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My TBM700 neighbour that... his plane at the same mechanic as me just overhauled his PT6. Almost all compressor/turbine blades were out of spec and had to be replaced. It cost north of $350K to get it done. Turbines need proper budgeting and fund allocation, or else one is in deep dodo - can't just wing it like I do on my piston twin and pay as you go!

A hot start, or three?

Would you fly with your piston engine at 500F CHT for a few hours, or if you like would you fly it leaned to peak EGT at 100% power, for half an hour, at Vx?

Shoreham EGKA, United Kingdom

Funnily, I did that for a little bit recently. Because I had never leaned very much coming from small single engine bimbles, and then going to an auto-leaning carb in the Commander. I didn't know you'r not supposed to climb with them leaned - I thought it was simply altitude that dictated leaning, not power . So I climbed. Until I could smell a faint smell of burning and saw my EGT temps were at redline... You live and learn..;)

EGT temps at redline? CHT you meant or TIT? I have not seen an engine that has a redline for EGT.

The problem with leaning at full power is detonation due to uneven fuel mixture. If it happens, your engine is a big block of melted metal.

$250K plus is not unusual for a PT6, without any hot starts. All turbines are expensive to overhaul, hence why many operators have an engine plan under which you pay by the hour and all maintenance and overhauls are covered.

Darley Moor, Gamston (UK)

At what engine time was that done? At 3600 TBO, that's $100 per hour, high, but not outrageous.

Biggin Hill

achimha, Lycoming TIO-540 in the aircraft I fly as redline for EGT.

the only EGT redlines I have seen were in jet aircraft ...

EDxx, Germany

The TIO-540 does have a TIT redline of 1750F. Not exactly a EGT limit but similar and measured just a little bit down the exhaust system.

Mine has a TIT redline (1650F), too but that is not an EGT redline because it does not exist to protect the engine but the turbocharger. For the engine, the absolute EGT value does not matter.

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