Assuming no changes in aerodynamic drag, you would expect the speed percentage change to be roughly the cube root of the horsepower percentage change. So -

Old speed x ((700/600)^1/3) = Old speed x 1.053 = New speed

About a 5% increase in speed from the horsepower change.

But they may have made other changes to reduce drag, which would be potentially more significant.

Based on the numbers I’ve seen flying my M600 for five years, five percent isn’t going to get you close to 300ktas, flying book torques in level flight. It will be interesting to see real world numbers, flying the plane in accordance with Pratt recommendations.

I do not fly max cruise but I have tried it to see the speed and at FL250 I have seen 284KTS which multiplied by 1.053 is 299KTS so it does get close,but I would assume at normal cruise the increase is about 10-15KTS.

The cruise speeds I normally saw were mid 260s, and low 260s when high and heavy. As I mentioned, I flew book torques.

What are the speeds for the max cruise, normal cruise, and max range in the M600?

It's not as simple as adding 5%/100 hp. It's the available hp at cruising altitudes.

I don't know the thermodynamics of either derivative, but I would ascertain that it's holding more available power as altitude climbs and may be able run with a higher % of power before temping out at above ISA temps.

Looked up the type data sheet from EASA: https://www.easa.europa.eu/sites/default/files/dfu/EASA_TCDS_IM.E.078_PT6A_41_20220317.pdf

- Both are rated to the same power 634 kw or 850 hp.
- 32# core engine weight difference.
- The 52 has 20 c higher allowable operating temp - 820 c
- The 52 is flat rated to a higher ambient temp of 61 c vs. 41 c which should speak of it's ability to handle higher ISA temps at altitude.

This is a lot like what Cessna did with the TIO540 in the Turbo Skylane. Derate a 300+ hp motor to 235 hp and you can run 82% all day and maintain power into the FL's. This may very well end up being an extremely durable combo that ends up costing less to own than the M600 if they get extended overhauls.

This is definitely a good point.

My main point was adding X% power for a given flight condition would be expected to increase the speed in that flight condition by the cube root of X. If the NET horsepower gain at a high cruising altitude was higher than X due to improvements in flat rating, you'd have to use the cube root of whatever the HP difference at that altitude to figure the expected speed change for that flight condition.

For example, and to show the flip side of that equation, to achieve a 10% increase in cruise speed at a given altitude, you would have to increase the horsepower available at that altitude by about 33%. (1.1^3=1.33).

Max cruise is 274 KTS
Normal cruise is around 257-259
Max range is 181-186

I think I saw 274 one time in five years. Normally I flew the plane full fuel and FL260-290. My typical flights were about 1000nm.

Leif is right on available hp.

Below are your thermodynamic ratings of a -42 and -52.

The -52 is a -60A's gas generator with a 42's gearbox. Also happens to be exactly the same as the -61 but the 61's redline is 20° lower at 800°.

Don't ask me how the 60A and 61 have the same thermodynamic HP with different redlines while the -52 somehow makes 130 more HP.

They're all the same gas generator

"Piper Aircraft has unveiled the fastest single-engine aircraft ever"

https://supercarblondie.com/fastest-eve ... -unveiled/

Uh, no.

The PR department is hurting Piper's credibility.

A TBM will easily out run an M700.

Mike C.

Super Car Blondie works for Piper?

Chip-

So will an F-16...

Piper's Press Release refers to it as the fastest-single engine Piper ever built. I assume SupercarBlondie has poor reading comprehension, or maybe just an innate sense of how to tweak the truth for more clicks.

I have flown several M600's, they have all been 5-10 knots faster than book. Our M600 cruises about 7 knots faster. Here is an example in smooth air, fairly heavy with max luggage near full fuel and 3 onboard. 7 Knots faster than book, burning 9 pph less than book. Does this all day long. If you run by ITT at max continuous it will run in the 280's, I have seen 286, but we will likely be taking this one to hot section, so we baby it. I flight plan 265 at all altitudes from 18000 to 30,000. Makes it easy.

I have been told the range on the M700 is pretty much the same as the M600. This is not vapor wear the plane has been flying for a couple years. The LRC is longer than the M600, so would expect normal cruise to be around the same as the M600. Not mentioned is that the 1740 lbs max fuel is a light top off. I have been able to get 1900 lbs in the plane. Yesterday at KMAI (cheapest JetA full serve that I could find down there), got 1840 lbs. just ordered a regular top off, nothing special. Notwithstanding, at normal cruise and IFR reserve, we have about 1400 nm no wind range. I expect the M700 to do the same, but the beauty is that you can pull the power back a little and get much better range. up to 20%, fairly linearly depending on power settings. In cruise you are bring about 1 pound per nm, so can look at the tanks and see how much range you have left in cruise. If you pull the power back in the descent, you keep the 1 nm per pound range. But nobody buys an M600/M700 to not see that barber pole every now and then .

Did this flight yesterday in a friends M600 with a slight headwind from Utah all the way through Colorado before changing to neutral and then headwind. 1468 nm landing with 1.5 hours reserve fuel.



These planes go westbound as well. From a few days ago, with a brutal headwind, flying at max gross weight with 4 onboard. 1158 nm landing with almost 2 hours reserve fuel.