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
Boeing Chinook (UK variants) 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. The RAF has a total of 60 active Chinooks in inventory as of 2015. In 2018 the UK issued a request to the United States to purchase 16 additional aircraft. The Chinook is expected to remain in RAF service until the 2040s. 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