Dates

Event

1948

Constructed as a XS-4.

1948

Redesignated as X-4.

1948

Photographer: Charlene Aro Collection
Notes: Photographed at the Stategic Air Command Museum.

1949

Construction completed.

Circa 1949

Photographer: National Museum of the USAF
Notes: Before turned over to the USAF and NACA

7 June 1949

First flight.

27 February 1950

20th flight, Northrops part of the test program ended.

February 1950

Taken on Strength/Charge with the United States Air Force with s/n 46-0677.

May 1950

Turned over to the National Advisory Committe for Aeronautics (NACA), High-Speed Flight Research Station, Edwards AFB, CA. The remaining 82 flights were all flown in the No. 2 ship by USAF and NACA pilots including such luminaries as Stanley Butchart (NACA), Scott Crossfield (NACA), Pete Everest (USAF), Jack McKay (NACA), Joe Walker (NACA) and Chuck Yeager (USAF).

12 December 1950

Photographer: NASA Dryden Flight Research Cent

Circa 1953

Photographer: NASA Dryden Flight Research Cent

29 September 1953

Last flight.
Last flight of 102 total flights after proving that swept wing aircraft without horizontal tails were not suitable for transonic flight.

Circa October 1953

To United States Air Force Museum, Patterson Field (East Side), Dayton, OH.
View the Location Dossier

From 1955 to 1972

Loaned to Maxwell AFB, AL for display.

Circa 1972

To National Museum of the United States Air Force, Wright Field, Dayton, OH.
View the Location Dossier

From Circa 1972 to Circa 1973

Restored.
Restored by the Western Museum of Flight, Hawthorne, CA.

11 June 1990

Photographer: Glenn Chatfield

14 May 2010

Photographer: Glenn Chatfield

June 2016

Photographer: Gustavo Bonilla
Notes: National Museum of the U.S. Air Forces fourth building