Never heard of this happening but a turbocharger on my Aerostar (it was freshly rebuilt and installed on March 5, 2016) exploded at FL210 on Thursday this week. The airplane gave no sign at all of the impending doom. I learned a lot from this and the biggest lesson was how different the plane handles on landing with one motor caged. Unlike training where the "dead engine" is at idle, caged causes a lot more drag.

Wow - lucky I guess it was on the intake side! Did it look like FOD hit the impeller and caused the housing to crack or does it look like a defect in the housing or improper torque or similar caused the failure?

Impressive failure and management of said failure. Good Job. What was the immediate sign? Bang? Smoke? Gauges?

Glad it was on cold vs hot side. Who did the OH?

The rebuild was done by Martin Induction in Tulsa. I don't think it was FOD because in my Aerostar the intake for the turbo is the filter and that is only about 18" from the turbo. There was no sign at all of failure, just the motor rolled back and the plane yawed to the right. I was at FL210 and pretty quickly was heading down at 1500 FPM. My expectation is that the turbine wheel itself failed because it is mostly missing.

Although it was on the cool side I am still concerned whether any parts went down the induction side. We are going to start up tomorrow and see what we have.

Do you have an intercooler? Hopefully the pieces of the compressor were caught so they wouldn't go into the intake. To me it looks like you had a bearing failure and maybe check your oil drain line and your oil supply.

I have had one case where a nut got in a supercharger before the engine was installed on the aircraft. About 11 grand to fix and of course both the engine builder and installer denied any respect nobility. Another case a too long bolt was occasionally stalling the turbo when power was reduced. It had cut a nice groove in the impeller.

+1

Eric,

When you got lower to say 10k did the engine work fine? I thought these turbo engines were supposed to work fine and just become normally aspirated when turbos failed?

Remy

The failed turbo restricts the air intake and the engine will not operate as a normal non-turboed engine at low altitude.

Eric, shutdown and feathered the engine. Sounds like it was flying fine OEI and there was no reason for him to fool with trying to restart it at a low altitude.

Yes, below 10,000 the engine was fine and ran ok but above 14K there was very little power. I opted to stay at 17,500 since that was a reasonable altitude for my flight plan and I was in constant contact with ATC. They were ok with me at 17,500 and altitude was my friend as far as I was concerned. ATC seemed comfortable with the plan as was I because the plane was completely under control. Although I could have diverted to a closer airport there was really no reason to do so because at about 14,000 feet the right engine came back to life.

Did they find a cause Eric?

A known turbo failure at altitude should not be considered as an inconvenience of flying without boost, especially in a twin. It should be thought of as a potential exhaust failure blow torching the other side of the firewall and trying to burn your airplane.

I have a temperature probe between the turbo and the firewall that in the event of lost boost will tell me whether I should shut down even if I don't have a suitable airport at which to land.

Don't take a failed turbo lightly. It is a sign to land at the first suitable airport, if not sooner.

This sounds interesting. Where is it located and how is it displayed?

How true…once saw a C-421…she was on a short flight fortunately…MP went down, the engine interestingly enough operated smoothly albeit with a low MP…the crew thought that they had a wastegate failure…because they did have one two months before on that engine and did not shut her down…what had happened though, an exhaust stack upstream of the turbo had opened up and was torching the outside cowling very close to the fuel pump.. they could not see that from the cockpit…ten minutes more in the air and that bird probably would have had an ugly wing fire..when she taxied in that R/H outside cowling was black with the paint burnt away…

I do not have 421 literature anymore, but I think I do remember loss of MP to "unboosted" was an emergency item with the engine to be shut down and secured..not sure anymore..