EDWARDS AIR FORCE BASE, Calif -- The 416th Flight Test Squadron completed evaluation of software for the T‑38C’s Block 4 Avionics Upgrade Program. The AUP was an integrated modernization effort to increase the combat training value of the venerable trainer. It would also elevate all T-38A and AT-38B aircraft to T-38C configuration.
he Attitude and Heading Reference System (AHRS) for the 53 Air Force T-38A and eight AT-38B training jets needs replacing, according to the Air Force Life Cycle Management Center's T-38 program office (AFLCMC/WLD) at Hill Air Force Base, Utah. "The T-38A and AT-38B Attitude [and] Heading Reference System (AHRS) reliability has diminished to a point of concern," a representative for AFLCMC/WLD wrote in an email to Avionics International. "Spare parts for repairs are difficult to procure and the system requires replacement."
Avionics testing is a major portion of all current aircraft flight-test programs. Lessons learned from the T-38 Avionics Upgrade Program are given. While the details are unique to the T-38 Avionics Upgrade Program, the lessons apply to all flight-test programs. Since no formal technical report was done for this program, this paper also serves as a written account of the program's evolution. Four problem areas are listed which lead to the following lessons learned: do not let flying get ahead of data analysis. If the software does not work in software-in-the-loop facilities, it will not work in the airplane. However, software that works in software-in-the-loop facilities may not work in the airplane. Properly instrument the test aircraft based on its mission. Apply common sense logic when using existing drawings. If something does not look right, the drawing could actually be wrong. Incorporate operationally representative maneuvers in development test and evaluation. Test things one-by-one in development test and evaluation (i.e. use the scientific method of isolating one variable.