service with the Russian air force. F-117A Nighthawk program In the 1980s, Tonopah Airport became a major operating location for the Lockheed F-117A Nighthawk. The first flight testing of the stealth YF-117A aircraft began in June 1981 at Groom Lake Nevada. However, Groom Lake had too many other operations going on to support an operational unit. The F-117 test unit remained at Groom until shortly after the 1991 Gulf War. In addition, there were security concerns because an operational unit based at Groom Lake would involve many more people who could now see things that they should not be seeing. Therefore, a new covert base had to be established for F-117 operations. In the summer of 1979, Tonopah Test Range Airport was selected to be the home of the Tactical Air Command 4450th Tactical Group (4450th TG). The mission of the 4450th at Tonopah was to guide the classified F-117A Stealth Fighter to an initial operating capability. Beginning in October 1979 Tonopah Test Range Airport was reconstructed and expanded. The base was immediately staffed with US Air Force security police. The flight line was walled off with a double fence; the only access to the runway was through gates. The area between the fences was lighted at night and had intruder detectors. At first, the facilities were limited to a few buildings, a small mess hall, and sixteen winterized trailers. Security checkpoints were placed on the sole public access road which led to the TTR. The runway was lengthened to . Taxiways, a concrete apron, a large maintenance hangar, and a propane storage tank were added. Phase II of the expansion consisted of the construction of an extra taxiway, a new control tower, a hangar, a parts warehouse, a dining hall, a water storage tank, and extensive fuel storage tanks. Phase III expansion of the facility was a runway extension to a total length of . Extensions were made to taxiways, to the ramp, the runway gained arrester gear, and new navigation aids were installed. More fuel storage was provided, together with Liquid Oxygen (LOX) storage, a fire station, and the first 24 aircraft hangars. The cost was over $100 million. On 17 May 1982, the move of the 4450th TG from Groom Lake to Tonopah was initiated, with the final components of the move completed in early 1983. The Tactical Air Command ("R"-Unit), also known as the "Baja Scorpions"