The M117 is a 750-pound general purpose bomb that can be employed in several different configurations. The basic M117 dates from the Korean War and uses a low-drag tail fin for medium and high-altitude deliveries.
The M117R (Retarded) uses a special fin assembly providing either high-drag or low-drag release options. For low altitude deliveries, the tail assembly opens four large drag plates which rapidly slow the bomb and allow the aircraft to escape its blast.
The M117D (Destructor) looks similar to the M117R but uses a magnetic influence fuze, which enables the bomb to function as a mine. The M117D is released in a high-drag configuration for ground implant or shallow water mining. It detonates when an object passing near the bomb triggers the fuze.
The M117 series was used extensively during the Vietnam War, and B-52G aircraft dropped thousands of tons of M117 and M117R bombs during Operation Desert Storm.