Physics of .....

[mhorowit]

Before the accident, we found that the beast flew with left wing low. My A&P installed a tab on the trailing edge of the rudder and I believe we had adjusted it so it flew hands off. I recall we spent some time flying, bending and re-trying.

Can anyone explain how the rudder trim-tab resolved the wing low problem? - Mike

[Hank Jarrett]

Re: Physics of .....

Yes
Hank J ;-)

Get me off line and I will go over it with you. It isn't complicated. Works just like picking up a wing with a little rudder.

[VictorBravo]

Re: Physics of .....

Well, ASSUMING that the "wing low" problem ALSO included the fact that the airplane turned towards the low wing.....

Then a rudder trim tab might be the correct solution.

But if the wing was low and the airplane was still going straight, then that could be a multi-layered problem.

The way to do it is to fly the plane straight and level, forcing it to hold a course and attitude, wings level. THEN make a note of what control inputs you are holding to make it fly straight. While you are doing this, also do it at full power and at idle power.

If it took more rudder to keep the airplane going straight than aileron, then a rudder trim tab is the solution. If the rudder did not need any pressure to keep it going straight, but you needed aileron to keep the wing from falling, then it is a rear wing strut adjustment AND possibly a rudder problem.

If the airplane did one thing with full power, and another without power, it is an engine mount thrust line adjustment too

If you have a little bit of time, go find the group of model airplane guys flying olde tyme "free flight" models in your area. Don't matter whether they're gas powered or rubber band powered. Just find a group of free flight modelers who fly often. Find the oldest, grayest haired one of them who has been flying free flight models since the Civil War. He is more knowledagbe about trimming an aircraft to fly properly than the 30 year old guy with three engineering degrees from MIT.

If you test fly your airplane and tell me what control inputs youhave to hold to make it fly level, and at what power settings you have to use what control, I will light a DT fuse for incense, conjure up the spirits of Carl Goldberg and Chet Lanzo and Sal Taibi and Joe Konefes, and tell you the likely cause of the problem.

(Anyone who thinks free flight modeling is a thing of the past, have a look at how Rutan's space ship comes back to Earth)

Bill

[mhorowit]

Re: Physics of .....

Well, ASSUMING that the "wing low" problem ALSO included the fact that the airplane turned towards the low wing.....Then a rudder trim tab might be the correct solution. Bill

Them's the symptom - Mike