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Elevator Inoculation

Re: Elevator Inoculation

A little north of 210 aircraft have reported to the FAA. Spar cracking in one or both elevators - overall the fleet is in the 20% - 25% range. A more significant stat is that 40% - 50% of the 114/112TC sampled fleet is cracked. This level of incidence is of significant concern to the FAA. Those airframes were generally manufactured in the '76 - '79 time frame. The straight 112's have a much lower incidence of cracking as do the later 114/115 airframes but none of the model line subsets are completely free of cracking. The issue does NOT seem to be airframe TT related. There are low time spars that are cracked and high time spars that are crack free.

Good news you are in the latter category.
 
Re: Elevator Inoculation

I was lucky enough to have cracking in both of mine on a 112. Could have been worse. Could have found out the hard way rather than by looking.
 
Re: Elevator Inoculation

aaaprod said:
I was lucky enough to have cracking in both of mine on a 112. Could have been worse. Could have found out the hard way rather than by looking.
Click to expand...

Mark:

As a matter of interest do you know where the cracks are in your spars. Are they through the bolt holes or in the bend radii? I also have cracks in both spars (Serial 220).

Don
 
Re: Elevator Inoculation

aaaprod said:
I was lucky enough to have cracking in both of mine on a 112. Could have been worse. Could have found out the hard way rather than by looking.
Click to expand...

Hey Mark,

I've been renting an Arrow at Pontiac while mine is down. Contact me off list if you would like the contact info.

It Sucks to be without my Commander, but renting at least keeps me in the game.
 
Re: Elevator Inoculation

MSBradley said:
Hey Mark,

I've been renting an Arrow at Pontiac while mine is down. Contact me off list if you would like the contact info.

It Sucks to be without my Commander, but renting at least keeps me in the game.
Click to expand...

Mine is fixed and airborne again Mark. My cracks were near the bolt holes Don. Not running off the holes but perhaps 5 mm off the hole.
 
Re: Elevator Inoculation

Got bad news last month when I had the inspection done. The A&P with the hi-res camera said he saw a crack in one of the spars. Grounded...crap. So Got the email from Martine on Sunday letting me know the newly minted spar was on it way...woohoo. Call A&P to have the elevator removed and prepped for the new spar. After removing the end rib and a visual inspection, no crack. After a dye inspection, still no crack. I did order my inoculation kit, but in the mean time, we put it back together and off I went on a test flight. The funny thing is that the camera used is the 11000fiber kind with a controllable head. When we finally opened it up, it was a combination of tooling mark with a water stain and Arizona talc.
 
Re: Elevator Inoculation

unfortunately false positives are not unusual but still good you took a closer look.
 
Re: Elevator Inoculation

Bryan ... could have been worse .. there could have been a crack. Great news that you're back in the air.
 
Re: Elevator Inoculation

When I had my elevators off I personnally did some looking at the tail area. In fact, quite a bit of looking. Used mirrors, scopes, flashlights just about everything I could think of to look at every nook and cranny. During one of those lookings I saw what I thought was a crack in one of the tail ribs but no smoking. I could not reach the area so I used a long wooden dowel and it was a piece of thin string laying on the rib. Not sure what a scope would have revealed but it most certaintly looked like a thin crack.
 
Re: Elevator Inoculation

I had a similar situation... looked like a possible w/ no smoke. DP check showed nothing. Turned out to be a little extra chromate coating buildup creating a shadow line.
 
Re: Elevator Inoculation

Jim / Anyone
I have had my 112 repair,, complete spar replace pilot side. Problem FAA says it will take 3 weeks to 2 month for the sign off. This work was completed at a cert shop in Houston Tx. Do I have to wait for the FAA to sign off at a cert shop. I have the plane sold but can't deliver.
 
Re: Elevator Inoculation

Hi Mark,

Where did they get the replacement spar? If it was "duplicated", the only definite way out of the trap is for you to order a PMA spar and have it replaced again. The only FAA approved repair for cracked spars is to replace with new PMA 44211-RE9 or RE10.

Jim
 
Re: Elevator Inoculation

What is the difference from RE-9 10 and a cert shop spar. Are they considered factory parts?
 
Re: Elevator Inoculation

Hi Mark,

The Aerodyme PMA 44211-RE9 (left) and 44211-RE10 (right) are FAA-approved for compliance with AD2011-07-13, whereas "certified shop spars" are not. For your reference, I have attached copies of the PMA Letter and Special Approval for the AD by the Wichita ACO.

Jim
 

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Re: Elevator Inoculation

Jim
Can I buy the spar from Aerodyne. Without the hings
 
Re: Elevator Inoculation

Hi Mark,

Yes, we offer the PMA spars for $850 each. Leadtime is down to 1-2 weeks for RE10 (right) and 2-3 weeks for RE9 (left).

Jim
 
Re: Elevator Inoculation

Any clues why the difference? Looks like you could just turn the cookie cutter over.. ;)

Also, what's the outlook for hinges? And for a terminating action for the AD?

I know you don't have all the answers... occasional speculation goes a long way though. :)
 
Re: Elevator Inoculation

Hi Dave,

The majority of spar cracks are right hand, but we overcompensated and got a bit behind on lefts. The process is about 3 weeks from sheet to shipping tube.

Fitting production is on gate hold while Wichita puts us through a few more paces to make sure they are happy with the PMA (from the "Boston FAA"). We have completed our first trial installation of the fitting kit, and it went well. Tomorrow we'll be running an OEM fitting versus PMA fitting torsional stiffness comparison (at the elevator assembly level) to put a few few final questions to rest.

Re terminating action, don't look for any final decision soon... that process in the FAA: NPRM, review, drafting, amendment, etc may easily run through late this year. I am doing all I can to motivate the FAA to move quickly. The more I learn about this overload problem, the more concerned I am about new spars flying for any length of time with old fittings. After a year of that loads abuse, there is no way the spars could still be regarded as new.

Jim
 
Re: Elevator Inoculation

Way to go on this Jim! Most of us have no idea what it's taking to move this process through the hoops as you have.

We're anxiously awaiting those hinges!
k
 
Re: Elevator Inoculation

Hi All,

Pics below of the first PMA fitting installation, on a freshly installed PMA spar. Finally!

We are within a few spars of caught up on the spar backlog, and are now starting up the ramp of delivering the fitting kits. The first kits have shipped.

Today, someone asked:

Why can't I install pre-drilled PMA fittings on my existing, uncracked spar, instead of having to use the "SP" fittings and correspondence drill them?

Answer:

It seems neither Rockwell nor Commander were well tooled for installing the original fittings in the center of the spar channel. The existing holes in the spars are generally offset high, or low, in the channel, and are often also out of alignment with the hinge line. Thus, the only way to get a proper inoculation of an original spar is to correspondence the new PMA fittings. We include instructions which should result in the new fitting being well-centered and aligned, whereas the the holes in the new fitting will not be "square" on the base of the fitting. Make sense?

Jim
 

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