For almost 50 years, a secret facility has existed at Groom Lake, Nevada, to test classified aircraft. Originally built by the CIA, it is now operated by the Air Force as part of the Nellis Bombing and Gunnery Range. The U-2, SR-71, and F-117 aircraft have been tested there, among others.
Recently, there have been reports of exotic new low observable ("Stealth") and hypersonic aircraft at the Groom facility. These aircraft don't suddenly appear at the site, and so some attention should be given to where classified aircraft are known to have been designed and built, California's Antelope Valley, on the other side of the mountains north of Los Angeles County. Palmdale is the home of Air Force Plant 42, site of Lockheed-Martin's "Skunk Works" (Lockheed Advanced Development Co., on the west side of Plant 42), Northrop-Grumman's final assembly plant for the B-2 Stealth bomber, Rockwell, and other aerospace companies. Among the other sensitive sites around the Antelope Valley, are Northrop's Tejon Ranch radar cross section test facility (at the base of the Tehachapi mountains), Lockheed's radar cross section test site north of Hellendale, McDonnell Douglas's Llano facility, and the General Atomics El Mirage Flight Test Facility, where the CIA's Gnat-750 (Tier 1) and Predator (Tier 2) Unmanned Aerial Vehicles (UAVs, used for reconnaissance) are tested. To the north are Edwards AFB (classified aircraft have been tested on the northern part of the base) and the China Lake Naval Air Weapons Center, home of the Randsburg Wash Test Range, that the Navy described as "Sea Site I, a highly classified, sensitive, electronic warfare facility" in a land withdrawal handled by the California office of the Bureau of Land Management (BLM) in 1994.
Various parts of the aerospace industry tend to concentrate around various locations. For example, reconnaissance satellites and other advanced electronics tend to be clustered around El Segundo, CA (home of Los Angeles Air Force Station, TRW, etc.) and Sunnyvale, CA (home of Onizuka AFB, Lockheed Missiles and Space Co., and others.) A significant group of airplane builders is clustered in the Antelope Valley, because of lower population densities and year-round ideal flying weather.
Based on military documents, and other information, it isn't unreasonable to assume that there are strong connections between operations in the Antelope Valley (especially Air Force Plant 42) and Groom Lake. Since many of the classified aircraft contracts in the past have gone to Lockheed's "Skunk Works", investigation should probably start there. Lockheed operations are located in two different parts of Plant 42 - large hangars and other buildings on the west side of the base, known as the Plant 10 Complex (the Skunk Works shown in the photo), and U-2/F-117 upgrade activities located in Site 7, northwest of Palmdale Air Terminal.
There are two 12,000 foot long runways at Plant 42. Runway 4-22 is used by Lockheed (at Site 7), and EG&G [see below]. It has been reported that occasionally, Air Force C-5 and C-141 transport aircraft have been loaded with unknown cargoes (presumably disassembled aircraft) in the middle of the night from the big hangars in Plant 10, taken to the other runway, runway 7-25, and flown to unknown destinations.
Historically, Lockheed has conducted classified testing up at Groom Lake, Nevada, in programs like the U-2, SR-71, and F-117. To the northeast of the hangars and other buildings in Plant 10, one finds a large warehouse complex in Site 8, operated by Northrop-Grumman and a military contractor, Pacifica Services. (Perhaps this is what Bob Lazar means when he claims he received his education at "Pacifica")
At Groom Lake, base workers are flown in daily on 737s from a terminal at Las Vegas' McCarran Airport. This service is operated by Nevada Test Site contractor EG&G. Base workers at Groom Lake have been told to say they work for EG&G at the Nevada Test Site, rather than reveal they work at Groom Lake. Oddly enough, EG&G has a small hangar at Plant 42, (shown below) located in Site 6, near the control tower, and just off runway 4-22. It is not known what EG&G is doing at Plant 42, but it is supposed to be classified.
Radio frequencies for Plant 42 (Palmdale, CA). Frequencies (in MHz) (AM unless otherwise indicated):
121.9 - Palmdale ground control 123.325, 123.425 - Lockheed - aero band 123.7 - Palmdale tower 124.55 - Palmdale departures 126.1 - Joshua Approach/Departure (I have heard controller giving private planes instructions on how to avoid Plant 42's and Edwards AFB restricted air space on 126.1) 149.505 (FM) - Plant 42 (now encrypted?) 153.025 (FM) - EG&G 153.2 (FM), 158.295 (FM) - Lockheed Corp. (I have heard Lockheed's fire department on 158.295) 163.4875, 163.5875 - Air Force SPs [used nationwide] 460.1 (FM), 460.525 - Palmdale Airport police 462.425 - Lockheed (security?? encrypted some of the time) 482.8625 - Los Angeles County Sheriff (Antelope Valley - it's always good to have local law enforcement in your radio, in case a base calls them)