Adjusting fixed rudder trim tab

[dstclair]

I've got myself over thinking a very simple task so thought I throw this it to the group. Somehow my fixed rudder trim tab was slightly bent during a hangar reshuffling. I readjusted the trim tab to where I thought was the original angle (which is very slight). I now seem to have developed a yawing to the left with neutral rudder.

In determining which way to bend the tab, I found the following advice from http://members.eaa.org/home/homebuilder ... t%202.html:

All you have to remember is that a trim tab forces the control surface in the opposite direction from which the tab is bent.

For Example:

1. If the nose of the aircraft is yawing to the left, bend the rudder trim tab to the LEFT.

2. If the aircraft has a nose heavy condition, bend a fixed elevator trim tab DOWN.

3. If one wing is heavy, bend the trim tab on that wing UP.

So do I bend the tab to the LEFT as I'm facing the tail section or do I bend it to the LEFT as I'm looking from tip-to-tail?

[drseti]

By convention, left and right sides of aircraft, engine, or control surfaces are defined in terms of how the pilot normally sits. This is relevant, for example, in the case of pusher prop aircraft like Eddie's Sky Arrow, where what I consider the right side of my engine is actually his left side...

In your case, Dave, you'd bend the tab to the left as you're facing forward. Moving the tab left forces the rudder slightly to the right, which has the same aerodynamic effect as adding right rudder.

[MovingOn]

.......

[FastEddieB]

Without resorting to rote rules...

Just imagine what you're asking the tab to do.

If you need help holding right rudder, let's say, you'll need some sort of force to help you.

Think of the "little wing" (trim tab) as using air pressure get the "big wing" (rudder, in this case) to assist you in holding pressure, thereby alleviating you from needing to hold constant pressure.

So, left in this case.

Does that help, or just make it MORE confusing?

[FastEddieB]

Oh, one more thing...

The correct way is to clamp the trim tab between two blocks of wood, to maintain a uniform "crease".

If you don't, it can end up wrinkly. Still works but less aesthetically pleasing.

And though its done all the time, it's not on the list of things an owner can do.

Seems silly, but just sayin'.

[CharlieTango]

I ... have ... a yawing to the left with neutral rudder...

1. If the nose of the aircraft is yawing to the left, bend the rudder trim tab to the LEFT...

So do I bend the tab to the LEFT as I'm facing the tail section or do I bend it to the LEFT as I'm looking from tip-to-tail?

The problem and the solution both refer to left. In both cases it is the same left, as in the pilot flies from the left seat with the instructor in the right. The left is also known as the port side.

[drseti]

The left is also known as the port side.

Because that's the side on which you store your bottle of port. The right side of the plane, therefore, is the bourbon side (or is that the gin side?)

[dstclair]

The left is also known as the port side.

Because that's the side on which you store your bottle of port. The right side of the plane, therefore, is the bourbon side (or is that the gin side?)

Cognac!

[drseti]

Thanks for the correction, Dave. I always learn so much on these forums!

[deltafox]

Reference: http://beeradvocate.com/beer/profile/454/1569/

Arcadia Starboard Stout

[drseti]

Thanks, Dave - I never knew about that ASTMO rating scale before. As I said, I'm always learning something new here!

[dstclair]

Reference: http://beeradvocate.com/beer/profile/454/1569/

Arcadia Starboard Stout

You call that beer --> try Duvel at 100pts - http://beeradvocate.com/beer/profile/222/695/

[drseti]

You beer connoisseurs go right ahead and debate. I'm just drinking this all in.

[drseti]

Oh, and before somebody rightly accuses us of thread drift, I hasten to point out that this is just what a hangar flying session sounds like at my airport.

[Merlinspop]

Point the trim tab ever so slightly toward the side that has (or would have) the red light on the wingtip.

Oh, and before somebody rightly accuses us of thread drift, I hasten to point out that this is just what a hangar flying session sounds like at my airport.

I prefer forums that let discussions move around a little as they would if we were gathered around a BBQ grill and cooler.