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tip stalling issues

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Old 06-02-2007 | 11:33 PM
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Default tip stalling issues

Hey guys,
Well my question is regarding to tip stalling. i have a GP PW that tip stalls fairly easily, thus snaps rolls extremely fast.... really its only at pretty slow speeds(hovering and hanging, when i fall out she goes right into a tip stall)... I’m always a nervous wreck flying this plane due to its bad tip stalling. She weighs 15.5 pounds, which is in the weight range they recomend.... and have the da 50 on it. Is there something I don’t know about setting up the plane that makes the stalling charastics on this so violent? Its balanced right where the instructions call for... (Had to add nose weight)
Thanks for any advice---
Chris-
Old 06-03-2007 | 07:46 AM
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Default RE: tip stalling issues

Not really -the model is simply heavy for slow flying .
As for their recommendations.
What can they say?
"we wish it were lighter?"
This is one of many popular models where appearance took a back seat to function.
3D flying -for max fun -requires minimum wing loading and max power -
The same quest Orville and his bro were on
It is hard to find.
Old 06-03-2007 | 10:12 AM
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Default RE: tip stalling issues

Just a suggestion to make it possible for the less informed to take part in a discussion................

Spell out the name of your airplane.

"GP PW" really is going to mean nothing to an awful lot of readers. Even somewhat experienced readers who are used to seeing "GP" for Great Planes, are going to have a problem. I'm somewhat experienced and had no idea what the "PW" stands for. So I went to Tower's catalogue and did a search. And near as I can tell, they don't sell any Great Planes models with the initials "GP".

Anybody got any idea what the airplane is?
Old 06-03-2007 | 10:20 AM
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Default RE: tip stalling issues


Is stalling or "tip stalling" really the issue? The wing is not flying while hovering and hanging so I would think you could consider it already stalled.
Old 06-03-2007 | 11:23 AM
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Default RE: tip stalling issues

Great Planes --Patty Wagstaff EXTRA.
C'mon boy - get up to speed with today's 'nyms!!
The so called Tip stalling is just another catchword in most cases - typically the model is simply too heavy for the speed envelope - the model as it tries to recover can become a handful. the fix is - Mo power -less weight
Old 06-03-2007 | 05:26 PM
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Default RE: tip stalling issues

mike its more entering into the maneuver that it gets kinda squirrely... idk maybe im just not usto this kind of a plane. I’ve been flying something extras and my fun fly tiger for like my entire flying career. these will do a crawl and seemingly never tip stall.
Old 06-03-2007 | 08:14 PM
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Default RE: tip stalling issues

Actually, tip stall will make it "fall out", not fall out into a tip stall. If it is indeed tip stall ( would not bet on it ) it is common for people to use washout to help. That would be difficult at this point. Piper Aircraft and others use stall strips on the leading edge of their wings to get the same effect. You might try some triangle stock on the leading edge of the wing from the root to about half way out. Maybe two 4" to 6" pieces of 1/4 or 3/8 triangle on each side. This will cause the wing tips to stall last. It is possible to have some "washin" accidentally built in causing a problem. Stick it on with two sided servo tape for a quick check to see if it helps.
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Old 06-03-2007 | 08:38 PM
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Default RE: tip stalling issues

When you slow the plane down to a stall, does it always drop the same wing? Two things to check are wing twist and lateral balance.

First check the wing for twist with an incidence meter. If the wing is twisted it can usually be corrected by twisting the wing by hand until the covering wrinkles, then reshrink with your heat gun while holding the twist. It may take several tries. It's surprising how much twist you can put into or take out of a wing this way. It will make a huge difference in the stall characteristics.

Once you have the wing incidence trued test for lateral balance. Trim for level flight then make some long, straight inverted passes. Does it want to roll? Even a little? If so then it needs balancing. If it rolls left when inverted, add a little weight to the left wing tip and try again. A plane that is out of lateral balance will have aileron trim to correct it. This effectively gives more angle of attack on the side with the drooped aileron and that side will tend to stall first.

Let us know what you find.

Dave
Old 06-03-2007 | 10:26 PM
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Default RE: tip stalling issues

an easy way to try and stop this is to center both ailerons and then use subtrim to drop both about 3/32 of an inch,it will only make a small difference in flying the plane but will make a big difference in landing and slow speed handling.i had to do this on my 1/3 rd cap 580 and it made a enjoyable plane out of it.and at 26 pounds it ain't too heavy for the wing
Old 06-03-2007 | 11:23 PM
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Default RE: tip stalling issues

dbacque, when i flew the plane last (great planes patty wagstaff) I did stall her out up high to see if on wing was constantly dropping. found that no wing in particular was dropping. On twisting the wing, I’m not sure i can because the wing is sheeted with wood. What do you think? ill be out on Saturday an try that inverted pass and see what i find.

3dd- ive heard that dose help dropping both ailerons.. Essentially making flaperions. just to make sure I’m catching what your referring to is lower them not raise, because raising them in my mind would kill lift making an air brake.

ill let you guys know what i find on Saturday
thanks--
chris
Old 06-04-2007 | 07:33 AM
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Default RE: tip stalling issues


ORIGINAL: Holton50

3dd- ive heard that dose help dropping both ailerons.. Essentially making flaperions. just to make sure I’m catching what your referring to is lower them not raise, because raising them in my mind would kill lift making an air brake.
Not nessesarily! A lot of sailplanes, both models and full scale, reflex the ailerons up a few degrees when flying fast in order to cover ground in a headwind or while blasting through an area of sink. Trimming the plane with aileron reflex or droop instead of elevator allows the fusilage to remain aligned with the airstream over a wide range of trim speeds.
Old 06-04-2007 | 11:24 AM
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Default RE: tip stalling issues

Lowering the aileron lowers the stall angle of attack on that portion of the wing.
A plane that is already tip stalling won't like that at all!
The inner leading edge stall strips would be a better solution.
The best is what Dick says... keep your speed up!
Old 06-04-2007 | 01:01 PM
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Default RE: tip stalling issues

Drooping "barn door" style ailerons effectively gives the wing wash-in, not what you want during a landing. Reflexing them gives the wing wash-out. "Crow" is a combination of drooped flaps and reflexed ailerons which effectively gives the wing extreme washout and really puts the brakes on. Very popular with sailplanes that are so clean that they are almost impossible to land without spoilers or crow.
Old 06-04-2007 | 03:58 PM
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Default RE: tip stalling issues

BTW, the idea that all the cures know to man for tip stalling will make an overweight airplane pull through hard pitch maneuvers should be carefully considered.

A lot of what we so sagely refer to as tip stalling is simply "airplane stalling". The bloody bird is being flown too slowly for it's weight and area. And darned if most airplanes don't stall into a roll as opposed to stalling straight ahead. Especially when you're turning the sucker trying to do some maneuver or other.
Old 06-04-2007 | 04:00 PM
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Default RE: tip stalling issues


ORIGINAL: Holton50

On twisting the wing, I’m not sure i can because the wing is sheeted with wood. What do you think? ill be out on Saturday an try that inverted pass and see what i find.
Nope, if the wing is completely sheeted this trick doesn't work.

Dave
Old 06-05-2007 | 08:40 AM
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Default RE: tip stalling issues

Simple explanation... Large aerobatic (aka neutrally unstable) model+ flying at almost zero airspeed ".... really its only at pretty slow speeds(hovering and hanging, when i fall out she goes right into a tip stall)"= stall

The stall is violent because the model was designed for aerobatics. A model that can perform quick manuvers under control can perform them just as quick when it's out of control.

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