A-10 Flight Model Improvement Demonstrator

[hailstorm 4]

I tested this against the 1.12 beta, it's a definite improvement in the FM.

it seems to be much more improved during low speed handling - you can do much more realistic low speed-high engine maneuvers, like hard turning.

the low stalling speed is the most unrealistic change in this, but it negates two problems: the A-10 can now takeoff from grass strips without relying on the runway to run out and the ground to drop away first; and (as Rock said), it's now harder to stall out and crash when doing hard turns.

I think if BIS a) implement this and b) up the stall speed to a more realistic value, then they should consider the above two problems first - a higher thrust output

(= more acceleration and speed won't drop to stall speed while turning) would probably be the best solution i can think of.

Great work RockofSL, it's good to know what the ArmA engine is and isn't capable of!

[Guest RKSL-Rock]

I tested this against the 1.12 beta, it's a definite improvement in the FM.

it seems to be much more improved during low speed handling - you can do much more realistic low speed-high engine maneuvers, like hard turning.

the low stalling speed is the most unrealistic change in this, but it negates two problems: the A-10 can now takeoff from grass strips without relying on the runway to run out and the ground to drop away first; and (as Rock said), it's now harder to stall out and crash when doing hard turns.

I think if BIS a) implement this and b) up the stall speed to a more realistic value, then they should consider the above two problems first - a higher thrust output

(= more acceleration and speed won't drop to stall speed while turning) would probably be the best solution i can think of.

Great work RockofSL, it's good to know what the ArmA engine is and isn't capable of!

I have to confess I didn’t really consider the stall speed when I wrote the first config.  Like I said elsewhere it was a 20min job purely as a proof of concept.

In light of the Stall speed issue...here are some new less "aggressive" values.  There is still difference from the stock BIS ones but it allows you to maintain more positive control feeling in most speed regimes.  The values have all been reduced so you will notice less acceleration and slightly more loss of speed in turns compared to the first release.

Swap this for the envelope setup in the Config.cpp.  This brings the stall speed closer to that of the stock BIS A-10.  It also tones down the acceleration in most flight regimes but its still remains a more positive feel.

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Code Sample </td></tr><tr><td id="CODE"> envelope[]=

{

// speed relative to max. speed -> lift (G)

//REF - 0.0  0.1  0.2  0.3  0.4  0.5  0.6  0.7  0.8  0.9  1.0  1.1 // rel. speed

//BIS - 0.0, 0.1, 0.5, 1.5, 3.1, 4.3, 4.9, 5.0, 4.4, 2.8, 1.6, 0.8, 0};

//RKSL1-0.0, 0.5, 1.0 ,2.6, 4.9, 5.9, 6.9, 6.5, 6.4, 5.8, 5.6, 1.8, 0

0.0,0.1,0.65,2.2,3.7,5.3,6.0,5.5,5.6,4.8,3.6,1.8,0  // lift

};

Real world A-10 stall figures are 120kts (222 kph) on an empty A-10 with no flaps (according to the references I've found on the net - if anyone knows different speak up)  Compared to the BIS version it stalls 5-10kph lower depending on the AoA.

[Stag 0]

This is Very, Very, cool.

[suma 8]

This seems to be very good source: SimHQ History of A-10 Thunderbolt II

- confirms aprox. 120 IAS stall speed.

[LFO 0]

outstanding RockofSL, really the best method to let action speak rather than words. at first look the "new" a-10 almost felt too well after getting used to the stock one. unfortunately i still had no time to check the fixed envelope, i will try that later today.

after this a-10 i'm *really* looking forward to your hind fm...

many thanks!

[M.Andersson(SWE) 4]

Is there NO WAY AT ALL to have official sources...??

Like the ones that enginered it the first time...

Or Pilots that actually fly the bird...

Cant be that hard can it??

[Uziyahu--IDF 0]

As for moving CofG: I think you've been misinformed. From my experiments and experience with our aircraft I can’t see any evidence of it. ArmA engine appears to use the position and mass layout from the moment the addon is initialised. Animating parts of the Geo Lod has no significant effect on handling from what I can see.

The only other possibility would be that it’s coded into the engine itself but again I don’t really see any evidence of that.

I've not been misinformed. You misread, "Captain Adam Moore informed me that helicopters have a moving center-of-gravity," as some kind of statement about helicopters in-game. If I meant in-game, I would have said "in-game".

I served in an Air Cavalry squadron for 3 years, so I've had a bit of experience with helos. Furthermore, Captain Adam Moore, if he isn't, now, was a Helicopter Flight Instructor.

What Captain Adam Moore was referring to, for example, is that as fuel is depleted from the tank, the center-of-gravity of the vehicle moves. If I remember correctly, it also moves from its point during a hover to another point during forward flight.

[Guest RKSL-Rock]

As for moving CofG: I think you've been misinformed.  From my experiments and experience with our aircraft I can’t see any evidence of it.  ArmA engine appears to use the position and mass layout from the moment the addon is initialised.  Animating parts of the Geo Lod has no significant effect on handling from what I can see.

The only other possibility would be that it’s coded into the engine itself but again I don’t really see any evidence of that.

I've not been misinformed.  You misread, "Captain Adam Moore informed me that helicopters have a moving center-of-gravity," as some kind of statement about helicopters in-game.  If I meant in-game, I would have said "in-game".

I served in an Air Cavalry squadron for 3 years, so I've had a bit of experience with helos.

What Captain Adam Moore was referring to, for example, is that as fuel is depleted from the tank, the center-of-gravity of the vehicle moves.  If I remember correctly, it also moves from its point during a hover to another point during forward flight.

Considering the context of the topic i.e. ingame physics/flight model I don’t think it’s an unfair assumption.  You weren't exactly clear.

Any vehicle or object that can be loaded in various ways is going to have a moving CofG.  But since ArmA's engine doesn’t really support the kind of complex dynamics to simulate true fixed or rotary wing flight and all the factors upon it its really not relevant to this thread.  The topic is about ArmA’s  A-10 flight model improvements

This seems to be very good source: SimHQ History of A-10 Thunderbolt II

- confirms aprox. 120 IAS stall speed.

I think that the site I first used. It’s a nice read.

Is there NO WAY AT ALL to have official sources...??

Like the ones that enginered it the first time...

Or Pilots that actually fly the bird...

Cant be that hard can it??

It’s surprisingly hard to find a “real†A-10 pilot. The walts tend to come out of the wood work on when you ask questions like these. I have however managed to get confirmation via USAF ANG unit maintainer that (I know he’s genuine as I’ve met him via work) that 120-135kts depending on altitude and loading etc is not unrealistic.

[M.Andersson(SWE) 4]

127.5 seem like a compromise then

Just kidding...Would it be possible to have a dynamic stall

speed..

Like for diffren loads and stuff, and altitude..

[mandoble 1]

Is ArmA using indicated air speeds for stall speeds calculations or just a general measure of m/s based on raw displacement per time of the object in the space?

[Guest RKSL-Rock]

Just kidding...Would it be possible to have a dynamic stall

speed..

Like for diffren loads and stuff, and altitude..

In a word no.  ArmA's physics and FM doesn't seem to factor in weapons loads... maybe a feature for the future patches or ArmA 2

Is ArmA using indicated air speeds for stall speeds calculations or just a general measure of m/s based on raw displacement per time of the object in the space?

Its speed vs lift values as defined in the envelope command.

[mandoble 1]

Yep, speeds vs lifts, but are these speeds indicated air speeds or just plain speeds (displacement in time). If the former, then you might get a more or less accurate flight envelope, if the later, then stall speed would keep the same at sea level or 4000m altitude, which would be correct only if speed used by ArmA engine for planes flight envelopes is IAS. And this only would apply if ArmA considers air density/height. Else, the immediate noticeable effect would be that dogfighting at 5K is just the same as at sea level.

[Guest RKSL-Rock]

Yep, speeds vs lifts, but are these speeds indicated air speeds or just plain speeds (displacement in time). If the former, then you might get a more or less accurate flight envelope, if the later, then stall speed would keep the same at sea level or 4000m altitude, which would be correct only if speed used by ArmA engine for planes flight envelopes is IAS. And this only would apply if ArmA considers air density/height. Else, the immediate noticeable effect would be that dogfighting at 5K is just the same as at sea level.

In arma's physics I suspect it’s just a "plain speed" value. I can’t see any evidence that the simulated flight model physics is complex enough to model variances in altitude, mass, overt g-loading or CofG. I think it’s pretty well established; after all, this exact subject has been debated relentlessly in various FM threads, that the flight aspect of the game engine is pretty basic. It’s something I’d really like to see change in the future but right now it’s really not that complex.

[M.Andersson(SWE) 4]

LOL

A bit OT, i appologize for this:

If i had the money id hire a lot of you guys

in here to produce the ULTIMATE WAR SIM

ever...

It would take like 5-10 years but nontheless

it woule be awsome...

Sorry again for OT...

[kuIoodporny 45]

LOL

A bit OT, i appologize for this:

If i had the money id hire a lot of you guys

in here to produce the ULTIMATE WAR SIM

ever...

It would take like 5-10 years but nontheless

it woule be awsome...

Sorry again for OT...

Yeah, and all of us will be too old to play with such things xD

Hope ArmA 2 won't let us down again... BIS, never let me down again!

[Guest RKSL-Rock]

If i had the money id hire a lot of you guys

in here to produce the ULTIMATE WAR SIM

ever...

It would take like 5-10 years but nontheless

it woule be awsome...

Well if you have GBP1.4 million  you can buy the "Flight sim" I currently do 3D work for.  The flight model is a tad more complex than ArmA's

[somebloke 0]

I expected nothing less than top notch, and that's what I got.

[M.Andersson(SWE) 4]

Flight Sim, isnt that just flying in a Googlemap...??

Last time i tried it, it was.

I want the shabang from ArmA in Flightsim...That would

be nice...Imagine the whole world as a battlefield...

And EVERYTHING in 3D and FP...

[Guest RKSL-Rock]

Flight Sim, isnt that just flying in a Googlemap...??

Last time i tried it, it was.

The stuff I've done commercially isnt exactly used in google map type environments mate. For the last 2 years I've had contracts with various service providers supplying custom content, making 3D environment models etc for commercial and military Flight Training Simulators. Ive made 15-16 airports/bases in high detail, some 20+ aircraft and all sorts of feature models.

[CameronMcDonald 146]

You did a good job here, Rock. It'd be nice to see the rest of the BIS aircraft done in such detail as well, though I'll shut up now because it's clearly within my capabilities excepting motivation and sheer laziness. Nice job once again.

[Guest RKSL-Rock]

You did a good job here, Rock. It'd be nice to see the rest of the BIS aircraft done in such detail as well, though I'll shut up now because it's clearly within my capabilities excepting motivation and sheer laziness. Nice job once again.

Its within the range of most people.  I had thought someone would beat me to it which is why I’ve not done something similar earlier for public use.  

One of the groups i play with has the full set of ArmA stock aircraft tweaked in this fashion now.  It includes some pretty nice weapons loads and reskins too.  I'll ask if they will think about a public release.

[-HUNTER- 1]

Is the process of making an improved flightmodel very different from aircraft and helicopters?

And I know it would involve again lots of work (not spend on the real stuff, im scared of anderson )

to also bring out a helicopter like the cobra with improved flightmodel?

I understand its for addonmakers to learn from it with O2 work.

But to show the community how much better it could be.

And especially with the cobra it would clearly show the major improvement over the older fm, im sure of that.

edit

Oh I was typing while you added the above...

[M.Andersson(SWE) 4]

You did a good job here, Rock. It'd be nice to see the rest of the BIS aircraft done in such detail as well, though I'll shut up now because it's clearly within my capabilities excepting motivation and sheer laziness. Nice job once again.

Its within the range of most people.  I had thought someone would beat me to it which is why I’ve not done something similar earlier for public use.  

One of the groups i play with has the full set of ArmA stock aircraft tweaked in this fashion now.  It includes some pretty nice weapons loads and reskins too.  I'll ask if they will think about a public release.

NO NO NO NO.....

You ask first, and if the answer is YES. THEN you tell us they

have it...Not before...Thats not humane..

[einsena 0]

wow this is great! thanks for the release! now i really need a replacement pack lol!

[llama_thumper 0]

i second hunter on the improved flight model cobra - that would be fantastic.

the helicopter flight models are quite crap, imho, even compared to something lik BF2