Chinook HC2
31 helicopters (one is in the Falklands)
The famous Chinook has a tandem-rotor design, and is a large twin-engined helicopter that can carry up to 45 troops or 10 tonnes of gear or small vehicles. The Chinook was created in the 60s and widely used by the US in Vietnam. The Chinook normally has a crew of four. The updated HC2s have night-vision capabilities and new helicopters for special forces will be known as HC3s.

Puma HC1
33 helicopters
Can operate as a helicopter gunship, casualty evacuation aircraft, transport for up to 20 troops, or carry up to 5,500lbs of freight using under-fuselage hardpoints to sling loads externally. Equipped with night vision aids, defensive electronic countermeasure systems and advanced navigation aids. Came into service in 1971. Max speed: 163mph.

Wessex HC2
11 helicopters
The venerable Wessex are used as light support helicopters and have been in service for more than 30 years. Max speed: 132 mph.

Merlin HC3
22 helicopters
Anti-submarine variant of the EH101 helicopter. Came into service in 1995. Has autonomous capability to search for, locate and attack submarine targets. Normally flown by a crew of three, it has a range of 200 nautical miles. Capacity for up to four homing torpedoes or depth charges. Can also be used for load-lifting, casualty evacuation, carrying troops and search and rescue.