Turbo Failure mode! Single turbo Vs. Twin or TN?

[peevee]

24 minutes ago, aviatoreb said:

:-). Phew so I am not a COMPLETE dummy - just a partial dummy.

If you do your own oil changes you can inspect all that pretty well. Mouse milk the wastegate actuator to lube it and the vband clamp and look for cracks. This vband clamps really scare the shit out of me. No one needs a 1500 degree blowtorch under the cowl. Lower cowl on the rocket is kind of a bear to do by yourself and probably even more so with the 4 blade I bet.

Edited May 4, 2018 by peevee

[carusoam]

I’ll be working on that bullet list / summary...

The other thing you get by checking the inside of the exhaust pipe for oil... There are couple of places that oil can be coming from besides the turbo... worn valve guides and rings...

All would be worth knowing about... as soon as practical...

 

I was once told...

(A higher power) Only gives us challenges that he knows we can handle... (Something you tell HS aged kids, or yourself when needed...)

1) Our statistician is thrown an unknown turbo failure at 16+k’... Landed on a runway... given one minute to make a decision, followed by 14 more minutes doing calculations to see how well his decision is working!... all worked out extremely well...

2) Our most experienced Engineer has a few engine outs over his flying career... all worked out OK...

3) Another K pilot lost the oil through the quick drain... landed it on a runway... I believe... (Lawyer?)

4) Our ATC MSer had the turbo failure... found it on the ground...

5) Another Engineer, He has been teaching the benefits of CO monitoring after his off field, engine-out, GU, landing...

6) Thanks to Mr. Gilliland who is unable to be with us here today...  He reminds us of the V-bands... his CFII reminds us of the Amazon.smile charity program for fallen Mooney pilots... he and his Rocketman partner put together the Mooney Summit...

7) My most expensive engine problem... the airport manager dialed it in to me at home to tell me about...   

So much for me being proven to be a great pilot like these guys...

Keep the conversation going.  There is so much to be learned and shared...

Best regards,

-a-

[peevee]

I'd be lying if I told you turbos weren't more headache and expense but you couldn't give me a NA airplane. I won't go back. Big reason I haven't gone experimental. I'd really like to fly one of those extra 400s with the liquid cooled engine. People really like those.

 

I also think what they charge to overhaul aviation turbos is highway robbery. Our tat turbos are just t04s like you'd use in a car made by Garret or airesearch and rebranded. You can probably buy them new for 2k for the pair. Oh well.

Edited May 4, 2018 by peevee

[jlunseth]

Altitude is a real treasure.  Better to have lots of altitude and a need to find a way to lose it, than not having enough, which you can’t fix.  For quick math (that’s all the time you have), I use a two mulitplier.  The glide ratio at best glide is 12.7:1, which is a little over 2 nm per 1,000 feet AGL.  At 19,000, with most of the airports in the midwest at around 1,000 MSL, that’s 36 miles.  In Minn., where I fly quite a bit, its rare to find a place where the airports are more than 20 miles apart, so there are many options. Now Foreflight draws a constantly updated “glide circle,” flatter to windward than to leeward, have not needed to use it in a real situation though. The only time I can think of when altitude is not an advantage would be a fire that you are unable to put out, very rare but possible. I think I would choose to test Vd on that one.  Knock on wood.

[aviatoreb]

29 minutes ago, jlunseth said:

Altitude is a real treasure.  Better to have lots of altitude and a need to find a way to lose it, than not having enough, which you can’t fix.  For quick math (that’s all the time you have), I use a two mulitplier.  The glide ratio at best glide is 12.7:1, which is a little over 2 nm per 1,000 feet AGL.  At 19,000, with most of the airports in the midwest at around 1,000 MSL, that’s 36 miles.  In Minn., where I fly quite a bit, its rare to find a place where the airports are more than 20 miles apart, so there are many options. Now Foreflight draws a constantly updated “glide circle,” flatter to windward than to leeward, have not needed to use it in a real situation though. The only time I can think of when altitude is not an advantage would be a fire that you are unable to put out, very rare but possible. I think I would choose to test Vd on that one.  Knock on wood.

Hi - I agree that altitude is usually our friend, which is why I usually fly at altitude when cross country.  So a math note - if as you said you have 36 miles of glide at 19k, then airports on average would need to be about 72 miles apart to leave you in trouble since at 36 miles you would be half way in between (this does not count for winds so miles half way is not actually glide distance half way but that is what glide rings are for).

[N231BN]

Good discussion here. Back to the original question, TC vs TN, the installation has more to due with failure modes than the type. For example, my 150HP Citabria has a smaller C/R (7:1) than my 231 (7.5:1). It runs just fine at altitude. If you have a TAT TN installation with an automatic waste gate, a turbo failure puts you in the same boat as a factory installation. A stopped turbo with a closed waste gate will kill an engine real quick. If you have a TN installation with a manual waste gate (Rayjay), you can simply open the waste gate assuming you aren't on fire and fly on.

I had a turbo fail in a Cessna 414 over Rifle CO and simply pulled the throttle back and flew to Grand Junction. Back to the twin vs single debate...

[jlunseth]

 

1 hour ago, aviatoreb said:

Hi - I agree that altitude is usually our friend, which is why I usually fly at altitude when cross country.  So a math note - if as you said you have 36 miles of glide at 19k, then airports on average would need to be about 72 miles apart to leave you in trouble since at 36 miles you would be half way in between (this does not count for winds so miles half way is not actually glide distance half way but that is what glide rings are for).

I use that calculation when flight planning to cross Lake Michigan.  I try cross at the narrowest part, which from memory is 44 miles, and I try to get to at least 12k, not always possible because of weather, etc. but that is what I try for.  Also really need to be aware of the wind.  I have made several trips across where west to east we can coast to the eastern shore as soon as we break the western shore, but coming back east to west I will go around Chicago.  On a couple of occasions I have had to negotiate with ATC that sets up a course where a west to east perpendicular crossing can be done, particularly when I have human treasure on board.  Its just a planning thing to think about, eliminate a risk if you can.

[aviatoreb]

6 hours ago, jlunseth said:

 

I use that calculation when flight planning to cross Lake Michigan.  I try cross at the narrowest part, which from memory is 44 miles, and I try to get to at least 12k, not always possible because of weather, etc. but that is what I try for.  Also really need to be aware of the wind.  I have made several trips across where west to east we can coast to the eastern shore as soon as we break the western shore, but coming back east to west I will go around Chicago.  On a couple of occasions I have had to negotiate with ATC that sets up a course where a west to east perpendicular crossing can be done, particularly when I have human treasure on board.  Its just a planning thing to think about, eliminate a risk if you can.

I have crossed Lake Michigan with the same thoughts.  I have only done so in a handful of times, and at the upper teens.  On each of those occasions I was always in gliding range to land.  On those occasions I was calling altitude my virtual twin.