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Old 2nd Dec 2006, 16:12
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NickLappos
 
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Hillerbee and skadi are quite almost right. We just have to adjust for gamma (rigging adjustment for "precession").

The "pitch angle" is the measure of what the controls do to the blade angle. It is geometric, and is measured by a protractor.

The helo, in balanced flight at forward speed, must have more AoA on the downwind blade than the upwind blade, due to dysymmetry of lift, since the downwind blade has less airspeed, it must have more AoA to create equal lift. This means the pilot has "balanced" the condition by applying cyclic to create this difference in AoA.

To confuse things further, the rigging must be about 90 degrees off (for "gyroscopic precession" let us call it), so the pilot places the cyclic to the right as he flys faster (US/UK convention) and this makes the geometric pitch of the blade increase in the forward section of the disk, and decrease in the aft (90 degrees before the desired blade motion).

Thus, the answer is "pitch angle Increases in the front, decreases in the back" which is an answer not given!
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