Boeing CH-47 Chinook had remained in both production and frontline service for over 50 years. The military version of the helicopter has been subject to numerous export sales from nations across the world, typically using it as heavy-lift rotorcraft in a military context; the U.S. Army and the Royal Air Force (see Boeing Chinook (UK variants)) have been its two largest users. The civilian version of the Chinook is the Boeing Vertol 234. It has been used for a variety of purposes by a range of different civil operators, having often been used for passenger and cargo transport, along with niche roles such
San Francisco and Oakland Helicopter Airlines 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 to operate without a federal subsidy and it was also the first to operate with only turbine engine helicopters. Since helicopter landing sites were scarce