The Chinook is one of the most easily identified helicopters in the World. A tandem-rotor design, the large twin-engined medium-lift helicopter normally operates with a crew of four. Mounting the engines externally above the fuselage meant that the aircraft had a large spacious cabin capable of accommodating up to 45 fully-equipped troops, or up to 10 tonnes of cargo or small vehicles internally or externally on one of three mopunting points. The large cabin has a rear loading ramp door, which makes it a straightforward task to load and unload the aircraft in a very short time. The rotors counter-rotate and this means that no tail rotor is required to counter the torque of the powerful engines. This counter-rotation causes other problems in that the blades must be synchronised to avoid them striking each other.This large load carrying ability makes the Chinook an ideal battlefield support aircraft.

The original design dates back to the early 1960's and first took to the air in September 1961. Over 350 CH-47s as the were designated were built for the US Army and these weere widely used during the Vietnam war where there load-carrying capability made them the ideal medium-lift helicopter for the Army. Several versions have been developed over the years, and the aircraft ordered for the RAF in the late 1970's were equivalent to the CH-47C then available. These aircraft were known as Chinook HC1 in RAF service, and have themselves been the subject of many updates and are currently known as Chinook HC2s having been fitted with night vision goggle- (NVG) compatable flight deck amongst many other improvements. A number of new-biuld aircraft are also on order and these will be known as HC2As, dedicated special forces aircraft will become HC3s.

Powerplant: Two Avco Lycoming T55-712 turboshafts of 3,750shp.

Rotor Diameter: 60ft 0in (18.29m)

Length: 51ft 0in (15.54m)

Max Speed: 185mph (298 km/h)

Accommodation: Crew of two to four plus up to 44 troops or 28,000lb payload.

Recognition: Tubular fuselage with fairings along the lower edge to give a flat appearance to the underside. Front rotor blades on a fairing above the cockpit. Engines mounted either side and above the rear fuselage. Rear rotor on a rectangular 'fin' set above the front rotor blade arc. Rear loading ramp. Four-wheel undercarriage with two wheels at the rear and the second pair just beyond halfway along the fuselage. The HC2 has an enlarged air intake at the base of the rear engine pylon.