ramp_up
20th Dec 2008, 09:43
Hi Everyone,
Whilst I think I understand the principles of Yaw control in coaxial helicopters. Eg Increase pitch angle on one set of blades / decrease on the other use the Tq reaction to yaw the ac. How in practise is differential "Collective?" pitch actually applied to the sets of rotors. I have studied a number of photos of coaxial rotor heads and as far as I can see there are only 3 Jacks as per most helicopters designs. This would give standard pitch, collective and roll inputs to both heads. Using this design the only way yaw could be applied in my eyes if for one of the swash plates to move in the vertical plane( raised or lowered) along the rotort mast. Thus altering the collective pitch angle of only one set of blades but not the other.
Am I close or missed completely :ugh:
Whilst I think I understand the principles of Yaw control in coaxial helicopters. Eg Increase pitch angle on one set of blades / decrease on the other use the Tq reaction to yaw the ac. How in practise is differential "Collective?" pitch actually applied to the sets of rotors. I have studied a number of photos of coaxial rotor heads and as far as I can see there are only 3 Jacks as per most helicopters designs. This would give standard pitch, collective and roll inputs to both heads. Using this design the only way yaw could be applied in my eyes if for one of the swash plates to move in the vertical plane( raised or lowered) along the rotort mast. Thus altering the collective pitch angle of only one set of blades but not the other.
Am I close or missed completely :ugh: