MYTH: AT POSITIVE ANGLE OF ATTACK, THE DESCENDING PROP BLADE IS AT A HIGHER ANGLE OF ATTACK, SO IT PUTS OUT MORE LIFT, PULLING THE PLANE LEFT.
NOT THE WHOLE PICTURE!!! You only THINK this because you stand on the ramp beside your airplane on the ground, looking at the prop hub, imagining the nose pointing up and therefore the right-hand blade seeming to take a greater "bite" out of the air. Here is where your visualization is WRONG: If the nose is pointed up with respect to the air stream, then that right-hand prop blade is actually NOT DESCENDING STRAIGHT DOWN LIKE YOU ARE VISUALIZING, BUT IS INSTEAD MOVING FORWARDS A BIT AS IT DESCENDS, SO THE ANGLE OF ATTACK IS NOT INCREASED LIKE YOU THINK ON THE DESCENDING BLADE!! So why DOES the plane pull left in a climb even though the descending blade is NOT at a higher angle of attack? Look to helicopters for the answer. Their ADVANCING blade (the main rotor blade that is coming FORWARD) wants to put out a LOT more lift since it is moving at its rotational speed PLUS the speed of the aircraft. The RETREATING rotor is traveling a lot SLOWER!! It is traveling at its rotation speed MINUS the speed of the craft. So there tries to be a lot more lift on the right side of the rotor system, and the pilot has to enter a lot of correction in blade pitch to fly straight! A climbing airplane is the same: The DESCENDING blade is actually ADVANCING INTO THE AIR A LITTLE BIT (THUS MOVING FASTER) SINCE THE PLANE IS TILTED UP! The CLIMBING blade is retreating away from the onrushing air a bit for the same reason! Thus, the DESCENDING blade puts out more lift from its HIGHER SPEED when the airplane is at high angle of attack.
I have to admit that it will not kill you not to know this (;-)) but the aviation MYTH says otherwise so I want to correct it... also the angle of attack does change a bit as well since the air is not rushing head-on into the prop but instead coming up from underneath a bit, but it is the "advancing/retreating" speed change that you do not know about.
This is a quote I came across from what I thought would be a Reputable source...
I am having trouble understanding how he (Lets call him Mr X) How Mr X is trying to disspell the P Factor theory.
To me, It appears he has a slight mix-up with heli theory similarities, and is trying to use the heli flap back theory and also the RBS theory to add to the Other forces at play on a rigid prop. when I think all he has done is not realized that they are one in the same (Without the mix-up)
I posted this hear. because I know most of you are Reputable. and I have seen a few posters here that (If still Active on the forum) will probably see the same slight Misconception Mr X has Mixed up...
Any takers..