Calling all PC12 pilots & experts. Looking to the wealth of knowledge on this forum to point me in the right direction and help answer some questions about the Pilatus PC12 we are looking to purchase. Specifically any real world experience and numbers would be fanatic.
What is the real world cruise speed speed difference in the mid 20's between the PT6A-67B (legacy engine) vs the PT6A-67P (NG engine)? is it noticeable?
Is one prop type noticeably faster than another in cruise?
Does the Finoff -67P conversion provide any speed increase over an NG model?
Does anyone have any experience with the new Speed Cowl Mod from American Aviation? they are claiming 18kts increase in cruise?? but those are sales ads and wanted to hear from pilots who have flown it.
If you were to build the fastest PC12 what route would you take?

Thanks everyone for any answers or direction you can give.

Ive got enough time in behind the -67B and the 67P (with the 4 blade, hydraulic gear, the 4 blade prop, electric gear, and the 5 blade prop, electric gear) to know the differences pretty well.

The difference varies according to temps and altitudes obviously, but overall the 67B is about 10 knots slower in cruise-you’ll routinely see about 258-260 TAS in cruise (4 blade prop, 67B).

The 67P will get you about 266-270 TAS, routinely (4 blade prop).

The -67P with the 5 blade prop, -67P will get your 270-275 (never seen faster then 276 in cruise, with charted torque).

Now, with this being said, there’s no question the 5 blade -67P doesn’t perform better. It’s incredibly noticeable. The take off roll is shorter, the landing distance is shorter. The climb is absolutely better, and it’s smoother in flight. Getting to FL250 on a warm day with the back full is a bit slow in the 4 blades. The 5 blades will get you up better. It’s especially noticeable pusher ice mode.

If you ask any professional Pilatus pilot, they’ll tell you the 5 blade is better with short fields, and climb gradients-we all want the 5 blade. Now if your mission is sea level, with a long runway, going to another long runway, probably not worth spending the money on it.

I don’t know anything about the speed mod though. I’d want to see some proof first, that sounds like a lot of extra speed.

Also, this data isn’t a hard fact you read in the individual manuals, but as someone who flew 800+ hours behind these engines in the last calendar year alone, I feel pretty comfortable slapping my seal of approval on these numbers.

The American Aviation Speed Cowl was advertised as “up to 18 KTAS.” That was the increase we saw at FL280 with the airplane at max gross weight, on a 5 degree C hotter than standard day during back to back, same day, FAA flight testing with the Speed Cowl vs. the stock cowl. If lighter, or lower than that, you can expect 6 to 12 knots in the flight levels. In a back to back comparison on the same day under the same conditions, and setting the same torque, the airplane ran 30 degrees cooler on the ITT with the Speed Cowl. The speed increase comes from being able to run more torque at the same ITT. It is not an aerodynamic drag improvement of the cowling; rather it is the cowling’s ability to deliver better pressure recovery to the compressor section of the engine, lowering the power consumed by the compressor section, which in turn means more power is then available to drive the power turbine.
There is also a benefit in climb above the altitude where the stock airplane reaches its critical altitude and can no longer maintain full climb torque. The speed cowl can maintain more torque at the same ITT at every altitude above that critical altitude which reduces the time to climb to cruising altitude. In general, when operating above the engine’s critical altitude, proportionally more power is restored by the Speed Cowl over the stock cowl as density altitude increases.

Good info Kyle


Anyone know how much the Speed Cowl costs? 5 blades are 70k-ish +. For the money, I think you'd get comparatively better cruising speed and high altitude climb performance with a pitot-style cowl rather than an upgraded prop, but need a longer trip/winds to warrant the climb.

Impressive! I like the way it looks too

Hello Neema,

The Speed Cowl is currently priced at $85,000.00 and the labor is less than 2 hrs. to install. Then you have to paint to match the existing paint scheme. The cowl comes off with a few quick release latches so you can put it in a paint booth and don't need to mask the whole airplane.

Kyle,

Thanks for the kind words and the great information you posted earlier.

Best Regards,

Jim

Brandon,
Good luck with your search. I will assume that you are looking for a "Legacy" by the nature of your questions?

Kyle did an excellent job of a recap of the engines and props. I'll offer a few clarifications.



We own an NG that had a 4 blade prop and went with the Hartzel 5 blade at our overhaul interval. We saw all of the performance improvements that Kyle mentioned except for the TAS increase. We only saw 1 knot increase, maybe. We were not expecting a TAS increase anyway based on other operators experiences with upgrades. In addition the noise levels were slightly lower with the 5 blade.

I suspect the difference between Kyle's numbers and ours has to do with the serial number of the airplane. When Pilatus released the 5 blade prop on factory aircraft, they also made some aerodynamic cleanup improvements at the same time (that you cannot get from a older plane). Some improvements that I recall; flush mounted the door latch, cleanup of the light fairings, re-position of the VOR antennas; there are others I cannot recall. However, you cannot get these 'cleanups' on older NG or Legacy aircraft so it's likely that you will not see a speed increase with the just the 5 blade upgrade.

The Finoff -67P upgrade for legacy from my understanding has different torque performance charts than factory NG aircraft (which have the exact same engine). You can run higher torque in a Legacy upgraded to the -67P than a factory NG aircraft which should give you higher cruise speeds in the legacy than a NG.

Finally, there is a lot of great information on the POPA forums about these upgrades so I'd recommend that you consider joining.

Good luck with your search!

There has been some interest from Europe for our Ram Air Recovery "Speed Cowl" for the Pilatus so we applied for and just received EASA approval. The Speed Cowl is also now available directly from American Aviation Inc. http://www.AmericanAviationInc.com

I heard 4 kts TAS increase at high speed cruise at altitude from an operator that got one PC12 cowl done.

I have about 700 hrs single pilot PIC in PC12's. I wouldn't make a decision based on TAS between these engines/models.... it's just not significant enough to make a real difference. I'd flight plan both as 250 kt airplanes. The later NG book is 280 but I never see that, but I'll bank on 260-265 in cruise... It comes down to if you want the APEX and the other improvements in the NG. The difference between 255 and 265 kts is just not at all significant.

What he said! And you DO want the apex and the NG improvements. Our legacy 12 (-41) really flew like a dump truck compared to our NG. The aileron improvements really make the plane a lot better to fly feel wise. Also apex is just the best. Even better in the pc -24!

Any chance of a speed cowl for pre-900 TBM's?