
Fuze M131A1 is used only with fragmentation (butterfly) bombs. It is a time fuze armed by butterfly wings of the bomb and the time train is initiated after 50 feet of air travel. Detonation does not occur immediately upon impact, but only after a second shock initiates the sensitive antidisturbance mechanism.
Fuze M131A1 (or M131) is very similar in appearance to the M129, which is distinguished by the words AIR and GROUND embossed on its cap. Fuze M131A1 (or M131) is identical to fuze M130A1 (or M130) when assembled in a bomb.
No information about functioning.
Detonator M31, Primer M41A1, Tetryl booster.
MIL-HDBK-146, Fuze Catalog (1982)
TM 9-1385-51, Ammunition (Conventional) for Explosive Ordnance Disposal (1967)
TM 9-1325-200, Bombs and Bomb Components (1966)
OP 2216, Volume 1 - Aircraft Bombs, Fuzes, and Associated Components (1960)
OP 1664, Volume 2 - US Explosive Ordnance (1947)
USNBD - Bombs and Fuzes, Pyrotechnics (1945)