In 1992, as the USAF eliminated Major Command controlled (MAJCON) units, the 6520th was consolidated with the 420th and redesignated the 420th Flight Test Squadron.

It was assigned to the 413th Flight Test Group of AFRES at Phoenix-Mesa Gateway Airport, Arizona, where it was inactivated on 31 October 2007.

In September, the first American-built dedicated night fighter began to arrive, the Northrup YP-61 Black Widow and a few production P-61As.

In January 1944 the entire program moved to Hammer Field, California and was placed under IV Fighter Command.

[3] In March 1944 the 420th was disbanded when the AAF found that standard military units, based on relatively inflexible tables of organization were proving less well adapted to the training mission.

On 2nd February 1957, three KB-29Ps from RAF Sculthorpe were on a weekend training mission over France when two of them collided in poor visibility at 15,000 feet.

The increasing performance of swept-wing jet fighters such as the F-100 Super Sabre made it necessary to boost the performance of the tankers, and this was done by re-equipping with the KB-50J Superfortress, featuring an additional General Electric J47 turbojet engine under each wing which provided greater speed for the tanker aircraft.

[5] Unfortunately, these tanker aircraft were converted from B-50 bombers that had already seen up to 10 years service, and the already elderly KB-50Js began to deteriorate almost as soon as they were delivered.

Due to a chronic parts shortage TAC was forced to resort to cannibalization to keep the retrofitted tanker aircraft flying.

By 1963 the squadron's aircraft began to be phased out, the mission being taken over primarily by Air National Guard Boeing KC-97 Stratofreighters.

The squadron inactivated in early 1964[5] and its KB-50Js were sent to the Military Aircraft Storage and Disposition Center at Davis–Monthan Air Force Base.

The B-2 was first revealed to the public on 22 November 1988, when AV-1 (82-1066 "Spirit of America") was unveiled at Air Force Plant 42 near Palmdale, California.

In early 1993, AV-1 was placed in long term storage to await upgrading to full service configuration prior to joining the operational fleet.

The second test aircraft (AV-2, 82–1067 "Spirit of Arizona") flew for the first time on 19 October 1990 from Palmdale, landing at Edwards AFB.

In addition, pilots brought Talons to Mesa for upgrade and then delivered them to flying units after the work was complete.

[10] In September 2019 it was reported that the squadron would be reactivated to support flight testing of the Northrop Grumman B-21 Raider, reprising a similar role it performed in the development of the B-2.