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
Chinook salmon century. Maritime fur traders and explorers, such as George Vancouver, frequently acquired salmon by trade with the indigenous people of the Northwest coast. Lewis and Clark first encountered Chinook salmon as a gift from Chief Cameahwait, on August 13, 1805, near Lemhi Pass. Tasting it convinced Lewis they had crossed the continental divide. Known as the "king salmon" in Alaska for its large size and flavorful flesh, the Chinook is the state fish of this state and of Oregon. Chinook salmon The Chinook salmon ("Oncorhynchus tshawytscha") is the largest species in the Pacific salmon genus "Oncorhynchus". The common name refers