NTSB Final Is Out: N5895Q M20E Stillwater, OK

[1980Mooney]

Another case of "shade tree" repairs bringing a Mooney to the scrap pile.  Apparently, the induction air coupling had been duct taped for some time.  It collapsed blocking airflow to the engine which restricted power.  The 22,500+ hour ATP, who had been posting here on MS, had purchased the plane on about April 23, 2022.  The accident was on June 18, 2022.

The plane was sold by another member of MS who owned it for at least since 1998 (per AviationDB search).  It is not clear who repaired the damaged induction air coupling with tape - owner and/or A&P.  The A&P/IA at Craig Aviation LLC in Grove, OK, who signed off on the plane for the past 3 years did not respond to requests from the NTSB.  

The plane was sold a salvage auction in 2022.  The accident owner has since purchased a Cessna 310, N3048L, and left MS.  The seller of the accident plane is in his 80's and has not been on MS since 2019.

The pilot reported that, during cruise flight, the engine lost partial power, which necessitated an emergency landing on a highway. During the landing, the airplane impacted a road barrier, which resulted in substantial damage to the left wing.

'During a post accident examination, the induction air coupling was found wrapped in gray tape. When the tape was removed, separations were visible on the top and bottom at the flange on the inboard side. The top and bottom separations likely reduced the rigidity of the coupling when the engine was operating. Examination of the inside of the coupling showed that the lower portion appeared to be permanently deformed in a manner similar to compression. Therefore, because of the reduction in the coupling’s rigidity, the coupling had likely closed due to suction from the engine, which impeded airflow. Tape should not have been applied as a fix for the induction coupling separations. The investigation could not determine when the coupling separations appeared or the tape was applied, but those events had likely caused the permanent deformation to the coupling.

The airframe and powerplant mechanic, who performed annual inspections for the airplane during the 3 years before the accident should not have allowed the airplane to return to service with the tape applied and the coupling deformed.

The pilot reported that, about 20 to 25 minutes after departure and while in cruise flight at an altitude of about 4,500 ft mean sea level, the airplane lost partial engine power. The power had been set to 2,400 rpm and 24 inches of manifold pressure, which decreased to 2,000 rpm and between 11 and 12 inches of manifold pressure. The pilot manipulated the throttle control, but the engine did not respond. He moved the fuel selector through all positions while also moving the throttle, but the engine still did not respond. Because the airplane was unable to maintain level flight, the pilot elected to conduct a forced landing to a highway. As the airplane was about to land, the pilot became focused on avoiding a vehicle and failed to extend the landing gear. The airplane touched down “very softly” with the gear up, and the pilot turned the airplane slightly to the left to keep the propeller from impacting the vehicle, which resulted in the left wing impacting a road barrier and substantial damage to the wing.

The airframe and powerplant mechanic with inspection authorization who completed that annual inspection also completed the airplane’s two previous annual inspections. Those inspections were performed on November 11, 2018, and December 7, 2019, when the airplane’s tachometer time was about 4,380 and 4,396 hours, respectively. The maintenance entry dated November 11, 2018, noted “installed new Brackett induction air filter.” No other entries in the maintenance logbooks were associated with the induction air filter or coupling. Multiple attempts to contact the mechanic were made with no success. As a result, the investigation could not determine when the tape was applied to the induction coupling."

 

[1980Mooney]

[1980Mooney]

[EricJ]

A consequence of parts not being available is people trying to make do without replacements.   

[Ragsf15e]

Did the alternate air not automatically open or does that also feed through the rubber intake gasket?

[1980Mooney]

3 minutes ago, Ragsf15e said:

Did the alternate air not automatically open or does that also feed through the rubber intake gasket?

Here was an earlier comment from Clarence to an E owner.  

"Both filtered and bypass air pass thru the same accordion duct, so you’re more or less stuck with it.  Making sure that engines are installed correctly with good mounts, making sure the cowl is correctly aligned with the engine and lastly a propeller balance all should improve the life expectancy of the duct.

Clarence"

 

[Shadrach]

1 hour ago, 1980Mooney said:

Another case of "shade tree" repairs bringing a Mooney to the scrap pile.  Apparently, the induction air coupling had been duct taped for some time.  It collapsed blocking airflow to the engine which restricted power.  The 22,500+ hour ATP, who had been posting here on MS, had purchased the plane on about April 23, 2022.  The accident was on June 18, 2022.

How many cases of "Shade tree repairs bringing a Mooney to the scrap pile" is that now? I agree that this accident was caused by a substandard repair.  Whether it was "shadetree" as you describe (obvious pejorative), I don't know...and neither do you. 

[Shadrach]

15 minutes ago, Ragsf15e said:

Did the alternate air not automatically open or does that also feed through the rubber intake gasket?

The alternative air door is on the airbox and will only open when filtered air is blocked. Any blockages downstream of the airbox will not be affected by the door, which would not open under those circumstances anyway.

[1980Mooney]

4 hours ago, Shadrach said:

How many cases of "Shade tree repairs bringing a Mooney to the scrap pile" is that now? I agree that this accident was caused by a substandard repair.  Whether it was "shadetree" as you describe (obvious pejorative), I don't know...and neither do you. 

You are right - this may very well have been a "professional" repair........

 

 

[N201MKTurbo]

I know quite a few non A&P aircraft owners, who do most of their own maintenance, under supervision, of course. None that I know of would ever fly that.

[EricJ]

FWIW, the tape didn't cause the collapse.   The tape covered up and probably attempted to prevent leaks on a duct that was failing.   The tape couldn't prevent the duct from failing, and probably impeded inspection to detect that it was about to fail.    Definitely not good practice, obviously, but I suspect the duct would have been replaced long ago had parts been available.

[MikeOH]

At my last annual in May, TopGun noticed the intake duct was starting to deteriorate but was still airworthy.  They had a brand new one in stock...knowing those can be hard to come by I jumped on it.  $524.39 and well worth it not to worry.

[Shadrach]

15 hours ago, 1980Mooney said:

You are right - this may very well have been a "professional" repair........

No, you're right. You fully grasp this situation, the mode of failure and the cause...”shade tree maintenance”.

For those interested in what likely happened, I will explain what I think has taken place as someone who has first hand knowledge with this duct.  The part pictured is P/N 600115-005 and is what couples the airbox to the fuel servo in all vintage, injected, Mooneys.  The duct depicted is so badly worn and torn that it has lost all structural integrity. I have replaces at least 3 of these over the years and can say that the one pictured has likely been unairworthy for the better part of a decade.  The power loss was caused by the duct collapsing under suction which essentially throttled the engine completely. No air, No power.  We have no idea who put the duct tape around it.  I am sure it did not look like that when they first wrapped it as it appears to have been there for quite a while. It looks lousy and is unairworthy for sure. It should have been flagged many annuals ago.  Furthermore, duct tape is not a repair (there is currently no guidance for repairing his part) and in the end did nothing to prevent the duct from further deterioration and collapse. The only thing it did do was give grist for the mill to someone with an apparent axe to grind against owner assist maintenance.

As far as I know, The duct has been unavailable for quite some time.  The factory was asked on their parts forum on the Mooney website, back in 2020 by non other than our own @carusoam if they might produce the part as it had been unobtanium for a while.  Anthony does not need this part for his Ovation, but was asking because he new it was a problem for those of us flying E and F models. The factory rep said they would look into it. No further coms after that.

So we have the following scenario:

1) The part is not readily available for purchase  - There may be a few at various shops or on ebay from time to time, but Lasar is out of stock as far as I know as is Maxwell and most others.

2) There is no guidance for repairing the part.

3) It would be next to impossible for the part to be made as a single run OPP.

4) Owner efforts to make small production runs of OPP parts in the past have met with unfortunate and somewhat ambiguous statements from the FAA as to the legality of parts made under such a process. Th FAA has demonstrated that interpretation of owner participation is as important if not more so than the actual serviceability in determining airworthiness of an owner produced part. Anyone that was involved in the OPP gear block run knows what I am referring to...

I am grateful that I have a spare duct in good shape.  I am not sure what the hundreds of owners operating the vintage machines that utilize this part are going to do in the future. I suspect there are many in service that should be not be. Hopefully we don't see any more of off airport events due to this duct.  I am glad you found one when you did @MikeOH, I suspect Top Gun does not have anymore. Last I saw, the out of stock LASAR price was over $600.  The were about $225 when I replaced the first one and they were somewhat hard to get then.

 

[Ragsf15e]

14 hours ago, Shadrach said:

No, you're right. You fully grasp this situation, the mode of failure and the cause...”shade tree maintenance”.

For those interested in what likely happened, I will explain what I think has taken place as someone who has first hand knowledge with this duct.  The part pictured is P/N 600115-005 and is what couples the airbox to the fuel servo in all vintage, injected, Mooneys.  The duct depicted is so badly worn and torn that it has lost all structural integrity. I have replaces at least 3 of these over the years and can say that the one pictured has likely been unairworthy for the better part of a decade.  The power loss was caused by the duct collapsing under suction which essentially throttled the engine completely. No air, No power.  We have no idea who put the duct tape around it.  I am sure it did not look like that when they first wrapped it as it appears to have been there for quite a while. It looks lousy and is unairworthy for sure. It should have been flagged many annuals ago.  Furthermore, duct tape is not a repair (there is currently no guidance for repairing his part) and in the end did nothing to prevent the duct from further deterioration and collapse. The only thing it did do was give grist for the mill to someone with an apparent axe to grind against owner assist maintenance.

As far as I know, The duct has been unavailable for quite some time.  The factory was asked on their parts forum on the Mooney website, back in 2020 by non other than our own @carusoam if they might produce the part as it had been unobtanium for a while.  Anthony does not need this part for his Ovation, but was asking because he new it was a problem for those of us flying E and F models. The factory rep said they would look into it. No further coms after that.

So we have the following scenario:

1) The part is not readily available for purchase  - There may be a few at various shops or on ebay from time to time, but Lasar is out of stock as far as I know as is Maxwell and most others.

2) There is no guidance for repairing the part.

3) It would be next to impossible for the part to be made as a single run OPP.

4) Owner efforts to make small production runs of OPP parts in the past have met with unfortunate and somewhat ambiguous statements from the FAA as to the legality of parts made under such a process. Th FAA has demonstrated that interpretation of owner participation is as important if not more so than the actual serviceability in determining airworthiness of an owner produced part. Anyone that was involved in the OPP gear block run knows what I am referring to...

I am grateful that I have a spare duct in good shape.  I am not sure what the hundreds of owners operating the vintage machines that utilize this part are going to do in the future. I suspect there are many in service that should be not be. Hopefully we don't see any more of off airport events due to this duct.  I am glad you found one when you did @MikeOH, I suspect Top Gun does not have anymore. Last I saw, the out of stock LASAR price was over $600.  The were about $225 when I replaced the first one and they were somewhat hard to get then.

 

I thought for sure m20doc talked about mooney actually making a run of these before he left, maybe last year?  I even thought he said he had a couple available from the order?  I could be mistaken, but it’s scary not to have that available.  You’re totally grounded without it.

[1980Mooney]

17 hours ago, Shadrach said:

No, you're right. You fully grasp this situation, the mode of failure and the cause...”shade tree maintenance”.

.. Furthermore, duct tape is not a repair (there is currently no guidance for repairing his part) and in the end did nothing to prevent the duct from further deterioration and collapse. The only thing it did do was give grist for the mill to someone with an apparent axe to grind against owner assist maintenance.

So we have the following scenario:

2) There is no guidance for repairing the part.

Like so many things Mooney, parts are not available and there is no expressed desired by the company to provide support.  Although there is "no guidance for repairing the part" Mooney owners have been sharing their own homegrown bespoke induction air duct repair processes here on MS for a long time. 

Some opined, some made "hangar elves" repairs, some owners just declare that they made the repair, I referred to it as shade tree repair. I suspect that more are doing it than post on MS and I doubt all are doing it with A&P approval (or perhaps without an A&P even noticing the condition or repair of the duct if N5895Q is a guide).  Apparently, and unfortunately, the former owner or a former A&P of N5895Q thought duct tape would make an adequate repair.

• RR ENGINEER said "I am going to take mine off and spray that Flex Seal on it have put some on and it seems to be working just have to put layer after layer on let each layer dry before you add more. This part is very poorly constructed. Looks like to me the flex seal will make it better. Going to put it on and run it just be sure to inspect after flying each time for a while."
• David LLoyd said "I have used two pieces of thick plastic bag, put the fg cloth and RTV between, work it in and trim to size with a wheel cutter.  When ready to apply, remove one side of the plastic, put in place and remove the other plastic side, kind of like a real messy band-aid."
• kortopates suggested "I use this Rescue tape on heater air ducting and the like - a silicone self fusing tape:   https://www.aircraftspruce.com/catalog/appages/rescuetape.php  I started off with the uni-wrap silicone tape and found this superior. I wouln't use it on a induction hose or boots because I have to be super cautious with a turbo to prevent ingesting any foreign debris.
  • But I think this tape is better than some of the alternatives being discussed.
• hammdo said "I use the silicone tape also. The liquid electrical tape sticks and is very hard to get off but, one could tape over and then cover with the liquid tape. "
• A64Pilot opined "I would never use silicone as it’s not fuel safe or oil proof for that matter. ‘I’d be real suspicious of liquid electrical tape, I have some myself but don’t know if it holds up to fuel and oil. ‘For a temporary repair for something like that, I’d go to B2 every time , that’s what many call fuel tank sealer AKA Proseal, as I’m sure everyone knows it’s available as either A or B, the A is thinner than the B, the number is available from 1/2 to 2. that’s the number of hours it’s pot life is, so of course 1/2 sets up four times faster than the 2. We know it’s fuel and oil proof, and anyone who has removed it from a fuel tank can attest to how tough and resilient it is.
  • I’d think painting a layer of A on the boot would at least work as a temporary repair, certainly better than tape or silicone.
  • ‘B2 is an extremely useful thing to have, it’s not classified as an adhesive, but try to get parts it’s holding together apart and make up your own mind.
• N201MKTurbo advised "My hangar elves had very good results that lasted years. The repair was done with black RTV and light weight fiberglass cloth. Make all repairs on the outside to reduce the likelihood of the repair getting sucked in. When they were done, you couldn’t even tell it was repaired. If anybody is interested, I can get them to give me all the details.

  • Remove the duct. Scrub it with a toothbrush and Comet cleanser until it is clean in and out. Wait for it to be completely dry. 

  • Cut come squares and strips of 1oz plain weave fiberglass cloth. With a gloved finger, rub a very light coat of black high temp RTV over the damaged area on the outside of the boot. Make sure it is worked in well for good adhesion. Press the fiberglass into the RTV. Don’t worry about the edges of the fiberglass, you are going to trim those later, just make sure the fiberglass conforms to the shape of the boot and doesn’t have any bulges or wrinkles. Let it cure overnight. Come back the next day and trim all the fiberglass cloth that isn’t bonded to the boot. Apply some more RTV to the top of the fiberglass completely saturating the fiberglass with RTV. Use just enough to saturate the fiberglass, you don’t want any buildup of RTV. Place another layer of fiberglass cloth into the RTV and let cure overnight. The next day trim the edges of the fiberglass cloth and apply enough RTV completely cover the cloth and a bit beyond. Make it as smooth as possible. Let it cure overnight and inspect it. If it looks good an flexes OK, put it back on."

 

 

 

Edited September 17 by 1980Mooney

[hammdo]

Just to clarify, I never said I repaired my induction with those products. Just that I’ve used them. David, @Sabremech, did a new induction intake on my bird. I don't have a factory system anymore…

Context is important…

-Don

[1980Mooney]

12 minutes ago, hammdo said:

Just to clarify, I never said I repaired my induction with those products. Just that I’ve used them. David, @Sabremech, did a new induction intake on my bird. I don't have a factory system anymore…

Context is important…

-Don

Thanks for the clarification.  I didn't mean to imply that you did.  That is why i prefaced by "Some opined" and attached the original thread/post for anyone that wants to dig into it. 

Since that average Mooney is over 40 years old, practically everything posted nowadays on MS has been discussed before - usually multiple times.  It is hard to extract and summarize from the years of rambling posts on MS.  Perhaps we should just leave it to Chat GTP-4 or 5 or 6... in the future - I am sure it will be doing a better job than a mere flawed human like me.  

[EricJ]

6 hours ago, Ragsf15e said:

I thought for sure m20doc talked about mooney actually making a run of these before he left, maybe last year?  I even thought he said he had a couple available from the order?  I could be mistaken, but it’s scary not to have that available.  You’re totally grounded without it.

There was a limited production run of some, I don't recall if they were for M20C or M20E/F or both, and it appeared that most of them got sucked up pretty quickly.    This crash happened in June, 2022, so it may have been before those were available.

[Shadrach]

1 hour ago, Ragsf15e said:

I thought for sure m20doc talked about mooney actually making a run of these before he left, maybe last year?  I even thought he said he had a couple available from the order?  I could be mistaken, but it’s scary not to have that available.  You’re totally grounded without it.

I recall him saying it was "on the schedule" and to be patient.  Perhaps there was a run that I don't know about.  I'll admit that I do not fully grasp the economics of producing these parts. The molds were a sunk cost back in the sixties. It seems ridiculous that they are not being ordered in sufficient quantities to make pricing reasonable and availability plentiful. Not sure what he shelf life is, but I would commit to a group buy just to have a spare at all times.  They usually show signs of tearing after about 5 years. almost all of the where and tear appears to occur at startup and shutdown when the engine moves most, relative to the cowl. A improved solution is definitely doable, but the return would be small and the regulatory hurdle large.

[Shadrach]

On 9/17/2023 at 4:48 PM, 1980Mooney said:

Like so many things Mooney, parts are not available and there is no expressed desired by the company to provide support.  Although there is "no guidance for repairing the part" Mooney owners have been sharing their own homegrown bespoke induction air duct repair processes here on MS for a long time. 

Some opined, some made "hangar elves" repairs, some owners just declare that they made the repair, I referred to it as shade tree repair. I suspect that more are doing it than post on MS and I doubt all are doing it with A&P approval (or perhaps without an A&P even noticing the condition or repair of the duct if N5895Q is a guide).  Apparently, and unfortunately, the former owner or a former A&P of N5895Q thought duct tape would make an adequate repair.

• RR ENGINEER said "I am going to take mine off and spray that Flex Seal on it have put some on and it seems to be working just have to put layer after layer on let each layer dry before you add more. This part is very poorly constructed. Looks like to me the flex seal will make it better. Going to put it on and run it just be sure to inspect after flying each time for a while."
• David LLoyd said "I have used two pieces of thick plastic bag, put the fg cloth and RTV between, work it in and trim to size with a wheel cutter.  When ready to apply, remove one side of the plastic, put in place and remove the other plastic side, kind of like a real messy band-aid."
• kortopates suggested "I use this Rescue tape on heater air ducting and the like - a silicone self fusing tape:   https://www.aircraftspruce.com/catalog/appages/rescuetape.php  I started off with the uni-wrap silicone tape and found this superior. I wouln't use it on a induction hose or boots because I have to be super cautious with a turbo to prevent ingesting any foreign debris.
  • But I think this tape is better than some of the alternatives being discussed.
• hammdo said "I use the silicone tape also. The liquid electrical tape sticks and is very hard to get off but, one could tape over and then cover with the liquid tape. "
• A64Pilot opined "I would never use silicone as it’s not fuel safe or oil proof for that matter. ‘I’d be real suspicious of liquid electrical tape, I have some myself but don’t know if it holds up to fuel and oil. ‘For a temporary repair for something like that, I’d go to B2 every time , that’s what many call fuel tank sealer AKA Proseal, as I’m sure everyone knows it’s available as either A or B, the A is thinner than the B, the number is available from 1/2 to 2. that’s the number of hours it’s pot life is, so of course 1/2 sets up four times faster than the 2. We know it’s fuel and oil proof, and anyone who has removed it from a fuel tank can attest to how tough and resilient it is.
  • I’d think painting a layer of A on the boot would at least work as a temporary repair, certainly better than tape or silicone.
  • ‘B2 is an extremely useful thing to have, it’s not classified as an adhesive, but try to get parts it’s holding together apart and make up your own mind.
• N201MKTurbo advised "My hangar elves had very good results that lasted years. The repair was done with black RTV and light weight fiberglass cloth. Make all repairs on the outside to reduce the likelihood of the repair getting sucked in. When they were done, you couldn’t even tell it was repaired. If anybody is interested, I can get them to give me all the details.

  • Remove the duct. Scrub it with a toothbrush and Comet cleanser until it is clean in and out. Wait for it to be completely dry. 

  • Cut come squares and strips of 1oz plain weave fiberglass cloth. With a gloved finger, rub a very light coat of black high temp RTV over the damaged area on the outside of the boot. Make sure it is worked in well for good adhesion. Press the fiberglass into the RTV. Don’t worry about the edges of the fiberglass, you are going to trim those later, just make sure the fiberglass conforms to the shape of the boot and doesn’t have any bulges or wrinkles. Let it cure overnight. Come back the next day and trim all the fiberglass cloth that isn’t bonded to the boot. Apply some more RTV to the top of the fiberglass completely saturating the fiberglass with RTV. Use just enough to saturate the fiberglass, you don’t want any buildup of RTV. Place another layer of fiberglass cloth into the RTV and let cure overnight. The next day trim the edges of the fiberglass cloth and apply enough RTV completely cover the cloth and a bit beyond. Make it as smooth as possible. Let it cure overnight and inspect it. If it looks good an flexes OK, put it back on."

 

 

 

I am just as baffled as anyone else as to how this aircraft was returned to service after annual. I am also surprised that anyone would use duct tape as a means of repair or attempt to extend the life of a component of the intake system. This was a lousy maintenance practice, but the degradation of that duct was in the works for years. It was likely unairworthy long before the plane changed hands.  That means its unairworthy condition was unnoticed through multiple annuals and perhaps a pre-buy; whether it was taped or not isn't really important, it was unairworthy with or without. The fact that the owner elected to purchase and fly the plane in such a condition speaks not only to his ignorance but also the poor quality of the maintenance professionals he was contracting to maintain his aircraft.  The tape may have been a contributing factor, but this situation had started to go pear shaped years before the plane changed hands.  Unlike the new owner of N5895Q, most of the members of this forum are not ignorant to this situation, whether A&P/IAs, hands on or passive owners.  As you so graciously showcased above, we have been openly discussing ways to safely extend the service life of unobtainium parts while additional parts are made or an alternative solution is presented.  I am not saying all or any of the above listed ideas are good ones, however, it's not a crime for the community to try to spitball potential solutions.  Had the individual who taped up N5895Q been a member of this forum, perhaps this could have been avoided.  I can say with almost complete certainty that there is not a maintenance professional, pilot or "shadetree" mechanic on this forum that would have recommended he fly that airplane in the condition that it was being operated.

[Fly Boomer]

4 hours ago, Shadrach said:

I'll admit that I do not fully grasp the economics of producing these parts. The molds were a sunk cost back in the sixties. It seems ridiculous that they are not being ordered in sufficient quantities to make pricing reasonable and availability plentiful. Not sure what he shelf life is, but I would commit to a group buy just to have a spare at all times. 

I suspect a consideration these days is they don't want anything sitting on the shelf.

[Pinecone]

It sounds like they would not sit long.

Someone should reach out to Frank Crawford and see what he has to say.

[Ragsf15e]

52 minutes ago, Pinecone said:

It sounds like they would not sit long.

Someone should reach out to Frank Crawford and see what he has to say.

I just did.  He said contact the MSCs to order.  So I contacted Lasar and they told me backorder for ~ year.  I told them I’ll buy one next time they get some.  I briefly checked eBay with no luck.  Frank did mention Chandler, DMax and Lasar bought most last time so maybe one of the others still has one?

[Echo]

Photos from a 2022 loss of power crash.  Maybe damage is from crash.  Maybe not...

[Shadrach]

 

1 hour ago, Echo said:

Photos from a 2022 loss of power crash.  Maybe damage is from crash.  Maybe not...

Maybe some, but it's pretty clear that the intake boot has been smeared with some sort of goop in an attempt to seal it.  It's been long gone for a long time.  I have never seen one with anything near that level of deterioration. Horrible.