Boeing Chinook (UK variants)

Chinook
A Royal Air Force Chinook HC2 in 2008
Role	Transport helicopter
Manufacturer	Boeing Rotorcraft Systems
First flight	23 March 1980 (HC1)
Introduction	1980 with RAF
Status	Active service
Primary user	Royal Air Force
Number built	58
Unit cost	£60.1m (HC6, 2012)
Developed from	Boeing CH-47 Chinook

The Boeing Chinook is a tandem rotor helicopter operated by the Royal Air Force (RAF). A series of variants based on the United States Army's Boeing CH-47 Chinook, the RAF Chinook fleet is the largest outside the United States. RAF Chinooks have seen extensive service including fighting in the Falklands War, peace-keeping commitments in the Balkans, and action in the Iraq and Afghanistan wars.

The Chinook aircraft, normally based at RAF Odiham, provides heavy-lift support and transport across all branches of the British armed forces, and is supported by the smaller, medium-lift helicopters such as the AgustaWestland Merlin HC.3 of the Royal Navy's Commando Helicopter Force and the RAF's Westland Puma HC.2, based at RNAS Yeovilton and RAF Benson.

In March 1967 an order was placed for fifteen Chinook HC Mk1s, standing for Helicopter, Cargo Mark 1, for the Royal Air Force to replace the Bristol Belvedere. This original MK1 variant was to be based on the CH-47B but the order was cancelled in a review of defence spending in November 1967.

UK Chinook procurement ambitions were revived in 1978 with an announced requirement for a new heavy-lift helicopter to replace the Westland Wessex. Thirty Chinooks were ordered at a price of US$200 million. These helicopters, comparable to the CH-47C with Lycoming T55-L-11E engines, were again designated Chinook HC Mk1, and entered service in December 1980. Eight more Mk1s were delivered from 1984 to 1986 with the CH-47D's Lycoming T55-L-712 turboshafts.