The CH-47 Chinook cargo helicopter of US Boeing is very easy to identify. In other words, it looks quite strange. It is all because of its` tandem-rotor design which makes itself rather different from other helicopters. Development of the medium lift Boeing models 114 and 414, CH-47 Series Chinook began in 1956. Since then successive product improvements carried out, the main variations include CH-47A, CH-47B, CH-47C and CH-47D.
The tandem rotors are both high above the fuselage. And the two engines are externally outside the rearward of the fuselage, the rotor on the head is driven by the rotors with a transmission shaft on the top of the cabin.
This design means that the aircraft had a 50 feet long cabin capable of carry up to 45 fully-equipped troops, or 10 tonnes of cargo, or 155mm howitzer, or small vehicles internally or externally on one of three mopunting points, without any structure limit. That`s why the tandem rotors is chosen. At the end of the cabin, the tail of CH-47, there is a rear loading ramp door, easily load or unload the cargo. The small vechiles can be driven out of the cabin by themselves through this door. Two big size side doors are on the aircraft, too. The large payload makes CH-47 an ideal battlefield support aircraft.