P Factor

[Glasairmell]

Those who have this do you find the P Factor accurate on take off?

Cheers!

Edited April 3, 2019 by Glasairmell

[Coop]

8 hours ago, Glasairmell said:

Those who have this do you find the P Factor accurate on take off?

Cheers!

There is a P-Factor that is determined by X-Plane as it runs - We are looking into making sure it is sufficient P-factor to represent the high torque of the aircraft.

[Gregg Seipp]

I just want to say this about P-factor on the runway.  Yes, from what I understand, there is a tendency for the aircraft to want to steer left on takeoff.  But, what this means is that the forces push the airplane left which makes the nosewheel want to turn to the left.  This means that, in the real airplane, you can feel the right pedal trying to come up under your foot..  A real pilot has to apply right foot pressure in order to keep it from coming up...to keep the pedals even and the airplane centered.

However, unless you have force-feedback pedals with your sim the two pedals are going to stay centered...which *should* mean that your nosewheel *is* centered.  So, with your nosewheel centered, if you press your right pedal in the sim in order to simulate the foot pressure real pilots do (making it further down than the left pedal) you are going to be turning the nosewheel to the right and, if your airplane staying centered, you are skidding...which is *not* what you want...at all.  So, while I'm all for having P-factor and torque effects in the climb, I'd be very cautious about making such changes while the airplane is on takeoff roll.  

Gregg

Edited April 3, 2019 by Gregg Seipp

[Glasairmell]

At a point in take off roll rudder compensates for P Factor.  Many planes do not have nose wheel steering.  At lower speed, brakes keep the plane on center line to over come the P Factor.

On a high horse power turbine driven airplane such as the Pocket Rocket P Factor can be a real problem.   There is not enough rudder authority  to overcome the P Factor from that mill.  Therefore punching full throttle on take off is usually not a good idea.

For a good simulation for this aircraft design you should have a hard time keeping it straight at full throttle on take off. 

Edited April 3, 2019 by Glasairmell

[sdflyer]

P-factor is prominent during climb.
What you experience on take off run in mostly torque and slipstream. Also there is gyroscopic precession that predominantly noticeable in tail draggers when tail is raised


Sent from my iPhone using Tapatalk

[Glasairmell]

@sdflyer yes torque and prop wash on take off roll not P factor since there is no angle between relative wind and the axis of the propeller.  I did not word that correctly.  So you are saying P factor is prominent during climb on the Pocket Rocket?

Edited April 4, 2019 by Glasairmell

[Bourrinopathe]

I'm certainly not qualified to have an educated opinion on the flight behavior but the PR is surprisingly docile and doesn't suffer from huge torque and p-factor effects.
I pushed it on steep climbs, descents, rapid torque changes (low to max, max to low in seconds), and some aerobatics (she's also beautifully stable in knife edge flying) - but I can't tell how realistic this could be, especially as X-Plane has its own limitations (gyroscopic precession is still not modeled iirc? - but I understand the effects should be marginally noticeable during normal flight phases - except for specific aerobatics).
Good question @Glasairmell
And it must be difficult to fine tune a plane with such insane performances.

Edited April 4, 2019 by Bourrinopathe

[sdflyer]

I don’t know what you guys are looking for. Let go of controls and observe. Does airplane yaw and rolls?

Try slow flight Vso + 5. Do you feel you need to give more right rudder? Can you use power for altitude and pitch for airspeed ? I think it’s just a basic things to discover before go to much into science.

 

A lot of WW2 birds had huge powerful engines and 50 hours pilots could handle them just fine. Also remember in most cases designers try to offset prop factors by tweaking thrust line, placing empennage certain way and etc

 

 

Sent from my iPhone using Tapatalk