How to turn the heading with the rudder pedal?

[Michael-Fr]

Hello,

How do I change heading with the pedals?

This is beyond my understanding. Inputting the pedals puts the aircraft into a crab position, then when I release the pedals, the aircraft returns to the direction it was on when I started the input.
I tried disabling the flight controls (AFCS) and the ARI: the aircraft can then change heading with the pedals, but it's too slow.

There's surely something I don't understand, or maybe it's not designed to maneuver like this at all, and heading changes only occur with pitch movements.

If anyone can clarify this for me, that would be great.
Sincerely,
Michael

[OmasRachE]

As far as I know, the rudders are not designed to change course of the aircraft. As I understand there are only two usecases for the rudders. First to adjust the noseheading on final approach in the case of crosswinds to hold the glidepath and second you can use the rudders on high angles of attac and low speed to roll the aircraft, because aileron inputs cause the opposite reaction than intended under these conditions. And of course you can use the rudders to make smoother turns while banking like you would do on a light prop plane but honestly I didn´t noticed any positiv effect on my turns, so I just keep my feet off the pedals during the normal flight.

 

[Michael-Fr]

Thank you very much for your reply. I was confused when comparing this experience with that of other aircraft. All I can do now is return to my training sessions, cursing myself.
Sincerely,
Michael

[Raven (Elysian Angel)]

3 minutes ago, Michael-Fr said:

I was confused when comparing this experience with that of other aircraft.

Pedals are no meant to change heading in fixed-wing aircraft, only in helicopters and only in certain flight regimes at that.

[Lace]

It sounds to me like there is a fundamental lack of understanding on how aircraft manoeuvre in the air.  Turns are made by banking the aircraft in the direction you want to turn, ie. to increase the heading roll right, to decrease it roll left.  This is combined with some stick back pressure to maintain level flight.  The aircraft rolls by increasing lift on one side, and decreasing it on the other.  This is achieved by ailerons moving in opposition.  The result of more lift on one side is more drag on the same side (which wants to yaw the aircraft to the outside of the turn).  This is where the rudder comes in.  The rudder induces yaw primarily, and the second order effect is roll.  To counteract the yawing moment from the asymmetric drag, a little rudder in the direction of the turn is used.  This effect varies airframe-to-airframe, and is dealt with by the computer in a FBW aircraft, meaning in (almost) all flight regimes, there is no real need to touch the rudder pedals. 

In the F4 at high angles of attack (i.e. nose pitched up but without the resultant climb) the rudder can be used to start a turn.  This is the second order effect.  By yawing at low speed the fuselage is blanking a large portion of the inside wing, resulting in a reduction in airflow, which in turn reduces the lift, causing the wing to drop, hence roll. 

Rudder is also used to counteract the p-factor on large piston-engined aircraft, but that isn't relevant to the F-4.

Aerodynamics is a complex subject, and rather than spend all day doing this, I politely direct you to John Denkers old but brilliantly written website, av8n.com.  

[Michael-Fr]

Thanks for this lesson; it will be very useful.

(...I do remember using the rudder pedals for heading changes, while playing the "lock-on" version released in 2003. At the time, the jets weren't yet coded in high-fidelity, which might explain why.)

[ricktoberfest]

7 minutes ago, Michael-Fr said:

Thanks for this lesson; it will be very useful.

(...I do remember using the rudder pedals for heading changes, while playing the "lock-on" version released in 2003. At the time, the jets weren't yet coded in high-fidelity, which might explain why.)

The airflow along the fuselage and vertical stabilizer makes the plane straighten out as soon as the rudder input is removed. That, and the uncomfortable skidding feeling is why planes bank to turn. You can force it by holding the rudder over for long periods but it’s not a very efficient way to turn as you’re fighting aerodynamics. 

[Ziggy123]

 

[Dragon1-1]

Holding a forward slip will eventually induce a heading change, but it's very slow, and also rather counterintuitive, because the flight path moves far less than the nose does, and the nose will snap back into trim, seemingly undoing the heading change (if you look closely, you'll notice you've turned a few degrees). In LOMAC, this was probably exaggerated. Either way, except for high AoA and stunts like rudder reversal, the pedals are not used to turn. You roll and pull a little, and it'll turn perfectly well.

[=475FG= Dawger]

You can swing the nose through a turn using rudder. It isn’t the most efficient method but it can certainly be done in any airplane. 
 

If you are using ailerons simultaneously to keep the wings level, you are fighting yourself.