A-10 stall behaviour in DCS is incorrect

Point is, pulling the jet into chopped warning tone & even slightly pulling more ---> wing drop shouldn't happen. Other behaviour should happen like buffeting, but lets just get past the initial issue.

Quite often I pull to the chopped tone in DCS, sometimes sustaining it for a few seconds. Not quite as long as some HUD videos show, but then again I'm using a cheap plastic joystick instead of a floor mounted metal stick.

The -1 mentions light buffet near the stall, which is currently simulated to some extent.

In the airshow videos they show the plane briefly being pulled well past stall AoA at the end of each "gun run". This matches the Sim very well, you can pull all the way to 20 degrees as long as you don't stick around.

Edit: reread your post, we don't know if the pilots were pulling more into the chopped tone.

Quite often I pull to the chopped tone in DCS, sometimes sustaining it for a few seconds. Not quite as long as some HUD videos show

Yep at specific Mach speeds the wing drop is slightly delayed than at other speeds so that you can ride the chopped tone inside of those M speeds.

The -1 mentions light buffet near the stall, which is currently simulated to some extent.

But it doesn't mention the wing drop behaviour the way we get it in DCS.

In the airshow videos they show the plane briefly being pulled well past stall AoA at the end of each "gun run". This matches the Sim very well, you can pull all the way to 20 degrees as long as you don't stick around.

 

Edit: reread your post, we don't know if the pilots were pulling more into the chopped tone.

We can pull to 25 even and yeah in the sim most of the time it is possible without wing drop as shown in the track i posted earlier but as you said that's as long as we don't stick around.

It still holds true that we can't perform

Something I noticed last night, I was teaching somebody the ropes of the A-10A and for some reason you can ride the chopped tone all day long.

I did some more experimenting and found the A-10A matches very closely with most of the videos/manuals. Especially the A-10A vs F-16.

More testing is needed but the A-10A definitely has a more resonable reaction to stalling... mostly small roll oscillations with lots of "mush" as you'd expect from such an airframe.

Also, is the A-10A -1 allowed to be posted here? They're essentially the same airframe but I haven't heard anything about the A-10A -1 being restricted. I've read it and it definitely talks about the great post stall behavior.

This is called 'wing rock'.

Something I noticed last night, I was teaching somebody the ropes of the A-10A and for some reason you can ride the chopped tone all day long.

 

I did some more experimenting and found the A-10A matches very closely with most of the videos/manuals. Especially the A-10A vs F-16.

 

More testing is needed but the A-10A definitely has a more resonable reaction to stalling... mostly small roll oscillations with lots of "mush" as you'd expect from such an airframe.

 

Also, is the A-10A -1 allowed to be posted here? They're essentially the same airframe but I haven't heard anything about the A-10A -1 being restricted. I've read it and it definitely talks about the great post stall behavior.

Something I noticed last night, I was teaching somebody the ropes of the A-10A and for some reason you can ride the chopped tone all day long.

 

I did some more experimenting and found the A-10A matches very closely with most of the videos/manuals. Especially the A-10A vs F-16.

 

More testing is needed but the A-10A definitely has a more resonable reaction to stalling... mostly small roll oscillations with lots of "mush" as you'd expect from such an airframe.

I've just tested the A-10A and you're correct. While the wing drop or rock, as GGTharos puts it, doesn't happen when reaching chopped tone, it's still there when pulling more into the tone so it's either wing drop is delayed or the stall tones are triggered a bit earlier in the A version.

I've read it and it definitely talks about the great post stall behavior.

Same thing in the C version manual.

This is called 'wing rock'.

BTW the manual mentions "wing rolloff", is that the same thing? (That "rolloff" is mentioned to happen with large speed brake deflections & are usually mild but more abrupt with flaps down)

Wing rock is an oscillation - basically, maintain a particular AoA with only pitch and throttle, and no aileron or rudder input - you'll find an effect called 'wing rock', which will have one wing drop, get out of the stall, then the other wing drops ... and this will just keep going indefinitely.

A wing roll off is probably a similar effect but there's no oscillation - the wing just drops and remains stalled out.

Also, IIRC both tones in the A-10A/C come around 1-2 degrees of AoA before the stall angle, but measurements aren't 'computer precise' as the instruments may lag, so when you're riding the edge, you're really riding close to the edge with a small buffer/margin of error. I don't recall the exact details though.

Wing rock is an oscillation - basically, maintain a particular AoA with only pitch and throttle, and no aileron or rudder input - you'll find an effect called 'wing rock', which will have one wing drop, get out of the stall, then the other wing drops ... and this will just keep going indefinitely.

Ah well good to know, I got them all mixed up to be different names for the same thing :P.

A wing roll off is probably a similar effect but there's no oscillation - the wing just drops and remains stalled out.

If I get you correctly then that's what I always meant by "wing drop".

Y'all are forgetting two key components in this discussion:

1 - Stores drag and mass will influence yaw moment during a stall

2 - SAS has a vote in everything that's happening (if it's working).

1- In all my tests in DCS I'm using clean wings & light weight with basicly the same result.

2- From the dash 1: "Power setting or SAS do not significantly affect stall characteristics.".

I understand how busy someone like YoYo is. But not getting as much as a comment from any of the A-10C's developers for almost a month now? This a serious issue & it's quite a shame it has gone unfixed for 5 years now (?)..

 

I've provided evidence for my claim. If i'm proven wrong then so be it, but I can't be proven wrong when the devs won't even reply to me :music_whistling:.

They are probably pretty busy with more fantastic future projects. I would fly the A10 more if it didn't drop a wing so easily. A big straight wing jet like that should be more stable and forgiving than this simulated one. I love DCS and am behind it all the way! Is it possible that the community mod this flight model to make it more realistic and then the DCS team can test and possibly incorporate the mod?n Or at least we can fly something that we feel simulates flight in a more realistic fashion?

Thanks, it would be nice to see some acknowledgment of our concerns but I'm sure some A10 driver told them it was fine!

Good job DCS! I love the sim in VR, hard to beat.

W

BTW SCU, in your defense I will state following

After 1.2.8 I noticed that A-10C handling changed drastically. And just getting in to choppy tone it stops right then and there. The moment you go back to steady she starts to handle like nothing happened.

1-0-1 ? :D

Does anyone else feel like the behavior changed in 1.5.5 or is it just a placebo?

With a medium load I did 380KIAS in a 20 degree dive and pulled 7.5G during the CSEM. I never got a tone and never dropped a wing, even when decelerating through 200KIAS.

Does anyone else feel like the behavior changed in 1.5.5 or is it just a placebo?

 

With a medium load I did 380KIAS in a 20 degree dive and pulled 7.5G during the CSEM. I never got a tone and never dropped a wing, even when decelerating through 200KIAS.

Placebo. Just tested. Wing still drops it like it's hot.

Does anyone else feel like the behavior changed in 1.5.5 or is it just a placebo?

 

With a medium load I did 380KIAS in a 20 degree dive and pulled 7.5G during the CSEM. I never got a tone and never dropped a wing, even when decelerating through 200KIAS.

Pitot heat on?

If at high altitude with it off the AoA probe freezes and stall warnings sound constantly or become INOP.

Wing still drops it like it's hot.

:megalol:

It definitely still drops but it seems like I'm able to load more alpha before it does. I'll keep testing different conditions. I might even revert to 1.5.4 to do a more direct comparison.

Pitot heat on?

 

If at high altitude with it off the AoA probe freezes and stall warnings sound constantly or become INOP.

Yes, turned it on at EOR before departure.

I agree, it still tip stalls too early with the onset of "G".

Watch an A-10 put on a lightly loaded demo on Youtube, these guys are horsing these jets around tight, close to the crowd and under high "G".

This is impossible in DCS. Should be easy to make the change. In the case of the Hog, I would allow a little wiggle room on the side of docile to allow the sim experience to be enjoyable. Aircraft are a LOT easier to fly than most that are simulated. You should have to work HARD to get the straight or swept wing aircraft to drop a wing...hard wing F4 phantom 2 not included. :)

I agree, it still tip stalls too early with the onset of "G".

Watch an A-10 put on a lightly loaded demo on Youtube, these guys are horsing these jets around tight, close to the crowd and under high "G".

This is impossible in DCS.

That's all subjective, though. I can maneuver a lightly loaded A-10 very tightly with a bit of practice.

If only I had a better joystick and more training, then I could probably ride the chopped tone all day long. Oh wait....

Yep, it is subjective. In my experience, my opinion of the handling qualities is correct.

I'm happy to discuss this further offline if you'd like.

Will

Pocket, I realize you are HIGHLY experienced with this sim. I Will give you that the A10 flies pretty nicely and is getting close to what I feel it should be when lightly loaded.

Thanks, I do LOVE this sim and want the experience to be as close to my real world experience as possible.

:)

Will

I guess the only valuable input I can make other than something about the -1 is that when the real A-10C pilot had a Q&A (and I think another, or few other pilots), he/they mentioned that the real plane is definitely more forgiving in high AoA and also had more powerful engines than the one modeled in the sim.

I too want the A10 or any simulated aircraft to closely match the IRL aircraft available data and within simulation reason.

You need to also look at this form an engineers standpoint, and just how hard it would be to get this correct if there really is a problem?

The aircraft would have been tested by A10 pilots, there are limitations here too because they lack the feel of G's when maneuvering on PC in turns and also the proper full matching controls, so they to also need to look at this differently and fly by the aircraft known chart numbers.

There is speculation out there from other pilots online saying it's not right, what there not saying is how it was tested, what controls etc? What numbers are not matching in the flight performance? So the engineer can take a look under the hood. There is no real feeling in your pants here too for edge of the envelope as you get in the real aircraft.

I did ask one of the crew chiefs here long time ago, to see if if they could get an A10 pilot to stall the A10 with a helmet gopro so we can take a good look and know the temp, loadout, weight etc. You would think they would be up for it too. Plus, it would be a cool video if it turn out like the one in the link below.

Anyway, this would not be ease to massage out, if there is a slight problem here? The FM's are extremely complex and the fight model matches the numbers on paper now.

I guess the only valuable input I can make other than something about the -1 is that when the real A-10C pilot had a Q&A (and I think another, or few other pilots), he/they mentioned that the real plane is definitely more forgiving in high AoA and also had more powerful engines than the one modeled in the sim.

Like I said, the A10 hits the numbers, so the plane cannot be less powerful, it’s possible a sim thing vs IRL feeling here I guess.

Also this is still a simulation guy’s, very very very accurate simulation, but even level D simulators that pilots have check rides in every year have limitations, especially at the edge of the envelope.

Belsimtek/TFC Associate

 

We break the aircraft down into sub-elements (including breaking the rotor blades/propeller blades/wings/stabilizers into sub-elements like the root, mid-section, trailing edge) and apply physics equations to each element in real time to determine the forces and moments acting on it at any point in time.

 

 

Full Post here

Here's a module made by a forum member CptSmiley, he now works with RAZBAM building FM's, you can take a look at this project to see just what goes into building these, this is at the public EFM API level, you can start to understand just how complex the FM's are in DCS, any slight change here could impact other parts across the entire flight model.

F-16 High Fidelity Flight Dynamics and Tech/Academic Initial Demonstration

Some statistics:

- Lines of code: >5000

- Aerodynamic look-up tables: >24

- Breakpoints (data resolution): tables range from 5 breakpoints up to 1900 for most of them

- Data source - NASA technical papers

How accurate is the flight model (aerodynamics)?

- As accurate as possible with all flight data available (mostly from wind tunnels)

How accurate is the control system?

- As accurate as the NASA manned sim, using the same math model and block diagrams

- Modeling of the mechanical servo-dynamics are in there as well

How accurate is the engine model?

- Extrapolated equations from the NASA manned sim

Now, I’m not saying something's not wrong or is right here, what i'm saying tho is, to get this very small perhaps 1% problem out if it's there? Could potentially take the same amount of time it took to build the FM at the beginning (Years), as any changes to parts of the FM could constantly mess up other areas of flight performance.

I’ve never flown the A10, so I don't know if it is right or not, the data matches so…. It doesn't stop me enjoying this very very very close to IRL, simulated A-10C.

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The simulated A-10 does not hit the numbers though.

I got that from a former member here in a discussion quite a while ago and he was a Beta tester, guy's testing said it matches the E-M diagrams.

He did questioned the stall behavior still.

Like I said, it may be out? Or may just be in the data that was given to ED, I cannot see Yo-Yo playing around with this until it feels right for some pilots on the internet.

The simulated A-10 does not hit the numbers though.

Edit: What numbers do you think is out, so it can be shown to Yo-Yo?

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I'm speaking of the engines. The official documentation clearly mentions 800 ITT as a viable and reachable value, whereas ingame it's more around 750 ITT.