All T-34's to be grounded???

[Roger Cain]

Just got some bad news from the T-34 Association as posted below:

Breaking News

The FAA has contacted the T-34 Association informing us that they are
issuing an "Emergency Airworthiness Directive" grounding the entire
T-34 Fleet. This AD, we are told will be published today.

We have not yet seen this AD, but are expecting that it will have
provisions for 10 hours flight time, to fly the aircraft back to its
home base if it is currently away.

The T-34 Association does have our DER, Victor Juarez on site today
with the FAA and NTSB accident investigators and hopefully we will
have information to start addressing any airworthiness concerns that
might be found as a result of this particular accident.

Jud Nogle
T-34 Association, Inc.

A copy of the Actual AD will be posted on the Association's website
at http://www.t-34.com

Too bad that a few aerobatics T-34's will ground all the others that just fly for the pleasure.

[Ollie]

Yikes!

Let's see if TC reacts to this since there's only one up North.

[Ollie]

Rob, easy now.

Julie Clark did the 1999 or 2001 AD plus a big mod that cost her 60 000$ (read that in AOPA Pilot).

Now, it's usually standard to ground an aicraft type that has suffered a major crash. When the CRJ crashed in China the other day, they grounded all the Bombardier Regional Jets pending the enquiry, and then the grounding was lifted as it progressed. Same thing here when the Snowbirds crashed yesterday, the Tutors were grounded while they figured out what had happened.

I think it's time someone steps in to stop the usge of T-34 for ACM purposes. They'll probably do just that.

Anyways, it's winter here, it's bloody snowing so I'm more concerned about shoveling snow than Avgas!

[D Fisher]

Ollie

With regared to the CRJ crash in China, they did not ground all CRJ's, the Chinese grounded there CRJ's until they knew more about the crash. CRJs elsewhere continued to operate as normal.

Off the T34 topic, but thought I'd correct that.

Cheers

[Ollie]

Oups, I meant in China! I forgot to add the country...

Thanks for correcting me...

[Cvairwerks]

Just read a copy of the AD. It requires some additional inspection further out the spars than the previous one. Prelim from the NTSB is the spar down in Houston failed 4" outboard of the area that previously had been identified on the front spar. It had signs of fatigue cracking running through several of the rivets in that area. It would appear that the approved repairs simply moved the failure point further outboard.

Maybe it's time to take a midtime T-34 and instrument it and run an accelerated lifespan test on it, with a significant amount of time being loaded to near 100% and a load cyclic time approaching that found in most of these BFM manuevers. With that we can find out engineering wise what is really happening to the spars.

[krlang]

Ouch,
Like the owners of all those T-34s need another hit in the wallet.
Nevermind the expense of a repair but the value of the aircraft must be taking a huge hit also. What a shame.

[Jase]

George Braly of GAMI has already done just exactly that. He's the only one who has ANY inflight engineering data from strain gages etc.

Just read a copy of the AD. It requires some additional inspection further out the spars than the previous one. Prelim from the NTSB is the spar down in Houston failed 4" outboard of the area that previously had been identified on the front spar. It had signs of fatigue cracking running through several of the rivets in that area. It would appear that the approved repairs simply moved the failure point further outboard.

Maybe it's time to take a midtime T-34 and instrument it and run an accelerated lifespan test on it, with a significant amount of time being loaded to near 100% and a load cyclic time approaching that found in most of these BFM manuevers. With that we can find out engineering wise what is really happening to the spars.

[Cvairwerks]

Jase: Just inflight data isn't going to be enough. Been there and done that with the company that I work for. We've had our basic design in production for 28 years and we still have had to go back and redesign and upgrade the structure numerous times. Even with having worn out more than a dozen flight test aircraft you can't hit every load combination that you need to and the number of cycles to induce a failure. There has to be gound based testing with cycling to failure with these, and with some kinds of loads you only do them ground based so you don't endanger your pilots. With a properly set up test rig, a bird could be cycled with the same approximate load pattern as the failed aircraft and run til failure within a couple of weeks.

[bdk]

I think it's time someone steps in to stop the usge of T-34 for ACM purposes.

And that someone will be the insurance companies.

I think that ACM is not recognized by the FAA in any other fashion than "aerobatics." The FAA cannot cherry-pick ACM operations from the T-34's repertoire, they would have to either restrict aerobatics or commercial operations I think.

[Paul Draper]

Hi All,

If I was the T-34 Assoc. I would be asking the FAA to pass an AD that restricts all T-34 from doing any type of Air Combat stuff.

Also since I haven't had a chance to read the AD will this effect the civilian stuff. I would think it would since the spar came from a Baron.

RER

The used Baron (Front Main) spar installed on that T-34 wasn't what failed. The rear spar failed. Once the rear spar failed, the front spar carry-through structure failed Inboard of the wing attach fitting. The Baron and Bonanza spars, while similar and interchangable (with some mods?) are not identical, so the AD will probably not affect them.

Somehow, even though the spars are different for the T-34A and T-34B, they get grouped together. Even though only A's have had wings come off. Why is that? Because all these Air Combat Schools use the T-34A. Why do they use the A model? Because it is certified in the aerobatic catagory, and the B model is not.

[Ollie]

I think that there are only 2 or 3 T-34Bs flying, no? And they have the underwing hardpoints?

Correct me if I'm wrong.


If I hear from TC, I'll let you guys know what's up for us in Canuckistan.

[srpatterson]

Hi All,

If I was the T-34 Assoc. I would be asking the FAA to pass an AD that restricts all T-34 from doing any type of Air Combat stuff.

Rob,

The airplane doesn't know the difference between "Aerobatics" and "Air Combat". The result of all this will be the revocation of the Aerobatic type certificate and a re-issue in the Normal catagory, or a greatly reduced G limit (say 2 G's) and a lower Vne as well.

Just removing the "Air Combat" will not keep wings from coming off.

[Ollie]

I think that removing Air Combat will help solve the problem since the pattern of losing wings is restrained to T-34s doing air combat.

It's a matter of logical deduction, but I doubt that a ruling instance is capable of logical deduction.

[SaxMan]

Pardon my ignorance, but who is Julie Clark?

The only Julie Clark we know around this house is the one who founded the "Baby Einstein" Company. If you have an infant or a toddler, you definitely know who I'm talking about. I'm not sure if they are the same person, but based on how much we've spent on Baby Einstein products, I'm sure this Julie Clark could easily afford several T-34s.