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Les Parson

FSX Turboprop ITT Comparison

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Greetings,

 

I prepared a brief, unscientific comparison of ITT performance between a variety of aircraft. At issue is if ITT increases or decreases with altitude due to thinner air.

Only the Flight 1 B200 ITT increased with altitude. I assume this is a FSX limitation.

 

1.) Carenado B200

2.) RealAir B60 Turbine Duke

3.) Milviz B350i (ALPHA)*

4.) Flight 1 B200

 

*Note - The Milviz B350i remains in Alpha mode without documentation.

FSX TURBOPROP ITT COMPARISON            

          1.) CARENADO B200  PT6A-42     ALT OAT C TQ ITT RPM 10000 9 2093 713 1907 15000 -3 1959 667 1908 FL180 -8 1842 647 1906 FL200 -12 1738 634 1906 FL220 -16 1628 622 1908 FL240 -20 1519 611 1908

 

          2.) REALAIR B60 TURBINE DUKE PT6A-35   ALT OAT C TQ ITT RPM 10000 11 713 747 1906 15000 -2 879 764 1906 FL180 -9 881 756 1906 FL200 -12 886 735 1906 FL220 -16 888 715 1906 FL240 -20 887 688 1906

 

          3.) MILVIZ B350i PT6A-60A (ALPHA)   ALT OAT C TQ ITT RPM 10000 12 63.9 717 1627 15000 -1 64.1 682 1627 FL180 -8 63.7 663 1627 FL200 -11 63.3 654 1627 FL220 -15 64.2 656 1627 FL240 -19 63.5 643 1627

 

          4.) FLIGHT 1 B200 PT6A-52     ALT OAT C TQ ITT RPM 10000 12 2040 704 1805 15000 -2 1935 703 1805 FL180 -8 2077 724 1805 FL200 -12 2064 731 1805 FL220 -16 2064 739 1805 FL240 -20 2055 754 1805

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Carenado PC-12 with the Engine mod from Autogyro fixes this bug in the Carenado PC-12. No other Carenado models it properly. It is an issue with the fsx engine.

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There is more to the story than ITT. More important issues to me are whether torque increases when you lower RPM and does the drag of the prop at beta or when you go to props full forward come into play. The Realair Duke Turbine V2 and the Twotter Extended from Aerosoft model these perfectly.

 

Donald

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Nice test!! I like this kind of stuff. Yes ITT isn't modelled correctly in most add-ons bar a couple.

 

Did I read that right and see that the Duke'ss ITT drops with altitude?

 

 

Are you able to run a test for me with the Flight 1 B200?

 

At ISA + 20 FL260 Normal cruise TQ 1700 rpm?

 

Also FL270 TQ 1550 1700 RPM

OAT -22 C.

 

I have some real word numbers and want to see how close it is.

I'll see what I can do.

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King_Air Fan:

 

How's this?

 

FL250, ISA +10

ITT - 748

TQ - 2029

RPM - 1704

FF - 342

IAS 201

TAS - 297

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Did I read that right and see that the Duke'ss ITT drops with altitude?

 

 

Actually it both rises AND falls, as it should. ITT in turboprops tends to rise up to a certain level all other things being equal, and then drops when getting into super-cooled air masses. 

 

On the other hand there are wonderful things to enjoy in life apart from being glued to an ITT gauge to check it is "correct".

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With an altitude increase for a given torque setting both N1 and ITT will increase for a free, gas coupled turbine such as the PT6. At higher altitudes available torque will be limited when N1 and ITT reach their respective limits.

.

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Sad to know that the Milviz 350i not give the correct model to the PT6, I have all hope for that, the team of milviz will have a PT6 correctly and we'll done. Carenado all know that they don't modeled the turboprop correctly. Real air I don't know that they can't done that too, well I hope that milviz make the garrett of they Moooooooo well done, a geared turbine it's a goal, only PMDG in their JS42 has done that in the garrett turboprop. The people of flysimware are others that can't done the garrett in their 2 planes correctly.

Milviz please

........ Moo garrett well modeled!!

Redgard

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Actually it both rises AND falls, as it should. ITT in turboprops tends to rise up to a certain level all other things being equal, and then drops when getting into super-cooled air masses. 

 

On the other hand there are wonderful things to enjoy in life apart from being glued to an ITT gauge to check it is "correct".

 

Yes indeed!!!

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Pretty much this. At high OAT temps torque will be reducd which is why of course the torque charts for ISA+20 show less torque then ISA OAT.

 

What doesn't get mentioned is the ITT becomes a limiting factor on the climb. As mentioned above, N1 and ITT rise. And at high OAT, the ITT limit - depending on aircraft and engines, cruise climb ITT is less then Max continuous - so the pilot reduces torque to keep the ITT from exceeding any limits.

 

And since company limits can be and are often less again, correct ITT indications ARE an important part of MSFS aircraft indications and should be modelled.

 

The engine mod for the Carenado PC-12 has turned it into a new plane, you really have to look out for the temps on climb and on hot days.

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The engine (and ITT) control system isn't even IN the alpha that was put out.

 

Hence the reason it's called ALPHA... 

 

We're working hard in close conjunction with Tomas and he's got THAT end totally covered.

 

Worry not, it will do as it's supposed to do.

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In some engines in some conditions you'll actually reach the N1 limit first. One kingair I flew has the -21(-20 front end and a -27 back end) and at altitude one of the engines would reach the N1 limit of 101.5% while the ITT was just under max limit. Of course available torque was way reduced.

Interesting thread. FSX and P3D have their limits in modelling engines. That said some flight sim aircraft producers get much closer to the real thing than others.

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The engine mod for the Carenado PC-12 has turned it into a new plane, you really have to look out for the temps on climb and on hot days.

Do you think it may be possible for a Carenado C90 mod? Should I/we reach out to "Autogyro"?

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Do you think it may be possible for a Carenado C90 mod? Should I/we reach out to "Autogyro"?

 

Here is the engine mod topic

 

http://www.avsim.com/topic/461589-pc12-overhaul-mod-v10-and-n594wa-repaint-released/

 

I'd ask him, he's been away from updating the mod for a few months but said hed be back. Couldn't hurt to ask. I don't own the C90 but have their C200 and would like the mod for that too. But it looks like a lot of work.

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