because its cockpit layout and avionics were considered similar to those in the F-117. It was also a single-seat attack fighter, as the F-117 was programmed to be. It therefore would bring all pilots to a common flight training base line. The 4450th TG was the last active USAF unit to fly the A-7D. Along with the A-7Ds that came from England AFB, the group acquired one of the new A-7K twin-seat trainers from the Arizona Air National Guard for checkout flights at Nellis. A second A-7K was acquired from Edwards AFB (73-1008), which was the prototype two-seater that had been converted from its original A-7D configuration in 1978. In doing so, the group became the only active-duty unit to fly the A-7K. A-7D flight operations began in June 1981 concurrent with the very first YF-117A flights. The A-7's wore a unique "LV" tailcode (for Las Vegas) and were based officially at Nellis Air Force Base. They were maintained by the 4450th Maintenance Squadron, based at Nellis. Some A-7s operated from Tonopah from the beginning, and care was taken to leave them outside the hangars, so that satellites passing overhead could see that Tonopah operated nothing more exciting than some Corsairs. There were approximately 20 aircraft, including a couple of A-7K trainers. In addition to providing an excuse for the 4450th's existence and activities the A-7's were also used to maintain pilot currency, particularly in the early stages when very few production F-117As were available. The pilots learned to fly chase on F-117A test and training flights, perform practice covert deployments, and practice any other purpose that could not be accomplished using F-117As, given the tight restrictions imposed on all F-117A operations. On off-range flights, the pilots talked to the air traffic controllers as if they were in an A-7D Corsair II. Each F-117 aircraft also carried a transponder that indicated to radar operators that it was an A-7. In January 1989, just three months after the USAF admitted the F-117A existed, the aging A-7's were replaced with newer T-38A and AT-38B Talon trainers as a measure to streamline the F-117A's training operation. Many of these "Talons" formerly belonged to the 4447th TS "Red Hats" that flew "acquired" Soviet aircraft at Groom Lake, Nevada. One of the AT-38B Talons even served as a USAF Thunderbird in the 1970s. With the arrival of the T-38s, the squadrons Corsairs were retired; the