Elevator trim tab movement

[Jansgi]

I noticed that when I trim nose up the trim tab on the elevator pitches down and the other way around. I'm not an expert on aerodynamics but shouldn't it pitch up when trimming up and down when trimming down? The plane does pitch in the correct direction when trimming tho. If the whole elevator moves when trimming then I know this is the right behaviour but I only see the trim tab moving when trimming.

Edited November 18, 2015 by Jansgi

[Sporg]

I noticed that when I trim nose up the trim tab on the elevator pitches down and the other way around. I'm not an expert on aerodynamics but shouldn't it pitch up when trimming up and down when trimming down? The plane does pitch in the correct direction when trimming tho. If the whole elevator moves when trimming then I know this is the right behaviour but I only see the trim tab moving when trimming.

 

You should think of the trim tab as a separate elevator, moving the edge of the big elevator up and down in the air stream.

 

So if you for instance trim up, the trim tab is moved down.

When it encounters air stream, it forces the rear edge of the big elevator upwards, and thus you get the aircraft trimmed up.

[Jansgi]

So if you for instance trim up, the trim tab is moved down.

When it encounters air stream, it forces the rear edge of the big elevator upwards, and thus you get the aircraft trimmed up.

 

I know it should work like this, but atm only the trim tab was moving while flying but elevator was in the same position regardless of the trim.

 

I don't see it working like this atm:

 

Need to experiment on higher speeds to see if it works as it should.

Edited November 18, 2015 by Jansgi

[Echo38]

Are you using a force-feedback joystick, or a spring-centered one? If you're using FFB, and holding it in a constant position, then the trim tab should move but not the elevator. Only when you release the stick should the elevator move to the trimmed position. With a spring-centered stick, this behavior isn't possible, but if you're using an FFB and holding it steady when you trim, then what you're seeing (if I read you correctly) is accurate behavior.

[Jansgi]

Are you using a force-feedback joystick, or a spring-centered one? If you're using FFB, and holding it in a constant position, then the trim tab should move but not the elevator. Only when you release the stick should the elevator move to the trimmed position. With a spring-centered stick, this behavior isn't possible, but if you're using an FFB and holding it steady when you trim, then what you're seeing (if I read you correctly) is accurate behavior.

 

I did some testing with different speeds and regardless of FFB or spring-centered the elevators are moving when trimming. The trim tab is working as it should. I didn't see it for some reason in the first tests I did :doh: