MIL-STD-1529, MILITARY STANDARD: VENDOR SUBSTANTIATION FOR AEROSPACE PROPULSION SYSTEM ITEMS (18 APR 1972) [NO S/S DOCUMENT]., The purpose of this standard is to establish a requirement for and prescribe the procedure by which substantiation tests will be conducted foraerospace propulsion system items manufactured by fabrication sources not represented in the specific aerospace propulsion system which passed the aerospace propulsion system qualification tests.