No, it is not a Garrett

[onduty 5]

Hi Guys,

 

No, it is not even a turboprop behaviour. Flysimware advertise this product as "custom coding for the Garrett TPE331 turboprop engines and sounds for the most realistic Garrett simulation ever produced."

When I purchased the C441 I was looking forward to it with great expectations, especially the engine behaviour. To my dissapointment I found that it is just a basic, unrealistic FSX turbine engine. I.e: During climb, the EGT decreases with altitude and T/Q remains constant. This is just the opposite to real world! In FS history a couple of addons were able to circumnavigate that basic FS coding. But not Flysimware.

I' ve checked a couple of Flysimware MU-2 vidoeos on you tube and to my dismay the engine parameters still behaved the wrong way.

Now, I do not understand why it is the "most realistic Garrett"?

It would be interestnig to have that "experienced RW MU-2 beta pilot's" opinion on that.

 

Cheers,

 

Tamas

[hangar 661]

I understand what you are saying in regards to the temps not rising with alt, and I agree it would be nice if it did, but just to be clear...the torque does not stay constant and does drop with gain in alt.

 

Also regarding torque, keep in mind they have not modeled the ability to run this plane with anything less than 100% rpm.  So you won't see the torque rise from a drop in rpm's as it should.The real plane is typically run at either 96% or 100%.

 

I personally believe that when they used the term Garrett simulation that they were referring only to the engine start-up effects. As far as their experience with the mu2 I'd say that's mostly over-hyped marketing IMO.

 

...to be fair, however...the coder/owner of Flysimware has shown that he is willing to come back and fix certain aspects of his work as his skills progress and time permits...so there's always the possibility these issues may be rectified at some point in the future.

[mjrhealth 820]

Actually the torque on teh MU2 does decrease with altitude Temps may need to be looked into though.. Found this good video gives one good perspective of engine . Also nice grass short field take off.

 

[mjrhealth 820]

From what I can see from teh videos it behaves as it should. RPm is either grnd idle(taxi) or flight 100%,.  It ceratinly doesnt change in videos. Torque does decrease with altitude and I dont think you can even get 90% at Fl250, mind you at that altitude the book says 65% torque. The book I thinks says 100% below FL120. Even though temp varies with engine rpm i cant tell what it is supposed to do, though in other turbine as mentioned I believe it does increase as teh air gets thinner therby requiring power reduction. Must review more videos.

[mjrhealth 820]

Further looking , teh condition lever is either 72 to 74% RPM at taxi, 96% at Minimum Cruise, 100% TO and Land. In teh flight videos, teh EGT was aroun 62 @ FL250 with 60% Torque but that is air trmp dependent.

[onduty 5]

Hi Dear Guys,

 

Many thanks for your replies. In my original post I simplified a bit to be short enough.

I don't have to check videos, my experience/opinion is based on rw encounters with turboprop aircraft.

A basic turboprop engine with "simple" hydro-mechanic engine controls (not with that fancy FADEC) behaves like

this (no matter if it is a Pratt or Garett):

1. During a steady state climb with a fixed throttle setting the T/Q drops gradually while the EGT (ITT) remaining basically steady.

2. Since you have not reached max. EGT at the early stage of climb, you can recover the T/Q drop by gradually advancing the power levers. By adding more fuel to the engine, EGT will increase of course!

3. At a certain altitude you will reach redline or max. EGT (the engine "temps out"). After this point you cannot

advance the power levers further and the T/Q will drop eventually (the engine will lose power).

4. Yes, you can check inflight videos and will see the typical cruise scenario: the T/Q is around 50-70% and the EGT is near the redline limit.

 

That's all in a nutshell and I expected roughly this behaviour based on the Flysimware promo text.

I'm sure that Flysimware's beta pilot with all that MU-2 experience will confirm my short description.

Anyway, in FS world I only know two addons that come out with proper turboprop handling: the good old Aerosoft/digital Aviation Piper Cheyenne and the F1 King Air.

 

Cheers,

 

Tamas

[hangar 661]

If I remember correctly, the Flight1 Kingair does not behave realistically either...in that it has no increase in torque as you drop the rpm, and it should. The DA Kingair was probably a better engine sim that the F1 version is. Flight1 is all about profits, where DA was all about passion.

 

As I already said above...no one can argue that the toque and temps in this mu2 do not perfectly represent how it behaves in real life, and yea maybe their webpage over-hyped your expectations a little bit...but that said it's still the best mu2 simulation we currently have for the MS platform and for fans of the type it can sure be an interesting and fun ride :-)

[louisdecoolste 12]

Some of these errors could be explained by the poor state of weather modelling.

 

Tamas, to give qualification to your statements, please provide the sim, version, your choice of aftermarket weather engine and bets of all a specific flight scenario for others to test. Otherwise how do we know the problem isn't with your system, or another addon?

 

The reason that I ask is that your knowledge of Garretts is flawed. The TPE's engines on the Moo modelled here are flat-rated. A flat-rated turboprop will hold a constant torque until the limit of its rating is reached, usually defined by ITT/EGT or RPM limitation.

 

IIRC (and I'm not in front of tech docs at this time) the Maximum Recommended Cruise Power chart for the TPE331 shows the power setting is torque limited to 1738 ft. lb from sea level to about 16,000 ft. From there the max. power setting is limited by hitting the max. EGT of 450 C - and that can be dependent on weather factors not just engine operation parameters. 

 

Everything I've read concurs with your notion EGT for Garrett engines rises with altitude and becomes the limit for setting power- but torque or Vmo isn't a factor and should remain constant until the `critical altitude` (he says, mixing his technical metaphors). If that is the case then torque should remain constant as set rather than wander downwards until passing 16K.

I have no idea if this can be properly modelled in FSX/P3D as a number of old air file parameters have been irrelevant and ignored since FS9 days. 

Be happy to be proved wrong, but somehow I don't think I am.

 

While you correctly highlight a FM inconsistency, you are partly wrong in your conclusion. Torque should, I believe, remain fixed in relation to power lever position until a certain altitude is reached, and the PL should then need moving forward to compensate for torque drop, OR back to retain EGT increases within limits.

 

And you missed out on two very good engine models for TP's  - the Real Air Turbine Duke and the daddy - the Majestic Dash 8, which does it's engine modelling OUTSIDE the sim, thereby circumventing the limitations of the internal model, as well as highlighting it.  

 

Marty?

[OneWhoKnocks53 51]

I agree, this is not a perfect Garrett, but its a pretty good MU-2. And it is active development, making the best MU2 available.

 

And you missed out on two very good engine models for TP's  - the Real Air Turbine Duke and the daddy - the Majestic Dash 8,

 

The pt6 modeling on the realair tduke v2 is amazing, I believe they had to use an external module outside of the fs framework to get it that good, check it out if you haven't already. I'm told that the majestic q400 is even better, engine wise.

[louisdecoolste 12]

And for FSX at least, the Garrett simulation provided by the PMDG J41 kicked DA and F1 into another county. 

[onduty 5]

Ok Guys,

 

I really enjoyed this discussion, your points are taken, but I still strongly believe that my basic description of the engine management of a simple turboprop is correct.

Yes, I have "flown" all the models of various FS dev.teams mentioned here except the PMDG J41. The reason is that I could not find rw manuals especially performance manuals on the J41. Pitty! I like to fly "by the book" even is FS world.

Coming back to the MU-2: I am convinced now that it is the best MU-2 for FSX, I will buy it to have a closer look. It is a really unique, high performance, demanding aircraft .

Thank you all,

 

Tamas

[louisdecoolste 12]

Then this may be of interest

 

http://eastaire.us/newchecklist.pdf

 

And don't forget to ping Dave (hangar) for a copy of his 1.7 FDE amendment 4c. 

 

You will get an appreciation of what the Moo can Doo... 

[mjrhealth 820]

Funny thing is one of the oldest FSX turbopros(PA31T  Piper Cheyene) looks pretty well moddelled and that plane is 2008 vintage. Considering its age has one of the nicest VC,s.

[onduty 5]

Thanks Louis, I' ve got it, plus a RW POH/AFM from the net. So, I'm prepared to study!

Mjrh, agreed, it is surprisingly good.

 

Cheers,

 

Tamas

[CSCARLOS 0]

Hi everybody,

 

Once having the opportunity to give Flysimware MU-2 a brief try in a friend's system, knowing other sim products, having consulted the real life Mu-2B-60 Marquise Flight Manual and some technical posts on the internet about this great aircraft... let me say that:

First (already discused in the forum, so not going in too much detail):
Contrary to what Flysimware claims, the turbine model is really incorrect in regard to Torque and Temperature, and also due to the fact that it's not possible to stablish correct power settings from the 100% down to 96% range as needed specifically for cruise, descend and holdings... according to tables contained in the real Aircraft's Flight Manual.

Second- there is an animation issue concerning the elevators trim tabs. As for inflight trimming purposes, a Trim Tab is actually required to move in the opposite direction to that of the control surface it is connected to.

So, in Flysimware's  MU2, for an inflight Nose-Up trimming, Tabs are incorrectly modelled moving upward -when they must move downward to force elevators upward and hence lower the aircraft's tail resulting in a nose-up attitude. Logically enough ...for trimming Nose-Down... just the opposite as described is observed.  In case of disagreement, then it can be easily verified just observing another quality product... or real life aircraft !

The problem here is not the issues themselves (if being able to fix them and not leaving the product as it is now), but Flysimware's claiming what actually is not true when advertising the product as "the most realistic Garrett turboprop simulation aircraft on the market".  It`s then when the above mentioned issues become unacceptable... specially when looking at the competence -RealAir, Majestic Software, PMDG... where more than one virtually perfect model, by far superior in flight dynamics refinament, systems, turbine behavior and aesthetics- can be found... one selling for just € 32.95 !

Hope Flysimware be able to fix the aforementioned issues, then the product will worth the price and become a good virtual version of the great and venerable Mitubishi Mu-2 Marquise.

Sorry for any mistakes in my english....
Cheers,

Carlos