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
Robinson Helicopter Company Robinson Helicopter Company The Robinson Helicopter Company, based at Zamperini Field in Torrance, California, is a manufacturer of civil helicopters. Robinson produces three models – the two-seat R22, the four-seat R44, both of which use Lycoming piston engines, and the five-seat R66, which uses a turbine engine. The company was founded in 1973 by Frank Robinson, a former employee of Bell Helicopter and Hughes Helicopters. Since delivering its first helicopter in 1979, Robinson Helicopter has produced over 12,000 aircraft. Plans for production of the Robinson R66 were announced in March 2007. It is a five-seat helicopter of similar configuration to