The situation becomes more complex when helicopters with two sets of rotor blades are considered, since in theory at least, the dissymetry of lift of one rotor disc is cancelled by the increased lift of the other rotor disc : the two rotor discs of twin-rotor helicopters rotate in opposite senses, thus reversing the relevant directions of vector addition.
32.
The situation becomes more complex when helicopters with two sets of rotor blades are considered, since in theory at least, the dissymetry of lift of one rotor disc is cancelled by the increased lift of the other rotor disc : the two rotor discs of twin-rotor helicopters rotate in opposite senses, thus reversing the relevant directions of vector addition.
