Engine maintenance period

[Gábor]

Captains,

what are the engine maintenance periods for PT6 engine?

I tell you a story. In my airframe I had a turbine with 67 hours of lifetime.

After my route when I finished I put the engine to low idle before shut down. I realised that my ITT went to red section around 880 Celsius. I shut down the engine. I felt something is not good, I wanted to check. I did motoring to cool ITT below 150, and after added fuel into starting sequence, ITT was rocketing into hell and even flames came out from engine. I aborted the start up straight away. Unfortunately my chamber was destroyed. I repaired it. I did again the startup, but the same happened, but this time my chamber survived.

I serviced all part of the turbine to make it work, but I had to replace the turbine chamber because I could not repair it anymore. I spent 550.000 dollars ( ok, 150.000 could have been spared).

What part caused this issue? My all turbine parts were in good or as new conditions.

After how many working hours do you recommend preventive maintenance to avoid this? And for which part?

Thanks.

Edited April 27, 2021 by Gábor

[fehrster]

https://www.tbm.aero/wp-content/uploads/2016/10/PIM_TBM900__E1.pdf

Page 302 and following - Maybe your shutdown procedure should be changed ^^

[Gábor]

I thought the taxing, which is usually more than 2 minutes, is enough to cool down the turbine... Maybe I am wrong.

Do you believe that this wrong methodology what I used caused this engine malfunction by the time?

Thanks.