That is a good point. Have always been the mindset of running things a little on the soft side. In the case of the turbine, this one is pretty de-rated, and at least at this time we have the engine under warranty and on plans ESP Gold, so probably doesn't make sense to trade Hobbs times for slightly reduced wear.

Chris, can you elaborate on what problems can be caused by running a PT6 cool?

Chris, can you elaborate on what problems can be caused by running a PT6 cool?

Sulfidation of the blades.

In the King Air side of things, a great example is the C90 with -21s. Marketing set an artificially low ITT to keep it from competing with E90. Once E90 was gone, ITT magically went up. Raisbeck includes this new limit in their STCs, as it is a documentation thing. At the artificially low limit of 660, sulfidation would occur.

Took a trip in the 200 yesterday where I was at FL270 and FL280. My Ng was just a touch under 100%. Chuck, what is your Ng at altitude usually?

Thanks for the info on sulfidation. I’m not Chuck, but I’m usually at around 93.7% at altitude at 270-280 max speed cruise and usually 690 ITT in my Meridian.

Yeah, in a PA46T the -42 is so derated for the airframe limits, it is loafing. I would not be afraid to run it up to Torque redline, as I bet you will still be plenty far away from the ITT "comfort" limits.

Spent 20+ hours in a Meridian, but cannot remember what the ITT was doing at altitude with max torque. Again, in a King Air the -42 is limited to 2230 ft/lbs. You are not "hurting" the engine or RGB by running your further derated -42 to the much lower Torque redline.

However, you do burn more fuel and that is a personal choice. At least in a King Air, you can see the dollar bills flying out the stacks. In a PA46T they tend to be harder to see since the exhaust hugs the fuselage.

Me too, but I’m not sure if it helps.

If you took 4 adults and luggage how far could you goon a tank of Jet A?

Ps. Nice. Very nice.

In the King Air side of things, a great example is the C90 with -21s. Marketing set an artificially low ITT to keep it from competing with E90. Once E90 was gone, ITT magically went up. Raisbeck includes this new limit in their STCs, as it is a documentation thing. At the artificially low limit of 660, sulfidation would occur.

Took a trip in the 200 yesterday where I was at FL270 and FL280. My Ng was just a touch under 100%. Chuck, what is your Ng at altitude usually?

Sounds like the generator's barely working

The engine in the P46T/M600 variants is silly oversized/derated for the application. It does have some payoff in the philosophy of Piper for making a mostly idiot proof aircraft. On the ground, you never get close to over-temp conditions, when idling, starting, taxing or takeoff. Your take off power whether you are at sea-level on a cold day, or at a mountain airport on the hottest of days is exactly the same. Set the torque the same place every time. Up to 1313 for the M500 and up to 1575 for the M600. You are never Ng or ITT limited. It also makes the take off performance a lot more predictable. You still have the effect of density altitude on prop efficiency and airfoil performance, but your takeoff power is always the same.

The engine in the P46T/M600 variants is silly oversized/derated for the application. It does have some payoff in the philosophy of Piper for making a mostly idiot proof aircraft. On the ground, you never get close to over-temp conditions, when idling, starting, taxing or takeoff. Your take off power whether you are at sea-level on a cold day, or at a mountain airport on the hottest of days is exactly the same. Set the torque the same place every time. Up to 1313 for the M500 and up to 1575 for the M600. You are never Ng or ITT limited. It also makes the take off performance a lot more predictable. You still have the effect of density altitude on prop efficiency and airfoil performance, but your takeoff power is always the same.

The Conquest is the same way with the PT6-112. Temps out at 16,000 +/- and impossible to over torque for all intents and purposes. Just after got the plane I was doing some air work by myself and after a stall I noticed that I overtorqued by about 100 ft-lbs during the recovery (limit is 1244 ft-lbs). I was literally panicked thinking I had ruined the engines. Should I fess up and tell the mechanic? How much will this cost? What will my wife say when I tell her we have to take out a 2nd mortgage to pay for the damage I just did to the plane? I was really distraught. Then I got a hold of a MX manual and found the over torque limits for my model engine. It's ridiculously derated. I am certain you could just firewall it at pretty much any point and not do anything that requires maintenance.