B747 The Shuttle Carrier Aircraft

The Shuttle Carrier Aircraft (SCA) are two extensively modified Boeing 747 airliners that NASA uses to transport Space Shuttle Orbiter. One is a Boeing 747-100 model, while the other is a short range 747-100SR.

The first Model Aircraft, a Boeing 747-100 registered N905NA, was originally manufactured for American Airlines and still carried visible American side stripes while testing Enterprise in the 1970s. It was acquired in 1974 and initially used for trailing wake vortex research as part of a broader study by NASA Dryden as well as Shuttle tests involving an F-104 flying in close formation and simulating a “release” from the 747.

The Model Aircraft was extensively modified by Boeing in 1976 Its cabin was stripped, mounting struts added, and the fuselage strengthened; vertical stabilizers were added to the tail to aid stability when the Orbiter was being carried. The avionics and engines were also upgraded, and an escape tunnel system similar to that used on Boeing’s first 747 test flights was added.