The 1st YF-17A Cobra prototype at its birthing grounds Hawthorne (CA). It was rolled out at Hawthorne on 4 Apr'74, and was trucked to Edwards AFB (CA). The Cobra made its first flight on 9 Jun'74 and became on 11 Jun'74 the first US fighter to exceed the speed of sound in level flight without the use of an afterburner. The 2nd YF-17A (72-1570) flew for the first time on 21 Aug'74. The 2 prototypes carried out a series of 288 testflights totalling 345 hrs and participated in the Lightweight Fighter (LWF) program that the F-16 won. In 1976, this 1569 was sent to NASA Dryden for base drag studies

Northrop's addition to the Lightweight Fighter (LWF) program. After losing the LWF competition to the YF-16 it was used by the NASA. The YF-17 evolved of course developed into the successful F/A-18 Hornet. After a restoration at Western Museum of Flight it was given a paint scheme and a Top Gun marking once used by 72-1570.