Airfoiled Vert. Stab.

[coosbaylumber]

The German Me 109 had a airfoil shape to the fin/rudder to offset torque from the engine.

Did any other A/C have such, like maybe the Me 110?

Wm.

[Tom Harper]

Wm,

I don't know of any but the idea must have appeared elsewhere. On the ME109 it was probably designed in because of the large engine. It had little effect at low speed where it was needed. A significant number of airplanes were lost due to lateral problems in take off and landing.

[Sparky Paul]

Offsetting the fin was more usual than airfoiling it.

[JRuggiero]

The Macchi 202 (and maybe the 200) used an offset fin.

Jim R

[BMatthews]

... as do the Mustang, Spitfire and most private aviation aircraft. In fact I think you'll find that pretty much all full sized prop planes use a built in fin offset.

[coosbaylumber]

Nope, no offset, but a genuine semi-symetrical airfoil was used on the 109. Look it up.

I (thought) that the Me 110 also had same situation. It used two airfoiled ones though.

Wm.

[Ollie]

A semi-symetrical airfoil has zero lift angle of attack which is minus degrees. So that the aerodynamic functions are the same between semi-symetrical or off-set-symetrical airfoils.

[Salto]

So that the aerodynamic functions are the same between semi-symetrical or off-set-symetrical airfoils.
Not always the case. On the Supergee 2 DLG the fin is airfoiled because it has to correct a large yaw force on launch. The large yaw force is always in one direction. In this case, a cambered airfoil can develop a higher lift force to resist that yaw, and do it with lower drag. There will be some small cost of increased drag in un-yawed flight, but because the launch is crucial for DLGs this cost is worth paying for. So the aerodynamic behaviour of a cambered fin airfoil (even if it is set with it's zero lift angle of attack aligned with the fuselage) will be different in yawed flight.

On a powered plane the problem is not the same. I presume the requirement is to produce a constant small yaw force to counter the roll produced by prop torque or spiral prop wash. I guess there is some very small L/D advantage in having a cambered fin airfoil to do this, but a symmetrical airfoil will perform almost as well (for small lift co-efficients), so that's why we observe both solutions used in full size plane.

Graham.

[harveyweewax]

So how much offset is required? In my particular case I am building a scale model of an Albatros DIII (approx 30" wing span) and I would like to incorporate some offset into the vertical stab to counteract the prop effects. I would normally add 1 to 2 degrees of right thrust but, for aesthetics, I would prefer to keep the thrust line parallel to the fuse datum line. Would offsetting the stab by 1 or 2 degrees provide the same effect? Is there a rough rule of thumb one can use?

Regards,

Sven

[Sparky Paul]

The Albatross had no engine or vertical fin offset.
For real scale, you shouldn't have any either...
Use the rudder to accomodate any thrust problems, like the Baron did. :)

[harveyweewax]

The Albatross had no engine or vertical fin offset.
For real scale, you shouldn't have any either...
Use the rudder to accomodate any thrust problems, like the Baron did. :)


So, in other words, work on improving my flying skills. :D . Thanks Sparky!

Regards,

Sven