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Flight model and other early impressions


AcroGimp

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The Ugly:

 

  • I flew at 170 KPH and 300 KPH, two very different speeds, both feet on the floor, both resulted in ball centered which is nonsense. There is only one single engine prop plane that behaves like that, because it has a complicated Trim Aid Device that automagically positions rudder trim to compensate for power, speed and rate of change in all 3 axes (USAF/USN T-6A/B).
  • At the top of a loop where a significant amount of left rudder is required to keep the plane from torqueing off IRL I input normal rudder and almost caused a roll off.
  • This suggests that DCS is either not simulating, or perhaps not accurately simulating Torque and Slipstream/P-Factor effects, at least for this module.

I'll try and spend more time for a more in depth review and possibly record another video as well as experiment with trim settings in the LUA to see if there is a setting or combination of settings that more accurately reflect the real plane's performance.

 

 

DISCO

 

This is why I don't fly DCS props. It is as if the FM creators do not acknowledge that the torque produced by the engine/propeller exists ALL THE TIME and must be compensated for at all times.

 

I don't own the YAK 52 (this is why to be honest) because the P-51D very obviously does not have torque modeled. You can slam the throttle stop to stop at 125 mph without touching the controls and get very little response from the aircraft. The Bf-109 is slightly better but still very wrong.

 

Lately I have been flying DCS daily for several hours but the props stay in the barn because this basic FM failure is not even acknowledged. In fact, one may expect ridicule for bringing it up in the other props. I don't expect too many folks will argue with someone who actually regularly flies a real YAK52.

 

 

 

 

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1.The deceleration with removal of power in the break is too extreme.

2. I flew at 170 KPH and 300 KPH, two very different speeds, both feet on the floor, both resulted in ball centered which is nonsense.

1. Reminds my a lot of the PZL104 I used to fly ;)

2. Even at 110km/h very close to stall you basically don't need any rudder. In the meantime I've deleted the Yak because aerobatic training makes no sense in its current FM state.

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stop to stop at 125 mph without touching the controls

 

Can't do this with the Dora at least, you'll need to compensate a lot with the controls if you go from idle to max. Not sure about the Mustang though, haven't flown it in ages.

The DCS Mi-8MTV2. The best aviational BBW experience you could ever dream of.

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Can't do this with the Dora at least, you'll need to compensate a lot with the controls if you go from idle to max. Not sure about the Mustang though, haven't flown it in ages.

 

I don't own the Dora and I won't until I get some indication that the prop aircraft FM has been revised to include a somewhat realistic level of torque.

 

While I do not doubt your word, I do suspect that even in the Dora whatever torque is included is milquetoast at best.

 

An immutable fact of flying a single engine prop aircraft is that EVERY power or airspeed change requires a new control position to maintain the desired path.

 

On high power single engine propeller aircraft, these changes are fairly dramatic and at a low enough airspeed but above stall speed, almost all of them do not have enough control deflection to fully counteract the torque. The P51D, Bf109K, FW190D9 and Spit Mark IX are all firmly in the category of not enough control authority at slow speed to fully counter torque.

 

This doesn't mean the aircraft were difficult to fly. If you understand the relationship between the force generated by the engine torque and the airspeed required to counter that torque, all that is required is to stay out of the range of power and airspeed combinations that result in torque overcoming available control force.

 

In a real airplane, you move the controls as required to make the airplane do what you want. You don't have any choice. You may not even realize that you are doing it, as it truly is an automatic act. Online, many seem to get upset when the controls must be displaced from center to maintain straight and level flight and consider this a modeling error.

 

DCS is missing a critical flight modeling component of the raw power of piston engine aircraft and, for those with experience in the real thing, it totally destroys the experience.

 

I can certainly accept some errors or omissions but to find that the basic essence of flying a single engine propeller driven high performance aircraft is absent is very disappointing.

 

 

 

 

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EVERY power or airspeed change requires a new control position

 

Exactly what happens with the Dora. Although it has to be said that I fly with some controller curvature dialled in, which of course affects the displacement needed - it's all too twitchy without.

 

Regadless, the phenomenon is there. Again, not sure about the Mustang since I don't fly it nowadays. And ditto with the Yak because I won't touch it until it's finished (ground effect lacking, ADF received not working etcetera).

 

But I don't know. We've debated this before, and all I can say is that our experiences differ :dunno:

The DCS Mi-8MTV2. The best aviational BBW experience you could ever dream of.

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These changes happen with the Yak and the TF-51 as well, but they are very mild.

 

The question is, can you fly the 190D at full power, close to the stall and keep the direction by just keeping the wings level with the ailerons but without any rudder input?

 

That's possible with the Yak and the TF-51. I'm not flying the TF-51 either, but testing requires only a few minutes.

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  • ED Team

 

DCS is missing a critical flight modeling component of the raw power of piston engine aircraft and, for those with experience in the real thing, it totally destroys the experience.

 

I can certainly accept some errors or omissions but to find that the basic essence of flying a single engine propeller driven high performance aircraft is absent is very disappointing.

 

 

I think that you have to prove your statement with a typical trim diagram for P-51 or Spitfire that shows the required ampount of "torque countering" controls input. As far as I remember, you complain to the insufficient aileron input to compensate "massive torque"?

Ніщо так сильно не ранить мозок, як уламки 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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This is why I don't fly DCS props. It is as if the FM creators do not acknowledge that the torque produced by the engine/propeller exists ALL THE TIME and must be compensated for at all times.

 

I don't own the YAK 52 (this is why to be honest) because the P-51D very obviously does not have torque modeled. You can slam the throttle stop to stop at 125 mph without touching the controls and get very little response from the aircraft. The Bf-109 is slightly better but still very wrong.

 

Lately I have been flying DCS daily for several hours but the props stay in the barn because this basic FM failure is not even acknowledged. In fact, one may expect ridicule for bringing it up in the other props. I don't expect too many folks will argue with someone who actually regularly flies a real YAK52.

 

 

You can slam the throttle stop to stop at 125 mph without touching the controls and get very little response from the aircraft.

 

This is very little response from the aircraft then?

 

 

This was also without WEP. So that would make it worse if you really went full stop to stop.


Edited by JNelson
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These changes happen with the Yak and the TF-51 as well, but they are very mild.

 

The question is, can you fly the 190D at full power, close to the stall and keep the direction by just keeping the wings level with the ailerons but without any rudder input?

 

That's possible with the Yak and the TF-51. I'm not flying the TF-51 either, but testing requires only a few minutes.

 

I did it at 120 and 110 mph in this video which are kinda close to stall be the effect can still be seen. Furthermore I rolled slightly extra just to be sure.

 

 

The fact of the matter is that the ball is displaced to the right meaning that if you are wings level you will turn left no matter what because there is no force to balance the force of the tail and propeller.

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you cant fly streight w/o rudder input, unless you have auto trim or auto rudder activated in options

If you watch the videos you will see that the rudder is centered all the time. No auto anything enabled.

i7-7700K 4.2GHz, 16GB, GTX 1070 

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  • 2 months later...

- There is something VERY off for rudder/yaw modeling - aircraft should require an increasing amount of right rudder when speed increases, the model requires left rudder which is literally the exact opposite of real life observations further if requested.

 

Sorry for asking if the answer is in this threat, but isn’t a right turning tendency normal for a counterclockwise turning prop?

 

Different, western engine?

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  • ED Team
мое мнение - Гироскопический момент от вращающегося ВМГ или ТРД не рассчитывается в DCS...

 

Это неправильное мнение.

Ніщо так сильно не ранить мозок, як уламки 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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Sorry for asking if the answer is in this threat, but isn’t a right turning tendency normal for a counterclockwise turning prop?

 

Different, western engine?

 

AcroGimp is probably referring to the adverse yaw tendency at higher speeds. Same engine in his plane - counter-clockwise rotation.

 

The Yak has probably been tweaked since his latest impressions.

 

The ball is not centered at 170 kph (ball slightly right) and 300 kph (ball further right).

The plane requires some right rudder correction at any speed (so I'm assuming the trim tab is still not set at any value by default - both aileron and rudder trim set to zero in the Special options - it should be possible to set a rudder trim tab for a specific speed now).

 

Beyond that, I'm not a pilot so I'll avoid any conclusions. ;)

I love that little plane :thumbup: (and I'm extremely grateful AcroGimp shared his impressions and videos!)

(and hopefully, we'll get more updates along the way)


Edited by Bourrinopathe

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  • ED Team
AcroGimp is probably referring to the adverse yaw tendency at higher speeds. Same engine in his plane - counter-clockwise rotation.

 

The Yak has probably been tweaked since his latest impressions.

 

The ball is not centered at 170 kph (ball slightly right) and 300 kph (ball further right).

The plane requires some right rudder correction at any speed (so I'm assuming the trim tab is still not set at any value by default - both aileron and rudder trim set to zero in the Special options - it should be possible to set a rudder trim tab for a specific speed now).

 

Beyond that, I'm not a pilot so I'll avoid any conclusions. ;)

I love that little plane :thumbup: (and I'm extremely grateful AcroGimp shared his impressions and videos!)

(and hopefully, we'll get more updates along the way)

 

Special options set additions to the default factory setting of the trim tab. You can obviously see the non-neutral rudder position due to default setting.

Ніщо так сильно не ранить мозок, як уламки 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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  • 4 months later...
This is very little response from the aircraft then?

 

 

This was also without WEP. So that would make it worse if you really went full stop to stop.

 

I stepped out of this thread months ago because it was a pointless exercise as I was no longer flying DCS propeller aircraft. However, since then I have decided to give DCS propeller aircraft another go.

 

The issues with insufficient torque levels remain.

 

As to this video, that is, indeed, very little response from the aircraft.

 

I have resigned myself to the fact that DCS propeller driven aircraft are not going to have appropriate levels of engine torque modeled.

 

I do not know if the root issue is a design decision or a failure of understanding of basic Newtonian physics.

 

In the Mustang, it is well known that moving the throttle from idle to full power quickly below approximately 130-140 MPH will result in an uncontrollable roll until either the airspeed increases or the power is reduced. It is a commonly known war time demonstration event for new pilot to experience this for themselves at a safe altitude in order to prevent them doing it in a panic go around. All other similar aircraft exhibit the same reaction to such ill considered actions.

 

We do not see anywhere near this level of torque modeled in DCS. It affects the entire flight envelope so we are not experiencing what it is truly like to handle one of these aircraft.

 

When there is insufficient air flow to counter the forces turning the aircraft in opposition to the powerplant rotation, the aircraft will roll and nothing the pilot does will counter that.

 

The precise power/airspeed combination where this occurs differs according to the power and control surface authority available.

 

My only aim is to see DCS aircraft truly represent the real world handling qualities of the aircraft they represent. It may bruise egos to know that the current modeling is sufficiently difficult to be a serious challenge for some but that it is indeed too mild.

 

And modeling torque correctly does not mean these aircraft would become wildly uncontrollable. It does mean they should require a reaction from the pilot for every change in the power/airspeed combination. Constant trim management is a fact of life in any high performance single engine propeller driven aircraft.

 

 

 

 

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@pmiceli,

 

although this thread is under Yak-52, you brought the P-51, and the only comparison I have is what I was able to test in:

 

- FSX / P3D using the A2A models;

- A well known model for X-Plane;

- IL-2 Great Battles

- War Thunder

 

In none of the above I notice that much torque effect under the circumstances you describe as I do in DCS TF51 and P51D.

 

Same regarding the almost constant need to readjust aileron and rudder as well as pitch trim for any power / airspeed change.

 

If you can point me to a better modeled P51d among the available desktop flight simulation games please do.


Edited by jcomm

Flight Simulation is the Virtual Materialization of a Dream...

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I stepped out of this thread months ago because it was a pointless exercise as I was no longer flying DCS propeller aircraft. However, since then I have decided to give DCS propeller aircraft another go.

 

The issues with insufficient torque levels remain.

 

As to this video, that is, indeed, very little response from the aircraft.

 

I have resigned myself to the fact that DCS propeller driven aircraft are not going to have appropriate levels of engine torque modeled.

 

I do not know if the root issue is a design decision or a failure of understanding of basic Newtonian physics.

 

In the Mustang, it is well known that moving the throttle from idle to full power quickly below approximately 130-140 MPH will result in an uncontrollable roll until either the airspeed increases or the power is reduced. It is a commonly known war time demonstration event for new pilot to experience this for themselves at a safe altitude in order to prevent them doing it in a panic go around. All other similar aircraft exhibit the same reaction to such ill considered actions.

 

We do not see anywhere near this level of torque modeled in DCS. It affects the entire flight envelope so we are not experiencing what it is truly like to handle one of these aircraft.

 

When there is insufficient air flow to counter the forces turning the aircraft in opposition to the powerplant rotation, the aircraft will roll and nothing the pilot does will counter that.

 

The precise power/airspeed combination where this occurs differs according to the power and control surface authority available.

 

My only aim is to see DCS aircraft truly represent the real world handling qualities of the aircraft they represent. It may bruise egos to know that the current modeling is sufficiently difficult to be a serious challenge for some but that it is indeed too mild.

 

And modeling torque correctly does not mean these aircraft would become wildly uncontrollable. It does mean they should require a reaction from the pilot for every change in the power/airspeed combination. Constant trim management is a fact of life in any high performance single engine propeller driven aircraft.

 

Earlier I tried to point your attention to the trim diagrams of prop planes you want to be truly represented. These diagrams show that only a very small amount of ailerons input is needed to counteract TORQUE even at near stall IAS.

 

I think that the discrepancy you stated would be noticed with a lot of real pilots with hundreds and thousands hours in WWII prop planes that tested DCS P-51.

 

If you want the newest detailed review, I can offer this one:

 

Ніщо так сильно не ранить мозок, як уламки 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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@yoyo

Really interesting video =) I dispute his assessment the 51 lacks thrust in the taxi. EVERY aircraft seems sticky to start rolling. Probably too much ground friction or something else odd like that. Wish we could have a look at that.

Де вороги, знайдуться козаки їх перемогти.

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