Question about wings not being level on a Sting plane

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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Warmi
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Question about wings not being level on a Sting plane

Postby Warmi » Sat Sep 30, 2017 1:04 pm

I had my Sting for about 3 months now , it is a pretty new plane with only about 200 hours ( bough it at about 150h) ...

Just the other day, while we were cleaning the plane, my wife noticed that the right wing ( on the pilot side ) is about 3-4 inches lower than the left wing ( you can' t really tell just by looking at the plane , you need to measure it )
At first I thought it was perhaps uneven hangar floor but we measured it and it was pretty darn even. Then we measured distances between wing roots (on both sides ), both wheels and the entire landing gear on both sides -everything checks out, even distance from the ground on both sides, except the darn wing-tips.
Both wings seem solid and there is no play there at all and the plane flies just fine but I am wondering what would cause this discrepancy ?

Attaching a picture that may explain better what I was trying to convey.


Wings.JPG
Wings.JPG (80.8 KiB) Viewed 644 times
Flying Sting S4 ( N184WA ) out of Illinois

3Dreaming
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Re: Question about wings not being level on a Sting plane

Postby 3Dreaming » Sat Sep 30, 2017 6:32 pm

With a CTSW the first thing I expect is a bent landing gear, but I am not saying that is your problem. Simple things first. Tire pressure imbalance. Tire worn more on low wing. A little bit on a tire is amplified at the wing tip.

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drdehave
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Re: Question about wings not being level on a Sting plane

Postby drdehave » Mon Oct 02, 2017 5:48 pm

Did you turn it, when pushing into the hangar? That can torque one strut to a different angle than the other. Try pulling it straight out, about 30-50 feet, then re-do the wing-tip measures to see if they are then equal. That's all I can think of, right now, other than air pressure.
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chicagorandy
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Re: Question about wings not being level on a Sting plane

Postby chicagorandy » Mon Oct 02, 2017 6:08 pm

I'll suggest getting one of those inexpensive laser levels and shoot a few lines to make sure the wings are not slightly 'curved' or bent out of spec? Is the left one low or is it the right one that is high?

Other than that? I got nuthin'.

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Re: Question about wings not being level on a Sting plane

Postby Warmi » Mon Oct 02, 2017 7:18 pm

Today I went out and actually took the wheel pants off and right away it was very much clear that the tires are quite flat.
Measuring PSI , the lower wing one came out at 10 PSI and the opposite at 22 or so . They are supposed to be at 44 PSI so that was one of the problems.
After getting both tires up to 44 PSI, the wing is still uneven to some degree, better than before, but still not even so will have to look further but at least learned one lesson today - you can't really tell if pressure is off ( even significantly, as in my case ) until you look really close and frankly, until you measure it.

And as always, thank you for your help guys,
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Question about wings not being level on a Sting plane

Postby zodiac flyer » Sun Oct 08, 2017 2:12 pm

so you flew three months and 50 hours and never checked your tire pressure?
I check mine weekly.
Dave

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Re: Question about wings not being level on a Sting plane

Postby FastEddieB » Sun Oct 08, 2017 2:22 pm

zodiac flyer wrote:so you flew three months and 50 hours and never checked your tire pressure?
I check mine weekly.
Dave


I generally check mine monthly, or right before a long trip. Experience will guide you regarding an interval for any particular plane.
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3Dreaming
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Re: Question about wings not being level on a Sting plane

Postby 3Dreaming » Sun Oct 08, 2017 2:44 pm

I'm not as diligent about checking mine as I should be. With the smaller size tires that are on many of the new LSA aircraft they are more suseptable to damage and flat tires from under inflation that the older aircraft fleet in general.

Warmi
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Re: Question about wings not being level on a Sting plane

Postby Warmi » Sun Oct 08, 2017 6:20 pm

zodiac flyer wrote:so you flew three months and 50 hours and never checked your tire pressure?
I check mine weekly.
Dave

Yeah, pretty much.
This is the very first plane I own and I was going on my car experience - now I know better.
Flying Sting S4 ( N184WA ) out of Illinois

zodiac flyer
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Re: Question about wings not being level on a Sting plane

Postby zodiac flyer » Tue Oct 10, 2017 12:41 pm

A flat tire on an airplane is a much more serious incident than on a car.
keep that in mind when you are doing your pre flight inspections.
Dave

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Re: Question about wings not being level on a Sting plane

Postby FastEddieB » Tue Oct 10, 2017 1:31 pm

For those with wheel pants, one trick is to measure the distance from the fairing to the ground with a properly inflated tire. Then fabricate a simple gauge - even a length of dowel rod would suffice. If it doesn’t fit, you can be pretty sure your tire pressure is low.
Fast Eddie B.

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Warmi
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Re: Question about wings not being level on a Sting plane

Postby Warmi » Tue Oct 10, 2017 1:38 pm

Something was wrong with the left tire .. I inflated it twice, it deflated twice halfway after very short time so the next step was to replace both tires.
Unfortunately, I got a complete 100% flat on my way to the mechanic shop - thankfully only during slow taxing , the only damage ( beside the tire) was a slightly scraped wheel pant - we put the busted wheel on a small trolley and pushed it about 100 feet to the shop :-)
Flying Sting S4 ( N184WA ) out of Illinois

chicagorandy
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Re: Question about wings not being level on a Sting plane

Postby chicagorandy » Tue Oct 10, 2017 3:57 pm

Are the tires tubeless or tubed o the Sting? Just wondering.

Warmi
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Re: Question about wings not being level on a Sting plane

Postby Warmi » Tue Oct 10, 2017 4:00 pm

Tubeless.

But it had tires which , according to the manufacturer, were not rated as tubeless and they didn't recommend using them that way - these were put in by the dealer in 2015.
I ordered replacement, this time with proper tubeless tires (about $180 per tire )- and , going forward, will make sure to check the pressure weekly :-)

BTW.. I have my plane parked at : http://www.theultralightplace.com/ in Kankakee ... frankly, since it is stuck there , I my as well do the annual and 5 years rubber replacement ( my Sting is 2012 model and it is due ) , all in one go - owning a plane is basically a bottomless money pit , you learn that pretty quick :-)
Last edited by Warmi on Tue Oct 10, 2017 4:05 pm, edited 1 time in total.
Flying Sting S4 ( N184WA ) out of Illinois

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drdehave
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Re: Question about wings not being level on a Sting plane

Postby drdehave » Tue Oct 10, 2017 4:05 pm

I once mounted two tires on my Sting (it uses utility trailer tires and tubes; it sounds like you have aircraft tires), long before I knew what I was doing. Then I went flying, came back and parked the plane in the hangar. One tire blew up, whilst I was sitting at my desk recording in my logbook. Be sure you know what you're doing regarding mounting and balancing your tires. They can be pretty dangerous--or at least annoying--done wrong. This older video of mine is a start: https://www.youtube.com/watch?v=OqpfFhJax1Y&t=2s
Last edited by drdehave on Thu Oct 12, 2017 12:26 pm, edited 1 time in total.
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