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Austrian772

Problem with engine power

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Hello guys,

 

after spending some time reading the manuals for this beautiful bird, I finally took off for my first flight. Everything went fine except for one thing: after reaching my cruise altitude of 31.000ft I took out the performance tables. I decided to go for the Max. cruise settings and the table says 91% of TRQ at FL310 at a temperature of -36C. However, I can not get the engine to that setting and my TRQ was around 75% - 80% although I had set the flap lever to "850".

 

Any advice?

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It was off for sure. I also tried lowering my Prop RPMs to reach the torque described in the manual,but that only made the speed drop...

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After another test flight, I still could not solve the problem. However, I lowered my Prop Rpms to around 1800 to get the torque setting displayed in the performance table for Normal Cruise. I still have not found out how to achieve the Max Cruise torque...

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I have the same problem here. It feels like if the TBM850 is actually having the TBM700 engine. Otherwise it's still a joy to fly =@

 

Flying Prepar3d v3.3.5 with Berk's and Captain Z mode.

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I did a couple of flights in the TBM this week and compared the numbers to the conditions. I haven't tried max cruise yet, but normal cruise settings are pretty close to what is in the charts. I also noticed as the plane gets lighter with fuel burn, the numbers get better and torque/rpm settings even out to where they should be. What's the duration of flights you're performing? Does the plane have enough time to even out like what I've been seeing?

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I also manage to get to the Normal Cruise torque, but only if I pull the Prop back to 1800 - 1850 RPMs. Normally, my legs are about 600 - 900nm.

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Charts suggest 1700-2000 RPM is the range you should expect for normal cruise, so that sounds about right.

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Okay, Normal Cruise works fine for me now, but Max Cruise just doesn't cut it. I would have to pull the prop back too much, which causes me to lose speed compared to the Normal Cruise setting. I don't really understand why this is the case, but anyway Normal Cruise is more economic and who doesn't want to save fuel  :wink:

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I just did a flight to try out max cruise and it seems ok to me. I was at FL190 with an OAT of -10 which, according to the charts says I should be at 121% TRQ (RPM between 1700 and 2000). Given my weight, I should be cruising with an IAS between 217/220 and a TAS between 297/304.

 

My actuals are:

 

TRQ 120.6

RPM 1704

IAS 211
TAS 286

+15kt head wind.

 

You have to move the flap setting up to 850 to allow you to exceed 100% TRQ, but once you do, it seems Max cruise numbers are pretty close to the charts.

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Just to add my 2 cents, I have found this ^^^ to be pretty accurate.  However, I leave my RPM at 2000 and routinely cruise at IAS 225, TAS 300.  This is cruising at FL200.  At higher altitudes things would change of course.

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I always make sure to go to 850 mode. Mostly, I am cruising at FL 280 - 310 and Max Power doesn`t cut it for me...

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I'm currently running a flight from KAUS to KNEW at FL290 and am getting good numbers at max cruise at the half way point. I've got the following:

 

OAT -25

Weights: 6300kg

TRQ: 87.4%

RPM: 1922

Flaps: 850

 

IAS: 183

TAS: 296 (4kt head wind)

 

Charts:

 

TRQ 87%

IAS: 179-174

TAS: 302-300

 

Pretty close at MAX Cruise. You might want to tweak your controls in flight and see if you can get close. It's not enough to firewall the controls and leave them there, you have to move back the condition lever some to get the TRQ levels where you want them.

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