MIL-S-7998A, MILITARY SPECIFICATION: SANDWICH CONSTRUCTION CORE MATERIAL, BALSA WOOD (06 MAR 1970) [NO S/S DOCUMENT]

MIL-S-7998A, MILITARY SPECIFICATION: SANDWICH CONSTRUCTION CORE MATERIAL, BALSA WOOD (06 MAR 1970) [NO S/S DOCUMENT]., This specification covers one grade of balsa for use as a core material in the preparation of sandwich sheets and shapes for aircraft.