Simviation Forums

Simple question: what's the secret to overcoming Torque and P-Factor?

Also, does the 172 have rudder trim?

Simple answer:  Opposite rudder...

I can't remember if the MSFS C172 has rudder-trim. Some real C172s do.. some do not.


Note..  In a C172, you don't use rudder trim to counteract these forces. They're only significant at full power, and at steep angles of attack. Just modulate the rudder when you appy takeoff power, and keep some opposite rudder in during the climb.

With bigger, more powerful, piston planes (especially single-engine), you can trim some rudder (and/or aileron) for an extended cllimb... Some even need it during cruise... it depends on the plane.

Don't react with the rudder, anticipate. When you go to add full power for takeoff, you know that you'll need right rudder, so start adding it in to keep yourself on centerline rather than waiting until you've drifted off to start applying the rudder.

Don't react with the rudder, anticipate. When you go to add full power for takeoff, you know that you'll need right rudder, so start adding it in to keep yourself on centerline rather than waiting until you've drifted off to start applying the rudder.

Excellent point.. or even one step further, like I do when I fly a 300hp  C206  or  C210 for real....  I'll be pointing a little to the right before adding takeoff power,,,

And if you're 6'5" like me, you can use the left rudder pedal on the left side, and the right rudder pedal on the right side.  Although, this usually works best when you're alone in the aircraft during cruising flight, and I've only tried it in a Cessna, and I highly recommend not doing this during takeoff or landing, but it's up to you.  Heck, you could probably fly with with your feet on the yoke and your hands on the pedals, but that makes it tough to reach the throttle.

Sorry, it's just one of those long nights.  Please disregard anything I say as my brain is completely melted from a homework overload. [smiley=birthdays.gif]

Never needed rudder trim in a 172, in real life or the sim... even during a prolonged climbout, once you lower the nose a bit for Vy, you don't need a whole lot of rudder. How much? "Step on the ball", that's how much.

If it's still a major pain for you in the sim (perhaps you're flying with a twist-grip joystick?), just go into Aircraft Realism and disable those effects. No shame there, as controlling rudder with the stick is a rough way to do it; not very realistic.

The 172 I flew to get my instrument rating had rudder trim, and the only time I ever touched it was once to center it after someone had moved it a notch.

So I'm still finding p-factor and torque at 75% power in level flight.  Any thoughts?

You'll still have torque and spiraling slip-stream effects at cruise, however, aircraft manufacturers usually put a small, permanently deflected trim tab on the rudder to account for this, so it might be a controller issue.

Try flying strait and level

I never really knew how much of an effect torque and p-factor had on an airplane until I did some hammerheads and humpty bumps in my aerobatic training.  I remember it was especially noticable in the humpty bump because when I did my first one over the top the nose would just go sailing off to the right (pull humpty... nose goes to the left when you push it).  So much so that on the very first time (my instructor had me do it this way the first time as a demonstration as to how much things want to move) when my nose had rotated just 90 degrees (so I was inverted at this point) the wings were at about a  20 degree angle and the nose was about 15 degrees off heading!  The only thing I moved was the elevator, the rotating prop did the rest in a fraction of a second.  

Since you won't be doing that in a Cessna 172 you won't need very much rudder.