Allegheny Airlines was a regional airline that operated out of Pittsburgh, Pennsylvania, from 1952 to 1979 with routes primarily located in the eastern U.S. It was the forerunner of USAir that was subsequently renamed US Airways, which itself merged with American Airlines. Its headquarters were at Washington National Airport in Arlington County, Virginia. History Allegheny Airlines began as All American Aviation Company providing mail delivery starting on 7 March 1939. It was founded by du Pont family brothers Richard C. du Pont and Alexis Felix du Pont Jr. Allegheny before 1979 In 1949 the company was renamed All American Airways as it switched from air mail to passenger service. On 1 January 1953 it was again renamed, to Allegheny Airlines. Like other local service airlines, Allegheny was subsidized; in 1962 its revenue of $23.5 million included $6.5 million in "public service revenue". In 1960, Allegheny headquarters were in Washington, D.C. In 1953 Allegheny's network blanketed Pennsylvania, reaching Newark NJ to Cleveland and Huntington WV. It added Detroit (YIP) in 1956, Boston in April 1960, La Guardia in 1964, Norfolk in 1966, Toronto in 1967, and Louisville-Nashville-Memphis in 1968. The Lake Central Airlines merger in July 1968 added Chicago and St Louis, and the Mohawk Airlines merger in April 1972 added Montreal, Minneapolis and many New York cities. Houston in 1978, then Florida at the end of 1978 (TPA-MCO-PBI) and Phoenix in 1979. In 1959 Allegheny debuted its first turbine airliner—a Convair 540, a Convair 340 with the piston engines replaced by Napier Elands. When Rolls-Royce bought Napier it dropped the Eland, so 540s in the United States reverted to piston; Allegheny's last 540 flights were in 1962. The airline bought new Fairchild F-27Js that the company named "Vistaliner". The F-27J was a U.S.-built version of the Fokker F27. The airline switched to General Motors/Allison turboprops in the Convair 580 which the carrier named the "Vistacruiser", the first CV580 flight was in June 1965. The last DC-3 flights were in 1962 and the last piston flights were in 1967. In 1965 Allegheny announced it would add the first jet aircraft type to its fleet—the Douglas DC-9-10—which the airline stated would be placed into service in 1966. Allegheny then added other jets, notably the McDonnell Douglas DC-9-30 which the company named the "Vistajet". Later jets included Boeing 727-100s, 727-200s and McDonnell Douglas DC-9-50s. The Mohawk merger added British Aircraft Corporation BAC One-Eleven