Engineering Development for the FMU-54A/B (Fuze, Inertial Bomb Tail) and FMU-70/B (Fuze, Inertial Bomb Nose)

The objectives of this development program were to utilize the FMU-54/B Fuze (Inertial Bomb, Tail) design as the basis for the design of the FMU-54A/B Fuze (Inertial Bomb, Tail) and the FMU-70/B Fuze (Inertial Bomb, Nose). Both fuzes must retain all characteristics of the basic fuze and be of the same size and configuration. The FMU-54A/B Fuze must have the settable delay time increased from a maximum of 3.5 to 6.0 seconds to provide safe escape distance for the delivery aircraft and must have the added capability of an air burst upon receipt of an electrical signal from a proximity sensor. To attain these objectives, the timing mechanism was redesigned for both fuzes, the retardation sensing system for the FMU-70/B Fuze was designed to sense the lack of retardation as well as retardation, components of the FMU-54A/B Fuze were reduced in size and weight to make space for the electrical detonator as well as the impact detonator, and the lanyards were redesigned to accommodate the electrical signal for the proximity sensor and the electrical detonator.