See: United States Air Force Plant 42 for the United States Government use of the facility Palmdale Regional Airport is an airport in Palmdale, California, United States. The city of Palmdale took over the airport at the end of 2013, managing it via the Palmdale Airport Authority. The airport currently does not have any scheduled passenger airline service. PMD and Plant 42 are separate facilities that share a common runway at the site. The facility is located in the Antelope Valley, approximately 60 miles from downtown Los Angeles. The airport covers 5,832 acres (2,360 ha) at an elevation of 2,543 feet (775 m) above mean sea level. It has three runways with concrete surfaces: 4/22 is 12,001 by 150 feet (3,658 x 46 m); 7/25 is 12,002 by 200 feet (3,658 x 61 m); 72/252 is 6,000 by 75 feet (1,829 x 23 m). 7/25 was built to withstand an 8.3 Richter Scale earthquake, making it one of the world's strongest runways. Another smaller runway, 72/252, is used as an assault strip. Palmdale Regional Airport has a small airline terminal and a hangar. The airport terminal is at the southwest corner of the airport and began civilian operations in 1971. Los Angeles World Airports (LAWA) owns 17,000 acres east of Plant 42 that was acquired for an airport. The city of Los Angeles bought the land in the 1960s when it planned to build an airport in Palmdale, but the airport was never built. The regional transportation plans formulated by the Southern California Association of Governments focused on having airports in Burbank, Ontario, Irvine and El Toro to handle the excess air-passenger service for the Southern California region. The Blackbird Airpark Museum and the adjacent Joe Davies Heritage Airpark (formerly the Palmdale Plant 42 Heritage Airpark) have been opened on Plant 42 property along Avenue P, with displays of the SR-71, U-2, Century Series fighters and other aircraft designed, engineered, manufactured, and flight tested at its facilities. Both museums are free to the public.