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Old 07-15-2018, 07:48 PM   #41
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This doesn't match with the observation that even way below stall speed, down to 0kts there's no aileron needed….
The goal is to have slip and turn indicator in 0. Waiting a video as you trim the plane at 130 mph in 2700/46" climb using NO ailerons...
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Ніщо так сильно не ранить мозок, як осколки скла від розбитих рожевих окулярів
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Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me
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Old 07-15-2018, 08:05 PM   #42
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Doesn't the L-39 count as a (motor) glider The only really impressive glider I've seen in many years is the SZD 59 Acro.

Ah! SZDs I just flew two other great models, the Cobra 15 and the Standard Mucha....


Regarding the P-51 in DCS, last time I flew it, long ago, t did show excellent torque effects, that I used to compare to the previous best experience I have had with a P-51 in a flight simulator : the A2A P51d Civil and Military versions, which could easily climb without torque effects until speed got down to Vs0...


Maybe things changed with the latest DCS updates ?
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Old 07-16-2018, 04:19 AM   #43
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The goal is to have slip and turn indicator in 0. Waiting a video as you trim the plane at 130 mph in 2700/46" climb using NO ailerons...
Does this mean that you confirm there actually is a very basic bug in DCS?

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Regarding the P-51 in DCS, last time I flew it, long ago, t did show excellent torque effects, that I used to compare to the previous best experience I have had with a P-51 in a flight simulator : the A2A P51d Civil and Military versions, which could easily climb without torque effects until speed got down to Vs0..
Torque effects are very nice on the DCS TF-51 during normal ops, but apparently there's something seriously wrong with the basic torque calculation.
Yo-Yo already mentioned how ED calculated torque and it presently does look like it is (mostly) speed/AoA dependent, which would be plain and simple wrong.

I never understood the hype about A2A. IMO people get too easily exited about loosing ailerons, fouling spark plugs and shaking instrument needles.
I've bought their Spitfire which had horrible basic flaws in the FDE (e.g. torque) and the T-6 which shows severe bugs when doing aerobatics like loops.

Concerning handling and aerodynamics I still like the FSX FR 109K the most.
Just tested and in a vertical full power climb you have to use quite a bit of aileron to keep the 109 vertical and below 50-60kts you can't stop the 109 from rolling despite full opposite aileron.
Btw, it's nice how she smoothly translates into a flat spin during this maneuver.

It would be great if someone could test the DCS 109 and/or Spitfire in a vertical climb.

Last edited by bbrz; 07-16-2018 at 04:53 AM.
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Old 07-16-2018, 04:57 AM   #44
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Concerning handling and aerodynamics I still like the FSX FR 109K the most.
Just tested and in a vertical full power climb you have to use quite a bit of aileron to keep the 109 vertical and below 50-60kts you can't stop the 109 from rolling despite full opposite aileron.
Btw, it's nice how she smoothly translates into a flat spin during this maneuver.
They must have done a really good job, even with all the problems in FSX. The Q400 used an independent Flight Dynamics Engine to be able to get it right for the sim(s), the sim is only for scenery files. I think they used this dynamics engine.
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Old 07-16-2018, 06:33 AM   #45
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The FR 109K uses the standard FSX SDK, no external modelling, pretty basic.
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Old 07-16-2018, 07:45 AM   #46
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I think in as far as engine / prop torque go, it's being calculated correctly, speed and AoA only contributing to enhance or "shadow" it's effects.

P-factor that's a different story, and same regarding slipstream, which I believe is also calculated taking into consideration various interactions.

Actually the only aspect I always found a bit overdone ( but have no real world data or experience to base my affirmation in… ) is P-factor. P-fcator plays a very important role at least in the P51d, and it shows during final approach when I always see the nose wanting to wobble around...


BTW: Believe the OP is referring to what he recorded in this video: https://www.youtube.com/watch?v=Fqgpcad_h-k
which was recorded at 16k feet!

Last edited by jcomm; 07-16-2018 at 02:12 PM.
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Old 07-16-2018, 04:05 PM   #47
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Torque effects are very nice on the DCS TF-51 during normal ops, but apparently there's something seriously wrong with the basic torque calculation.
Yo-Yo already mentioned how ED calculated torque and it presently does look like it is (mostly) speed/AoA dependent, which would be plain and simple wrong.
I never mentioned the ideas you wrote here. Of course, AoA and speed have effect on torque as in RL, but in the calculations for prop effects are very sophisticated in DCS. Torque is not equal to engine torque regarding a single engine prop planes, because of slipstream interaction with the airframe, so, the momentum of the free slipstream behind the plane is much less than it was after the prop.
DCS models slipstream position and velocities distribution in it, then - the interaction with the airframe. So, the model is much more complicated, and, that is important, corresponds either to test reports or real pilots experience. I mean the pilots with hundreds and thousands hours in WWII props.
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Ніщо так сильно не ранить мозок, як осколки скла від розбитих рожевих окулярів
There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.
Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me
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Old 07-16-2018, 06:22 PM   #48
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So, the model is much more complicated, and, that is important, corresponds either to test reports or real pilots experience. I mean the pilots with hundreds and thousands hours in WWII props.
Maybe it's 'complicated, nevertheless it's wrong. Furthermore that's still no answer concerning this basic, rather serious bug.

I don't think that you will find a single pirep about torque effect way below stall speed and close to and/or at 0kts airspeed for the P-51, but this doesn't mean the effect is not there IRL!
Even on a rather low powered Pitts with it small lightweight prop this effect is noticable and has to be taken into account during vertical maneuvers.

This effect exists on all prop planes IRL and is simulated in most (if not all) other flightsims.

My expectations for the Yak-52 and it's aerobatic capabilities have suddenly dropped close to zero
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Old 07-16-2018, 06:33 PM   #49
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Hello guys!


I have decided to test the torque effect, in close to zero speed conditions on the top of a vertical climb.


Track is attached!


- during climb throttle was idle
- at close to zero speed throttle was slammed to max.
- no control input was made until the plane has stabilized itself in the following dive.


It's fun, so Bf-109 and Spitfire will follow soon
Attached Files
File Type: trk TF-51 Torque Test.trk (462.3 KB, 9 views)
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Old 07-16-2018, 06:46 PM   #50
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Quote:
Originally Posted by HWasp View Post
Hello guys!


I have decided to test the torque effect, in close to zero speed conditions on the top of a vertical climb.


Track is attached!


- during climb throttle was idle
- at close to zero speed throttle was slammed to max.
- no control input was made until the plane has stabilized itself in the following dive.


It's fun, so Bf-109 and Spitfire will follow soon
What are your conclusions though?
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