Emergency training with a turbo

[xavierde]

So I recently got a 252 and I would like to go through some emergency training e.g. loss of engine after take-off. 

How do I do that without damaging the engine? Should I just rent a J?

Thank you

Edited September 24, 2019 by xavierde

[gsxrpilot]

You won't damage the engine. None of that has had any negative effect on my engine. I do steep spirals, power off descents out of the flight levels, etc. No issues and coming up on TBO.

[carusoam]

+1 with Paul’s response...

Also add to the book work... restarts after turbo failure at high altitudes...

PP thoughts only, not a CFI...

best regards,

-a-

[thinwing]

That’s the important point...turbo failure at alitude with lower alitude restarts

[81X]

On 9/24/2019 at 11:14 AM, gsxrpilot said:

You won't damage the engine. None of that has had any negative effect on my engine. I do steep spirals, power off descents out of the flight levels, etc. No issues and coming up on TBO.

I think that the most dangerous thing here is having the gear warning going off with the power out and the gear up; it will drive you nuts. 

[jlunseth]

I have to disagree that one can practice engine out maneuvers in a turbo without worrying about engine temps.  The POH for my 231 warns about two issues.  The first is a need to "slow warm" the cylinders to 250F before powering up.  I don't agree with that one.  I routinely have one or more cylinders under 250 when I power up for takeoff and I am getting great engine longevity. Knock on wood.

The bigger issue in my opinion is Oil Temp.  The POH warns repeatedly that 100dF is a minimum. It does this in several places, in the Limitations section, and then in several sections pertaining to emergencies.  In the air start section, under a square that says "CAUTION" in big bold letters, it says: "Operating the engine at too high an RPM before reaching minimum oil temperatures may cause loss of oil pressure." Then under another CAUTION box it says: "Should the engine excessively cool during engine out care should be exercised during restart to avoid excessive oil pressure. Allow the engine to warm up at minimum governing RPM and 16-18 inches MP."

There are two issues, and they have little or nothing to do with CHTs. One is that the turbo bearing requires a constant stream of oil through the bushing/bearings and the tolerances are very tight.  Oil that is too viscous may not lube the turbo.  High viscosity is also a problem in the prop controller, which may not be able to regulate RPM's.

I did quite a lot of steep spirals and engine out exercises for my commercial a few years ago.  During the summer I never saw a problem. But when fall and lower temperatures arrived, just a couple of steep spirals would cool the OT below 100.  When that happened, I started doing the exercises in such a way that I never had to immediately power up. For example, a succession of spirals plus a power off 180 was not something I considered safe in the cooler fall temperatures, because the POH made clear that a full power go around could cause loss of oil pressure or excessive oil pressure.

I did once have a loss of oil pressure because of cold temps.  It was winter and the air/oil separator froze, blocking the breather and blowing oil out of the engine everywhere.  That is not the same as the low temp problem, but once was enough for me.