tapered axle landing gear inspection

[PA1195]

Re: tapered axle landing gear inspection

If you saw pics of that airplane, it should have never been flying to begin with.

Maybe the RIP's resume prevented any questioning about the airworthiness of his plane.

Owner/pilot/mechanics from my experience "may" have different tolerances than others. Not to say all or most, just some I've seen figure it's theirs to worry about, so why worry?

Gary

[Dick Smith]

Re: tapered axle landing gear inspection

If you saw pics of that airplane, it should have never been flying to begin with.

Are you referring to pictures taken Pre-crash or Post-crash? Dick

[Garry Crookham]

Re: tapered axle landing gear inspection

Here is what the NTSB had to say about N13060: Visual examination of the fractured wing strut attachment fitting showed substantial corrosion and pitting throughout the assembly. Further examination utilizing a scanning electron microscope (SEM) revealed that the left wing strut fitting fractured due to extensive corrosion followed by fatigue cracking. The lower side of the fitting had corrosion pitting that extended from the interior of the fitting completely through the thickness in some areas. The upper side of the fitting was also thinned due to corrosion. Several areas of the fracture surfaces showed oxidation consistent with progressive crack growth over an extended period of time, and fatigue features were found in areas not damaged by rubbing or corrosion. The most recent annual inspection was completed 2 months prior to the accident by the owner, who held an airframe and powerplant technician license.

[Guest]

Re: tapered axle landing gear inspection

I recall seeing pictures of the fitting and there was excess fabric stuffed into the attachment fitting. I suspect that it held water and resulted in corrosion.

I think those pictures were on this forum somewhere.

Dave

p.s. oops! I found them on my computer and attached them.

[PA1195]

Re: tapered axle landing gear inspection

Was the drain hole on the bottom an original factory job? First thing a local visiting mechanic did to mine when he was in the hangar and saw my plane was to look and poke into that hole. He mentioned he'd seen them painted shut by tubing primer before.

But these pics are beyond normal. I wonder if the rest of the exposed tubing and parts were as corroded? That belt shackle looks like it was surely visible for some time. Easy to criticize I know.

My mechanic had to replace his lower longerons (PA-18) and inter-gear X-tubing a year ago. Knew they needed it in one spot but when the lower fuselage fabric was removed it just kept getting worse.

When we rebuilt my PA-11 in 2001 I pressurized the fuselage to 100 PSI at the tailpost drain holes. Weak corroded areas in tubing near the side windows blew out...known to collect water there on Cubs. Some smaller leaks were inspected and repaired.

Gary

[M Towsley]

Re: tapered axle landing gear inspection

Dave,

Curious, what was the source of those pictures? Pretty nasty, first time I have seen those.

[N96337]

Re: tapered axle landing gear inspection

I have those pictures too, Dave. Thanks for finding them....they're on my other computer. If I remember, they were on the forum... it's not too much of a wonder why it failed, looking at that. But the reminder has to be, it wasn't a strut at all...but the fitting tearing out because of an unbelievable amount of corrosion! It's a testament as to how sturdy these planes are, that it flew at all!!
John

[Guest]

Re: tapered axle landing gear inspection

Dave,

Curious, what was the source of those pictures? Pretty nasty, first time I have seen those.

I believe they came from the FAA engineer that worked on the AD I recall his name was Andy McNaul or something close to that.

I talked to him a few times. I have some other pictures of struts that had been cross sectioned and inspected, pics posted below.

I recall that they also came from the engineer and at the time I think that he did not want me to share them for fear of panic.

It has been nine years so I may have some fuzzy in the story bu not much.

Dave

[Guest]

Re: tapered axle landing gear inspection

Was the drain hole on the bottom an original factory job? First thing a local visiting mechanic did to mine when he was in the hangar and saw my plane was to look and poke into that hole. He mentioned he'd seen them painted shut by tubing primer before.

But these pics are beyond normal. I wonder if the rest of the exposed tubing and parts were as corroded? That belt shackle looks like it was surely visible for some time. Easy to criticize I know.

My mechanic had to replace his lower longerons (PA-18) and inter-gear X-tubing a year ago. Knew they needed it in one spot but when the lower fuselage fabric was removed it just kept getting worse.

When we rebuilt my PA-11 in 2001 I pressurized the fuselage to 100 PSI at the tailpost drain holes. Weak corroded areas in tubing near the side windows blew out...known to collect water there on Cubs. Some smaller leaks were inspected and repaired.

Gary

Yes

They are beyond normal and never should have passed annual inspection, the fabric should have been pulled out and permanently removed and a visual inspection conducted. A tragedy for sure but there were likely many chances to prevent it.

[Ragwing nut]

Re: tapered axle landing gear inspection

The strut AD came about because someone wanted a market to sell parts, thats my opinion though. It happens more than you think. Someone finds a freak a nature on a flying airplane due to a worthless mechanic paper annualing airplanes for years until the airplane gets sold and into the hands of a real mechanic that starts posting pictures, and asking questions. next thing you know you have a manufacturer catching wind of it and exploiting the issue legit or not.

[Ragwing nut]

Re: tapered axle landing gear inspection

Are you referring to pictures taken Pre-crash or Post-crash? Dick

there was pics of both on here at one time or another. It was obvious no one had looked at the airplane for many years although it was flying.

[M Towsley]

Re: tapered axle landing gear inspection

I found some more pictures on this thread, too lazy to cut and paste. http://vb.taylorcraft.org/showthread...ht=wiley+crash

[Guest]

Re: tapered axle landing gear inspection

I found some more pictures on this thread, too lazy to cut and paste. http://vb.taylorcraft.org/showthread...ht=wiley+crash

Marty,

I looked thru that thread and wow it brings back memories and is depressing.

I am glad I bought new Univair struts and was able to stop thinking about it for all these years.

Dave

[PA1195]

Re: tapered axle landing gear inspection

Read the Thread, thanks for the link Marty. Might have seen it during earlier browsing.

My gear/strut fitting was well exposed during recover or later inspection. Drain holes are open and pumped full of Corrosion-X there and the ears when the AN5 bolt was removed for bolt and strut replacement and strut adjustment. Fuselage side is easy to see with my seat arrangement. I can have the lower strut ends off the fuselage fitting in 10 minutes or less with my wing jack under the front strut tiedown.

As far as the landing gear axles I will have a look at them tomorrow. They are atypical in design at the strut attach point (see below) and the gear assembly is overall powder coated. When I had the gear off for floats I flushed the shock strut with Corrosion-X bottom to top through the drain hole and no rusty lube came out. Those two spots (axle and shock strut) should be looked at.

[Hank Jarrett]

Re: tapered axle landing gear inspection

Before I put my new sealed struts on I made a cover for the attach area so it can be inspected. The covers go around the longeron and when the gear to fuselage cover is removed I just need to take 5 more screws out and the whole area is wide open to clean and inspect. I made 4 small wood pieced with "T" nuts for the screws to go through inside of the fuselage. The photo is of my plane before the new struts were delivered. I keep any old parts that have failed with the red tags since they make GREAT support struts while the good ones are off. Those are my OLD struts in the photos. I DO NOT fly with them, but have loaned them out a few times so that struts can be sent for inspection. I pull the covers EVERY ANNUAL as well as pulling the tail wheel for disassembly, cleaning, inspection and lube before putting everything back together.