Question of the day

My sailplane always turns to the left. Can I adjust the left aileron down a bit
to make it fly straight?
JJ Sinclair

First try putting the chip on the right shoulder.

On 30 Aug 2003 20:52:11 GMT, (JJ Sinclair) wrote:

My sailplane always turns to the left. Can I adjust the left aileron down a bit
to make it fly straight?
JJ Sinclair

It might be easier to adjust your stick hand a little to the right.

But since this is the question of the day . . . If the left turning tendency
is caused by a slightly twisted wing or other rigging problem, and I assume
it is, then adjusting the left aileron down a bit will not help at all.
Instead both ailerons will now trail slightly down, the stick will be offset
to the left, and the same twisted wing will continue to cause a left turning
tendency.

Instead, you would have to put a trim tab (or stick on a trim wedge) to
raise the right aileron and lower the left. This assumes that the problem
isn't rudder related as evidenced by the yaw string or ball being centered
before this exercise. Any of these "fixes" might be used on a power plane,
but wouldn't correcting the out of rig problem be the proper, low-drag fix
for a glider?

--
bumper
"Dare to be different . . . circle in sink."
to reply, the last half is right to left
"JJ Sinclair" wrote in message
...
My sailplane always turns to the left. Can I adjust the left aileron down
a bit
to make it fly straight?
JJ Sinclair


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Why not try flying south of the equator and see if it turns the other
way? Otherwise, try centering the stick.

Geez, JJ, is the weather out there as bad on the east coast?

Chip F

"JJ Sinclair" wrote in message
...
John Morgan is 100 % correct, Go to the head of the class and come up with
the
next QUESTION of the DAY

Okay . . .

"Would eagles and hawks be considered self-launchers or pure gliders? If not
pure gliders does this mean they're cheating?"


--
bumper
"Dare to be different . . . circle in sink."
to reply, the last half is right to left




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JJ
I think the answer is NO.
A turn is a coordinated maneuver.
Adding a left aileron correction is an
uncoordinated fix. You may be able
to achieve wings level, but you will not
center the T&B. It will show you flyinig
in a yaw, wings level. Wings level
will probably occur at only 1 trim speed.

Coordinated trim fixes are needed. But the first
step is to find out WHAT is causing the left
hand displacement.

Start with the simple stuff. Is/are all the
gap seals good, wing clean etc.....

Your shoes.
Wear some really thin soled shoes that let you feel
pressure on your feet. Something like ballet slippers.
Everybody has one leg longer than the other and you might
be stepping on the pedal without feeling it.

After that, check rig to correct spec.
If the bird checks out that way, you'll need to set up an
optics shoot to find the problem.

Scott Correa
Ex-Wing Tooling Engineer @ Boeing.
That ******** of a company that is outsourcing the future......

"JJ Sinclair" wrote in message
...
My sailplane always turns to the left. Can I adjust the left aileron down
a bit
to make it fly straight?
JJ Sinclair

All good answers, Scott, but my real point in the question was to point out
that just moving one aileron down will not make any change in the ships
tendency to turn left. Only a trim tab on the aileron (bent up) to make that
ailerom fly down will accomplish the desired correction. As you pointed out, a
trim tab on the rudder (bent left) would also do the same thing.

Trim tabs = drag and we seldom see them on sailplanes. The real problem is
usually a bad repair in the wing or bad rigging. Believe it or not, a major
sailplane manufacturer has eccentric lift fittings that will correct for wing
misalignment that came from the factory with twisted wings. You just tell them
*how bad your ship turns left* and they determine how much *off center* your
new drag fittinge should be.
JJ Sinclair

If the glider has flaps... should you check to see if both flaps are a
the exact same reference point?

Could it be possible for the flaps to have an asemetric configuration
that could be causing the turn?




(JJ Sinclair) wrote in message ...
All good answers, Scott, but my real point in the question was to point out
that just moving one aileron down will not make any change in the ships
tendency to turn left. Only a trim tab on the aileron (bent up) to make that
ailerom fly down will accomplish the desired correction. As you pointed out, a
trim tab on the rudder (bent left) would also do the same thing.

Trim tabs = drag and we seldom see them on sailplanes. The real problem is
usually a bad repair in the wing or bad rigging. Believe it or not, a major
sailplane manufacturer has eccentric lift fittings that will correct for wing
misalignment that came from the factory with twisted wings. You just tell them
*how bad your ship turns left* and they determine how much *off center* your
new drag fittinge should be.
JJ Sinclair

Steve wrote
Could it be possible for the flaps to have an asemetric configuration
that could be causing the turn?


Yes it can, Steve. A good point, even with flaps that move with the ailerons
(ASW-20, etc.) The flap misalignment may cause a turn. That is to say, if the
gap between the flap and aileron (on the left side) is greater than the gap (on
the right side), the added drag on the left side may be the culprit.
JJ Sinclair