A helicopter used by armed forces worldwide and manufactured by Boeing in Philadelphia, the Chinook is the common name for the aircraft officially designated the CH-47D. The basic model was first designed in the mid-1950s and the first models came into service in 1962. The entire design was reworked in the late 1970s with upgraded materials and control units.

Chinook helicopters are instantly distinguishable by their twin rotors which operate in tandem, the one at the front of the aircraft being approximately 18" lower than the one at the rear. The Chinook can carry up to 25,000 pounds (11.5 tonnes) of cargo or personnel which gives it one of the lowest cost-per-payload of all helicopters currently in production.

When used as a personnel carrier the Chinook can hold 33 soldiers in full combat gear, or 50 in a lighter load. During medical evacuation operations up to 24 stretchers can be carried at a time. With an air speed of up to 180 knots it is an extremely versatile machine. Its primary military use is for airlifting troops, vehicles and supplies, while in civilian life Chinooks are frequently used in for disaster relief and search and rescue missions.

The usefulness of the Chinook, together with its unique looks has meant that it has become one of the best-known models of all helicopters. There are over 1000 Chinooks in current use around the world.