Commando Helicopter Force The Commando Helicopter Force ( CHF ) is a part of the Fleet Air Arm , and is an element of the Joint Helicopter Command of the British Armed Forces ; which provides Rotary - Wing ( helicopter ) support to 3 Commando Brigade Royal Marines and other elements . The CHF uses a combination of attack and transport helicopter s provided by the Royal Navy ' s Fleet Air Arm based at Royal Naval Air Station Yeovilton in Somerset , England . History . The Commando Helicopter Force was formed in 1997 to consolidate command and control of the various Fleet Air Arm and Royal Marines helicopter squadrons which supported 3 Commando Brigade under Flag Officer Naval Aviation . In 1999 , the CHF merged with various Royal Air Force and Army Air Corps force elements to become the Joint Helicopter Command , whilst maintaining its status as a formed unit . It is based at Royal Naval Air Station Yeovilton in Somerset , England ; although aircraft are regularly deployed with 3 Cdo Brigade , overseas and to the ships of the Amphibious Ready Group ; HMS " Ocean " ( Landing Platform Helicopter ) , HMS " Bulwark " and HMS " Albion " ( Landing Platform Docks ) . Elements of the force have operated in Northern Ireland to 2002 , Sierra Leone in 2000 and Bosnia and it was an element of the amphibious force for Operation Telic , the British involvement in the 2003 invasion of Iraq , notably supporting the landings to secure the Al Faw Peninsula as well as being a major part of JHC ( Joint Helicopter Command ) Operation Herrick , until pulling out late 2011 . The force supports the 3 Cdo Brigade annual Cold Weather Warfare exercise in Norway . In 2005 the Gazelle reconnaissance helicopter was retired from service in the CHF . The RAF ' s Merlin HC3 helicopters are to undergo an upgrade to HC4 standard and then be transferred to the Royal Navy in the Commando Helicopter role , replacing the ageing Sea King . Command and Control . The CHF is a Fleet Air Arm asset and as such remains under the Operational Command of Commander in Chief Fleet , Operational Control is delegated to the Joint Helicopter Command , under HQ Land Command , who will task assets in accordance with Permanent Joint Headquarters or Front Line Command requirements . Organisation . The Commando Helicopter Force has four naval air squadrons with separate roles : 845 Naval Air Squadron operates the Westland HC Mk . 4 Sea King helicopter ; a variant that has been specially modified for medium - lift and flying in all sorts of weather conditions and terrains . 845 has had at least two of it Sea Kings deployed to the Bosnian theatre since 1992 . Besides Bosnia , they have operated in Albania , Egypt , Honduras , Nigeria , and Sierra Leone . 846 Naval Air Squadron operates the same aircraft as 845 NAS , but has not seen action in Bosnia , being more focused on the Northern flank of the Nato theatre . Until recently 846 maintained a base in Northern Ireland that allowed it to become very proficient in cold weather and winter operations . Their operations are not limited to northern flying conditions , however . 846 Squadron has also operated in South East Asia , Australia , The United States , and Germany . Two Aircraft of 846 were sent to Turkey following the major earthquake it suffered in November 1999 . 847 Naval Air Squadron operates Army - owned Westland Lynx AH7 helicopters , flown by Royal Navy and Royal Marines pilots . It is possible that the Royal Navy ' s Commando Helicopter Force will also replace the Lynx in the anti - armour role with the Apache AH Mk1 ( WAH - 64 Apache Longbow ) . However no other helicopter can match the Lynx for light - lift / assault during combat situations . The Lynx AH . 7 can also be outfitted for the anti - armour role , with the attachment of 2 pylons each carrying 4 TOW anti - Tank missiles . In the light - lift role , it can also carry an Aircrewman armed with a cabin door machinegun and Marines for fastrope or rappelling insertions , or regular landings . It is also used to transport cargo . 848 Naval Air Squadron is the Commando Sea King HC4 training squadron for the group , and trains not only the aircrews but also the ground crews . In addition to the skills necessary to fly their missions , Commando Helicopter Force members are trained in small - arms weapons as well as tactics and survival fieldcraft . Being a naval unit that is directly tasked with supporting the Royal Marines , trainees are also schooled in shipboard and amphibious assault operations . A special unit with 848 Squadron , M Flight , is tasked with supporting the Special Boat Service ( SBS ) in their operations . Personnel . It is commanded by a Royal Navy Captain . Squadron personnel are drawn from all three armed services , although the majority are from the Royal Navy . Aircrew join the force , already trained in helicopter operations , from the Defence Helicopter Flying School at RAF Shawbury . Type training for the Sea King is conducted in 848 Squadron and type training for the Lynx is conducted with the Army Air Corps . Technician and engineer training is conducted within the single services as appropriate for the aircraft type and supporting trades are filled by qualified single service personnel . Squadrons conduct organic continuation training and life support and security continuation training is supported from within the force , each Squadron maintaining a complement of survival , military skills and cold weather warfare instructors .