Boeing CH-47 Chinook

The Boeing CH-47 Chinook is a tandem-rotor helicopter originally developed by American rotorcraft company Vertol and now manufactured by Boeing Defense, Space & Security. The Chinook is the second-heaviest-lifting Western heavy-lift helicopter, behind the Sikorsky CH-53. Its name comes from the Chinook people, who are indigenous to the Pacific Northwest of the United States.

The Chinook was designed by Vertol, which had begun work in 1957 on a new tandem-rotor helicopter, designated as the Vertol Model 107 or V-107. Around the same time, the United States Department of the Army announced its intention to replace the piston-engine–powered Sikorsky CH-37 Mojave with a new, gas turbine–powered helicopter. During June 1958, the U.S. Army ordered a small number of V-107s from Vertol under the YHC-1A designation; following testing, some Army officials considered it to be too heavy for the assault missions and too light for transport purposes. While the YHC-1A would be improved and adopted by the U.S. Marine Corps as the CH-46 Sea Knight, the Army sought a heavier transport helicopter and ordered an enlarged derivative of the V-107 with the Vertol designation Model 114. Initially designated as the YHC-1B, on 21 September 1961, the preproduction rotorcraft performed its maiden flight. In 1962, the HC-1B was redesignated CH-47A under the 1962 United States Tri-Service aircraft designation system. Boeing had purchased Vertol in 1960, forming the Vertol division of Boeing, leading to some early production variants being produced as Boeing Vertol CH-47 Chinook.