MIL-STD-1529 Base Document:1955

Initital qualification tests serve the dual purpose of establishing qualification approval of both the design of an aerospace propulsion system and the fabrication sources of propulsion system items. However, such approval applies only to those fabrication sources whose items were represented in the specific aerospace propulsion system which satisfactorily passed the qualification tests. Substantiation tests have the single objective of proving the ability of an alternate source to process, fabricate, and manufacture aerospace propulsion system items which are at least equal in quality to those items on the latest or current production aerospace propulsion system.