<P> Mines Field opened as the airport of Los Angeles in 1930 and the city purchased it to be a municipal airfield in 1937 . The name became Los Angeles Airport in 1941 and Los Angeles International Airport in 1949 . In the 1930s the main airline airports were Burbank Airport (then known as Union Air Terminal, and later Lockheed) in Burbank and the Grand Central Airport in Glendale . (In 1940 the airlines were all at Burbank except for Mexicana's three departures a week from Glendale; in late 1946 most airline flights moved to LAX, but Burbank always retained a few .) </P> <P> Mines Field did not extend west of Sepulveda Boulevard; Sepulveda was rerouted circa 1950 to loop around the west ends of the extended east--west runways (now runways 25L and 25R), which by November 1950 were 6,000 feet (1,800 m) long . A tunnel was completed in 1953 allowing Sepulveda Boulevard to revert to straight and pass beneath the two runways; it was the first tunnel of its kind . For the next few years the two runways were 8,500 feet (2,600 m) long . </P> <P> Before the 1930s, existing airports used a two - letter abbreviation based on the weather stations at the airports . At that time, "LA" served as the designation for Los Angeles Airport . But with the rapid growth in the aviation industry the designations expanded to three letters c. 1947, and "LA" became "LAX ." The letter "X" has no specific meaning in this identifier . "LAX" is also used for the Port of Los Angeles in San Pedro and by Amtrak for Union Station in downtown Los Angeles . </P> <P> The "Imperial Hill" area (also known as Clutter's Park) in El Segundo is a prime location for aircraft spotting, especially for takeoffs . Another popular spotting location sits under the final approach for runways 24 L&R on a lawn next to the Westchester In - N - Out Burger on Sepulveda Boulevard . This is one of the few remaining locations in Southern California from which spotters may watch such a wide variety of low - flying commercial airliners from directly underneath a flight path . </P>

What does the x in lax airport stand for
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