Boeing CH-47 Chinook Transport Helicopter
The Boeing CH-47 Chinook is an American twin-engine, tandem rotor heavy-lift helicopter. Its top speed of 170 knots (196 mph, 315 km/h) is faster than contemporary utility and attack helicopters of the 1960s. It is one of the few aircraft of that era, such as the C-130 Hercules and the UH-1 Iroquois, that is still in production and front line service with over 1,179 built to date. Its primary roles include troop movement, artillery emplacement and battlefield resupply. It has a wide loading ramp at the rear of the fuselage and three external-cargo hooks.
The name "Chinook" alludes to the Chinook people of the Pacific Northwest. The CH-47 is powered by two turboshaft engines, mounted on each side of the helicopter's rear end and connected to the rotors by driveshafts. Initial models were fitted with engines of 2,200 horsepower. The counter-rotating rotors eliminate the need for an anti-torque vertical rotor, allowing all power to be used for lift and thrust. The ability to adjust lift in either rotor makes it less sensitive to changes in the center of gravity, important for the cargo lifting role. If one engine fails, the other can drive both rotors. The "sizing" of the Chinook was directly related to the growth of the Huey and the Army's tacticians' insistence that initial air assaults be built around the squad. The Army pushed for both the Huey and the Chinook, and this focus was responsible for the acceleration of its air mobility effort.