Removing Sting S3 Parachute for Service=Major “Ouch!”

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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drdehave
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Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Mon Oct 02, 2017 7:15 pm

If you followed the other recent thread here on SportPilotTalk (viewtopic.php?f=3&t=4865), you know that I recently removed my Galaxy parachute system (GRS) for required maintenance. What I failed to describe in that thread was the significant unanticipated cost that was incurred. Here’s what happened.

We had just deactivated (per instructions) the black powder packet & rocket fuel and placed the rocket trigger (i.e., containing a percussion cap) in a vice, to detonate it with a rubber mallet. The resulting “boom” was way greater than either of us expected!

Then, my mechanic, who is a beefy guy at 240 lbs, headed back to the cockpit to tidy up, before I took to the air for the return home (the GRS is not required equipment in the Sting). As he stepped onto the lower (trailing edge near the root) wing, we heard another loud “pop.” It was a piece of core-board-rib breaking and delaminating from the skin of the lower (underside) wing where the flap control rod passes through a cut-out in the rib.

My mechanic tried to shoulder the blame. But I assured him it wasn’t his fault. He’s been walking around uneventfully on those wings for nearly 10 years now. It appears that this is a known weak spot and all it took was someone at the Sting “person” weight limit (i.e., 240 lbs) stepping in the wrong place. Have you noticed the prominent “NO STEP” placards in that same area (trailing edge, near root) on the latest models of Stings? I think there’s a message worth heeding, there.

However, during the repairs, we also discovered two other likely contributing factors in my particular case: 1) the cut-out area of the core-board, that the flap control rod passes through, had obviously been damaged by that rod during repeated (for annuals and other purposes) removal and installation of the wings (Fellow Sting owners: this is something you should really be very careful about. Have a “spotter” monitor that cut-out the flap rod passes through anytime you are taking off and/or replacing the wings); and 2) the right wing (where the break & de-lamination occurred) appeared to have a faulty lay-up of flox (thick fiberglass paste) in the corner, where the carbon-fiber skin of the wing meets the core-board rib. Most of the injected flox (or more likely, just applied with a wooden stick) had fallen down after application, possibly due to lack of viscosity, rendering it ineffective.

Our repairs focused on laying down some new fiberglass in key areas and injecting copious amounts of viscous flox into the right places, using a large syringe with attached tube. The German epoxy the airplane is built with-–MGS L-285–-was used. For insurance, we fixed not only the damaged right wing, but also the apparently undamaged, but nevertheless weak, left (pilot-side) wing, too. Repairs were accomplished by removing the wings (and then the flaps), placing them on sawhorses, and then working on one side at a time, utilizing gravity to assist with proper flox injection & contact. It was also a great time for deep cleaning and putting a good coat of wax on the undersides of the wings (as opposed to working on them from below, when attached to the airplane).

After removing the 35-lb GRS, I offset the weight loss and retained the original CG (center of gravity) by placing a 20-lb sandbag in the rear of each of the two luggage boxes; alternatively, I could have foregone the sandbags and just adjusted the trim, while still retaining an allowable CG. With the sand bags, once the GRS is returned and reinstalled, I’ll still have my original, near-perfect, trim setting.

I also want to take this opportunity to memorialize for fellow Sting owners (and other USA-sold, European LSAs which utilize the GRS) our (i.e., USA owners) options for required GRS maintenance. There are two GRS dealers in the USA: SportairUSA at Little Rock, Arkansas and SportPilotShop at Torrance, California. If you choose Sportair, you can expect to take your airplane to Little Rock for a minimum of 2 days; however, when you leave, your updated GRS will have been installed. If the trip to Little Rock is not your cup of tea, or is otherwise infeasible, you may want to consider the SportPilotShop option I am using. They provide instructions for removing and disarming the GRS which you then ship to them. They forward it on to the manufacturer in the Czech Republic. It then comes back to you about 6 weeks later, serviced and ready for reinstallation (we'll see--it ain't happened yet). Costs for these two dealer options vary widely and are themselves moving targets, so I won’t give dollar numbers here. Inquire for yourself. Just be aware that if using option B through SportPilotShop, you’ll need a knowledgeable mechanic to accomplish and record GRS removal and reinstallation. And this is a relatively dangerous process.

How dangerous? Well consider this. I was just told by a friend and fellow Sting owner in Germany, that in one European incident when the chute was being serviced, an accidental firing sent the rocket completely through the wall of a house, then a ricochet sent it back and completely through the hull of the Sting, before "going off into nature." I rest my case...

I will report the conclusion of my story when my GRS is returned and safely reinstalled--and I have removed that "in-op" placard from the dash.
027 (1328 x 747).jpg
027 (1328 x 747).jpg (215.24 KiB) Viewed 1970 times

041 (1328 x 747).jpg
041 (1328 x 747).jpg (160.21 KiB) Viewed 1970 times

049 (1328 x 747).jpg
049 (1328 x 747).jpg (116.92 KiB) Viewed 1970 times
Last edited by drdehave on Wed Oct 04, 2017 11:27 am, edited 4 times in total.
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Mon Oct 02, 2017 7:19 pm

Three more pics in this series:
flox 002 (1328 x 747).jpg
flox 002 (1328 x 747).jpg (187.54 KiB) Viewed 1970 times

013 (1328 x 747).jpg
013 (1328 x 747).jpg (116.05 KiB) Viewed 1970 times

030 (1328 x 747).jpg
030 (1328 x 747).jpg (153.57 KiB) Viewed 1970 times
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Mon Oct 02, 2017 7:21 pm

Final three pics in this series:
025 (1328 x 747).jpg
025 (1328 x 747).jpg (244.63 KiB) Viewed 1970 times

042 (1328 x 747).jpg
042 (1328 x 747).jpg (221.47 KiB) Viewed 1970 times

049B (1328 x 747).jpg
049B (1328 x 747).jpg (248.62 KiB) Viewed 1970 times
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Thu Dec 21, 2017 3:30 pm

One correction and one update to this story:

1. It is the SportFlyingShop, not SportPilotShop, that is one of two USA Galaxy BRS dealers--and the dealer I went through for my update; they are located at the airport at Torrance, CA.

2. As of today, December 21, 2017, my updated BRS has finally been delivered just moments ago by Fedex hazardous materials delivery (a full 14 weeks since removal, versus "about 6 weeks" advertised by SFS) from the Czech Republic and is resting comfortably on my living room floor. It'll be "good" without servicing (and without need for another "inoperative" placard) this time, for 9 years. My mechanic and I will be installing it the day after Christmas. Wahoo, the wife has been waiting to go flying again!

Now, here's a kind of scary footnote: This thing came all the way, fully locked and loaded (with the ballistic components)!!! The box did say, "not for transport on passenger planes--only cargo planes." Isn't that nice?

Anyway, happy new year, everyone.--Rich
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Warmi
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Warmi » Thu Dec 21, 2017 3:54 pm

Well, it is a rocket after all - remember what happened when they loaded oxygen canisters on ValuJet flight 592 ?
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Thu Dec 28, 2017 11:20 pm

December 26, 2017, the GRS was reinstalled (after re-pack/re-armament in the Czech Republic) in my 2007 Sting, without any major hiccups. However, there were two minor annoyances: 1. getting that pop-out window and gasket back on over the GRS was very tricky and definitely a two-person job (be sure to read the "How To" for this procedure on the Sting owners' website); and 2. slithering down inside the fuselage, to reinstall two pop rivets through the aluminum tubes holding the bottoms of the chute to its composite base, was NO fun at all (I volunteered, since my mechanic is a bit too hefty for such a tight space).

Afterwards, I removed the parachute "inoperative placard" from the panel and went flying. The next GRS service date now is 9 years out, in November 2026 :lol:
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Warmi » Fri Dec 29, 2017 12:01 am

Given how awfully long it took to get it back ...I think I would opt for a trip to N Little Rock and get it done in 2 days ( and 1 or 2 K more )....
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby dstclair » Fri Dec 29, 2017 9:47 am

I'll let you know in April.
dave

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Fri Dec 29, 2017 10:47 am

Neither option is very appealing to me, but I'm sure glad its done. :mrgreen: and, having been intimately involved in the whole process I can rest assured that GRS is of highest quality. Photos (and story) of the install day, are here: https://www.facebook.com/Sting-Flight-334060526751303/
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Warmi » Fri Dec 29, 2017 4:50 pm

A somewhat unrelated questions .

When you talk about fixing wings and making similar structural repairs, do you guys actually attempt to get some kind of blessing from the manufacturer or do you do it entirely "in-house" and rely on the manual/experience ?

I am asking cause , as I mentioned in another post, looks like I may need LOA just to install, already approved, ELT in another location ( which will mean potential changes to W&B etc ) ... let alone make structural repairs to wings :-)
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Sun Dec 31, 2017 12:10 pm

Yes, there is "gray area" between what is just a repair and what requires an LOA--at least at first glance. But, if I'm following MM procedures and returning something to its original "as manufactured" condition, it's a repair. On the other hand, if I start moving things around, adding new stuff, or removing original stuff, assuming my mechanic(s) & I know more that the folks who designed and built the airplane, LOA territory definitely comes into view. With that often comes hesitancy from the manufacturer--partly (maybe largely) due to risk of lawsuits. Nevertheless, when I went through my fuel tank delamination/repair fiasco almost 3 years ago, I did briefly consider just converting my Sting to "Experimental," to get out from under the manufacturer's umbrella--who didn't help me one iota beyond the MM. But, now that that sad event is long past, and my repair was actually done by the book and is holding, I'm glad I left it as S-LSA. Long story short, go 'experimental' if you want more repair & maintenance freedom.
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Wm.Ince » Sun Dec 31, 2017 1:01 pm

drdehave wrote:Yes, there is "gray area" between what is just a repair and what requires an LOA--at least at first glance. But, if I'm following MM procedures and returning something to its original "as manufactured" condition, it's a repair. On the other hand, if I start moving things around, adding new stuff, or removing original stuff, assuming my mechanic(s) & I know more that the folks who designed and built the airplane, LOA territory definitely comes into view. With that often comes hesitancy from the manufacturer--partly (maybe largely) due to risk of lawsuits. Nevertheless, when I went through my fuel tank delamination/repair fiasco almost 3 years ago, I did briefly consider just converting my Sting to "Experimental," to get out from under the manufacturer's umbrella--who didn't help me one iota beyond the MM. But, now that that sad event is long past, and my repair was actually done by the book and is holding, I'm glad I left it as S-LSA. Long story short, go 'experimental' if you want more repair & maintenance freedom.

Good advice.
I remember your fuel tank debacle. For me personally, that was a nightmare. But you dove right in and dealt with it nicely. I did not know the manufacturer was that worthless, beyond the maintenance manual. Based on that, I would hesitate to buy a Sting.
Glad it turned out okay for you. Well done on your part.
Bill Ince
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Retired Heavy Equipment Operator

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Warmi » Sun Dec 31, 2017 1:19 pm

So far I had great service from TL Ultralight and ,after reading the whole tank debacle thread , to me it seems that it is still very much in the air what really caused it.
The net effect of this isolated accident ( 2 or 3 occurrences out of 600 planes ) is that we are all now prohibited from using ethanol based gasoline despite the fact that it most likely was not the main issue here ( and 100s of other Stings were flying just fine on it for years ) -to me it is not really a problem since I have both non-ethanol Mogas and UL94 avgas within a stone throw distance of my place but , from what I understand , for some it was a problem.

I am not sure what else TL Ultralight could have done here ...
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby drdehave » Sun Dec 31, 2017 2:00 pm

Warmi, those are very good points and I agree with them. However, what they could have done better was communicate back to me after we submitted our "treatment" plan. They didn't. This is where they let me down. But, as I said, it is now a moot point, because the way we fixed it actually worked :mrgreen:
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Re: Removing Sting S3 Parachute for Service=Major “Ouch!”

Postby Warmi » Sun Dec 31, 2017 2:10 pm

Of course, I have no real idea how painful the episode was for you , so of all people here you are pretty much the most qualified to opine on TL Ultralight and their customer support but I can't help but to think that part of it is the out of control litigation-friendly system ( which is, frankly, getting worse ) for which we have only ourselves to blame ... just look at Rotax and their Bahamas business :-)
Flying Sting S4 ( N184WA ) out of Illinois


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