using silver-zinc batteries. HALSOL made nine test flights.
Maj. Frank T. Birk piloted the first flight of a "classified technology demonstrator" at Groom Lake in 1985. For his work on the project, the Society of Experimental Test Pilots gave Birk the Lieutenant General Bobby Bond Memorial Aviator Award that "recognizes an AFSC military rated crew member for outstanding contribution to AFSC's test and evaluation mission while participating in aerial duties."
On 2 October 1992, the 413th Flight Test Squadron was activated at Edwards to provide test and evaluation capability for electronic warfare (EW) systems. This change supported a consolidation of all Air Force electronic combat assets in the western United States.
The mission of the 413th included planning, providing for, and organizing worldwide ground and flight tests of EW systems and equipment. A detachment of the 413th FLTS conducted EW testing at Groom Lake. In May 2004 the 413th Flight Test Squadron was inactivated as part of another consolidation and realignment of EW assets that were then absorbed by the EW Directorate at Edwards.
In the early 1990s Dennis F. "Bones" Sager was handpicked to lead a "classified prototype aircraft" called the YF-113G from design to first flight. As a fighter pilot and experimental test pilot, Sager accumulated over 2,900 flight hours in 54 aircraft types including Soviet fighters at Groom Lake. He was first Air Force pilot to fly the YF-113G.
On October 18, 2002, Boeing uncloaked its secret Bird of Prey technology demonstrator that was used to pioneer revolutionary advances in low-observables, aircraft design, and rapid prototyping.
The project, initiated in 1992, remained highly classified even after its conclusion in 1999. A Boeing spokesman announced that it had been declassified "because the technologies and capabilities developed [during the program] have become industry standards, and it is no longer necessary to conceal the aircraft's existence." Phantom Works chief test pilot Rudy Haug piloted the maiden flight of Bird of Prey in the fall of 1996. After McDonnell Douglas merged with Boeing on August 1, 1997, The Boeing Company continued to fund the project. Three pilots flew only 38 missions between 1996 and 1999.
Doug Benjamin, assigned to the Special Projects Flight Test Squadron, was the only Air Force pilot to fly the Bird of Prey. He flew 21 test flights including envelope expansion, mission utility, and tactical applications sorties. Following Benjamin's retirement from the military service in 2000, it was revealed that he had flown three other classified aircraft.
Daniel R. Vanderhorst has flown at least seven classified aircraft including TACIT BLUE. Many of his flights have involved one-of-a-kind technology demonstrators. In one such aircraft he tested modified landing gear and conducted initial tests of internal weapons bays, and weapon separation tests. He holds the altitude record in this still-classified aircraft.
There have also been reports of Advanced Concept Technology Demonstrator (ACTD) projects undergoing flight tests at Groom Lake.
Other projects at the site may include stealth helicopters, weapons development, unmanned aerial vehicles, and avionics testing.
For half a century, the Groom Lake test site has been a valuable asset for the development of aerospace vehicles and weapon systems. There, workers toil in relative isolation and inhospitable conditions to prove revolutionary technologies and enhance the readiness of today's warfighter and support national requirements.