The Langley 737 "Flying laboratory" in flight.

The NASA Transport Systems Research Vehicle (TSRV) 737 was, without a doubt, a oneofakind airplane. NASA had many other research aircraft, and the Federal Aviation Administration (FAA), the military, and the airframe manufacturers all had transport class test planes, but the NASA 737 possessed a unique combination of equipment and capabilities. In addition to having a complete second flight deck exclusively for research purposes, electronic flight displays, and a computerized flight control system, the airplane had extremely precise instrumentation and data gathering capabilities. The onboard research computers could record up to 540 pieces of data from various locations on the airplane at any given time. [Ref 8-1] Video equipment could record the screen displays in the aft cockpit as well as the view out the nose of the airplane. Since the research equipment and computers were installed in individual pallets in the back of the airplane, the airplane could be outfitted for different types of experiments fairly easily, and the large interior cabin of the 737 could accommodate up to 30 researchers and observers. The equipment on the Transport Systems Research Vehicle (TSRV) 737 also allowed it to fly complex flight paths and perform extremely accurate navigation.

The helmet mounted display worn by research pilot Lee Person, being tested in 737 aircraft

As a result, although NASA purchased the airplane specifically for the Terminal Configured Vehicle (TCV) program research, the airplane was also able to support a variety of other research projects over the years. Before the plane had been at the Langley Research Center a complete year, for example, the FAA requested its participation in the U.S. microwave landing system (MLS) demonstrations. Although the work was not part of the original TCV program agenda, the MLS managers in the FAA realized that the computerization and electronic flight displays in the 737 made it capable of providing a much more dramatic and convincing demonstration of the U.S. system than any airplane the FAA had available.

In the years that followed, the TSRV 737 was also used to flight test experimental wing surface coatings, evaluate the effect of poor weather conditions on runway surfaces and the ability of ground vehicles to measure those conditions accurately, and to gather data on air flow over fuselage and wing surfaces to help engineers improve the design of future transport aircraft. The McDonnell Douglas Corporation used the TSRV airplane to test a helmetmounted display concept the company was developing for the X30 National Aerospace Plane. Because the 737 could fly such complex and precise flight paths, the Department of Defense used it to determine if flight operations at the new proposed airport in Denver, Colorado would interfere with national defense satellites. The FAA enlisted also its help to model the Instrument Landing System (ILS) signal to the Los Angeles International Airport.

In short, the TSRV 737 had evolved from a support aircraft for a specific research program into a national airborne research facility. Whether the customer was a research directorate at Langley, another government agency, or an industry manufacturer, the 737 provided a flexible, highly capable platform that could gather valuable research data and flight test a wide variety of aeronautical and aerospace concepts.