![]() In 1976, NASA 946 and NASA 947 rolled off Grumman's Gulfstream assembly line with significant modifications to flight controls, engines, thrust reversers, and landing gear, to create the first Shuttle Training Aircraft (STA). When NASA retired the fleet of four highly-modified Gulfstream II, in 2011, at the end of the Shuttle program, it was the end of a highly successful in-flight crew training program. The Shuttle Training Aircraft were specially modified aircraft developed to support training the approach and landing phase of the Space Shuttle Orbiter. However, the girls are much more interesting than I am. Not many engineers get to be actively involved in the design, modification, manufacture, implementation, test, verification, inspection and maintenance of all aspects of a system, much less an entire fleet of aircraft. Working on those aircraft gave me the experience and insight that allows me to perform risk assessments, failure investigations, and system and crew survivability analyses, to name a few. I've had a lot of really challenging assignments at NASA, but being the STA project engineer was my favorite. I was responsible for the STA fleet maintenance and modifications. ![]() ![]() Of my 28 years with NASA, I spent my first ten as the Shuttle Training Aircraft Project Engineer (1985-1995). The STAs are and will always be my girls, each with a unique personality. I've drafted some history on the STAs in case any of it is of interest. The instructor pilot deselects the simulation mode, stows the thrust reversers, and executes a go-around, never-during practic e approaches-actually landing the aircraft. In the exercise, the STA is still flying 20 feet (6 m) above the ground. This is the exact position that the pilot's head would be during actual landing. If the speed is correct, a green light on the instrument panel simulates shuttle landing when the pilot's eyes are 32 feet (10 m) above the runway. The nose gear of the STA is lowered at 150 feet (46 m) AGL in case of an inadvertent contact with the runway surface. The shuttle landing gear release is simulated at 300 feet (90 m) above the ground surface, since the STA main gear has been down for the entire simulation. At 2,000 feet AGL the guidance system changes to pre-flare and shortly after, at 1,700 feet (518 m), the pilot starts the flare maneuver to gradually reduce the descent angle and transition to the Inner Glide Slope (IGS) which is 1.5 degrees from 300 feet onwards, using a "Ball-bar" system for visual guidance. The Outer Glide Slope aiming point is 7,500 feet short of the runway threshold, and uses PAPI's for visual guidance in addition to the MLS system. The nose of the aircraft is then dropped to increase speed to 300 knots (560 km/h), descending at a 20-degree angle on the Outer Glide Slope (OGS). The pilot then rolls the STA at 12,000 feet (3,700 m), 7 miles (11 km) from landing. In a normal exercise, the pilot descends from 37,000 feet (11,300 m) to 20,000 feet (6,000 m) at an airspeed of 280 knots (519 km/h), 15 miles (24 km) from the landing target. Both seat positions have a Head Up Display (HUD). The STA's normal flight controls exist at the right-hand instructor's seat. Flaps could be deflected upwards to decrease lift as well as downwards to increase lift.Ĭovers were placed on the left hand cockpit windows to provide the same view as from a Shuttle cockpit, and the left-hand pilot's seat is fitted with the same controls as a Shuttle. In order to match the descent rate and drag profile of the real Shuttle, at 37,000 feet (11,300 m), the main landing gear was lowered (the nose gear stayed retracted due to wind load constraints) and engine thrust was reversed.
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