Following WWII, the US Army Aviation Branch sought to upgrade their soldiers' Aircrew Survival Egress Knives, or ASEKs. Required specs included: the ability to cut through both aircraft bodies and acrylic/glass windows; designs for cutting and hammering; a sharpened tip for stabbing; and hand guard and lashing points so the tool could serve as a spear. Maker Ontario Knife Co. developed the pictured ASEK in response, adding an insulated rubber handle to protect users who may encounter live wires during escape from a downed aircraft.
Ontario's ASEK knife kit is stocked with a flame-retardant nylon sheath, 2 oxygen valve and shackle wrenches, a strap-cutter multi-tool, and a 10-1/4" knife. The latter has a 5" long, 0.1875" thick blade forged from 1095 carbon steel, with a zinc phosphate finish to thwart rust. Its hardness rating is Rockwell C 50-54. A glass breaker on the knife's butt cap assists in escape efforts and getting a new cell phone before the warranty runs out.