MIL-H-43925D (NOTICE 1), MILITARY SPECIFICATION: HELMET, FLYER'S, PROTECTIVE, SPH-4 (04 JAN 2000)
MIL-H-43925D (NOTICE 1), MILITARY SPECIFICATION: HELMET, FLYER'S, PROTECTIVE, SPH-4 (04 JAN 2000)., This document covers the SPH-4 flyer's protective helmet.