Which 747 carried Enterprise "piggyback"?

Short answer

The first Shuttle Carrier Aircraft was a Boeing 747-123 registered N905NA, originally built for American Airlines and acquired by NASA in 1974. Boeing modified it in 1976 with attachment struts on top and vertical stabilizers on the tail. Enterprise flew free for the first time on August 13, 1977.

Published: November 5, 2026 · Updated: November 5, 2026 · Edited by Above Ten Thousand · Editorial policy

Which 747 carried Enterprise "piggyback"?

Lufthansa Boeing 747-400 departing BostonFoto: 4300streetcar (CC BY 4.0)

A 747-123 born for American Airlines

The first Shuttle Carrier Aircraft was a Boeing 747-123 registered N905NA, originally built for American Airlines. NASA acquired it in 1974 and initially used it to study wake vortices, as part of a broader NASA Dryden research program.

The 1976 modifications

In 1976, Boeing thoroughly reworked N905NA with components designed by NASA. Attachment struts were installed on top of the 747, positioned to match the orbiter's hardpoints. Vertical stabilizers were added to the tail to improve stability when the aircraft carried the orbiter.

From the 1977 tests to the Endeavour transfer

The Approach and Landing Tests were a series of taxi and flight trials of the Enterprise shuttle prototype, carried out at Edwards Air Force Base in 1977. They included three taxi tests, eight captive flights, and five free flights, in which the Enterprise separated from the SCA in flight and glided to its own landing. The first free flight took place on August 13, 1977. In 1988, after the Challenger disaster, NASA acquired a surplus Japan Airlines 747SR-46. Registered N911NA, it entered NASA service in 1990 after receiving modifications similar to those of N905NA. That second aircraft was first used in 1991 to transport the new Endeavour orbiter from its manufacturer in Palmdale, California.