How to use Rudder during takeoff in single engine propeller aircraft? e.g. Cessna 172

Question

Background: I am a complete beginner on Flight Simulator X: Steam edition, using a simulator setup with rudder pedals with realism set to the max (to simulate more realistic flying).

I understand that rudder use is essential to align the aircraft to the runway centreline during takeoff due to the left turning tendencies. However, I cannot seem to consistently align the aircraft to the runway centreline during takeoff. Sometimes, I just run parallel to the centreline.

Questions:

1. Is this common in real life flying? Are actual pilots consistently able to align the nose wheel to the runway centreline during takeoff in such single engine propeller plane or am I being too idealistic?

2. How is the operation of rudders in an actual aircraft like? Slow smooth gentle depression e.g. to the right pedal each time the aircraft swerve to the left or are the left and right legs constantly moving in quick succession to keep the aircraft aligned to the runway centreline?

3. Generally, how much of a push is required on the pedals during takeoff? It seems to be very very slight 1cm touches to my rudder pedal on the simulator. Is that realistic?

Thanks so much everyone! All answers are appreciated!

Answer 1

Is this common in real life flying? Are actual pilots consistently able to align the nose wheel to the runway centreline during takeoff in such single engine propeller plane or am I being too idealistic?

In my experience flying primarily light singles its not terribly difficult to stay aligned on the centerline during takeoff. Even my first solo was nicely centerline. However the more powerful the aircraft the more the tendency and the more control/care may be required.

How is the operation of rudders in an actual aircraft like? Slow smooth gentle depression e.g. to the right pedal each time the aircraft swerve to the left or are the left and right legs constantly moving in quick succession to keep the aircraft aligned to the runway centreline?

All control inputs should be smooth and with care. I generally ease onto the right pedal as I apply throttle and ease off/back on to stay center line.

Generally, how much of a push is required on the pedals during takeoff? It seems to be very very slight 1cm touches to my rudder pedal on the simulator. Is that realistic?

This is what most home sims are worst at. Real light aircraft rudder pedals take a fair bit of force to work an have far more than a 1cm throw. I would add a curve to your response so that the initial throw of the pedals is less sensitive.

Answer 2

In actual practice you will find it easier to quickly perceive any deviation (drifting) toward the left or right edge of the runway if you positon the aircraft so that the runway centerline goes right under your seat. So that you are essentially "sitting on" the centerline. This makes the runway centerline appear to project perfectly forward in your vision, issueing out from behind the instrument panel from a point directly above the center of your control yoke, without "leaning" left or right. Any slight "lean" in the centerline to either side means you have drifted slight left or right of this ideal position. (A photo or illustration would really help here.) You'll be to see this immediately, and make a correction to come back to your original position, as far as left/ right drift goes.

In an airplane with side-by-side seating, this method does not put the nosewheel exactly on the centerline, but that's ok. There's rarely any reason to put the nosewheel exactly on the centerline, and this method allows you to perceive any lateral drift sooner than if the nosewheel were on the centerline, because of the way it allows the centerline to project perfectly straight forward in your visual field as long as you are maintaining the target picture.

It's like the difference between sighting a gun by holding it directly in front of you, versus sighting a gun by holding it several feet off to one side of you. The latter is analogous to the sight picture you get in a side-by side airplane when trying to take-off or land with the nosewheel, rather than the center of your own seat, aligned with the runway centerline. Unless the runway is incredibly narrow, the tradeoff in terms of increased obstacle clearance at the wingtips is not worth the greater difficulty in recognizing that you are drifting further to one side or the other, or that you are not actually aimed perfectly parallel to the runway heading. Both of those things are bad for the landing gear, whereas having the nosewheel two feet to one side is not bad for the landing gear.

To get a hands-on feel for how useful the effect I'm talking about is, sometime when you are driving down a long straight road with no other cars around, move your car over so you are driving with the highway centerline passing right under your seat-- as if you are "straddling" the centerline between your legs. If the road is very long and straight, you'll get the sight picture I'm describing here, and any slight deviation from this position will be immediately apparently. It will be much easier to maintain this position very precisely to a tolerance of just a few inches, than it is in the usual driving position.

At the very least, don't move on to try landing or taking off with the nosewheel right on the centerline, until you have completely mastered the simpler method described in this answer.

Try this: while taxiing down a long straight taxiway, position the aircraft so that the taxiway centerline goes right under your seat and projects forward in a perfectly straight line, and make sure you are sitting up perfectly straight, directly behind the middle of the control yoke, and memorize the exact point on the front of the cowl where the centerline disappears from view behind the cowl. That's your "sweet spot" or "gunsight point" -- remember it for later. (It's much closer to the edge of the cowling-- much further from the center of the cowling-- than you may expect.) When you are lining up on final approach, you can determine whether the aircraft is left or right of the runway centerline by looking at whether the runway centerline is "leaning" slightly to either side, and you can detect any left or right "drift" by looking for the first slight hint of any "lean" starting to develop in the appearance of the runway centerline, and you can tell whether the aircraft heading is exactly the same as the runway heading by seeing that the (non-leaning) runway centerline disappears behind the cowl exactly at the "gunsight" point described above, and not at some other spot a few inches off to either side. Note that you must actually be in motion on the taxiway when you pick the "sweet spot" or "gunsight point". Otherwise, even if the runway centerline is passing directly under your seat, the aircraft could be pointed a few degrees off from the actual runway heading, and it might be hard for you to detect that. When you are in motion, it is obvious-- if the wheels are firmly on the ground, and the centerline is staying under your seat, then the aircraft must be pointing exactly parallel to the taxiway centerline.

Naturally, on final approach, this cowling "gunsight" tip only applies when there is no crosswind or when you using the wing-down method rather than the crabbing method to correct for crosswind. If you are crabbing, the centerline will disappear under the cowling at some other point. But looking for the appearance of any "lean" in the runway centerline always will tell you whether you are on the centerline or not, and as long as you are trying to land with your seat rather than the nosewheel on the centerline, it will work just as well during the actual flare and touchdown as it worked when you were still a mile away on final approach.

PS-- if you a pilot with left-seat experience just learning to fly from the right seat, and you find yourself tending to land with the nose cocked off to the left, pay attention to the "gunsight spot" on the cowling the next time you are taxiing down a long straight taxiway (or while you are in motion on the runway). You may that your landings suddenly improve.

Answer 3

It is very rare to take off in perfectly calm conditions (wind can add or subtract from "left turning forces"). Rudder inputs are added on a "as needed" basis by the pilot, usually in small increments. Taking an hour at a local airport in a 172 may be your best answer.

Keep in mind, with side by side seating, your eyes are slightly off the centerline when the nose of the plane is on it. The important thing is to have throttle and rudder working together. Smoothly add throttle, don't just jam it. You need to accelerate to rotation speed (around 55 knots), controlling your line with the rudder. The center line is your reference, it does not have to be perfect, just as straight as you can until lift-off.

A few tries with an instructor should be sufficient to compare with your simulator.

Answer 4

I cannot talk about the realism in flight simulator these days, I haven't used it since I became a pilot many years ago. From my experience back then I found that ground handling was one of the least realistic aspects of the experience compared to the real thing, so I wouldn't worry too much about that aspect.

Keeping on centerline is a matter of experience, you learn to anticipate how much rudder you need. I can't even tell you how much I push because I don't even think about it, it's natural. I don't make full-deflection inputs on the rudder on takeoff, and I may be constantly adjusting my input depending on conditions. I have no problem keeping it on the centerline, although in training it's very common to make mistakes.