The Museum of Flight describes this aircraft on its own collection page, so its identity and early story rest on a museum source. Photo-database captions add the construction number and its time on display.
Identity
59-4987 is Northrop's prototype Freedom Fighter, the first of three N-156F airframes built, with the construction number N6001. It was redesignated YF-5A in 1962. [1] [2]
Recorded history
30 May 1959
Unveiled in front of visitors from 40 countries. [1]
30 July 1959
First flight at Edwards Air Force Base. Northrop chief test pilot Lew Nelson takes it supersonic on that very first flight. [1] [3]
Early 1960s
Used for pilot familiarisation and demonstration flights, including with weapons loads, then as a test aircraft for later F-5 versions. [1] [4]
1962
Redesignated YF-5A. [2]
From 1987
On display in the Great Gallery of the Museum of Flight in Seattle, which opened that year. [2]
Displayed markings
When it was first displayed at the Museum of Flight, it carried its U.S. Air Force serial but otherwise wore Northrop company markings, a reminder that this was a manufacturer's demonstrator before it was ever a military airplane. [3]
Where it fits
Everything else on this site descends from this airframe. The second prototype, 59-4988, tried out rough-field flying; the third, 59-4989, got the stronger wing that turned the design into the production F-5A. Its trainer cousin, the T-38, had flown three months earlier, a story told in F-5 vs. T-38.
Last updated
Source and limits
[1] Northrop YF-5A (N-156F) Freedom Fighter, The Museum of Flight. [2] N-156F c/n N6001, AirHistory.net. [3] 59-4987 in the Great Gallery, AirHistory.net. [4] YF-5A 59-4987 photos, National Museum of the U.S. Air Force. The museum page tells this jet's early story; it is not a complete flight log.