420th Flight Test Flight

420th Night Fighter Squadron Northrop P-61A Black Widow

The squadron was activated on 1 June 1943 at Orlando Army Air Base, Florida as the third night fighter training squadron of the 481st Night Fighter Operational Training Group (481 NFOTG). Its mission was to be a Replacement Training Unit (RTU) for Night Fighter pilots. It accepted Army Air Forces Training Command's twin-engine flying training and B–25 transition school graduates and trained them as night fighter pilots.[3]

The initial squadron personnel were veteran pilots of the 481 NFOTG, with some being transferred from the group's 348th and 349th Night Fighter Squadrons which performed Operational Training of new squadrons. It was initially equipped with Douglas DB-7s and Douglas P-70s.[3]

As 1943 progressed additional aircraft and equipment arrived and the program expanded. 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. The move placed the squadron near Northrop manufacturing facility at Hawthorne, California and most programmed P-61 squadrons were planned for operations in the Pacific and China Burma India Theaters.[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. Accordingly, a more functional system was adopted in which each base was organized into a separate numbered unit during a reorganization of units in the United States.[4] The squadron's personnel and equipment were transferred to Squadron C of the 450th Army Air Forces Base Unit (Night Fighter Replacement Training Unit).[3]

420th Air Refueling Squadron Boeing KB-29P Superfortress at RAF Sculthorpe 1956

420th Air Refueling Squadron Boeing KB-50 Superfortress, about 1961

The 420th Air Refueling Squadron was activated in 1954 by Tactical Air Command to provide dedicated air refueling for TAC bombers, fighters, and fighter bombers. The 420th was activated at Alexandria Air Force Base, Louisiana and was the first TAC air refueling squadron. The squadron received KB-29Ps fitted with the refueling boom.[5]

In 1955 the unit deployed to United States Air Forces in Europe and was based at RAF Sculthorpe, Norfolk, England to provide air refueling for USAFE squadrons. However, the KB-29s were simply too slow to refuel jet fighters. The increasing performance of operational fighters made it necessary to boost the performance of the tankers, and this was done by re-equipping with the KB-50 Superfortress starting in December 1956[5] which provided greater speed to refuel jet aircraft. The squadron received its first KB-50J in 1958.[5] This model added a J-47 turbojet engine underneath each wing in place of the auxiliary fuel tanks to increase the speed of the aircraft. The KB-29P was phased out in 1959.[5]

Unfortunately, the elderly KB-50Js began to deteriorate almost as soon as they were delivered, and due to a chronic parts shortage TAC was forced to resort to cannibalization to keep the retrofitted tanker aircraft flying. Landing gear malfunctions were frequent, and many parts started to break simply because of old age. More and more maintenance had to be performed in order to keep the aircraft flying.[6]

With the 47th Bombardment Wing's inactivation the 420th ARS at Sculthorpe was assigned to the 7375th Combat Support Group, a temporary unit at Sculthorpe after its turnover to the Air Ministry. On 1 September 1963 it was reassigned directly to Third Air Force.

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. rotating to Europe under Operation Creek Party. 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. Arizona.

Air Force Systems Command activated the 6520th Test Squadron in March 1989 at Edwards Air Force Base, California. Its mission was the pre-operational testing of the B-2 Spirit stealth bomber. 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. At this time the aircraft was still not ready for its first flight. Taxi tests began on 10 July 1989. The B-2 finally made its first flight on 17 July 1989 from Palmdale. The flight lasted 112 minutes and ended with a landing at Edwards and delivery to the 6520th.[7]

B-2 Spirit Rollout – 22 November 1988. The 420th Flight Test Squadron performed test flights with the B-2.

After carrying out initial tests, AV-1 was used for radar cross section tests. 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. It was heavily instrumented and served as the loads test aircraft.[7]

AV-3 (82-1068 "Spirit of New York") took to the air for the first time on 18 June 1991. It was the first radar and navigation test aircraft. AV-4 (82-1069 "Spirit of Indiana") followed on 17 April 1992, and AV-5 (82-1070 "Spirit of Ohio") on 5 October 1992. These two planes were used for avionics and weapons testing. The first bomb to be tested with the B-2 was a 2000-lb Mk 84, which was dropped from AV-4 on 12 September 1992. AV-5 was the intended for armament, climatic, and low-observability testing.[7]

On 1 October 1992, the 6520th Test Squadron was consolidated with the 420th Air Refueling Squadron. The next day the consolidated unit was renamed the 420th Test Squadron.[1]

The last development aircraft, AV-6 (82-1071 "Spirit of Mississippi") flew on 2 February 1993. It was used for technical order validation and for further weapons and avionics testing.[7][8] By January 1995 the six B-2s had logged more than 2300 hours in the air in more than 490 flights. Terrain-following certification flights were undertaken by AV-4 in September 1996. By January 1997, the B-2 had reached limited operational capability and testing at Edwards was phased down. B-2 flight testing was transferred to the 419th Flight Test Squadron and the squadron was inactivated at the end of 1997.

The 420th was reactivated in 2001 at Phoenix–Mesa Gateway Airport, Arizona (formerly Williams Air Force Base) as the 420th Flight Test Flight. The flight acted as a Northrop T-38 Talon functional check flight organization. The 420th replaced Operating Location E of the 622d Regional Support Group, which originally stood up in May 2000. After the 413th Flight Test Group was created at Robins Air Force Base, Georgia, the flight was reassigned to the group in 2003.[1][9]

The unit supported Boeing's modification of the T-38C trainer's flight, engine and navigational avionics and the addition of a heads-up display, inertial navigation system, and a flight recorder. The 420th flew depot-level test sorties and acceptance check flights after the upgrades were completed. In addition, pilots brought Talons to Mesa for upgrade and then delivered them to flying units after the work was complete. The squadron was inactivated on 31 October 2007 when the cockpit upgrade program was completed.[9]

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.[10] The squadron was reactivated on 4 October 2019.[11]

• Air Defense Department, Army Air Forces School of Applied Tactics, 1 June 1943 (attached to 481st Night Fighter Operational Training Group after 17 July 1943)
• 481st Night Fighter Operational Training Group, 26 July 1943 – 31 March 1944
• Ninth Air Force, 18 March 1954 (attached to 366th Fighter-Bomber Wing until 22 September 1955)
• Third Air Force, 9 October 1955 (attached to 47th Bombardment Wing after 15 March 1960)
• Seventeenth Air Force, 1 July 1961 (remained attached to 47th Bombardment Wing)
• 47th Bombardment Wing, 8 November 1961
• Seventeenth Air Force, 22 June 1962 (attached to 7375th Combat Support Group after c. June 1962)
• 7375th Combat Support Group, 1 October 1962 – 25 March 1964
• 6510th Test Group (later 412th Test Group), 10 March 1989 – 30 December 1997
• 622d Regional Support Group, 1 October 2001
• 413th Flight Test Group, 1 October 2003 – 31 October 2007[1][9]

 This article incorporates public domain material from the Air Force Historical Research Agency.

• Goss, William A (1955). "The Organization and its Responsibilities, Chapter 2 The AAF". In Craven, Wesley F; Cate, James L (eds.). The Army Air Forces in World War II. Vol. VI, Men & Planes. Chicago, Illinois: University of Chicago Press. LCCN 48-3657.
• Knaack, Marcelle Size (1978). Encyclopedia of US Air Force Aircraft and Missile Systems (PDF). Vol. 2, Post-World War II Bombers 1945–1973. Washington, DC: Office of Air Force History. ISBN 0-912799-59-5. Retrieved 17 December 2016.
• Maurer, Maurer, ed. (1982) [1969]. Combat Squadrons of the Air Force, World War II (PDF) (reprint ed.). Washington, DC: Office of Air Force History. ISBN 0-405-12194-6. LCCN 70605402. OCLC 72556. Retrieved 17 December 2016.
• Pape, Garry R., John M. and Donna Campbell. (1991) Northrop P-61 Black Widow: The Complete History and Combat Record. St. Paul, Minnesota: Motorbooks International, ISBN 0-87938-509-X