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 …

