MIL-W-5521B, MILITARY SPECIFICATION: WASHER, AIRCRAFT HYDRAULIC PACKING BACK-UP (13-DEC-1968) [S/S BY MIL-DTL-5521C]

MIL-W-5521B, MILITARY SPECIFICATION: WASHER, AIRCRAFT HYDRAULIC PACKING BACK-UP (13-DEC-1968) [S/S BY MIL-DTL-5521C]., INACTIVE FOR NEW DESIGN AFTER 22 AUGUST 1994. This specification establishes the requirements for one type of packing back-up washers for use in aircraft hydraulic systems.