Mooney crash ADS

[DCarlton]

10 minutes ago, bonal said:

Not for nothing, first wishing a speedy and complete recovery for the flyers.  Lots of discussion about breaking windows to evacuate I’m confused am I the only one that had it drilled into me from the beginning of my flight training that you should open the door when a forced off field landing is evident.

Merry Christmas to all and to all a good night 

I've got that drilled in to me too and think about it often, but I'm not convinced my passengers will always leave the door in the correct position with the door open and the latch closed to keep it from wedging in the opening.  It also seems like it would be easier to kick the door open than crawl into the rear to open the package door if you were still able to kick.   Might be much quicker.  

[LANCECASPER]

48 minutes ago, ilovecornfields said:

Funny. That looks identical to my “pilot isolate” tool for the intercom.

It looks like the same tool I use if the front passenger ignores the "WARNING: Only the PILOT is permitted to OPEN - CLOSE - LOCK this door" placard or the "DO NOT SLAM DOOR" placard.

So far I've never seen them do it a second time, or should I say be able to do it a second time.  

[Fly Boomer]

3 hours ago, ilovecornfields said:

Funny. That looks identical to my “pilot isolate” tool for the intercom.

I thought that's what the fire bottle is for.

[Sue Bon]

2 hours ago, LANCECASPER said:

the "DO NOT SLAM DOOR" placard.

Why does this never work? It's such a pet peeve of mine.

[Ibra]

5 hours ago, LANCECASPER said:

So far I've never seen them do it a second time, or should I say be able to do it a second time.

In C172, they get to do it load of times with their hands untouched !

With one friend we rented one C172 in NYC while ago, the checkout CFI leaned over and slammed the left hand side door so hard that my friend jumped of his seat, no luck !

I was the fun guy in the backseat (waiting for my checkout turn and making jokes about aircraft state), I asked him if he needs to switch master & fuel OFF and cage the gyros before we slam that door again 

We laughed to death on those flights, we were not even sure they will hand us the keys…

Edited December 19, 2022 by Ibra

[mike_elliott]

@WSMD, I sent a PM earlier, if you are able please reach out to me. I'm so glad your ok

 

[Griswold]

N231GZ

NTSB probable cause:

The fatigue failure of the engine’s camshaft gear teeth which resulted in a loss of all engine power. Contributing to the accident was the non-compliance with the engine manufacturer’s recommended service bulletin.

https://data.ntsb.gov/Docket?ProjectID=106448

Why would you not comply with a critical service bulletin?

 

[Aerodon]

2 hours ago, Griswold said:

 

Why would you not comply with a critical service bulletin?

 

As far as I can see this could have been a 1600 or 1800 TBO engine with 2000 hours.

We had an O360 (TBO 2000) that was running fine at 2900 hours.  We made a decision to overhaul at 3000 hours because we did not want to put ourselves in the position of trying to answer that question.

This was not such an easy CSB to comply with and I may not have complied with it.  But this report is making me more conservative, so I think this should be one of the issues to take into account when stretching your TBO.

 

Aerodon

 

 

[MikeOH]

@1980Mooney

You're looking at the wrong SB.  The one in question requires replacement of the CAMSHAFT GEAR, specifically because certain camshaft part numbers, including the one found failed in the accident aircraft, are prone to this EXACT failure mode.

[Aerodon]

Yes, I don't know how you could overhaul an engine and not replace this gear without worrying about the liability.....

"To eliminate the possibility of camshaft gear tooth fracture, resulting in power loss or in-flight shutdown, and to inspect and remove from service P/Ns 631845, 655430, 655516, or 656031 and replace with camshaft gear, P/N 656818. This Service Document initially announced the release of improved camshaft gear P/N 656818 in 2005. It now clarifies part number superseding action and amplifies camshaft gear replacement instructions."

 

[MikeOH]

Even after reading the rather detailed metallurgical report what is not clear to me is what defect is present in those certain gear part numbers that make them subject to failure.  The report talked about hardness and alloys and fracture photos and SEM and XRS and...and, near as I could tell, concluded the gears broke!  No $hit Sherlock...it would have been nice to have an explanation as to why!

[PT20J]

13 minutes ago, MikeOH said:

Even after reading the rather detailed metallurgical report what is not clear to me is what defect is present in those certain gear part numbers that make them subject to failure.  The report talked about hardness and alloys and fracture photos and SEM and XRS and...and, near as I could tell, concluded the gears broke!  No $hit Sherlock...it would have been nice to have an explanation as to why!

The replacement gear is thicker by .060" 

[MikeOH]

@PT20J

Thanks, I missed that in the summary.

So, it would appear it was just an under engineered gear. 

[Hank]

15 minutes ago, MikeOH said:

@PT20J

So, it would appear it was just an under engineered gear. 

Wow, i can't erase the fallout on my phone.  . .

Is the gear really "under"engineered if it didn't fail until significantly after its anticipated service life, i.e., TBO? Seems to me ti be not seriously overengineered.

But what do I know about gear design? All I've ever done is buy, review and approve molds to make plastic ones, then run the fool out of them in production. 

[MikeOH]

Just now, Hank said:

Wow, i can't erase the fallout on my phone.  . .

Is the gear really "under"engineered if it didn't fail until significantly after its anticipated service life, i.e., TBO? Seems to me ti be not seriously overengineered.

But what do I know about gear design? All I've ever done is buy, review and approve molds to make plastic ones, then run the fool out of them in production. 

Well, you tell me, then.  What was wrong with the gear design that necessitated the manufacturer to issue a CSB to REPLACE the damn things?  SOMETHING was wrong with them...sorry, but design to fail once reaching TBO hours without significant margin is POOR engineering.  Not to mention the replacement gear part numbers were REDESIGNED to be thicker...I guess they shouldn't have done that since that would be beyond seriously over engineered, huh?

[MB65E]

Such a large piece of rotating material compared to Lycoming’s design. 
Thanks for posting the SB I wasn’t aware it was such a known issue. 
-Matt

[Schllc]

I’m not sure I understand the purpose of a “critical service bulletin”,  if engine failure as a result is imminent, why would it not be an AD?

[aviatoreb]

Well that is friggin scary!

So that big gear is visible in the cowl behind the prop during preflight isnt it?  Did that gear failure happen all at once or was it showing signs that was missed during preflight before the incident flight?

Well this is scary indeed since I fly the same exact engine and I am 2050hrs TBO.  All signs are good as far as I know but I did declare enough is enough and I already signed a contract for major overhaul to begin in early November to happen largely during the winter months.  Knock on wood then I get a few more hours.  But seriously - is there something I can see visually that would have been a sign?

[Fly Boomer]

2 hours ago, Schllc said:

I’m not sure I understand the purpose of a “critical service bulletin”,  if engine failure as a result is imminent, why would it not be an AD?

Manufacturer publishes a "critical" or "mandatory" SB.  FAA knows most pilots will ignore it so, if they think it's a safety of flight issue, they will publish an AD -- often just referencing the SB.

[Aerodon]

1 hour ago, aviatoreb said:

Well that is friggin scary!

So that big gear is visible in the cowl behind the prop during preflight isnt it?  Did that gear failure happen all at once or was it showing signs that was missed during preflight before the incident flight?

Well this is scary indeed since I fly the same exact engine and I am 2050hrs TBO.  All signs are good as far as I know but I did declare enough is enough and I already signed a contract for major overhaul to begin in early November to happen largely during the winter months.  Knock on wood then I get a few more hours.  But seriously - is there something I can see visually that would have been a sign?

Erik, the gear is not visible, its one of the gears in the accessory case, that why it is so difficult to change.

 

Aerodon

[Aerodon]

10 hours ago, Hank said:

Wow, i can't erase the fallout on my phone.  . .

Is the gear really "under"engineered if it didn't fail until significantly after its anticipated service life, i.e., TBO? Seems to me ti be not seriously overengineered.

But what do I know about gear design? All I've ever done is buy, review and approve molds to make plastic ones, then run the fool out of them in production. 

Hank

It would appear the engine had about 2700 hours and about 230 SMOH.  And it was either a 1600 or 1800 TBO to start with (depends on serial numbers).

A factory overhaul would have replaced the gear.  A field overhaul should NDT all the gears and make a decision.  Not compulsory I would imagine, but apparently not wise in this case.

So it was 'engineered' well enough to get to TBO, but I think major components should get at least 2 overhauls?

 

Aerodon

 

 

 

 

 

 

 

[EricJ]

4 hours ago, Schllc said:

I’m not sure I understand the purpose of a “critical service bulletin”,  if engine failure as a result is imminent, why would it not be an AD?

The manufacturer can't issue an AD, only a SB or CSB or whatever.   If the FAA determines there's sufficient reason, then an AD will be issued, which may still happen.    This is why ADs often reference SBs.

[N201MKTurbo]

The factory remans reuse the gears too. 
 

[kortopates]

The factory remans reuse the gears too. 
 

But only after complying with all their SB’s.


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[N201MKTurbo]

3 minutes ago, kortopates said:

But only after complying with all their SB’s.


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Absolutely. 
 

When I rebuilt my engine, I took all the gears to the local engine shop for NDT. I noticed they were all marked with a suffix (-84?). I thought it was a date code. The engine shop told me that is a marking Lycoming puts on parts reused in a factory reman. My engine was a factory reman.