Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

[N96337]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

Can you give us a link to these pictures?

Danny Deger

Danny, they're on the strut inspection results thread.
JH

[Dano"T"]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

Well, I agree that a floatplane can touch down as smooth as silk and the passengers may not even know they have arrived yet. Conversely I have experienced conditions that would be somewhat akin to wheel landing a landplane across the furrows of a plowed field. I think what the posters are trying to convey is that in a floatplane the landing stresses, if there are any, are transmitted directly to the airframe as there is nothing else to dampen them such as tires, bungees, etc. Not that all landings are like hitting a wall. Thus, there will obviously be more stresses applied to the fuselage attach points. I believe that visual inspection will still identify any problems before they become failure issues, especially now that operators have their antennae up. This floatplane that had the failure may have been one of the highest time T-craft on floats ever, who knows? I don't feel that shotgunning the entire fleet with complex inspections is a viable solution.

Agreed...I was just trying to avoid everyone thinking that every water landing was like hitting concrete.

[Forrest Barber]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

I hope I have caught up on my reading, what a wealth of information is contained in these threads. Yes, Bill and others, we know that C.G. even commented to me at a Fly-In way back when I was wringing out the Taylorcraft that this was an "old airplane" and to be careful!!
BAck in the 50's we "recovered" many ships , then in the 60's we "recovered" again. At that time Irish Linen was used to extend the life of the fabric. Then we ahd Eonite , Ennox, Fibraglas, Dacon, Nylon, and many others;
some was approved to be applied right over the old covering ( no good inspection of the interior) , YES right over rotten cotton.........
Then we had Ceconite, Polyfiber, Blue River and many other processes my spelling may be wrong on some. THEN Mr. & Mrs. Feris developed the Taylorcraft process Randolph dope and dacron process, some ships were ordered special with Fiberglas or other ways..... In the 1970-80 era we did more than "recover" we started to "rebuild" then "restore" and now darn near build from scratch..... "Aging Aircraft" is indeed an area that needs a lot of study. Be careful out there and inspect, inspect, inspect.... cracked spars do show up. It is amazing the things that are found during restoration that are not desiminated to us all.

[ClipWing_T]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

The aircraft that had the fitting failure was poorly maintained. Some may say , not so , But I garuntee you we had an old AI here that WOULD have
found that corroded and rotten fitting on THAT airplane. He was slow and
thorough with his inspections too.....And a LOT of people wanted a pencil
whipped annual. To me the problem is one of poor maintainence and to
condemnthe whole fleet seems unecessary . The AI that signed that plane
off has to look in the mirror knowing he didn't do a good enough job. Maybe
he thought a 1969 sandblast and epoxy prime was the END OF THE STORY!
Might be in your case but it sure as hell wasn't in the failed aircraft we have
been talking about . Of course a hangared airplanes fittings are perfect in
most cases. But what about airplanes that are not?
Mike

[alwaysoar]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

No offense intended here, but I don't think an inspection done in 1969 is the end of story. That was almost 40 years ago, and a lot can happen in that number of years. My plane was rebuilt in '99, and I plan to do a very careful inspection including Xray asap if I can find someone to do it.

[fearofpavement]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

Well, I agree that a floatplane can touch down as smooth as silk and the passengers may not even know they have arrived yet. Conversely I have experienced conditions that would be somewhat akin to wheel landing a landplane across the furrows of a plowed field. I think what the posters are trying to convey is that in a floatplane the landing stresses, if there are any, are transmitted directly to the airframe as there is nothing else to dampen them such as tires, bungees, etc. Not that all landings are like hitting a wall. Thus, there will obviously be more stresses applied to the fuselage attach points. I believe that visual inspection will still identify any problems before they become failure issues, especially now that operators have their antennae up. This floatplane that had the failure may have been one of the highest time T-craft on floats ever, who knows? I don't feel that shotgunning the entire fleet with complex inspections is a viable solution.

[Smithfield Slim]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

The strut fittings are something we should all be checking during recover/restoration. I performed this inspection on mine back in 1969, after which I coated with epoxy primer; end of story.

Bruce Patten
N44184

[Dano"T"]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

Don't forget that float operations also cause greater stress concentrations on fuselage fittings than land operations....water at 50mph is like concrete, whereas land operations have bungees & tyres to absorb shock.

That's why the original fitting crack AD (back in God-knows-when) was quite sensibly restricted to floatplane operations.

Rob

I agree that there are occassionally conditions that make float landings and takeoffs harder on the airframe....but to assume that touching down on the water at 50 mph is like hitting conctrete is completely inaccurate....actually, under fair weather conditions with no waves....(like 99% of my landings on inland lakes) the landings are softer and put very little stress on anything.....it's those instances when the wind kicks up a chop that those stresses become an issue. I just want to set the record straight so people don't go assuming things that are not true....ask Mike Cushway(1938BF50) I took him flying and he was surprised how gentle the touchdowns were.

[DannyDot]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

It looks to me like x-ray could do both the fitting and the strut at the same time, still on the aircraft...look at Bill's pics on the other thread... now THAT would be nice!
JH

Can you give us a link to these pictures?

Danny Deger

[tawadc95]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

My grandpa,who was no Charles Lindbergh, took a half hour to preflight his hangared family cruiser every time even if he flew the day before. It seemed to work for him quite well as he started flying in 1927 and quit in 1994 at 86 with only one incident but never a mechanical one.My dad thought grandpa had the pedals and grandpa thought dad had the pedals and they ended going into a ditch during a rollout but that was it for grandpa in 67 years of flight.
I am not as patient as him and just can't take that long to preflight so I have started to post flight. I am still debating as to whether or not that is a good idea but herwe is why.I am always in a hurry to fly and never wanting to leave Sneaky when I am done flying, sooooo,I wipe her down real good and give her a thoruogh preflight for the next time. I like to wax in different areas for a bit as well as you get rather intimate if you wax.
When I go out for the next flight I look at the oil and for bugs etc in the cowl and drain the sump then it is off the terra firma.I would not do that if I was parked outside though...I only consider that safe enough for a hangared plane.

[LLBOYD]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

I agree with John about the longer duration between recovering the aircraft. I can remember back in the fifty and sixties we were using grade A or Irish Linen with lots of silver to extend the life of the cover to 6 or 8 years. Now with the rayons and fiberglass the cover material lasts much longer and thus the underlying structure is not exposed as often for inspection. Careful preflight is where some of these abnormalities can be discovered. When I was a lad I was told a story about a couple of pilots sitting in an airport coffee shop in Florida observing an elderly gentleman very meticulously preflighting an old airplane. One commented to the other about the time the elder was taking to simply preflight the airplane. This comment was overheard by a third pilot who simply stated that the time spent on the ground was well worth it if it prevented a problem in the air. And by the way the gentleman doing the preflight is Charles Lindbergh. Make it a habit to do a good through preflight for the life you save my be your own or a loved one's.

[Robert Lees]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

X-Ray seems to be emerging as the answer

I strongly disagree. The correct adherence to existing standards of good inspection and maintenance is the answer.

Else we'd all be falling out of the sky.

[Howard Wilson]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

Well, between the strut situation and an engine swap, I figured it was a good time to pull the wings for a winter project. Got the wings hung in the barn and noticed a split/crack about 1/4" deep running from inboard to outboard along the top of the left rear spar and disapearing under the butt rib. OH !@#$%!!! More investigation needed!! Bill's point above about taking a closer look every once in a while is a good one. While you are pulling your struts this year take a few minutes and take off the top wing fairings and have a good look!! Howard

[N96337]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

I agree Bill, it's a great idea to pull the struts once in a while to look at things really well, and it's not that big of a deal to do...but what I was getting at was maybe a compliance for both issues at one time... not having to pull struts and go one place, then head the fuselage somewhere else... and I do like those x-ray images. Maybe a "strut pull" every 5 years for a good look see including tapping to listen for loose "stuff" and an xray every??? OR even better yet..one xray and then visual inspections.....
What was the cost of the x-ray that you had done? I don't remember reading that...or maybe I just lost it in the cobwebs...
I also agree that the aircraft were most likely never expected to go 20 years with no change in cover.
JH

[VictorBravo]

Re: Fuselage strut fitting - FAA Airworthiness Concern Sheet (merged)

I wouldn't be that afraid to remove the struts. There is way too much panic going on here over that issue. It is a minor pain the ass, not a major one. Some of you have spent more time talking about it than it actually takes to do.

Reality check... it's a 60+ year old airplane, taking the struts off to have a good look every once in a while is good. If it were not for the fact that I had taken the wings off recently and looked at the bolts, fittings, etc, I would have had to admit that this strut BS (as bogus as it may turn out to be) would have been a good excuse to have a look in there.

Many many airplanes haven't had the struts off in decades. The spars flex a tiny little bit (they're wood, you know) in flight, and as such they cause a very very small amount of rotation on the lower attach bolts all the time. It's nothing that the bolts can't handle, but after 20 years you might want to at least have the bolt out and verify everything is OK i n there... aside from the corrosion question.

Forrest, please correct me here if I'm barking up the wrong tree... but I do believe that the airplane was DESIGNED for, and assumed by all parties involved, that it would be normal practice to be re-covered every ten years or less because of the original cotton fabric. It is very easy for me to believe that old C. G. had every reason to think these planes would NEVER go 20 or 30 years on the same fabric and not be disassembled.

Bill