in many of the engines had a replacement value of $8,000 to $18,000 each and from 8 to 16 years of useful life when the contractors replaced them. In view of the above circumstances, we suggest the Air Force reevaluate its program for the used JT3D-3B engines being purchased to reengine the KC-135 and adjust its refurbishment criteria accordingly.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 27, 1983
- Accession Number
- AD1119383
Entities
People
- Donald J. Horan
Organizations
- United States Government Accountability Office