Monica, during which time the airport area was cleverly disguised from the air with the construction of a false "town" (built with the help of Hollywood craftsmen) suspended atop it. Post-World War II Transition to general aviation reliever airport In 1958, Donald Douglas asked the city to lengthen the airport's runway so that Douglas Aircraft could produce and test the DC-8 there. The city, bowing to objections of residents, refused to do so, and Douglas closed a plant that had employed 44,000 workers in World War II, moving airliner production to Long Beach Airport. With the departure of Douglas, the airport became a principal general aviation "reliever" airport for the Greater Los Angeles area, accommodating mostly business aircraft, training aircraft, and personal planes. In 1968, the Federal Aviation Administration (FAA), in exchange for an airport-development grant, contracted with the City of Santa Monica to ensure the airport land would be used for aviation services, including fuel, maintenance and fixed base operations, until 1988. Battles to limit or close the airport Starting in the late-1970s, the airport became the object of numerous political battles seeking to limit or close the airport -- ultimately becoming a key precedent for various such airport battles across the nation -- pitting local area residents, land developers and local government against airport users and general aviation industry organizations, sometimes supported by the FAA. Initially, residents off the departure end of Runway 21 complained of noise, and the Santa Monica city government imposed a noise limit of 100 decibels on departing aircraft. Airport supporters, including airport users, the General Aviation Manufacturers Association (GAMA), National Business Aircraft Association (NBAA), and Aircraft Owners and Pilots Association (AOPA), fought the city in federal court. However, in their first conflict, the U.S. Ninth Circuit Court of Appeals ruled that a city could impose reasonable restrictions on airport activity and noise. The City responded by preparing 85 decibel restrictions, which threatened to oust most aircraft from the field. It also began other actions against the airport, including evictions of most aviation operators. Further, in 1981, the airport's occupied five percent of the usable land of Santa Monica, in the heart of the burgeoning population of the Greater Los Angeles area, making it highly desirable real estate for development. One study indicated that intense development of the airport land could double the city's revenue. Additionally, the city was mostly populated by apartment renters,