What did you do to my MiG?

[CORMAC ogaruu]

Why is it flying like a rabid seagull with a 10 pound shit in its ass? Is this wing rocking, barrel rolling atrocity truly the best you have? It was just fine before. A bit of a workout, sure, but not...this. You even had an entire thread on this forum thanking you for the flight model. And you go and ruin it. Why?

[Hiromachi]

Could you produce a little bit more constructive bug report ? I fly 21 every single day and test it. I did not experience any unusual wing rocking different to what we had 2 - 5 days ago.

[CORMAC ogaruu]

Could you produce a little bit more constructive bug report ? I fly 21 every single day and test it. I did not experience any unusual wing rocking different to what we had 2 - 5 days ago.

 

Yeah, I fly it every single day too. Did you also test it in combat? It's simply horrible to fly now with the latest open beta update. If you didn't experience any unusual wing rocking try fighting a BLUFOR human on the cold war servers.

[Hiromachi]

I do fly CW every day as well.

[BIGNEWY]

Why is it flying like a rabid seagull with a 10 pound shit in its ass? Is this wing rocking, barrel rolling atrocity truly the best you have? It was just fine before. A bit of a workout, sure, but not...this. You even had an entire thread on this forum thanking you for the flight model. And you go and ruin it. Why?

 

Please attach a track replay showing the potential issue.

 

Please also be aware of our forum rules here, they can be found at the top of the page.

 

thank you

[rossmum]

It feels no different to me now than it did before the patch. The stall onset has not changed at all, the approx. amount of commanded pitch at ARU long arm to ride the critical angle hasn't changed - nothing. The only thing that felt like it had been altered to me today was that it feels like I can't quite get as many G out of it at high (>700km/h IAS) speeds, but at low speed, it's exactly the same as it has been for months...

[mrmach]

Any change in the FM was introduced in this new beta?

Edited August 28, 2020 by mrmach

[Hiromachi]

No, I've asked Dolphin (our FM programmer), and no changes were introduced yet. Of course there is a possibility of a bug appearing but I don't see any difference at low speed at least.

[Rudel_chw]

Why is it flying like a rabid seagull with a 10 pound shit in its ass? ....

 

What a way to describe a bug :doh: .. was that the best you could come up for describing the issue? attach a track file, so that others can see exactly what is the issue ... you have only two posts, and both are of this level .. think about it :mad:

[EnvyC]

I'd argue its even more stable, especially at higher speeds. Theres nothing wrong with it, you're just pitching it into the stall envelope.

[Alpenwolf]

He didn't choose the right words for it but it did give me a laugh to be honest, and I think it's maybe obvious what he's talking about if you fly the Mig-21 everyday or very often. Or let me say obvious to me at least.

 

I think he refers to being unable to turn in on a bandit in a merge at a high speed like before the update any more. Which what happened to me in the first 2-3 turnfights after the update. After some testing, I think at a speed of ca. 730 kph with 2 x R3S missiles on the inner pylons and 2 x R3R missile on the outer pylons without a central fuel tank it performs no differnetly than before. Unless your experience is different?

I'll run more tests for sure...

[Peter5on]

I came back to MIG-21 after 5 years to check the flight model, but i think there is still some issues with it? I actually stopped flying it because flight model was changing so many times over the years that i lost trust in it. It behaves like it has thrust vectoring of some sort, is that how it suppose to be?

 

 

 

Look at video that i made today, and at the one i've made in 2015

 

 

2020 last open beta patch video:

 

 

 

 

my orginal topic from 2015 about spirral of death:

 

https://forums.eagle.ru/showthread.php?t=150686

 

 

and the 2015 video:

 

[rossmum]

I mean, it's a tailed delta with good control authority. At 600km/h the ARU would be in long arm mode, so you're getting maximum control response, and you can very easily throw the aircraft into a departure like you did there. There's no thrust vectoring about it, you just made a very violent control input, stalled the aircraft, deliberately (?) induced a severe pitch oscillation that coupled into the stall and produced something you couldn't recover from. If the aircraft had thrust vectoring or behaved as though it did, you would've been able to control and recover from that manoeuvre, but as it is you managed to find about the one thing the 21 can't recover itself from and rode it all the way into the ground.

 

It's also worth bearing in mind that the more you stray outside the aircraft's normal flight envelope, the less we can be sure about what the exact 'right' behaviour is, because no pilot in their right mind would ever do what you just did in that video - or if they did, they probably didn't live to tell the tale. If you fly the plane within said envelope or at least reasonably close to it, it behaves a lot more 'normally'.

 

Obviously, the 2015 video is showing some bizarre things, but the module was very new then and a lot less complete than it is now.

[gavagai]

He didn't choose the right words for it but it did give me a laugh to be honest, and I think it's maybe obvious what he's talking about if you fly the Mig-21 everyday or very often. Or let me say obvious to me at least.

 

I think he refers to being unable to turn in on a bandit in a merge at a high speed like before the update any more. Which what happened to me in the first 2-3 turnfights after the update. After some testing, I think at a speed of ca. 730 kph with 2 x R3S missiles on the inner pylons and 2 x R3R missile on the outer pylons without a central fuel tank it performs no differnetly than before. Unless your experience is different?

I'll run more tests for sure...

 

The pitch authority is gone. Can't pull enough g at higher airspeeds. Impossible to blackout now.

[rossmum]

It seems the ARU is limiting control authority too much in short arm mode, topping out around 5-6G. I'll have to test some more later, but that was the one change I did notice - the ARU seems more restrictive at speed. When people said they couldn't pull AoA my brain switched into long arm mode and assumed they meant at low speed, which is the only time I'd be looking at that gauge.

 

In long arm mode there's no effect on handling, as you'd expect, and the aircraft still behaves exactly the same way it has for months.

 

So yeah - at high speed, you've got decreased turn performance (and I also noticed a few odd oscillations around the transonic region, but only occasionally). At low speed, business as usual. She still stalls ~33* UUA-1 as expected. If you're experiencing violent wing rock the only thing I can suggest is don't stick wank quite so much and keep an eye on the UUA, try and commit the sweet spot for 30-32* to memory so you can edge the stall when you need to. Be mindful that at very low speed or as the ARU switches modes, a miniscule amount of extra pull can very easily tip you over the edge and cause a stall.

[erniedaoage]

Just did a bit of free flight but i wasn't able to get anywhere near a blackout with pulling positive gs in all sorts of maneuvers. While on the other hand there was an instant blackout when i rapidly pulled negative gs.

[gavagai]

Just did a bit of free flight but i wasn't able to get anywhere near a blackout with pulling positive gs in all sorts of maneuvers. While on the other hand there was an instant blackout when i rapidly pulled negative gs.

 

Lack of pitch authority is a confirmed bug!

https://forums.eagle.ru/showpost.php?p=4470317&postcount=179

[xnomad]

What has always bothered me about the flight model is the rubber band effect in pitch. Not sure if it is realistic or not but it doesn't feel realistic to me.

 

As we know you have to be careful with your AOA in a delta wing, however if you accidentally exceed and try to recover by pushing down to get some airflow over the wings, the nose will bounce back and forth from low to high exceeding AOA and dumping all the airspeed you tried to gain. It's like the plane is purposely trying to stall the wings when you are trying to stop it from happening. I remember US test pilots saying it was an honest plane (ok not the Bis in particular), but this one feels like it's trying to get you killed. :)

 

Maybe that's the way it was but doesn't seem right as if weight or momentum is off. I can't think what would cause pitch to oscillate like that so elastically in a real plane. What do others think or do you know why it's modeled like that?

Edited August 31, 2020 by xnomad

[AeriaGloria]

It’s just a very unstable plane, around stall AOA and elsewhere throughout AOA it’s stability often degrades from positive stability to neutral. I don’t have the stability versus AOA charts handy, but it’s only really positively stable in the lower number AOA zone IIRC while being close to neutral at stall. All of its AOA characteristics are made worse by the Bis spine.

 

I think the real difference would be if you were actually in it and felt it in your butt, then I think the natural constant stick movement would feel more natural, it is a little contradictory when you’re only way to escape PIO is :joystick:, but my amateur armchair opinion is that it feels like the natural result of balancing a long pencil with that small tail and delta wings so swept that they produce destabilizing vortexes that move the aerodynamic center forward at high alpha. I feel that it makes sense why it is such a big factor in why pilots hate the Bis compared to earlier generations.

[rossmum]

Did some quick testing. Interim solution:

 

- Turn ARU from AUTO to MANUAL;

- Hold ARU selector switch UP until gauge displays it's on long arm mode (FULLY LEFT)

- Don't pull more than approx. 1/3 stick travel. Half travel if you're feeling spicy.

 

This should give you the authority you're missing without overstressing the jet. It might take a bit of getting used to, though. Bonus here is that it also teaches you to edge the AoA at low speed as the permissible stick travel is about the same (albeit the consequence there is a stall, not ripping your plane apart).

 

e/ The poor longitudinal stability is also one of the MiG-29's most noticeable flight characteristics in DCS, it's not just the 21, and it is indeed a feature of the design from everything I've read.

[xnomad]

 

I think the real difference would be if you were actually in it and felt it in your butt, then I think the natural constant stick movement would feel more natural, it is a little contradictory when you’re only way to escape PIO is :joystick:, but my amateur armchair opinion is that it feels like the natural result of balancing a long pencil with that small tail and delta wings so swept that they produce destabilizing vortexes that move the aerodynamic center forward at high alpha. I feel that it makes sense why it is such a big factor in why pilots hate the Bis compared to earlier generations.

 

Thanks, yeah I'm thinking of actually getting a buttkicker/jetpad or similar for this mod and to improve immersion overall in the others. I would normally fly planes like this with my FFB stick but my new Virpil is so mind-blowingly amazing and precise that I can't go back to the old FFB stick.

[AeriaGloria]

Thanks, yeah I'm thinking of actually getting a buttkicker/jetpad or similar for this mod and to improve immersion overall in the others. I would normally fly planes like this with my FFB stick but my new Virpil is so mind-blowingly amazing and precise that I can't go back to the old FFB stick.

 

With jet seat you can feel the perfect AOA. I don’t like the G feedback though so I keep it off and i recommend the same so you can feel everything else unless you have an iron back and chair to take all the force

[Fri13]

What has always bothered me about the flight model is the rubber band effect in pitch. Not sure if it is realistic or not but it doesn't feel realistic to me.

 

One test pilot said that where MiG-21F flew like a dart, the MiG-21Bis was like a beer bottle. That analogy might be about the handling where it oscillates heavily in pitch attitude even in level flight and like to have a head authority but no lift to turn (requires high AoA to turn).

[_Firefly]

One test pilot said that where MiG-21F flew like a dart, the MiG-21Bis was like a beer bottle. That analogy might be about the handling where it oscillates heavily in pitch attitude even in level flight and like to have a head authority but no lift to turn (requires high AoA to turn).

 

That's the primary reason why I'd love to see the F-13 in the game. Along with the Fresco it'd create a perfect REDFOR lineup for Vietnam war operations as well as some early to mid-1960s Middle East scenarios.

 

My friends and I did some testing of the Bis today. The loss of pitch authority occurs at above 780-800 kph IAS. With the stick fully aft the plane is incapable of exceeding 5 g and ~11 deg alpha (as indicated by the cockpit gauge). I tried the manual ARU and it does improve matters a lot, but one has to be careful as the plane is perfectly capable of ripping its wings off at high enough g loadings (which is hardly a surprise).

[rossmum]

I use about a 15% pitch curve and 1/3-1/2 back stick travel is safe with the ARU in manual. Not sure about forward stick because I'm almost as allergic to abrupt negative G as the 21's fuel system is.