OVERVIEW: The JM117 is an unguided, free-fall general-purpose bomb equipped with a 175 kg high-explosive warhead. It is intended for use against structures, soft targets, and runway or infrastructure elements, and is manufactured under license in Japan for use by the Japan Air Self-Defense Force (JASDF).

DETAIL: The JM117 in Japanese service is locally produced under license and closely mirrors the U.S.-developed M117 bomb, maintaining the same external dimensions and explosive configuration. It is designed for use from medium-altitude strike profiles and integrates standard NATO-compatible fuzing systems. The bomb casing is optimized for fragmentation and blast effect, making it suitable for both area and precision engagements using manual or assisted aiming systems. Its steel body and aerodynamic profile provide stable ballistic performance and broad platform compatibility.

Japan adopted the JM117 to equip its multirole combat aircraft with a domestically supported high-explosive air-to-ground option. The weapon is typically carried externally on wing or centerline stations. While unguided, its use alongside modern targeting pods ensures improved delivery accuracy. The JM117 remains a standard general-purpose bomb in JASDF inventories, alongside more modern guided alternatives.

It is typically employed from strike fighters during live training, readiness drills, or potential high-intensity conflicts. Release occurs in level or dive bombing profiles from aircraft equipped with conventional targeting systems. Bomb delivery is unguided, relying on pilot targeting inputs or onboard ballistic computers.

NOTE:
IOC: ~1980s
Operators: Japan (Japan Air Self-Defense Force)
Platform: Mitsubishi F-4EJ Kai, Mitsubishi F-15J/DJ, F-2A/B
Conflicts: Training, readiness exercises only (non-combat use)

SOURCE:
U.S. Air Force Armament Museum ; Jane’s Weapons: Air-Launched ; Japanese Ministry of Defense Publications ; Federation of American Scientists (FAS)
https://www.fas.org/programs/ssp/man/uswpns/air/bombs.html