[1] The product of Project Constant Peg, the unit was created to expose the tactical air forces to the flight characteristics of fighter aircraft used by the Soviet Union during the Cold War.

The longest continuing United States classified military airplane program is the testing and evaluation of Foreign Aircraft Technology.

During the Cold War, secret test flying of Mikoyan-and-Gurevich Design Bureau (MiG) and other Soviet aircraft was an ongoing mission dating back to the acquisition of the first Soviet-built Yakovlev Yak-23 in 1953.

The knowledge gained from testing the aircraft the squadron flew was reflected in the success of United States air operations during the Vietnam War, as well as the founding of the Air Force's Red Flag program and the United States Navy's TOPGUN school.

[5] In the 1950s in the United States, with the development of air-to-air missiles, such as AIM-4 Falcon, AIM-7 Sparrow III, and AIM-9 Sidewinder, the paradigm for the new generation of jet fighters was that dog-fighting was obsolete.

For roughly every two North Vietnamese Mikoyan-Gurevich MiG-17s or MiG-21s shot down, an American F-4 Phantom II, F-105 Thunderchief, or F-8 Crusader would be lost.

[6] The emphasis on air-to-air missile interception meant the fighter combat crews had only the sketchiest knowledge of dogfighting.

[2] Data from the HAVE DOUGHNUT and HAVE DRILL tests were provided to the newly formed United States Navy Fighter Weapons School (TOPGUN) at NAS Miramar, California.

MiGs were acquired from scrapyards, dug out of remote places where they’d crashed, recovered from warehouses where they had been left or just bought from other air forces.

The AEC airport had the potential for improvement and expansion, with the only public land overlooking the base miles away.

In fact, the security surrounding the Tonopah Test Range was so effective that the new base was not publicly reported as an Air Force military airfield until 1985.

[8] The 4477th pilots and tactical controllers were Aggressors, Fighter Weapons School or Top Gun instructors.

USAF claims pilots had no manuals for the aircraft, although some tried to write one, nor was there a consistent supply of spare parts, which had to be refurbished or manufactured at high cost or procured from friendly nations.

The mission of 4477th squadron was to train U.S. Air Force, U.S. Navy, and U.S. Marine Corps pilots on the best ways to fight and win when encountering MiGs in aerial combat.

The United States-operated MiGs received special designations due to the practical problem of what to call the aircraft in mission logs and paperwork.

[2][6] The focus of Air Force Systems Command (AFSC) limited the use of the MiGs as tools with which to understand the performance, capabilities, and qualities of the enemy.

TAC selected its MiG pilots primarily from the ranks of the Weapons School and Aggressors at Nellis AFB.

This practice proved to be very important as tests with real Soviet equipment proved several times that USAF equipment was designed according to American specifications, different from the Soviet ones, and results against the "real thing" were many times surprisingly different than expected.

They were also trained to fly against acquired Soviet air defense systems similar to those that US pilots had faced over North Vietnam.

Beginning in the spring of 1973, the squadron began deploying to TAC bases in the United States to perform DACT training against F-4 pilots.

The acquired Soviet air defense radar was installed at several locations on the Nellis range, and simulated Soviet integrated missile and antiaircraft artillery batteries, similar to what was faced in Vietnam and by Israeli pilots during the 1973 Yom Kippur War were set up.

[8] With the Fall of Saigon, the United States had some 70 F-5E Tiger II fighter aircraft in storage, which were paid for by Congress to send to the Republic of Vietnam Air Force.

The T-38s used by the Aggressor squadrons were trainers and similar to the F-5, but were not combat aircraft and were not ideal in the role of simulating the performance of the Soviet MiG, however the higher-performance F-5E was.

The plane hit the ground at a steep angle near the Tonopah Test Range airfield boundary, killing the pilot instantly.

Flight operations at Tonopah closed down in March 1988, although the 4477th was not inactivated until July 1990, according to one official Air Force history.

[2] The decision to shut down operations may have had something to do with the fact that a new generation of Soviet aircraft was entering service and also the inevitable round of budget cuts from Washington.

[2] There have been multiple sightings of foreign aircraft over Nevada since the end of Constant Peg and the inactivation of the 4477th TES: In a March 1994 article on Groom Lake in Popular Science, a photo was published of an Su-22 fighter in flight.

It was in frontline Russian Air Force service at the time and was exported widely to Eastern European and Third World countries during the 1970s and 1980s.

With East and West Germany now unified, there was an ample supply of both Soviet-built planes and the spare parts needed to support them.

[6] In 2014, it is believed that Air Combat Command (ACC) shares access to Mikoyan MiG-29s and Su-27 aircraft somewhere in Nevada (most likely Groom Lake) flying against Fighter Weapons School instructors, 422d Test and Evaluation Squadron aircrews and F-15 Eagle and F-16 Fighting Falcon "Aggressor" aircraft flying from Nellis AFB.