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
2011 Afghanistan Boeing Chinook shootdown Abad. Recovery of wreckage from the crash site lasted until 9 August 2011. A spokesman for the Taliban, Zabiullah Mujahid, confirmed that eight of the movement's fighters had been killed in the assault on the compound. He said: "They wanted to attack our Mujahideen who were in a house, but our Mujahideen resisted and destroyed a helicopter with a rocket-propelled grenade." In the afternoon of 6 August a flash flood swept through the area washing away parts of the wreckage. Early media reports suggested the army had been tardy to recover flight recorders from the downed Chinook, and, as a