Bob Grissman flew over 600 hours of direct test and test support missions as a flight test engineer at Edwards and Eglin Air Force Bases between 1963 and 1973. The aircraft included F-100, F-5B, F-4C and D, and F-111 A. He flew numerous "first time" aircraft weapon/store configurations and separations. He designed and verified the system used to introduce and train pilots in rocket and weapon release techniques.

He modified the F-111A weapons bay gun enclosure to enable gun firing missions after the initial in-flight firing test resulted in extensive aircraft damage. Most of these modifications were incorporated into the final design.

He determined that the stability tabs located on fin tips of a 500-pound dispenser munition prevented loading three stores onto a TER (triple ejector rack) and relocated them to correct the problem.

Following a fatal accident involving a proximity fuze, he designed the circuit now incorporated in all electronic fuzes to prevent that type failure. After determining that procedures used to evaluate developmental weapon proximity fuzes were inadequate, he developed a new approach, designed the instrumentation system and instituted valid techniques that accurately verified system performance. He designed and built the Safe/Arm/Fire system used for captive carriage and weapon separation phases of the F-111 conformal weapon system development tests (1990).