Please un-torque my neurons.... Prop effects et al...

[jcomm]

This very same questions have been asked certainly many times, on many forums, and I guess I even might have already raised the problem in other forms here at PPrune, but I really have to understand what's going on between Real Life, Theory and Flight Simulation....

I am a glider pilot since 1980. Have flown many times on prop aircraft, and even had the chance to "drive" a few, but I do not have a PPL for motorized aircraft other than SSG / SLG.

I have long been using flight simulators, and have found in almost all of them the prop effects: Torque, P-Factor, Gyroscopic Precession and Spiraling slipstream) translated mostly into roll instead of yaw, while, IRL, it is mostly yaw, and not bank, that results in the first place, on most GA aircraft ( naturally, a WW2 fighter is a different matter...) causing the nose of the aircraft to drift to the left ( on a CW rotating prop ) and the pilot to use right rudder to counter it. When he does it, the ball centers, there is no sideslip, and the wings are level.

Let's assume the aircraft in this post have all CW-rotating props.

Now, the books, and many texts for aviation name the torque effects as causing a rolling moment ( to the left ). The simulators I have used translate mostly into roll the sum of the 4 above mentioned prop effects, and you really have to use aileron, or aileron trim, because if you use only rudder, there will be a lot of it required to level the wings, and when they're level, "your ball" will be almost fully to the left (???) I always found this representation of the prop effects in most flight simulators not precise.

When I talk to fellow pilots and ask them about what they feel on their Cessnas, Pipers, Robins, etc... they all say that it's mostly yaw.

When I try to refute the arguments of flightsim designers they, most of the time, come up with a justification based on the fact that the pilot almost unconsciously adds yoke / manche inputs to counter the roll from torque, and levels the wings, but RL pilots tell me this is not the case, and that they can even let the hands off their yokes while they use pure rudder to counter the prop effects at high power / high AoA, keeping the ball centered and the wings level, without an hint of aileron or aileron trim use.

Also, most GA aircraft do not even have trimable rudder or ailerons and some have only a rudder trim. Yes I am aware that they have fixed trim tabs, some on the rudder others on the ailerons too.

Now, can you help me understanding why:

- In RL apparently the prop effects translate mostly into YAW, and of course roll will naturally be induced by if you do not take action to counter the yaw and stop the sideslip;

- In Theory, and many aviation syllabus the roll due to prop/engine torque effects is mentioned as existing and playing it's role;

Thanks in advance for any help/suggestions :-)