Helicopter rotor of gravity fore-aft. However, it requires the expense of two large rotors rather than the more common one large main rotor and a much smaller tail rotor. The Boeing CH-47 Chinook is the most common tandem rotor helicopter. Coaxial rotors are a pair of rotors mounted one above the other on the same shaft and turning in opposite directions. The advantage of the coaxial rotor is that, in forward flight, the lift provided by the advancing halves of each rotor compensates for the retreating half of the other, eliminating one of the key effects of dissymmetry of lift: retreating blade
Armed helicopter and support them on the ground. They were used successfully during the Scud Hunt. Other Army Special Operations include the MH-6 and AH-6 "Little Birds". The MH-6 carries special operators on benches outside the helicopters, from which they can move quickly. The AH-6 is for close air support. The MH-47 Chinook helicopter has been used to carry special operators using long-wheelbase Land Rovers and other vehicles in and out of an area of operations. For longer-range special operations, the Air Force had operated the MH-53 Pave Low helicopter with extensive avionics for navigation, flying at very low altitude, and electronic