YF-17

One based on the one used by the USAF for its light fighter the produced the F-16 and via the YF-17, the F-18 for the Navy?

Remembering Apollo 11 and the Legacy of Apollo - NASA Watch 2009

The Northrop design, the YF-17, was a twin-engine.

Hardware For Dummies: The Osprey Vs. The Hornet « Isegoria 2008

And to show that they were calling the shots, the Navy went and did the ultimate betrayal: they bought the Northrop design, and then froze Northrop itself out of the development process, the whole long, profitable business of converting the YF-17 into a carrier-based airplane that eventually became the F/A-18.

Hardware For Dummies: The Osprey Vs. The Hornet « Isegoria 2008

There were five entries, but it soon came down to two contenders: the General Dynamics YF-16 and the Northrop YF-17.

Hardware For Dummies: The Osprey Vs. The Hornet « Isegoria 2008

The Navy didn’t really think much of the Northrop YF-17, but they liked the fact that it would be all theirs.

Hardware For Dummies: The Osprey Vs. The Hornet « Isegoria 2008