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 Point Chinook Point Chinook Point is a headland in Pacific County, Washington. Located just northwest of the mouth of the Columbia River, it is historically significant for several reasons. Captain Robert Gray, the first non-native to enter the river, saw it from Chinook Point in 1792. In 1805, it was the site of an encampment by the Lewis and Clark Expedition. It has been the site of military fortifications since 1864, most notably in the late 1890s, when most of the presently surviving Fort Columbia structures were built. The point, which constitutes the most developed portion of Fort Columbia State Park,