Shuttle Training Aircraft

During the early phases of the Shuttle program, NASA considered using the Boeing 737 airliner as the basis for the STA, but rejected it due to cost and opted for the less-expensive Gulfstream II.

[3][4] The STA was particularly critical for Shuttle pilots in training because the Orbiter lacked atmospheric engines that would allow the craft to "go around" after a poor approach.

The nose of the aircraft was then dropped to increase speed to 300 knots (560 km/h), descending at a 20-degree angle on the outer glide slope (OGS).

The outer glide slope aiming point was 7,500 feet (2,286 m) short of the runway threshold, and used PAPIs for visual guidance in addition to the MLS system.

The nose gear of the STA was lowered at 150 ft (46 m) AGL in case of an inadvertent touchdown with the runway surface.

If the speed was correct, a green light on the instrument panel simulated shuttle landing when the pilot's eyes were 32 feet (10 m) above the runway.

A sophisticated computer system installed on board the STA simulated the flight dynamics of the orbiter with nearly perfect accuracy.

The STA's highly realistic simulation of the orbiter was not limited to handling characteristics, but also implemented the shuttle control interfaces for the pilot.

An STA flying above Discovery as it lands at the conclusion of STS-95 in 1998
The Shuttle Training Aircraft's cockpit. The commander's side of the cockpit, at left, featured a Shuttle-type heads-up display (HUD), rotational hand controller (RHC) used to fly the vehicle, and multi-function displays. The instructor pilot, who occupied the right-hand side of the STA cockpit, had access to a similar heads-up display, as well as conventional aircraft controls and instruments.