Ground crew member directs the Boeing 737 "flying laboratory" to its ramp position after a research flight at Orlando, Florida.

Developing better equipment and systems for individual aircraft was an important step toward increasing the safety and efficiency of air transport operations. But the Terminal Configured Vehicle (TCV) program grew out of a realization among researchers and policymakers that simply improving airplane components was no longer sufficient. Gaining a few extra knots of airspeed or better efficiency in cruise flight was useless if the airplane was then vectored around for 20 minutes at low altitude because of terminal area congestion. Researchers needed to focus not only on improvements to individual airplanes, but also on technology that would allow the airplanes to operate more efficiently within the air traffic control system.

Several of the TCV/Advanced Transport Operating Systems (ATOPS) program research projects focused on flight operations in the ATC environment. In 197980, NASA researchers conducted experiments with a fourdimensional (4D) navigation system to try to streamline descent and approach procedures into crowded terminal areas. Another research effort explored the use of a cockpit display of air traffic to help pilots maneuver more efficiently onto an approach course. A third series of experiments looked at the use of a twoway data link to improve and simplify communications between pilots and air traffic controllers.

The TCV/ATOPS researchers also worked on concepts to increase the efficiency of landing operations. If technology could be developed that could reliably reduce the length of time an airplane spent landing and taxiing off the runway, arriving airplanes could be spaced closer together by air traffic controllers. Closer spacing would, in turn, decrease delays and increase capacity at airports. In one joint effort between the Langley Research Center and the Boeing Commercial Aircraft Company, engineers developed and tested precision flare control laws that improved the ability of airplane autoland systems to land the aircraft at a specific point along a runway. The touchdown point could then be planned to coincide with runway turnoffs so the airplane could land and get off the runway in a minimum amount of time. A separate research project tested the use of a magnetic cable buried in the runway and taxiway surfaces to help guide airplanes off the runway quickly in low visibility conditions.

Improving the efficiency of transport operations within the air traffic control system offered significant benefits in terms of fuel savings and airport capacity. But improving operations in a system was a much more complex task, involving many more variables, than simply improving elements of a single airplane. Technology oriented toward system operations required not only the support of airframe manufacturers and airlines, but the Federal Aviation Administration (FAA), as well. Several of the airborne systems also relied on guidance or information from ground facilities, and all of the technology had to work in concert with air traffic controllers and other aircraft operating in the ATC environment.

As a result, some of these technologies proved very difficult to implement or transfer to industry. Changing technology or procedures in the air traffic control system, where the penalties for errors or malfunctions could be disastrous, was a slow and complex process. And airlines would not buy the technology if the ATC system could not support its use. Nonetheless, some of the concepts developed and tested with the NASA 737 Transport Systems Research Vehicle (TSRV) were adopted by manufacturers, and by the early 1990s, the FAA was working on updated air traffic control equipment that could support more advanced and efficient airborne technology.