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
Billy Chinook 160 feet into Lake Billy Chinook from the precipice of Crooked River Canyon, is known locally (unofficially) as "Billy Chinook Falls". Billy Chinook Billy Chinook was a chief and member of the Wasco tribe. Chinook was a guide for John C. Frémont and Kit Carson, who explored Central Oregon from 1843 to 1844 and from 1845 to 1847. Chinook also served as First Sergeant, U.S. Army Wasco Scouts during the Snake War. Lake Billy Chinook in Oregon is named in his honor. Billy Chinook (aka William Parker) was born circa 1827 in the area that was to become Fort Dalles,