That is to say, the blades will generate more lift while they advance into the direction of flight, and less while they retreat on the opposite side of the helicopter. This cone will also be tilted sideways with respect to the direction of flight because the blades see different airspeeds at different points in their cycle. The cyclic controls suffer the same effects, that is the least of their problems, see below.Ī single rotor in forward flight will assume a slightly conical shape due to the lifting force on the blades. In fact, this is how yaw is achieved when the pilot steps on the pedals, by letting the rotors generate differential lift, but ensuring their combined total stays the same so the aircraft retains level flight. This is important because a torque imbalance will make the aircraft yaw uncommanded. Since the lower rotor operates in the down-wash of the upper one, its collective pitch needs to be higher to produce the same lift (and thus torque). It does not just need to invert the rotation direction, it has two sets of cyclic and collective controls that also mimic the effect of a tail rotor. DisadvantagesĪ coaxial rotor has a much more complex hub than a regular one. I am going to assume the reader has a basic understanding of helicopter controls (cyclic, collective, antitorque).
The unique configuration of twin coaxial rotors presents both advantages and disadvantages, and the relative weight of each must be considered in light of the aircraft's mission.
0 kommentar(er)
