Jump to content

Flight Model modification question


Recommended Posts

  • Replies 122
  • Created
  • Last Reply

Top Posters In This Topic

You know it's unrealistic how?

Hardware: T-16000M Pack, Saitek 3 Throttle Quadrant, Homemade 32-function Leo Bodnar Button Box, MFG Crosswind Pedals Oculus Rift S

System Specs: MSI MPG X570 GAMING PLUS, GTX 1070 SC2, AMD RX3700, 32GB DDR4-3200, Samsung 860 EVO, Samsung 970 EVO 250GB

Modules: Ka-50, Mi-8MTV2, FC3, F/A-18C, F-14B, F-5E, P-51D, Spitfire Mk LF Mk. IXc, Bf-109K-4, Fw-190A-8

Maps: Normandy, Nevada

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

I'm sure it can be done offline...

 

 

 

But...

 

 

How do you know it isn't right? Do you have video, numbers... anything at all that backs up your claim? Also... this info you DO have... Is it from the specific P51 model we have in game?

Nvidia RTX3080 (HP Reverb), AMD 3800x

Asus Prime X570P, 64GB G-Skill RipJaw 3600

Saitek X-65F and Fanatec Club-Sport Pedals (Using VJoy and Gremlin to remap Throttle and Clutch into a Rudder axis)

Link to comment
Share on other sites

Is there a way to alter the flight model?

 

Specifically I want to set engine torque effects on the P-51D and TF-51D to a more realistic level. They are ridiculously light forces at the moment.

Maybe you've take off assist switched on? Sometimes after an update it goes back on without further notice.

 

 

When you get used to it Stang isn't definitely that hard like it was at first when we all started learning (that's 2012 IIRC? :cry: ), but still she's a tail dragger and whenever mistreated shows all its rage.

 

 

Last time I flew, on Friday, ̶t̶h̶e̶ ̶f̶o̶u̶r̶ ̶d̶i̶f̶f̶e̶r̶e̶n̶t̶ ̶f̶o̶r̶c̶e̶s̶ ̶t̶h̶a̶t̶ ̶w̶e̶ ̶u̶s̶u̶a̶l̶l̶y̶ ̶j̶u̶s̶t̶ ̶s̶i̶m̶p̶l̶i̶f̶y̶ ̶a̶s̶ torque were well present as always.

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

Maybe you've take off assist switched on? Sometimes after an update it goes back on without further notice.

 

 

When you get used to it Stang isn't definitely that hard like it was at first when we all started learning (that's 2012 IIRC? :cry: ), but still she's a tail dragger and whenever mistreated shows all its rage.

 

 

Last time I flew, on Friday, ̶t̶h̶e̶ ̶f̶o̶u̶r̶ ̶d̶i̶f̶f̶e̶r̶e̶n̶t̶ ̶f̶o̶r̶c̶e̶s̶ ̶t̶h̶a̶t̶ ̶w̶e̶ ̶u̶s̶u̶a̶l̶l̶y̶ ̶j̶u̶s̶t̶ ̶s̶i̶m̶p̶l̶i̶f̶y̶ ̶a̶s̶ torque were well present as always.

 

 

S!

 

That was the first thing I checked. It seems as if there is some level of rudder assist happening even though it is been confirmed to be unchecked. Takeoff assist is all the way left as well.

 

Looking in the FM files I did notice something that makes me suspect takeoff assist is always at least 70 percent although without being able to see the underlying code it is impossible to verify.

 

As to how I know its wrong.

 

1. I have considerable experience in high powered single engine piston aircraft. Not the P-51 specifically but enough to know what should be happening in general.

 

2. I have had frequent discussions with people who have actually flown the aircraft and have inquired specifically (through a third party) on this subject to someone who is currently flying this aircraft.

 

3. There are numerous descriptions of the method used to demonstrate torque effects to new P-51 pilots. They are all very similar. and go like this. Climb high (10,000 feet is often cited), slow down to below 140 mph (120 is often mentioned), flaps down or up, then quickly add 60 inches MP. There are reports of 2 and 1/2 snap rolls before recovery is effected but most just describe the airplane being almost instantly upside down.

 

Try this in either DCS P-51 and the results are incredibly tame. There is a little left yaw and no significant left rolling moment. Maybe my installation is broken.

 

Here are a few quotes

 

Torque on takeoff in a 51 was really a bitch if you failed to have the trim tabs set to compensate for that big fan in front. Trying to hold it on takeoff without the trim was almost impossible. I did it once and it taught me never to forget to set it again.

 

I remember telling everyone I ever checked out in the Mustang to take it up high, lower the gear and flaps, then back it off to about 15 inches with the prop up to 3 grand... slow it down easy to about 130 mph... then SLAM in 61 inches fast. The resulting torque roll might have helped save a few lives on full power go-arounds. None of my guys ever "torqued one in" anyway...

 

The pilot was making his first supervised solo flight in the same airplane that he received 31.5 hours of dual instruction in the 47 days preceding the accident. The flight instructor who provided the training witnessed the accident and reported that the pilot performed a "normal" takeoff followed by a left pattern to runway 26 with a "normal tail low wheel landing." He noted that as the airplane made contact with the ground, the pilot "had not pulled his throttle back to idle, as the noise level of the engine appeared greater than idle." After rolling 50 to 100 feet, the tail appeared to rise slightly, indicating the pilot was applying slight forward stick to pin the airplane to the ground. This was followed quickly by the rapid lowering of the tail to the point where the tailwheel struck the ground with a "loud bang noise." The airplane then "leaped back into the air" and the pilot applied takeoff power. The airplane pitched nose high and rolled left to the inverted position consistent with a torque induced roll. The upper surface of the left wing contacted the ground first, followed by the propeller and the canopy. The instructor expressed the opinion that the pilot "failed to successfully execute a standard go-around procedure after experiencing unexpected flight due to the lowering of the tail prematurely with power still on after touchdown."

 

I can't replicate anything like any of this in DCS.


Edited by pmiceli

 

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

Wasn't tame the last time I flew her a couple of months ago. However, I'm pretty sure I've seen people talking somewhere about a later OB bug that switches the takeoff assist / autorudder always on, so maybe you're suffering from that?

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

Link to comment
Share on other sites

… I can't replicate anything like any of this in DCS.
Interesting quotes. With regards to full power go arounds I've seen similar comments on actual Stang pilots talking about how many died doing it carelessly.

 

 

What version are you running? stable or beta? Actually Beta features a few broken things in WWII modules for a reason.

 

 

Anyway, those details are well on the edge of the envelope, which is the trickier part of FM to get right if ever.

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

Nah, it's not the version or options. The low torque efects at low speed have been brought up numerous times on this board for years... quoting the same accident account a few times as well (truth to be told, the fact that the poor guy snaprolled to the left after balooning isn't really quantitive about much of the roll was caused by the prop torque - you can end up doing the same at low power settings in DCS by mishandling elevator and rudder too). Beating a dead horse here. It's just the way all warbirds in DCS are indeed and the other WWII sims on the market are similar in this aspect too.

 

Not that it matters for original question anyway - FMs are hardcoded, so I don't think it's possible to alter them without some reverse engineering of the code and you sure as hell won't read about doing anything like that on official game forum.

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

Link to comment
Share on other sites

To"Pmicelli" you may be right, however this is not the only warbirds module that seems far from reality.

We are in a game

The wind, the temperature, the degree of hygrometry, the atmospheric pressure, the friction of the track, the altitude, the season,the weight,the centering... etc are represented very succinctly.Much of conditions which can transform, in real flight, your experience .

You are going to say that I am off topic, but I mention these effects to explain that in a game we are limited by the computing power of our rigs. Fortunately DCS programmers are reasonable, if not,only the wealthiest would be able to pay for offer a PC powerful enough to take into account all the parameters of aeronautics.

You want to change the power of the torque, ok.You will have to change at the same time all the code that will be disturbed.

For example look at each update the difficulties encountered to stabilize the game.

Link to comment
Share on other sites

It is quite sad that other, far less respected, WWII titles model torque better than DCS. There is no reason to not give us the option of flying at realistic levels of engine torque.

 

No point in flying a DCS prop driven module if they arent even going to attempt to get one of the biggest aspects of prop flight modeling reasonably correct.

 

I really hope this is a bug that gets corrected.

 

Cromhunt,

 

I have been involved in flight modeling of WWII aircraft in another title. Adjusting the torque value of an engine is not going to disturb other code unless the code is total garbage (I seriously doubt this is the case). The base FM code must be able to handle differences in torque values on the fly or we could not have different models or even different power settings. This fix is literally the adjustment of one input variable since I really only want to reproduce realistic engine torque (versus all of the many forces that affect a single engine propeller driven aircraft that we call "torque" for convenience)

 

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

I just tried the P-51, 109 and the Dora (neglecting the Spitfire because of its known tailwheel issues). All three had their special auto rudder unchecked and take off assist fully to the left. It seems to me that this has more to do with some sort rudder assist as mentioned previously in the thread than with the actual torque.

 

After take off, I pulled power to idle in all three. Each immediately rolled to the right with the lack of power (torque), then when applying full power, it would seemingly stabilize.

 

Clearly, pulling power to idle and quickly applying full power this quickly would not be recommended (as landing the 109 without an engine following the test would emphasize), however doing so seems to corroborate the idea that there is some form of artificial rudder stabilizing at work despite the options being selected otherwise.

 

Perhaps it might have something to do with torque settings, as well, though the sharp rolling tendency when pulling power to idle seems to suggest that it is at least modeled.

Link to comment
Share on other sites

We need a forum admin to see this, and give us their take on it. Maybe give us insight, or put word in to the ED team, whatever.

Hardware: T-16000M Pack, Saitek 3 Throttle Quadrant, Homemade 32-function Leo Bodnar Button Box, MFG Crosswind Pedals Oculus Rift S

System Specs: MSI MPG X570 GAMING PLUS, GTX 1070 SC2, AMD RX3700, 32GB DDR4-3200, Samsung 860 EVO, Samsung 970 EVO 250GB

Modules: Ka-50, Mi-8MTV2, FC3, F/A-18C, F-14B, F-5E, P-51D, Spitfire Mk LF Mk. IXc, Bf-109K-4, Fw-190A-8

Maps: Normandy, Nevada

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

I just tried the P-51, 109 and the Dora (neglecting the Spitfire because of its known tailwheel issues). All three had their special auto rudder unchecked and take off assist fully to the left. It seems to me that this has more to do with some sort rudder assist as mentioned previously in the thread than with the actual torque.

 

After take off, I pulled power to idle in all three. Each immediately rolled to the right with the lack of power (torque), then when applying full power, it would seemingly stabilize.

 

Clearly, pulling power to idle and quickly applying full power this quickly would not be recommended (as landing the 109 without an engine following the test would emphasize), however doing so seems to corroborate the idea that there is some form of artificial rudder stabilizing at work despite the options being selected otherwise.

 

Perhaps it might have something to do with torque settings, as well, though the sharp rolling tendency when pulling power to idle seems to suggest that it is at least modeled.

 

I was doing some testing this morning and there does seem to be some base level of trim preset because left stick is required at low power settings. This may or may not be a faithful re-creation of the actual airplane (you can make "zero" trim be any position. We often adjusted trim zero for aircraft that would not fly straight)

 

What bothers me most is there is almost zero rolling moment when slamming the throttle stop to stop at 110 mph.

 

There should be an airspeed at which full control deflection is required to prevent the aircraft from rolling around the long axis. Anything lower than that airspeed and full control deflection still will not stop the roll.

 

The P-51 in DCS seems to have almost no torque. There is a little bit of right rudder required on takeoff but it is very minor.

 

The way it should work is engine torque should be forcing the left main hard into the runway and the right main gets a bit lighter. To account for this early in the takeoff run right rudder (and right stick) is used and as the ailerons get more bite from airflow they take over the work and less rudder is required to account for torque.

 

Gyroscopic precession is still in play but this is generally most significant when lifting the tail up. DCS seems to do this pretty well as is demonstrated if you lift the tail too early or too quickly.

 

Spiraling slipstream is also a factor early in the takeoff run and to a small degree asymmetric propeller angle plays a role, although this is more evident in a steep climb.

 

The biggest force in any high powered prop fighter is going to be the torque of the engine itself which always must be countered by control input. The others three factors go away or are very minimal once a little speed is attained but torque is always there. The faster you go the more effective the controls are so less deflection is required to counter but it is always there.

 

Slamming the throttle stop to stop at ANY speed with you hands off the controls should elicit a fairly large response and at slow speed it should be very dramatic.

 

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

  • ED Team

If you take a look at the trim curves of XP-51 (lower TO power, I know, but smaller fin as well) you can see that almost no stick movement is necessary and not more than 50% of rudder to trim the plane.

 

The flip over at go-around is due to deep stall aggravated with P-factor causing pitch-up and left yaw moments. Sometimes people do it in DCS too.

XP-51.thumb.jpg.cc8a8c4b0bd81b2df9fd3646dc155b3b.jpg

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

Link to comment
Share on other sites

If you take a look at the trim curves of XP-51 (lower TO power, I know, but smaller fin as well) you can see that almost no stick movement is necessary and not more than 50% of rudder to trim the plane.

 

The flip over at go-around is due to deep stall aggravated with P-factor causing pitch-up and left yaw moments. Sometimes people do it in DCS too.

 

That chart is great.

 

It needs to be applied to the flight model.

 

No control inputs are necessary at the moment.

 

 

Yes, stalling one wing before the other will cause a roll but that roll is usually very abrupt, hence it is called a snap roll.

 

Go around accidents in WWII fighters start with a torque roll and end with a stall induced snap roll.

 

This happens because the instinctive reaction to the torque roll is full right stick. The down aileron further slows the left wing and the left wing stalls and the right wing doesn't.

 

Without the torque roll, the only way to really induce such a snap roll is gross mishandling of the controls.

 

 

 

There are plenty of anecdotes of the tremendous torque roll at low airspeed with the Mustang and other WWII single engine fighters.

 

Torque is missing in DCS.

 

Without control input the aircraft should roll opposite to the engine rotation. It is a fairly simple physics problem.

 

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

  • ED Team
That chart is great.

 

It needs to be applied to the flight model.

 

No control inputs are necessary at the moment.

 

 

Yes, stalling one wing before the other will cause a roll but that roll is usually very abrupt, hence it is called a snap roll.

 

Go around accidents in WWII fighters start with a torque roll and end with a stall induced snap roll.

 

This happens because the instinctive reaction to the torque roll is full right stick. The down aileron further slows the left wing and the left wing stalls and the right wing doesn't.

 

Without the torque roll, the only way to really induce such a snap roll is gross mishandling of the controls.

 

 

 

There are plenty of anecdotes of the tremendous torque roll at low airspeed with the Mustang and other WWII single engine fighters.

 

Torque is missing in DCS.

 

Without control input the aircraft should roll opposite to the engine rotation. It is a fairly simple physics problem.

 

How does it manage not to roll without aileron input at the chart?


Edited by Yo-Yo

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

Link to comment
Share on other sites

OK, just to make sure I'm not "interpolating" my experiences with very old versions of the game onto the new one, I just did some testing in todays OB and I have to take back some of my statements from the top of the page, while being once again pleasantly surprised by Yo-Yo's flight model.

 

Pmicelli, the situation is not as bad as you think it is. While replicating your experiment, it's true that firewalling the throttle from 140 IAS + 15" MAP causes rather tame effects, however doing the same from 110-120 IAS and idle MAP (to simulate landing and touchdown), with controls kept where they are always flips the plane on its back (strong left roll&yaw, pitch up, followed by stall), both in clean or landing config. Same happens in DCS Spit, didn't test German birds, but I'm sure with their much more powerful engines it's even worse.

 

Now, one could discuss at what speed and RPM range the plane should turn from flipper-killer to somewhat-controllable machine (how can one prove or disprove it anyway - it's not like pilots at North American tested it that precisely), but I'm sure now that firewalling the throttle after aborted landing will get me in trouble in DCS Mustang quickly.

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

Link to comment
Share on other sites

Torque is missing in DCS.
:huh: You must be kidding, right?

 

 

 

I have been involved in flight modeling of WWII aircraft in another title.
And so you should know ANY other tittle resembles even close the torque effects as DCS does. I mean, DCS doesn't just represent torque as a kind of constant swerve to the left (or right) like all of the "other tittles" does and that's why taking off and landing in those is ridiculously "easy", just pushing a constant rudder. On the contrary DCS models every detail in "torque", meaning engine torque itself, P-factor, differential lift of propeller blades with tail on ground-tail lifted, even gyroscopic effects of the wheels if I'm not wrong, and probably some more I'm forgetting right now and should remember from my license exams (if only you were the only RL pilot around here mate… but we're quite a bunch). That could be adjusted, and fine tuned (and it is by real Stang pilots AFAIK), but you must be kidding to say there's no torque effect in DCS :doh: .

 

 

That chart is great.

 

It needs to be applied to the flight model.

Again, you must be kidding… what kind of charts do you think are used to model DCS warbirds? :huh:

 

 

 

Of course, latest patches sometimes can be broken, or some detail that went unnoticed can be fine tuned, that sort of things obviously can happen and does happen now and then, but you should try better with some actual facts and data for such a claim like "there's no torque" when we all who fly DCS warbirds regularly know it's there and it's the best representation of it we have.

 

 

 

 

 

OK, just to make sure I'm not "interpolating" my experiences with very old versions of the game onto the new one, I just did some testing in todays OB and I have to take back some of my statements from the top of the page, while being once again pleasantly surprised by Yo-Yo's flight model.

 

Pmicelli, the situation is not as bad as you think it is. While replicating your experiment, it's true that firewalling the throttle from 140 IAS + 15" MAP causes rather tame effects, however doing the same from 110-120 IAS and idle MAP (to simulate landing and touchdown), with controls kept where they are always flips the plane on its back (strong left roll&yaw, pitch up, followed by stall), both in clean or landing config. Same happens in DCS Spit, didn't test German birds, but I'm sure with their much more powerful engines it's even worse.

 

Now, one could discuss at what speed and RPM range the plane should turn from flipper-killer to somewhat-controllable machine (how can one prove or disprove it anyway - it's not like pilots at North American tested it that precisely), but I'm sure now that firewalling the throttle after aborted landing will get me in trouble in DCS Mustang quickly.

:lol::lol::lol: That's exactly what happens to me every time I go testing some "wrong" thing somebody said :D . Anyway, I'm going right now to have a go in different situations, as atmosphere is so affecting FM in DCS (like in RL :doh: ).

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

  • 1 month later...
The plane didn't want to turn on its back.

 

I tested this just now. Speed down to 110MPH or so, prop full and throttle forward and the plane most definitely wanted to turn on its back and augur in. Plus I noticed a clear tendency for it to veer and roll left on takeoff, which I had to counteract by applying right rudder and aileron.

 

So I don't know what people are complaining about. Seems quite OK to me at least.

 

EDIT: I don't know if there's a bug where some folks get the game FM applied even when their config says otherwise. About the only thing that'd explain this I think.

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

Link to comment
Share on other sites

One question, are you sure that your not simply getting to be a better pilot and therefore more able to deal with it.

 

When I think of how bad I was at either hovering a Huey, or a warbird takeoff when I first switched off the landing aids, then I think of now. I don’t “feel” massively better, yet clearly my crash rate certainly shows otherwise

System: 9700, 64GB DDR4, 2070S, NVME2, Rift S, Jetseat, Thrustmaster F18 grip, VPC T50 stick base and throttle, CH Throttle, MFG crosswinds, custom button box, Logitech G502 and Marble mouse.

Server: i5 2500@3.9Ghz, 1080, 24GB DDR3, SSD.

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...