U.S. Air Force had planned to announce the ACF winner in May 1975, but the decision was advanced to the beginning of the year, and accelerated testing. ACF also raised the stakes for GD and Northrop because it brought in further competitors intent on securing the lucrative order that was touted at the time as "the arms deal of the century". These included the Dassault-Breguet Mirage F1 E (E for Europe) powered by a Snecma M53 engine and utilizing a fly-by-wire system similar to the one used in Dassault Mirage 2000 series. Only two prototypes were built for the ACF program, the Anglo-French SEPECAT Jaguar, and a proposed derivative of the Saab 37 Viggen named the Saab 37E Eurofighter (not to be confused with the later and unrelated Eurofighter Typhoon). Northrop also offered their earlier design, the P-530 Cobra, which looked very similar to its YF-17. The Jaguar and Cobra were dropped by the MFPG early on, leaving two European and the two U.S. LWF designs as candidates. On 11 September 1974, the U.S. Air Force confirmed firm plans to place an order for of the winning ACF design sufficient to equip five tactical fighter wings. The flight test program revealed that the YF-16 had superior acceleration, climb rates, endurance, and (except around Mach 0.7) turn rates. Another advantage was the fact that the YF-16 – unlike the YF-17 – employed the Pratt & Whitney F100 turbofan engine, which was the same powerplant used by the F-15; such commonality would lower the unit costs of the engines for both programs. On 13 January 1975, Secretary of the Air Force John L. McLucas announced that the YF-16 had been selected as the winner of the ACF competition. The chief reasons given by the Secretary for the decision were the YF-16's lower operating costs; greater range; and maneuver performance that was "significantly better" than that of the YF-17, especially at near-supersonic and supersonic speeds. However, in the Navy Air Combat Fighter (NACF) competition, the Navy announced on 2 May 1975 that it selected the YF-17 as the basis for what would become the McDonnell Douglas F/A-18 Hornet. References Notes Citations Bibliography Correll, John T. "The Reformers". Air Force Magazine Online, February 2008. Jenkins, Dennis R. F/A-18 Hornet, A Navy Success Story. McGraw-Hill, 2000. . Jenkins, Dennis R. McDonnell Douglas F-15 Eagle: Supreme Heavy-Weight Fighter. Hinckley, UK: Midland Publishing, 1998. . Michel, Col.