Lessons learned on the T-38 avionics upgrade program

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).