C-141 Starlifter
The Lockheed C-141 Starlifter was a military strategic airlifter in service with the United States Air Force. Introduced to replace slower piston-engined cargo planes such as the C-124 Globemaster II, the C-141 was designed to requirements set in 1960 and first flew in 1963. Production deliveries of an eventual 285 planes began in 1965: 284 for the Military Airlift Command, and one for NASA. The aircraft remained in service for almost 40 years until the USAF withdrew the C-141 from service on 5 May 2006, replacing the aircraft with the C-17 Globemaster III.
In service, the C-141 proved to "bulk out" before it "massed out", meaning that it often had additional lift capacity that went wasted because the cargo hold was too full. To correct the perceived deficiencies of the original model and utilize the C-141 to the fullest of its capabilities, the entire fleet of 270 in-service C-141As were stretched, adding needed payload volume. These modified aircraft were designated C-141B. Additional 'plug' sections were added before and after the wings, lengthening the fuselage by 23 ft 4 in (7.11 m) and allowing the carriage of 103 litters for wounded, 13 standard pallets, 205 troops, 168 paratroopers, or an equivalent increase in other loads. Also added at this time was a boom receptacle for inflight refueling. The conversion program took place between 1977 and 1982, with first delivery taking place in December 1979. It was estimated that this stretching program was the equivalent of buying 90 new aircraft, in terms of increased capacity.