in 1968, the usaf started work on a series of prototype proposals, which would lead to both the amst project and the light weight fighter. the official request for proposal (rfp) was issued in january 1972, asking for operations into a semi-prepared field with a payload and a mission radius. for comparison, the c-130 of that era required about for this load. proposals were submitted by bell, boeing, fairchild, mcdonnell douglas and the lockheed/north american rockwell team at this stage of the competition. on 10 november 1972, the two top bids (from boeing and mcdonnell douglas) were selected. the companies were awarded development contracts for two prototypes each. mcdonnell douglas' prototype was designated yc-15.