AD 2023-09-09

[N201MKTurbo]

None of the previous ADs that referred to turbo clamps applied to me, this one does. Danm, now I need to buy a new clamp.

https://www.federalregister.gov/documents/2023/06/12/2023-12417/airworthiness-directives-various-airplanes-helicopters-and-engines

 

[A64Pilot]

I posted that in the Modern Mooney section.

I’d place that order today, before they are all gone

[N201MKTurbo]

2 minutes ago, A64Pilot said:

I posted that in the Modern Mooney section.

I’d place that order today, before they are all gone

I get 50 hours after the middle of July. I will find one somewhere.

Most planes were covered by the previous ADs. And considering there are only 35 Turbo Js in the world. I don't think there will be a run on bands. 

My bands look like brand new except for discoloring from the heat. It is sad to throw away good parts (and money).

[N201MKTurbo]

It's too late, everybody is out of stock.

[kortopates]

3 minutes ago, N201MKTurbo said:

It's too late, everybody is out of stock.

What about inspecting it by every 6 months or 100 hrs TIS? That can buy you upto two years:

(2) As an alternative to initially removing the v-band coupling from service as required by paragraph (i)(1) of this AD, you may perform the inspections required by paragraphs (k)(1) through (7) or (l) of this AD. Do the initial inspections at the time the v-band coupling would have been removed from service and thereafter at intervals not to exceed 6 months or 100 hours TIS, whichever occurs first, for a period not to exceed 2 years after the effective date of this AD. 

But if you know the TIS, you can go up to 500 hrs TIS under paragraph (i)

[N201MKTurbo]

16 minutes ago, kortopates said:

What about inspecting it by every 6 months or 100 hrs TIS? That can buy you upto two years:

(2) As an alternative to initially removing the v-band coupling from service as required by paragraph (i)(1) of this AD, you may perform the inspections required by paragraphs (k)(1) through (7) or (l) of this AD. Do the initial inspections at the time the v-band coupling would have been removed from service and thereafter at intervals not to exceed 6 months or 100 hours TIS, whichever occurs first, for a period not to exceed 2 years after the effective date of this AD. 

But if you know the TIS, you can go up to 500 hrs TIS under paragraph (i)

Oh, I didn’t read that part. I’m sure they have more than 500 hours. I will order one and I have 2 years for it to show up. I need to update my AIP anyway, I can add this inspection and time tracking.

[Bruce]

I read through the AD and maybe I missed it, but does the AD apply to the V-Band clamp that is on the turbocharger between the exhaust side and the induction side?  Obviously the AD applies to the two smaller exhaust clamps.

Bruce

N231CH

[N201MKTurbo]

1 hour ago, Bruce said:

I read through the AD and maybe I missed it, but does the AD apply to the V-Band clamp that is on the turbocharger between the exhaust side and the induction side?  Obviously the AD applies to the two smaller exhaust clamps.

Bruce

N231CH

You mean the one that holds the turbo together. It isn’t mentioned. I don’t think it is much of a problem. I took my turbo apart once. After you remove the V-band clamp, the exhaust deposits hold it together quite well and seal it up quite well also. I think after the turbo has a few hundred hours on it, you could take the clamp off and it would run just fine and not come apart.

[Pinecone]

No, this only covers the clamp between the turbo and the exhaust pipe.

I am hoping, someone will make a batch of replacement clamps that are riveted as an AMOC to do a one time replacement and move on.

[A64Pilot]

Shouldn’t require an AMOC, if riveted clamps are allowed you simply terminate the AD by installing a part that the AD doesn’t cover.

To get an AMOC you of course have to go through the FAA and get it approved

[Pinecone]

That is even easier.

Now, where to get a riveted clamp...........

[Jan B.]

Could sombody explain the instructions?

(i)(2) says: „Do the initial inspections … and thereafter at intervals not to exceed 6 months or 100 hours TIS…“
(j) says: „at intervals not to exceed 12 months, visually inspect the v-band coupling“

So do they have inspection intervals of 6 or 12 month?

[A64Pilot]

8 hours ago, Jan B. said:

Could sombody explain the instructions?

(i)(2) says: „Do the initial inspections … and thereafter at intervals not to exceed 6 months or 100 hours TIS…“
(j) says: „at intervals not to exceed 12 months, visually inspect the v-band coupling“

So do they have inspection intervals of 6 or 12 month?

I believe it’s 6 months, I’ve not honestly dug into it, but nobody will ding you for more frequent inspections.

To be honest I’d inspect it every time I had the cowling off.

I assume though that you’ll have to get someone to do the inspection? 

[Jan B.]

1 hour ago, A64Pilot said:

I believe it’s 6 months, I’ve not honestly dug into it, but nobody will ding you for more frequent inspections.

To be honest I’d inspect it every time I had the cowling off.

I assume though that you’ll have to get someone to do the inspection? 

It would be easier to do it just at the annual. And yes, it seems that those inspections have to be done by a certified person. Or do You think, this can be done by the owner?

As I'm not a native english speaker, I hoped somebody could clarify the intervals.

[Pinecone]

So, let's try to parse this.

1) If your clamp has less than 500 hours, you have to replace it at 500 hours or 50 hours after the AD does into effect, whichever is later.  So if you just replaced it, you can go to 500.  If it has more than 451 hours, you have 50 hours to replace it.  Then replace it every 500 hours.

2) If yours have more than 500 hours or cannot determine how many, you have 50 hours to replace it.  And then replace it every 500 hours.

3)  Instead of replacing it, you can do the inspection when you would have removed it, and then every 6 months or 100 hours.  And you can do this for up to 2 years after the AD goes into effect.  So if you have one that is over 500 hours or not determined, you can do the inspections for 2 years, then have to replace it.  

This also seems to say, after 2 years from the AD effective date, you have to replace it, even if it passes inspection

4)  Paragraph J sets a requirement to inspect at every annual, even after you replace it.  
 

So the 6 month/100 hour inspection is for a clamp that is over 500 hour or not determined.    If less than 500 hours (including after you replace it), it needs to be inspected every annual.

[keithmiller]

On 6/13/2023 at 1:24 PM, N201MKTurbo said:

None of the previous ADs that referred to turbo clamps applied to me, this one does. Danm, now I need to buy a new clamp.

https://www.federalregister.gov/documents/2023/06/12/2023-12417/airworthiness-directives-various-airplanes-helicopters-and-engines

 

I hear they are very hard to come but 

[N201MKTurbo]

23 minutes ago, keithmiller said:

I hear they are very hard to come but 

Yep, they are. It looks like I have 2 years to get one after the AD is formally released. 

[cliffy]

Even if replaced I'm wondering if many A&Ps really understand how to install one correctly?

There is a technique involved.

[N201MKTurbo]

55 minutes ago, cliffy said:

Even if replaced I'm wondering if many A&Ps really understand how to install one correctly?

There is a technique involved.

Huh, I’ve had mine off and on more times then I care to think about. I don’t remember anything special. Line the parts up with a new gasket, snug up the nut and put some safety wire on it. The next time you have the cowl off, snug them up again. They never go bad and don’t leak. The gaskets are hard to find and kind of expensive.

The gaskets are RJ-0114 and RJ-0115 the nut should be 50 in Lbs.

[cliffy]

Ever hear about lightly tapping the circumference with a small hammer as you progressively tighten the clamp bolt? 

That was part of an AD on Navajos 40 years ago to get nice seating of the clamp on the tapered flanges, IIRC

Each time you tighten and the nut  gets lightly tight you tap and then the nut is lose again for another round. 

Do  this until the tapping doesn't lossen the nut and then go to the proper torque and safety. 

More torque is not always proper. Use a torque wrench. Never had one fail doing it this way. 

[N201MKTurbo]

1 minute ago, cliffy said:

Ever hear about lightly tapping the circumference with a small hammer as you progressively tighten the clamp bolt? 

That was part of an AD on Navajos 40 years ago to get nice seating of the clamp on the tapered flanges, IIRC

Each time you tighten and the nut  gets lightly tight you tap and then the nut is lose again for another round. 

Do  this until the tapping doesn't lossen the nut and then go to the proper torque and safety. 

More torque is not always proper. Use a torque wrench. Never had one fail doing it this way. 

I can see how that could help, but mine don’t seem to need it. It helps to make sure the exhaust pipe aligns perfectly with the turbo. On mine, there is the fixed waste gate pipe that goes back to the collector at the turbo input. I always sand both the inside and outside of the joint and put new anti seize on it. That makes it easy to get them aligned. If I’m doing both clamps, I will loosen all the turbo mounting bolts so it has some float, then tighten the clamps and then the mounting bolts. I think the turbo in this design is over constrained. FWIW.

[cliffy]

I've always been amazed at the heating of the pipes and turbo and how there must be some expansion of the metal that is restrained by all the clamps and bolts. 

On a Navajo at night you can see the orange glow of the exhaust through the louvers in the nacelle That sometimes upsets the passengers 

[kortopates]

Ever hear about lightly tapping the circumference with a small hammer as you progressively tighten the clamp bolt? 
That was part of an AD on Navajos 40 years ago to get nice seating of the clamp on the tapered flanges, IIRC
Each time you tighten and the nut  gets lightly tight you tap and then the nut is lose again for another round. 
Do  this until the tapping doesn't lossen the nut and then go to the proper torque and safety. 
More torque is not always proper. Use a torque wrench. Never had one fail doing it this way. 

That’s what the Continental documentation describes plus if i recall correctly i think they say to over torque a bit, then loosen and torque to the final amount.
I can’t recall if the Navajo is Lycoming powered? Just curious if they give the same guidance.


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[cliffy]

Lycoming TIO 540s  Great engine package in the Navajo  Much better than the C 421 engine package

Don't remember about the over torque  Just the tapping to seat properly and a torque wrench

Edited June 27, 2023 by cliffy

[A64Pilot]

Most turbines I’ve been around use these clamps to attach the exhaust.

On them often it was torque, tap around with a plastic hammer and re-torque. I think maybe on the GE T700 which had a clamp the size of a trash can and bolts 180 degrees opposite it was run the engine up, let it cool and retorque.

Those clamps when the broke it wasn’t usually the clamp band but the hat shaped piece that pulled the two pipes if you will together. 

They were all spot welded.

Surely somebody will PMA these things