Sport Pilot Talk

"have you reported the issue with the detailed pics with Sport Air and/or TL-Ultralight?"

Yes, both. We have a "treatment plan" proposed, from my composite expert, but will have to see what TL's position is, first.

I was sanding in there today, or attempting to, anyway. You won't believe how hard it is to get up into that filler neck--even with the tank lid off! I don't know how they did this.

"I have no reason to think I currently have the delamination or deterioration of the fuel tank that Richard is describing."

Troy--Here's how to tell if you have the problem:

1. Let the airplane sit at least 3 days with 12-15 gal (or more) of fuel. Then pull 1-2 pints out of the sump into a wide-mouth mason jar, whilst somebody gently rocks the wings. Then, hold that jar up to the sun and swirl it in a circular motion looking for beads and flakes of resin. They will be on the bottom, if any.

2. Lay on the ground, under the belly of the plane, feet towards the tail, with your chest directly below the sump drain. Now measure 8 inches and 12 inches fore of the sump. Then, put your two thumbs together and press up against the composite (in the 8-12-inch zone where the center of the tank is), just to the right--and then left--of the center line. This is where those two "stiffeners" are located. When you press up in these two zones, the composite should be firm; if not (i.e., it dimples >1/4-inch), one of both stiffeners may have already delaminated, like mine.

If there are no beads and flakes--and no "give" underneath--you are probably good.

(Today, my opera took a turn for the worse: I accidentally sanded through the supposedly "good" stiffener on the left side, and guess what? Gasoline started weeping out!)

Yes, the faa allows the S-LSA to be converted to an E-LSA, with a lot of paperwork of course, one time but it can not ever be converted back again. Makes sense as once you mess with the manufacturer's design you are no longer working with an airplane they are certified as airworthy. But, converting to experimental allows me to work on the aircraft and modify it any way I want, within FAA and airworthiness guidelines, of course. Also, as a graduate of the Rainbow Aviation LSA repairman course, I can work on my airplane and do the inspections but I can not modify anything as long as it stays an S-LSA.

Troy

Troy,

Mostly accurate, but really not a LOT of paperwork. And in my case what there was, was handled by the DAR.

troyball wrote:one time but it can not ever be converted back again.

In theory it can be taken back from E-LSA to S-LSA, but it requires factory approval. No manufacturer's lawyers would likely ever let them open that can of liability whoop ass.

MrMorden wrote:

troyball wrote:one time but it can not ever be converted back again.

In theory it can be taken back from E-LSA to S-LSA, but it requires factory approval. No manufacturer's lawyers would likely ever let them open that can of liability whoop ass.

I know of one SLSA that was switched to experimental and the changed back to SLSA. It may have been changed to experimental R&D though.

Troy, you can indeed modify an SLSA, without converting it to ELSA, but only with the manufacturer's approval. If you know someone at the factory who will write you an LOA, you're home free. They will probably require extensive engineering documentation. I've done this with Evektor. I had to produce a Service Instruction in standard ASTM format, as well as developing a flight test protocol. They issued me a temporary LOA, specifying that my aircraft could only be flown for testing purposes, over unpopulated areas, with no passengers. After I submitted my detailed flight test results, they issued the permanent LOA. If you're into engineering, the process isn't all that hard (and, it's kinda fun),
the temporary LOA, Service Instruction, flight test data, and permanent LOA can all be found on my website, in the Aircraft section.

Dr. Seti, I have already sent a request to the manufacturer requesting an LOA. They refused. No reason other than they do not think is needed. I responded, they have not responded to my response in over a month.

Rich, I will do your suggested test tomorrow. I have been out of town the last 4 days. I will let you know how it goes.

I know of a couple guys who added an extra filter to a Sting Sport. I'm not sure of the location in the system.

So, I went to the airplane this morning and did the testing Richard recommended. I found I do NOT have delamination, if his pressure testing is an accurate test. When I bought the airplane and had the first power failure because of the right carb main jet being occluded with a bit of rubber I drained the tank and cleaned the gascolator. There were bits of "amorphous debris" in the gascolator which I now suspect was indeed bits of resin flaking off the tank from the E-10 gasoline that had been used in it. Because I had several engine failures for the same reason as above, the airplane was not flown very much in 2014. The fuel hoses were replanced in Nov. last year and at the annual in January I replaced the fuel pump. I have 10 hours on the airplane since the annual with NO EFIS fuel light indications and of course no fuel delivery engine problems. The airplane was moved to Grand Junction in January when I moved there from AZ and I started using ethanol free auto gas at that time. I do drain a half quart or more each time I drain the sump at the fuel tank and since using this fuel have not had ANY debris in the fuel. NONE. So, I am dropping the price on the Sting to 59,00 and if I can get it sold, buying a Just Highlander so I can fly in and out of the many back country strips in CO and UTAH, maybe even venturing as far as Idaho. We want a tundra tire, stol, rag wing airplane and the highlander or even a kitfox would do the trick.

.......

Don't nod off yet on me, boys! Just kidding... Not much new to report, here. I've just been going to the hangar daily, for a little more sanding work, whilst we await word from the factory in the Czech Republic, as to whether our "treatment" plan is acceptable or they have some better "fix" in mind. The main issue is resin compatibility; we have to know which type(s) they used in the construction, to know what's going to work best for the repair, including bonding that tank lid back down on the tank. I don't want a bigger problem than I already have.

Anyway, yesterday, while attempting to sand the rest of that ruined Nomex Honeycomb material out of there, especially way up in the very confined space leading to the filler neck, I finally just threw in the towel in utter frustration. It was near impossible to get any of my sanding devices in there--and I ain't quite patient enough to do it all by hand with a sanding block.

So with nothing better to do, I drove to my nearest Harbor Freight Tools store. And as soon as I walked in the door, the little baby you see here in the picture greeted me. I couldn't believe they made such a tool (3/4 x 13-inch belt sander with adjustable belt-arm)--the perfect one for what has to be done in that tank of mine! And they were practically giving it away too, at the bargain price of $23 (reduced by another $4.60 with the 20% OFF coupon I always carry in my wallet).

This tool is amazing! It made short work of the rest of my sanding. The only problem with it is you need a good-sized compressor to keep it spinning; it gulps a lot of air.

Anyway, I thought I'd "memorialize" this tool here (item 60627), since the next Sting owner with my problem is definitely going to need one (for his mechanic).

*****

Just got my mini belt sander at Harbor Freight. $18.39 with coupon. Thanks for the heads-up, Rich.

drdehave wrote:Don't nod off yet, guys! Try this interesting read:

http://www.usjabiru.com/uploads/JSA-006 ... lletin.pdf

Interesting read indeed!

Part of the LSA 'mission' as it's sold to potential customers is 'it just sips auto-gas'. Though not perhaps a 'myth' it certainly bears some investigating by potential LSA pilots and customers, many of whom read this site, before ownership.

Some banish 100LL because of the effects of accumulated lead in the oil tank and gearbox, whilst promoting E10 as a much better alternative, and cheaper than 'pure gas' non-ethanol. Seems like various manufacturers, all using the same engines, have different views, about what's suitable but perhaps have done some owners a disservice. For me Vans said E-10 is fine to use. I have a metal tank albeit with sealants.

I took heed of Paul's wisdom a while back and have avoided the E10 because of the potential damage from the ethanol preferring to spend a few more cents per gallon for 93 non-ethanol.