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As far as I know, there are two part devices that involved when turning an airplane when it flying: aileron and rudder. How they work? Which one is first over another when turning/banking? In this case, the airplane is the common commercial airplane which is has ailerons, horizontal and vertical stabilizers, elevators, and rudder. Not the V or /-shape empennage like mostly used in drone.

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marked as duplicate by Sanchises, StephenS, fooot, ymb1, Ralph J Feb 6 at 18:14

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Ailerons are but one type of primary flight control surface, which are used to roll the airplane about the longitudinal axis, thereby directing the lift vector generated by the wings from the vertical to the direction of a desired turn, thereby providing the required force to cause the airplane to change direction. Ailerons aren’t the only primary flight control surfaces which can do this; other types can include flaperons, differential elevator inputs and differential spoilers.

Rudders are used to counter adverse yaw caused by the difference in induced drag created as a byproduct of aileron inputs, which cause the nose to swing toward the outside of the turn, resulting in uncoordinated sideslip and inefficient turning of the aircraft. In the case of a V or Swallow tail, ruddervators fulfill the function of both rudders and elevators and would be used to counter adverse yaw as well.

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  • $\begingroup$ Do we always need to activate (to use, whatever the best word for it) rudder when turning/banking? $\endgroup$ – AirCraft Lover Feb 6 at 5:40
  • $\begingroup$ Not necessarily, though rudder will be needed in order to execute a COORDINATED turn. Rudder is not needed simply to bank the aircraft, only to counter adverse yaw when rolling into and established in a coordinated turn. $\endgroup$ – Carlo Felicione Feb 6 at 6:05
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Airplanes turn by banking, displacing the lift vector to an angle from vertical. Same as a helicopter moves laterally by tilting its rotor disc, or a hovering rocket would move laterally by tilting off vertical. The airplane is moving forward as it moves laterally, so its lateral motion is an arc instead of a straight line sideways.

The elevator's job in a turn is limited to increasing the overall lift vector, by increasing the wing's angle of attack, to compensate for the loss of the vertical lift component in the turn. Same as a helicopter has to increase rotor thrust (or the hovering rocket its thrust) when moving laterally to keep from descending.

The rudder's job is only indirectly related to turning. It's only job is to keep the tail lined up behind the nose in the airstream, the fin doing so passively (like a weathervane), and the rudder surface doing so actively (to counter adverse yaw from the ailerons and engine torque, which tend to overpower the weathervaning effect of the fin), while also providing the ability to move the tail out of alignment with the nose if that is desired (sideslipping). Or to compensate for asymmetric thrust in the case of a multi-engine airplane.

If you have an airplane with zero adverse yaw effects and no torque effects, no rudder input is required at all to turn. In a jet, there are no torque effects to speak of, and adverse yaw is very minimal, requiring very little rudder input to counteract adverse yaw. The airplane's yaw damper system, which operates the rudder in a very limited range, has all the authority required to keep the tail lined up behind the nose when turning. You never touch the rudder pedals in a jet once airborne unless an engine quits.

Similarly, airplanes that bank by using spoilers only, like the Northrop P-61, or the Mitsubishi MU-2, and have zero adverse yaw effects, require no rudder at all in a turn.

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