More excitement at FL 19.5 with my Rocket

[Yooper Rocketman]

Many of you remember my turbo failure at FL 190 a few years ago on the way to see my dad on his death bed.  Well, my new engine gave me some excitement at nearly the same altitude today, at about the same time of the year too.

I decided to take the first flight out of my airport area (had over 3.5 hours right over the airport with no issues) by heading to Pittsburgh for some business.  I really wanted to fly the Lancair (time wise), but needed hours on the new Mooney engine so I can sell it.  I flew over at FL 240 with a decent tailwind, adjusting manifold pressure up or down 1" and/or RPM +/- 50 every 10 minutes, per Jewell Aviation's break in procedure for the first 10 hours.  It was an uneventful flight, other than getting a STAR and full ILS into KAGC.  Coming out, I was eventually cleared to FL 230, still flying the SID, climbing through FL19.5 and I heard a loud "pop" and then the engine started running a bit rough.  I first looked at RPM and oil pressure, everything was fine.  My next glance went to manifold pressure and it had dropped from 38" to 20".  

Knowing a bunch of my Lancair friends flying the big bore, turbocharged, Continentals have had trouble either blowing turbo boost hoses or clamps, I suspected this was my issue.  I was just being transferred from one Cleveland controller (the low altitude one handling FL 230 and below,) to the high altitude controller and was given FL 240.  I called him back and said I would likely not even hit FL 200 and would need to go down, explaining my engine issue and likely failure mode.  I asked for an airport to the west, as it appeared VMC compared to along my flight path.  A local pilot, hearing my situation, suggested New Philadelphia (KPHD) and that's where I headed.  He gave me FL 180 immediately and 9K within minutes.  He asked if I wanted to declare an emergency and I said not yet, as I suspected I would gain back some engine power as I descended (which I did).  He soon handed me over to Akron Approach and they were more than awesome helping me spiral down to the airport, even insisting I call when I landed so they knew everything worked out.  

While spiraling down the last 4K to the airport, I saw someone landing and was concerned they were doing T&G's, so announced my situation.  The guy, flying a Cherokee 6, not only offered help, he monitored my progress until I landed and then came over and helped me remove the engine cowls to find the issue...........a broken clamp on the very first intake hose coming off the turbo.  His name was Brian, and he called Eric, the airport manager/mechanic, who arrived within 30 minutes on a Sunday evening to help.  I had a serious weather system coming across the Midwest / Michigan, and if I didn't get out within a few hours, I would likely have been stuck there until Tuesday.  He had some new clamps and helped me install one and both guys helped me re-cowl the engine so I could depart.  Total ground time....less than 2 hours.  I appropriately compensated (with cash) the mechanic, although I may send him a check as well.  Brian would not take a thing from me........even getting insulted that I would try to pay him.  Pretty impressive!!!

I thought this might come back to an issue with the installing mechanic, but seeing the clamp failed at the base of the screw assy, it appears just fatigue.  

I did run into some weather with the delay.....seeing some pretty serious icing for a while (oh man, do I love that TKS!!) and turbulence.  But, I made it home for a late supper and a relaxing 20 minutes in my hot tub.

Now I know why the prospective buyer wants 10-20 hours on it before buying it.  

https://flightaware.com/live/flight/N1017L/history/20181125/2040Z/KAGC/KIMT

https://flightaware.com/live/flight/N1017L

Tom

  

[1964-M20E]

Wow I'm glad it was a relatively quick and easy fix and everything worked out for you.

[steingar]

Yeah, really.  Glad you made it back before what worst of the stuff hit too.  Good luck with the sale.

[aviatoreb]

Oh boy Tom.  Well handled.

Do you have any photographs of the offending clamp?

 

[FloridaMan]

Thank you for posting. You might save someone from an adrenaline dump and the sick feeling that follows by giving greater confidence as to the cause of a loud pop and rough running engine at altitude. 

[Yooper Rocketman]

32 minutes ago, aviatoreb said:

Oh boy Tom.  Well handled.

Do you have any photographs of the offending clamp?

 

I will later today.  I thought about you as I was spiraling down.  :>)  At least I had an engine still making noise!

Tom

[m20kmooney]

8 hours ago, Yooper Rocketman said:

But, I made it home for a late supper and a relaxing 20 minutes in my hot tub.

Twenty minutes only?! Glad all worked out for you!

[Yetti]

New clamp or reused?  Seems like something to add to the onboard spares.

[Yooper Rocketman]

1 minute ago, m20kmooney said:

Twenty minutes only?! Glad all worked out for you!

It WAS longer, but I didn't want to admit that!  Thank god I quit drinking wine at home 6 weeks ago since I went on my weight loss/exercise routine.  That would have been a "2 glasser".

Tom

[aviatoreb]

3 minutes ago, Yooper Rocketman said:

I will later today.  I thought about you as I was spiraling down.  :>)  At least I had an engine still making noise!

Tom

Thanks.

I'm changing oil today - I want to put eyes on this particular hose that you are describing.  It's the one immediately leading out of the turbo?

E

[Yooper Rocketman]

8 minutes ago, aviatoreb said:

Thanks.

I'm changing oil today - I want to put eyes on this particular hose that you are describing.  It's the one immediately leading out of the turbo?

E

Erik,

This is the only picture (poor quality) I took during the repair.  You can see the hose on the discharge from the turbo with no clamp on it, between the two vertical motor mount tubes.  If you look at the blurry shiny object just aft of the rear tube, that is the clamp on the other side of that same hose, where it is clamped to the intake transition tube.  The one that broke stayed hanging on the transition tube so I have it in the plane.  I will get a picture of it later this AM when I get out to my hangar.

[aviatoreb]

6 minutes ago, Yooper Rocketman said:

Erik,

This is the only picture (poor quality) I took during the repair.  You can see the hose on the discharge from the turbo with no clamp on it, between the two vertical motor mount tubes.  If you look at the blurry shiny object just aft of the rear tube, that is the clamp on the other side of that same hose, where it is clamped to the intake transition tube.  The one that broke stayed hanging on the transition tube so I have it in the plane.  I will get a picture of it later this AM when I get out to my hangar.

Thanks!

Question - so with a loose dislodged exit hose, why weren't extreme hot gases torching everything inside your cowl?

[Txbyker]

Tom, this is a great example of knowing your plane's systems.  You suspected the issue and also figured that the MP would increase down lower. Staying calm and thinking is pretty hard to do in situations such as this.

Russ

[LANCECASPER]

17 minutes ago, aviatoreb said:

Thanks!

Question - so with a loose dislodged exit hose, why weren't extreme hot gases torching everything inside your cowl?

I think he said it was the first intake hose on the turbo.

[alextstone]

Wow!  Well done.

[FloridaMan]

2 hours ago, aviatoreb said:

Thanks!

Question - so with a loose dislodged exit hose, why weren't extreme hot gases torching everything inside your cowl?

That comment made me think about how to handle that situation when reaching low altitude. I'm guessing the exhaust gas velocity isn't high enough to spool the turbo way up. Mine will start to bootstrap at around 2100 RPM and 26". I wonder about behavior at high power settings and low altitude if the exhaust velocity without forced induction could get high enough to spool up the turbo. If that could happen, which I'd be skeptical if it could reach full RPM without boosted exhaust, then on the one hand, it seems like the turbo could spin way faster than it's designed to do, but on the other, we can reach critical altitude in these planes to where the wastegate would be closed and we still can't reach a full 38" of manifold pressure. 

I'm also curious if you leaned the mixture when this happened and, if so, how it affected the engine running. 

[Yooper Rocketman]

[LANCECASPER]

6 minutes ago, Yooper Rocketman said:

So that was on the turbo side of the hose that goes from the intercooler to the turbo?

[aviatoreb]

46 minutes ago, Yooper Rocketman said:

That's it?  A plain old hose clamp?  :-/

[carusoam]

@aviatoreb Erik,

Some confusion may arise...

two turbine wheels each have an inlet and an exit ‘hose’...

One turbine is using the exhaust stream to turn the other turbine... (the hot side, turning the cold side via a shaft)

The other turbine is driven by a shaft from the first turbine...

1) Losing a v-clamp off the ‘hot’ side turbo... enables the cutting torch effect... while losing the MP not generated by the exhaust...

2) Losing a hose clamp off the ‘cold’ side turbo... loses some or all of the MP that was generated by the cold turbo...

 

3) Side effects of losing the cold side hose before the intercooler, some pretty warm air is being misdirected with the MP in a low condition...

 

4) Tom did a great job of airmanship letting ATC know what was happening... and getting down near an airport...

5) expect that.... There was still some MP being generated at the high altitude by the turbo system.   20” of MP is typical of an NA plane at  @10k’

6) If the hose came off completely... Expect the sounds of silence... at that altitude... as if either turbine has failed, driving MP to a low condition and requiring an adjustment of mixture to get the engine running at or below 14k’?

 

Tom, you are free to swap out a few re-used hose clamps... the loss of a hose clamp of this variety can cause the loss of MP...

PP thoughts Only, not a mechanic...

Best regards,

-a-

[Yooper Rocketman]

41 minutes ago, LANCECASPER said:

So that was on the turbo side of the hose that goes from the intercooler to the turbo?

Yes. The first hose in the intake transition from the turbo boost (compressor) heading out to the the twin intercoolers.  This clamp actually is securing that hose to the turbo housing   

Tom 

[Yetti]

Seems like it might be good to go to a stronger clamp.   http://ramproducts.com/Industrial-Supply/product/4076/T-Bolt

or a

[LANCECASPER]

 

45 minutes ago, Yooper Rocketman said:

Yes. The first hose in the intake transition from the turbo boost (compressor) heading out to the the twin intercoolers.  This clamp actually is securing that hose to the turbo housing   

Tom 

Rocket Engineering should be made aware of that. It probably should have something that could be safety-wired in case the clamp gives up. Even though they don't do any more Rocket conversions they still provide support and engineering.

[gsxrpilot]

New Philadelphia is where I found my 252. Eric handled the pre-buy/annual for me and did a great job. It's a good bunch of guys there. There also happens to be a beautiful Green/White Acclaim on that field. It's what replaced my 252 when I flew it home to Texas.

[Marauder]

 
Rocket Engineering should be made aware of that. It probably should have something that could be safety-wired in case the clamp gives up. Even though they don't do any more Rocket conversions they still provide support and engineering.

You would also think something this critical would have a double clamp on it to prevent the scenario if one of them did fail.


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