Tech Briefs

AFRL's Total In-Flight Simulator is celebrating 50 years of service.

In fact, pilots moving from TIFS to an actual aircraft frequently remark that the aircraft handles exactly the way that TIFS simulated its handling. Further, because TIFS allows pilots to operate during simulated failures, it provides them the opportunity to study and react to dangerous situations in a safe vehicle that can instantly revert to normal control. Mr. Weingarten recognizes the advantage this provides: "Often, you don't want to fail a system on an [actual] airplane, even in a test mode, because it might be too dangerous to fly [as a result]. Our airplane can do that safely."

Figure 2. TIFS ASTTA configuration
TIFS' many benefits extend to engineers as well. Normally, a test aircraft will accumulate several hundred hours of flight data, but "on the ground, all engineers [can] do is look at computer outputs, time histories, graphs, and displays. But actually being up there and experiencing all of the little oscillations and responses brings a sense of reality to the test. Flying helps engineers to appreciate the problems that they are investigating," Mr. Weingarten asserts.

Highly versatile, TIFS uses two interchangeable noses to perform a variety of tests. Depending upon the type of research, engineers can switch between a simulation cockpit nose (see Figure 1) and an avionics nose (see Figure 2) called the Avionics System Test and Training Aircraft (ASTTA) configuration. In the simulation cockpit configuration, a test pilot flies TIFS, which duplicates the characteristics of a simulation model programmed into its computer. During flight tests, the computer adjusts TIFS' handling characteristics by hydraulically actuating the plane's extra control surfaces, including its side-force surfaces and direct-lift flaps. The ASTTA configuration lets TIFS perform avionics testing using onboard radar, infrared electrooptical detection systems, inertial navigation, and a Global Positioning System. For both configurations, TIFS retains its safety cockpit, located above and behind the nose. A pilot stands by to take control and override the simulation, if necessary.