The "P" Factor, new articles

[Texas Buzzard]

I have been using 2 to 3 degrees of right thrust for many years. All that time I thought I was compensating for the Torque effect.
I had read a little of the "P" Factor way back wen, and had forgotten 75% of what I thought I knew about it. But in the October Issue of Model Aviation (a magazin from AMA) I read some things about the "P" Factor that were absolutely ne to me.

1. This aritcle said that the "P" Factor only effects plane when it is flying slowly and whenthe plane if flying with some positive attitude. I take that to mean during T.O. or at the end of a climb when the plane has lost airspeed with nose still up.
2. It says that there is no effect on a plane flying at a high airspeed.
Yeah, I know what is high speed and what is low speed. But the average pilot understands.

3. They say to add some right thrust to dampen the effect by using right thrust.

4. It contends that the "left turn" is induced from the downward moving blade of the prop on the plan's right ( assuming you have a stock glow enginewith a counter clockwis spin looking from out in front of it) The fellow says when the nose is up a bit relative to the path of the CG of the plane thru the air will the "P" Factor be evident.

Now I'd like to hear some comments. Is this article in line with the accepted understanding of the "P" Factor? Let's hear 'em.

[vintage1]

I think you have it pretty much the way I understand it.

There are three things that cause planes to turn associated with power. The largest effect is torque pure and simple.

P factor comes in when operating at a high angle of attack - typically with WWII warbirds landing.. and the other one is gyroscopic precession that swings the tail when you apply elevator.

I think torque dominates at normal airspeeds, but gyroscopic precession and P factor were real brutes halfway through a takeoff. With not enough airspeed to control the plane easily on the rudder, brakes had to be dabbed to keep it on the strip,..an art form, or a crash waiting.

[Brandano]

There's yet another factor: the swirling air coming from the prop and hitting the vertical stab at an angle, inducing a yaw. This is usually fixed offsetting the tail slightly and/or adding a ventral fin. This one doesn't disappear with speed, and has usually to be trimmed out on model planes.

[vintage1]

There's yet another factor: the swirling air coming from the prop and hitting the vertical stab at an angle, inducing a yaw. This is usually fixed offsetting the tail slightly and/or adding a ventral fin. This one doesn't disappear with speed, and has usually to be trimmed out on model planes.

I class that with torque really, as the spiral airflow is how the torque is produced..the torque is the reaction to accelerating the air into the spiral..

You are right that it does produce a yaw moment if it hits the fin assymmetrically, though.