Flaps

[David Davis]

Should I programme in down elevator when deploying flaps on my Telemasters, (high wing monoplanes.)

[Pete B]

Depends on the model, David. Most require some down ele but others require a bit of up.

 

I programmed my Easyglider with some spoileron and mistakenly added some down ele rather than up. When I switched them in it went into a very impressive 45deg dive.........

 

Go easy on the amount of flap you set initially and then apply them at a safe altitude to see the effect. If it balloons then set a couple of mill of down ele.

 

It's worth using a servo slow on the flaps to make it a more gentle transition!

 

Pete

[ken anderson.]

david-best to have a go high up and see how the model respond's to the flap's.......and then add what is reqd........dont try low down or else you may need a black bin liner...or two....  

 

 ken anderson    ne..1.

[James40]

Yep, exactly as Ken said.  I always see how they respond before doing any mix at the TX.

 

 

[Simon Chaddock]

David

The amount of up or down may also depend on the speed at which they are applied and the angle of flap.

For instance a significant "down" trim change as they are applied but it gets less as the plane slows down and the flap angle increases ending with some "up" at full 70 degrees flap close to the stall.

I only compensate for the initial down trim and then simply fly it as required.

 

As other have said fully explore the effect of flaps right down to the stall including an aborted landing from full flap (can be interesting!) at a safe altitude.

[Biggles' Elder Brother - Moderator]

I agree with the "suck it and see" three mistakes high approach!

 

But I'd also second Pete's observation about the value of servo slowers with flaps. I've tried with and without and the slowers definatively make life easier. The trim change is more gradual and if you have a situation as Simon describes where the initial application of flaps causes a trim change which eases off as the full flap setting comes in and the model slows down you can "fly through" that initial effect on controls and optimise your mix (if any) for the full condition so you have optimum set up on finals. I sometimes think that a lot of the "drama" associated with flaps comes not from the flaps themselves per se but from their sudden "switching in" suddenly disrupting an in balance aeroplane.

 

BEB 

Edited By Biggles' Elder Brother - Moderator on 08/01/2011 17:05:01

[Steve W-O]

I think Simons comments are worth noting.

 

I have limited my throttle on the Funcub to 60% when the flaps are full down, opening the throttle suddenly to go around again is quite sight to see, it will loop in about 10', but on a gentle approach, it doesn't need any down elevator.

 

If you take off with full throttle, full flap and plenty of down elevator, it climbs steeply but almost level.

 

Possibly the down elevator could be mixed with throttle after a certain percentage, which would cover most things.

 

 

Still going to try that, I doubt if yours will react in exactly the same way, But I'm sure some of the effects will be similar.