Moose/SR/Elite Stabilizer Hinge Mod

[Elite583]

Hi Guys

I've tossed this under general because there is no traffic under MSR Stabilizer and it applies to the Elite as well. If Mike wants to move it, that's fine as long as it gets some views from both groups of builders.

OK, my question of the day is how thick is the stainless steel sheet supplied for the stabilizer outboard hinge mount/spar fix (Horizontal Stabilizer Service Bulletin, dated Friday November 19, 2004)? Since this appears to be an Elite problem as well I'm working up mod parts for both the wings and stabilizer for #583E.

By the wording of the SB, the kit supplies material for both the stabilizer and the hinge mount at the wing tip so I'll presume the same thickness of St-Stl is used there as well, correct?

Thanks

Dave
http://www.Elite583.cjb.net

[Dale]

Dave,

How does the SB for the SR/Moose Stabilizer Tip Repair and Wing Tip Mod now become an Elite issue? Are you having cracking with your Elite stab and wing tip ribs?

As I see it, the only thing common to all 3 aircraft is the Elevator Horn Mod. Please enlighten us if you know of something different.

Thanks,

[Elite583]

Hi Dale

While there isn't an official SB addressing this for the Elite the same cracking of the aft spar of the stabilizer at the outer elevator hinges as in the SR/M has been seen in the Elite. I believe there is a case documented in the old archive, a yellow aircraft, in any case I have seen photos showing the cracks. ( EDIT: The link is: zenphoto/Elite/Horizontal%20Stab/) I have also heard via the list that one other Elite has shown the same failure at about 300(?) hours so given the failure quantity and fleet size and SR/M SB that's enough for me to decide to reinforce that area since the E & SR/M designs are very similar, perhaps with some scaling differences. I'll let the other owner speak up if he wants to add more.

The outer aileron bracket (mass balanced spade) is in the same SB and is similar enough to foresee the same problem so an ounce of prevention is appropriate risk management in my judgement. I'd rather reinforce today than find out in flight or be AOG where fixing it would be a problem.

I suspect we have not seen a bulletin from MAM because their Engineering activity appears dormant, we have not seen a bulletin or manual update from MAM on any aircraft in five years.

This is my opinion but looking at it from a failure modes and effects analysis (FMEA) and risk management perspective it's worth it to me to address it before flight even if it means modding some completed assemblies.

Have you had any SR/M though your shop to install the SB kit? Material thickness?

Cheers,

Dave
http://www.elite583.cjb.net

[Dale]

Dave,

Thanks for the pics. The material thickness you're looking for is .050"

Keep us posted on futher findings.

Cheers,

[irishfield]

The Elite in the pictures acquired said cracks in less than approximately 25 hours as well. I looked that bird over REAL good.. when it was here for over 200 hours of work, installing floats with every bell, whistle and warning system known to man. Reinforced the nose/floor pan and a few other things as well before it left. There was no visual evidence of stab cracks when it left my field.... to fly across Canada to Vancouver Island.

At the same time I look after another 180HP Elite on Clamar 2200's that we watch like a hawk, that gets flown hard and regularily. It hasn't shown any signs of fatique cracking.

[Elite583]

Dave,

Thanks for the pics. The material thickness you're looking for is .050"

Keep us posted on further findings.

Cheers,

Thanks Dale. When I move ahead with this I'll post an update to my web site http://www.elite583.cjb.net.

Wayne, is that to say that the Elite in the photos acquired the cracks within 25 hrs after leaving your shop? How many total hours?

How many hours on the other Elite you look after?

Dave

[irishfield]

Yes Dave... as far as I know, at least not obviously visible like they are in the pictures, there were no cracks evident while it was here. I flew it out of my field to CYEE.. it was then flown for about 5 hours for dual training for insurance purposes and then John flew it across the country to his new home in BC. Cracks found very shortly there after.

Total time.. I do not know, do not remember how many hours were on it when I installed the floats... but it was very few. The one that stays here, I'll find out when Bob comes over this week with his lower cowling that he took to the body shop for some mods.

[ericfo]

Hello All.

Been off the list for a while, so hope that this post works. I am in annual right now with my Elite on amphib 1800s. I checked my horizontal stabilizer outboard rib and rear spar at the hinge and no cracking. No cracking on the outboard aileron hinge area of the wing either. Perhaps different builder choices could be affecting this short or long term.

The airframe has 300 hours on it now. I have the original 8" wide aileron spades and the tips of the spades are not rounded, they are blunt per original parts. I have VGs under the horizontal stab just ahead of the elevator hinge. I use a constant speed prop and cruise at 2200-2300rpm. Prop RPM may be a factor because the cracking could be due to prop pulses beating the horiz stab (I'm not an engineer). I've spent about half my time on floats crusing around 95KIAS and the other half as a taildragger cruising around 110KIAS.

As for the wing, I have VGs only infront of the ailerons.

Just wanted to add those details to the discussion. Not planning to apply the SR/Moose mods at this time, but just keep an eye on these areas.

Eric
N645E

[irishfield]

Good chance it's prop pulses... that's how it started with the Moose with the Paddle prop beating the hell out of it running on the radial. I had a CH701 that I switched from a wood GSC prop to a Warp Drive prop a few years back and AFTER a flight the lexan windshield would shatter on the pilots side!

The Elite in question.. with cracks.. left here sporting a Sensenich aluminum prop, as far as I know it's still on there.

....also notice it has reduced elevator spade width and rounded tips.

[Walter Klatt]

This sounds almost similar to the Rebel left elevator issue with the outside rib and skin doublers needed there. Is it always the left side where this happens?

[Elite583]

Eric

Thanks for speaking up with detailed information, the more the better to get the best understanding of this. Good to hear it's not a problem for you at this point. A couple more questions; what are you running for an engine and what is the CS prop?

Interesting about the VGs, but I think I'll save that for another thread.


Wayne

What was the engine on the Yellow Elite? Any idea if it was also high compression?


When I saw the other Elite I mentioned, it had a Prince prop on a 180 HP (O-360?) engine. It also had narrowed spades but with the original profile.

Tks. guys,

Dave

[irishfield]

It's a carb'd 360 Dave.. with dual Emags. I think it was one of Bart's engines and probably hopped up a bit, it sure pulled itself out of the mud and into the air when I took it out of here just after the snow came off the field! Wish the owner would speak up....

[Elite583]

This sounds almost similar to the Rebel left elevator issue with the outside rib and skin doublers needed there. Is it always the left side where this happens?

Walter

The photos of the Yellow Elite in the archive show cracks on both sides, don't now about the other one.

EDIT: I've sent the owner a note asking.

Cheers,

Dave

[Elite583]

It's a carb'd 360 Dave.. with dual Emags. I think it was one of Bart's engines and probably hopped up a bit, it sure pulled itself out of the mud and into the air when I took it out of here just after the snow came off the field! Wish the owner would speak up....

Hmmm... on a sample of two, it's two 360's. Not enough data to draw any meaningful conclusions but I wonder if the power pulse/torque is a contributor to a vibration mode???

In some ways similar to the Moose paddle prop theory like you said...

UPDATE: I just looked back in the archive and the other Elite I have been speaking of found the right side cracked at 365 hours, all on wheels and hadn't taken the other side apart for inspection. He looked at his when the owner of the yellow Elite posted about his findings (at 273 TT).

Dave

[ericfo]

My Elite with 300 hours and no cracks (yet) has a Superior O-360 carb'd 180hp MT constant speed prop.

Eric
N645E