Idle Curiosity Re Hornet Rudders

[wolfie138]

i'm modelling a plane and like the F18, she has non-vertical tailfins, and an idle thought struck me ~ how do the rudders on an F18 work? being angled, doesn't that cause the plane to twist rather than move horizontally?

[Dazza37]

...how do the rudders on an F18 work? being angled, doesn't that cause the plane to twist rather than move horizontally?

No, the rudders, as with all other control surfaces are controlled by the jet's FCS, if the pilot inputs a rudder demand, the FCS decides how much is appropriate and will also add aileron or maybe even opposite rudder deflection if needed to counter any (if there even is any?) 'twisting' action, hope that helps...

-Dazza

[wolfie138]

thank you :-)
don't think i'll bother w/ that level of detail when i rig the rudders though, given the plane's a made-up concepty thing.

cheers

[Seahornet1]

thank you :-)
don't think i'll bother w/ that level of detail when i rig the rudders though, given the plane's a made-up concepty thing.

cheers

Almost all aircraft have a rudder(s) that is predominantly above the centre line, which means that a slight rolling force will be imposed in the opposite direction to that of the rudder deflection. However, this is more than counteracted by the (usually) much greater rolling force created by the aircraft yawing in the direction of the rudder. The angle of the Hornet's rudders will make no difference at all to these rolling forces. The only difference that the angle makes is that when both are equally deflected, one will tend to pitch the nose up, and the other will tend to pitch nose down; naturally, these forces will cancel each other out, so there's no net effect.

As for your model, you don't need to make any special arrangements for the angled rudders. Any slight differences in response (compared to the perpendicular variety) will be undetectable in comparison with the inevitable differences in control response from one aircraft to another.

[wolfie138]

very informative! thanks :-)