MIL-H-26671B (NOTICE 1), MILITARY SPECIFICATION: HELMET, FLYING, HQU-2A/P (01-OCT-1974) [NO S/S DOCUMENT]

MIL-H-26671B (NOTICE 1), MILITARY SPECIFICATION: HELMET, FLYING, HQU-2A/P (01-OCT-1974) [NO S/S DOCUMENT]., This notice should be filed in place of Military Specification MIL-H-26671B(USAF) dated 1 December 1960. MIL-H-26671B(USAF) is hereby cancelled. This specification is no longer required and there is no superseding document