Light Aircraft Association

Hi,

I have to fly with constant forward pressure on the stick in my taylor monoplane. if i let go it goes very quickly into a nose up attitude. it has no trim or elevator trim tabs. im looking to adjusting the tailplane as oposed to making induced drag to correct the problem. I have 4 bolts holding the tail plane in place and i feel if i lower the leading edge a matter of 1 degree it would make a difference. LAA inspector is looking at it monday but im looking for some advice.

cheers

Mine is the same, one could move forward in the seat. Needs a trim

You could rig up a piece of bungee or a light spring to introduce a countering nose down force on the stick but it would almost certainly require mod approval. You'd need to be able to show that it didn't restrict full fore and aft stick movement, so a long spring or bungee anchored some way from the stick horizontal bearing.

Best wishes,

Harry

If possible using a spirit level and small wedges measure the under wing angle (best with tail propped up in correct C of G determination position. The tail plane would - in regular a/c - be at minus 1 degree.

If not the chances are it's in need of tail-plane adjustment.

I had similar 'problems' with my Rans S6 and found an early AD saying the tail should be -1 degree and as that was the angle many other sources mentioned as a general "standard" for a/c it was a no brainer to reset it. Previously it had climbed too hard when stick hold relaxed !

FWIW Rans kits have a forward tail-plane bracket with several holes in to allow adjustment, but few builders seem to know, or care, about it and look to trim to 'cure' it. Which is a pity because excess trim or a stronger bungee all adds drag.

mike hallam

The tail plane would - in regular a/c - be at minus 1 degree.

The correct place to check is the designer's drawings(and any error correction documents). You should also check wing incidence and thrust lines are as per spec. I doubt John Taylor designed an aircraft that wants to pitch nose up at cruise speeds. Correcting the wrong 'problem' can result in a draggy airframe.

I think that “ lowering the tail leading edge” would make matters worse ?

Ian Melville wrote: I doubt John Issac designed an aircraft that wants to pitch nose up

Or John Taylor...

+ what Bill said.

I hang my head in shame

Now corrected

I have had a walk around with a inspector today and considered all options. His main belief however is a CofG problem. its first flight was in 1993 and then fitted with Leburg in 2004. the engine came offer this. we wondered if they removed a starter motor or heavy magnetos. the log book states the engine was removed and leburg fitted with a weight and balance test complete! it would make sense getting rid of something heavy from the front! now do i add weight to it, fit a trim tab or adjust the tail plain, millimetre by millimetre to find the right cure?

Hi Mark,

The first thing I would do is conduct a new weight and balance check. It wouldn't be the first time that errors have crept into the calculations for whatever reason.

When you know exactly what your aircraft weighs and where the C of G is then you can start looking at other things.

Tony

Would agree with CG issue. Mine needed light forward pressure to keep level at speed. I could
offset by moving forward in seat. Pressure so light not really a problem.

I also doubt the manufacturer would design it requiring forward pressure.
Having said that, I had a glider (K6E) that used a spring trimmer on the stick with an all flying tail.
It was an open coil with screw adjustment to either compress or stretch the spring.
Very effective, simple construction, no induced drag when correctly set.

of course nobody mentioned throttle up nose up throttle down nose down, simple

My Sluka has an escutcheon plate to the side of the stick with a light knotted bungee, fixed for’d, running through it. Therefore, more knots means, erm, more knots.

Bill McCarthy wrote:I think that “ lowering the tail leading edge” would make matters worse ?

Quit correct Bill.