Let's say you are at a safe altitude and landing gear is down and the aircraft is in To/L gains and you want to do aileron roll and apply full left (or right ) stick to do the rolling maneuver.The F16 doesn't have any ailerons only flaps moving up and down .But because is in the take off /landing gain's with the flaps deployed at maximum angle only one moves other stand still at 20 degrees down .Will the raised flaperon go above the wing cord or not , meaning will rise up above the cord line of that wing or not passing the wing line ?


2 Answers 2


As per flight control diagram from General Electric 1975:

The aileron control can command +/-21.5 degs.

The flap control can command +21.5 degs down (even though the HUD will say 20 but there is in this control a +1.5 electrical bias which will be neutralized by the mechanical bias). This is added to the aileron control output.

Then one should subtract the 1.5 degs mechanical flaperon bias.

The flaperons can move +20 to -23. (remember negative is up)

So one flaperon will be at +20 down while the other will be at -1.5 up above the cord given that the aileron produces max aileron roll.

So the question is will the aileron control command max deflection if you are airborne? Most likely no when the aircraft starts rolling, as when the gear is commanded down, internally in the roll system the command will be decreased due to roll rate, and the command is only about half with gears down.

But when you are weight on wheels and the roll rate is zero, you will get one of them 1.5 degs above the cord line, when you command max roll.

Source document: Diagram in AD-A055-417.

  • $\begingroup$ So if the F-16 is airborne, with the flaps down and pilot comanded full max roll, the flaperons gives half of max rolling rate(possibly the halfway travel of the flaperons(this is 10degrees under the cord line for the rise up one but this is influenced by the speed at the moment) and when weight is on main wheels then only oneflap will go up 1.5above the cord line. This is my understanding. It is ok? $\endgroup$
    – George Geo
    Jan 21, 2021 at 1:59
  • $\begingroup$ I made a mistake in my answer, I will update in a while. $\endgroup$
    – Invariant
    Jan 21, 2021 at 4:10

Contrary to the first answer, the flaperon will actually go up according to the control surface mixer from the DFLCS control block diagram in DTIC ADA 189675:

F16 aileron TEF mixing Take both the aileron deflection and TEF at maximum deflection, then you will get one flaperon at 21.93, and another at -21.5.


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