Boeing engine started in 1943 and Boeing's gas turbines were designated models 502 (T50), 520 (T60), 540, 551 and 553. Boeing built 2,461 engines before production ceased in April 1968. Many applications of the Boeing gas turbine engines were considered to be firsts, including the first turbine-powered helicopter and boat. Vertol Aircraft Corporation was acquired by Boeing in 1960, and was reorganized as Boeing's Vertol division. The twin-rotor CH-47 Chinook, produced by Vertol, took its first flight in 1961. This heavy-lift helicopter remains a work-horse vehicle to the present day. In 1964, Vertol also began production of the CH-46 Sea Knight.
San Francisco and Oakland Helicopter Airlines flights being operated with Bell 206 helicopters. The following destinations were served at various times by San Francisco and Oakland Helicopter Airlines during its existence: San Francisco and Oakland Helicopter Airlines San Francisco and Oakland Helicopter Airlines (also known as SFO Helicopter Airlines and SFO Helicopter) was a helicopter airline service offering scheduled passenger flights between San Francisco, Oakland, and other Bay Area cities. It was founded in 1961 but disappeared from the Official Airline Guide 15 years later before finally going out of business in 1986. San Francisco and Oakland Helicopter Airlines was one of the first helicopter airlines