<Tr> <Th> Headquarters </Th> <Td> San Diego, California </Td> </Tr> <Tr> <Th> Key people </Th> <Td> Kenny Friedkin (Founder and Original President) Jean Friedkin (Founder and Original Vice President) Eleanor Glithero (PSA's first employee) </Td> </Tr> <P> Pacific Southwest Airlines (PSA) was a United States airline headquartered in San Diego, California, that operated from 1949 to 1988 . It was the first large discount airline in the United States . PSA called itself "The World's Friendliest Airline" and painted a smile on the nose of its airplanes, the PSA Grinningbirds . Opinion L.A. of the Los Angeles Times called PSA "practically the unofficial flag carrier airline of California for almost 40 years ." </P> <P> The airline initially operated as an intrastate airline wholly within the state of California before expanding to other destinations in other western states in the U.S. following the Airline Deregulation Act of 1978 and also eventually operated international service to several destinations in Mexico . </P>

When did psa airlines go out of business