The Boeing CH-47 Chinook

Video from the channel Megaprojects about Boeing CH-47 Chinook, linked on its Above Ten Thousand entry. Duration: 16:57. Language: English. Video type: Documentary.

A documentary about the Boeing CH-47 Chinook, the US Army's tandem-rotor cargo helicopter. It covers its origin, design and operational history, from Vietnam to disaster-relief missions.

In 1956 the US Army announced it wanted to replace its radial-engined CH-37 Mojave with twin-rotor helicopters powered by two gas turbines. Vertol, later absorbed into Boeing, began the design in mid-1957. Its V-107 won a joint Army-Air Force competition in autumn 1958, but was deemed too heavy for assault use and underpowered for cargo work. An enlarged version, the Model 114, was therefore commissioned; it made its first hover flight in September 1961 and received the designation CH-47 Chinook. Production began in 1962. In Vietnam, at peak deployment there were 21 companies with roughly 700 aircraft, of which around 200 were lost to enemy fire or combat accidents. It later served on both sides of the Falklands War, with Iran in the war against Iraq, in Operation Desert Storm and in Afghanistan.

Its two Lycoming T55 turboshaft engines sit on either side of the rear pylon. They drive the two rotors, which are mechanically synchronized, and if one engine fails the other powers both through a central transmission gearbox. Because the rotors turn in opposite directions, they cancel out torque, so no tail rotor is needed. It can carry 33 soldiers or 24 litters, as well as slung loads such as the M198 155mm howitzer. Agusta built it under license in Italy. Four gunship ACH-47A versions were built, but the program was abandoned due to cost. In 2011 it was used at Fukushima to drop seawater onto the reactors. Around 1,400 have been built.