Forty six years ago this week the legendary F-16 Fighting Falcon fighter jet got off to a wobbly start. The prototype YF-16 jet nearly crashed during high speed ground tests, an incident that could have killed the pilot and quite possibly the aircraft program itself. The pilot skillfully prevented disaster by taking the airplane into the air for an impromptu first flight—where it stayed for six minutes.

In the early 1970s, the U.S. Air Force issued a requirement for an inexpensive, highly maneuverable lightweight fighter jet to complement the F-15 Eagle. Two companies answered the call: General Dynamics, with its YF-16 prototype, and Northrop, with its YF-17. The Air Force would eventually select the F-16, naming it the Fighting Falcon, while the U.S. Navy and Marine Corps would select a derivative of the YF-17, naming it the F/A-18 Hornet.

By December 1973, General Dynamics rolled out the first YF-16 prototype, and first flight was scheduled for February 1974. In the meantime, the aircraft was scheduled to perform high-speed ground tests throughout the month of January. It didn’t work out that way.

On January 20, 1974, test pilot Phil Oestricher was taking the YF-16 prototype down the runway at Edwards Air Force Base when things went, well, not according to plan.

Read more: popular mechanics