the request for proposal (rfp) was issued in january 1972, asking for operations into a 2,000-foot (610 m) semi-prepared field at with a 27,000 lb (12,000 kg) payload in both directions with no refueling. for comparison, the c-130 of that era required about 4,000 ft (1,200 m) for this load. five companies submitted designs at this stage of the competition, boeing with their model 953 in march 1972. on 10 november 1972 the downselect was carried out, and boeing and mcdonnell douglas won development contracts for two prototypes each.