AJS-37 overall behavior changed with the latest patch?

[grunf]

The stable 1.5 is still without these issues. It's just the OB that has it. I wonder if ED will even bother to commit the current OB update to the stable release branch before 2.5 hits.

Good point.

[funkyfranky]

The stable 1.5 is still without these issues. It's just the OB that has it. I wonder if ED will even bother to commit the current OB update to the stable release branch before 2.5 hits.

An if they commit OB into stable, they might just leave out the Viggen changes - provided there are no other dependencies.

[QuiGon]

An if they commit OB into stable, they might just leave out the Viggen changes - provided there are no other dependencies.

Or they could implement the fixes for the changes... if Heatblur provided them.

[Sephyrius]

Does anyone know whether 2.5 performance is on par with what's expected or affected by this bug?

 

Haven't flown it for a few months since I've been busy with the Harrier, but 2.5 is great for the Viggen. Yet it feels quite sluggish compared to what I remember, had trouble taking off with a heavy load and without burners I struggled to avoid stalling at a constant 300-350kph speed. With a light load it takes quite a long time to get up to cruise speed.

[Cobra847]

Does anyone know whether 2.5 performance is on par with what's expected or affected by this bug?

 

Haven't flown it for a few months since I've been busy with the Harrier, but 2.5 is great for the Viggen. Yet it feels quite sluggish compared to what I remember, had trouble taking off with a heavy load and without burners I struggled to avoid stalling at a constant 300-350kph speed. With a light load it takes quite a long time to get up to cruise speed.

 

Unaffected.

[QuiGon]

The cockpit in 2.5 is pretty dark now, especially at night. With the new lighting system of 2.5 the cockpit and instrument illumination is not sufficent at night. It is difficult or even impossible to see some of the gauges and instruments even with all the cockpit lights maxed out. Especially knobs and switches that are located beside an instrument (e.g. the knob to adjust barometric pressure next to the altitude indicator) are totally blacked out at night.

 

As this is a problem with pretty much all modules, I guess its on ED to make some adjustments to the lighting system?

 

And then there is this:

 

 

I guess this is also on ED?

Edited February 2, 2018 by QuiGon

[Vatikus]

this is more like on HB... cockpit was useless at night even before the 2.5.

[QuiGon]

this is more like on HB... cockpit was useless at night even before the 2.5.

 

It was fine in 1.5.8 Stable. I guess it still is fine with deffered shading turned off, although I have not tested it.

[merlin851526]

Ive been flying the Viggen for quite a time now and love every second in it. However since the latest patch Ive noticed some weird changes. For example the speed to rotate with a full loadout was always around 270+-10 km/h now I need almost 400 to get her up and even then she climbs really slow like a heavily loaded Bomber (almost feels overloaded imho). Also when I fly her without burners at max RPM the speed doesnt climb over Mach .65 and as soon as I need to make a tighter turn I have to go into full burners in order to make a turn without stalling her. Landing also seems to be an issue now since I almost have to go into burner stage I to keep the landing AoA and speed.

 

Is it just me experiencing this? Id rather ask in here just to make sure that its not a problem with my controls or something which I doubt is because Ive just checked them in the controls menue and all throttle axis seem to work just fine.

 

:joystick:

For the record this is one of the most beautiful aircraft in the game and my favourite. However I'm getting the above mentioned behaviour as well. Have to go to full burners to take off, feels like a heavy WW2 bomber trying to get into the air. Also the aircraft will yaw like crazy even with the auto pilot stabiliser on at random. Moreover the aircraft has a frightful tendency to roll over while stabilised as well from time to time.

[Zabuzard]

Interesting what you all experience. None of that ever happened to me^^

 

I takeoff and climb like usual (takeoff trim is 3° nose up). Without burner the speed is about 0.7, which always was like that, stage 1 for around 0.8-0.9. Turning works perfectly without burner for me. Note that the Viggen is not meant to do tight turns, it's not a designated fighter. Maximum allowed G is 7.

I need no burner for landing. Use the autothrottle and practice holding the correct angle first.

My Viggen also doesn't yaw around at random.

 

Also check your loadout, don't exceed the maximum allowed weight. The Viggen is supposed to only carry ammunition for one attack run + self defense like AA missiles or counter-measurements.

Edited March 4, 2018 by Zabuza

[QuiGon]

With a full A-G weapon load + 2 (E)CM pods + 2 sidewinders + fuel tank I experience similar behaviour to what merlin said.

[Cobra847]

We can't quite replicate this. Which versions?

[QuiGon]

What Merlin said might go a bit too far to describe for what I'm experiencing. It's just that the aircraft feels pretty heavy on takeoff with a full loadout that I wouldn't even dare to takeoff without AB (at least on Nevada in 2.5). Having loaded a U22 and a KB pod it has a tendency to roll right as well as yawing even with the AP activated. It's not much, just a little bit which might be realistic. :dunno:

On that note: I would love to have some clarity about the function AP yaw adjustment knob on left side of the cockpit as this sounds pretty useful, but doesn't seem to do anything.

Edited March 7, 2018 by QuiGon

[Zabuzard]

Ah, you are using an asymmetric loadout. Please refer to this thread:

 

https://forums.eagle.ru/showthread.php?t=189338

 

Use the RENFLYGNING knob (Autopilot yaw correction) to set the yaw trim the autopilot should use. Usually this is set to 0. But if you are using an asymmetric loadout you might want to adjust.

As soon as you hit the autopilot, the regular trim system disables and aircraft will fly by autopilot inputs only.

If you want to trim yaw outside of autopilot you should use the yaw trim switch. Note that you should not use the Roll/Pitch switches there since they would enable the emergency trim system (there is no emergency trim for yaw). Once the emergency trim system has been enabled the regular system is inoperable until you cycle the TRIMSYST circuit breaker (right side) (see manual page 75).

 

If the switches still don't work as they should, please post in the linked thread.

 

Note the following from manual page 266 cont.:

The yaw-roll oscillation (Dutch roll) is relatively poorly dampened and the dampening function reduces with increasing altitude. At high airspeeds the Dutch roll is mainly a pure yaw oscillation, but with increasing angles of attack the roll becomes more prominent.

Edited March 6, 2018 by Zabuza

[QuiGon]

Ah, you are using an asymmetric loadout. Please refer to this thread:

 

https://forums.eagle.ru/showthread.php?t=189338

 

Use the RENFLYGNING knob (Autopilot yaw correction) to set the yaw trim the autopilot should use. Usually this is set to 0. But if you are using an asymmetric loadout you might want to adjust.

As soon as you hit the autopilot, the regular trim system disables and aircraft will fly by autopilot inputs only.

If you want to trim yaw outside of autopilot you should use the yaw trim switch. Note that you should not use the Roll/Pitch switches there since they would enable the emergency trim system (there is no emergency trim for yaw). Once the emergency trim system has been enabled the regular system is inoperable until you cycle the TRIMSYST circuit breaker (right side) (see manual page 75).

 

If the switches still don't work as they should, please post in the linked thread.

 

Note the following from manual page 266 cont.:

The yaw-roll oscillation (Dutch roll) is relatively poorly dampened and the dampening function reduces with increasing altitude. At high airspeeds the Dutch roll is mainly a pure yaw oscillation, but with increasing angles of attack the roll becomes more prominent.

 

Thanks, but I'm already aware of the RENFLYGNING knob. That's actually the knob I was talking about in my last sentence in my previous comment. ;)

The knob is not working for me (when used with the mouse), which I have already stated in the other thread you have linked. It is not even clear what exactly this knob does as the manual says nothing about it and the devs are not sure either:

Truthfully and IIRC, I am not entirely sure there is a rudder trim in the Viggen except for the emergency one. Also, not sure what the “RENFLYGN” rotary actually does since the RL-manual is very light on information about that.

[outbaxx]

What Merlin said might go a bit too far too describe for what I'm experiencing. It's just that the aircraft feels pretty heavy on takeoff with a full loadout that I wouldn't even dare to takeoff without AB (at least on Nevada in 2.5). Having loaded a U22 and a KB pod it has a tendency to roll right as well as yawing even with the AP activated. It's not much, just a little bit which might be realistic. :dunno:

On that note: I would love to have some clarity about the function AP yaw adjustment knob on left side of the cockpit as this sounds pretty useful, but doesn't seem to do anything.

 

 

Actually you shouldn’t take off without afterburner even at lower weight, the drag risk to get too high. You need to get to 300km/h to have enough speed to continue accelerating without afterburner, the alpha at lift is 11 and it’s easy to over rotate and stall.

With a 60% fueled ac it takes 8 second from start to lift off and then another 18 seconds to reach 600km/h. That’s why it’s important to raise the gears short after take off.

 

Take off with afterburner should be done with minimum 50% of stage 2 due to risk of AB flame out with lower AB.

 

On take off the max speed due to the rotation of the gears is 320km/h and the risk of hitting that speed is said to be low.

The problem is that it’s impossible to rotate before 250-260km/h, at least for me :)

[Ramstein]

For the record this is one of the most beautiful aircraft in the game and my favourite. However I'm getting the above mentioned behaviour as well. Have to go to full burners to take off, feels like a heavy WW2 bomber trying to get into the air. Also the aircraft will yaw like crazy even with the auto pilot stabiliser on at random. Moreover the aircraft has a frightful tendency to roll over while stabilised as well from time to time.

 

I agree Merlin ! Something is wrong!

You said it best! :joystick:

[Kozality]

Hope this doesn't sound insulting for asking, but have you set takeoff trim? I've experienced the same sluggishness on takeoff with a heavy load (16 x M/71, XT, Rb-24s), but this is because my takeoff trim was either not set or too conservative. I usually set this to 5-6 degrees for such a heavy load, then back off on it as I pass 5-600KIAS. If I forget to set it (like I did once last night), then I usually end up having to use most of the runway.

[earnil]

Actually you shouldn’t take off without afterburner even at lower weight, the drag risk to get too high.

 

Can I ask what is the source of the information? For example Viggen's guide treats this as if take off with afterburner was optional

 

3. Release brakes, steer with pedals

4. If needed, ignite afterburner.

(Page 240)

 

On broader note, I thought it was just me imagining things, but since others seem to have similar experiences - it also feels to me as if there's something wrong about Viggen's performance, especially at low speeds:

 

1) I'm quite sure that I was able to take off without afterburner with combat load (regardless if that's correct procedure) like 2 ARAK, 2 missiles, X TANK but now I'm not, even stage 1 AFB is not enough. Again, not sure if this is a problem or not, it's just my observation of the change.

2) AFK has quite a trouble maintaining 550km/h speed even with relatively shallow climb. I understand that Viggen's dry thrust is not something spectacular, but again, my sense is that it was not 'that bad'

3) On Nevada map, during landing with gear out with AFK, the plane tends to settle at quite high AoA and even stalls if I don't disable AFK and fly it manually. Maybe that's because Nellis is relatively high compared to other places so again this may be intended behavior...

[outbaxx]

AJS-37 overall behavior changed with the latest patch?

 

Can I ask what is the source of the information? For example Viggen's guide treats this as if take off with afterburner was optional

 

It’s from a aerodynamic compendium, here is a screenshot: (in Swedish though)

 

I think there is something off with the added lift when the “canard flaps” is down, and that’s why it feels like there is a sink down even with afterburner, and a high alpha.

Edited March 7, 2018 by outbaxx