Jump to content

[FIXED] AJS 37 Viggen afterburner issue.


jojyrocks
 Share

Recommended Posts

As the title says...problems with Afterburner.

 

When climbing, like to 40000 plus feet, the Afterburner suddenly shuts down and it does not appear even after resetting to altitude of below 30000 feet. I was at AoA of 5-10 degree climb and no abrupt movements. Still no matter how many times I try to climb to 50000 plus. The afterburner automatically shuts down (the 3 zone lights are still lit though) around 40000 feet and stuck in just full military power only.

 

 

Location (Persian gulf map).

 

 

 

 


 

Edited by RagnarDa
Link to comment
Share on other sites

Turn on manual fuel regulation (BRÄNSLEREGL), as the automatic mode restricts performance at high altitude.

 

For work: iMac mid-2010 of 27" - Core i7 870 - 6 GB DDR3 1333 MHz - ATI HD5670 - SSD 256 GB - HDD 2 TB - macOS High Sierra

For Gaming: 34" Monitor - Ryzen 3600 - 32 GB DDR4 2400 - nVidia GTX1070ti - SSD 1.25 TB - HDD 10 TB - Win10 Pro - TM HOTAS Cougar - Oculus Rift CV1

Mobile: iPad Pro 12.9" of 256 GB

Link to comment
Share on other sites

Which altitude do I turn it on and how do I manually regulate the fuel?

Also when do I turn it OFF.

 

Manual mode means that the fuel flow is just proportional to the throttle position, without the automatic regulator trying to compensate for altitude & air temperature.

 

I dont know the answer to your other questions, as on my missions I never fly the Viggen at high altitude, as it has better protection flying low using terrain masking. My advice was based on items I have read on the forum :)

 

For work: iMac mid-2010 of 27" - Core i7 870 - 6 GB DDR3 1333 MHz - ATI HD5670 - SSD 256 GB - HDD 2 TB - macOS High Sierra

For Gaming: 34" Monitor - Ryzen 3600 - 32 GB DDR4 2400 - nVidia GTX1070ti - SSD 1.25 TB - HDD 10 TB - Win10 Pro - TM HOTAS Cougar - Oculus Rift CV1

Mobile: iPad Pro 12.9" of 256 GB

Link to comment
Share on other sites

Manual mode means that the fuel flow is just proportional to the throttle position, without the automatic regulator trying to compensate for altitude & air temperature.

 

I dont know the answer to your other questions, as on my missions I never fly the Viggen at high altitude, as it has better protection flying low using terrain masking. My advice was based on items I have read on the forum :)

 

Hitting the manual fuel regulator doesn't help this, the AB still stops around that altitude. Furthermore, I haven't been able to find something in the module manual or the real manual that indicates that as a procedure/solution. That is, this looks like a bug and nothing else.

i7-7700K @ 4.9 GHz | Gigabyte Aorus Geforce GTX 1080 Ti | 32 GB DDR4 Corsair Vengeance @ 2400 MHz (2800 OC) | Asus Strix Z270E Gaming | Samsung 970 EVO M.2 SSD 1 TB | Samsung 960 EVO M.2 SSD 500 GB | WD NAS Red 2TB SATA3 | Corsair Cooling Hydro Series H80i v2 | Thrustmaster Hotas Warthog | Saitek PRO rudder pedals | Valve Index

Link to comment
Share on other sites

Hitting the manual fuel regulator doesn't help this, the AB still stops around that altitude. Furthermore, I haven't been able to find something in the module manual or the real manual that indicates that as a procedure/solution. That is, this looks like a bug and nothing else.

 

 

 

 

 

 

That's what I thought. I just tried again with the setting to manual fuel regulator on, and still the AB system just cuts off at around 40000 feet plus. Sometimes even after getting to low altitudes, the afterburner wont function. I tried all to manual fuel regulator and AB regulator...nothing works!

 

Even the air restart system is bugged. My engine stalled at around 40000. Then pitched low and set the restart button after idling the engine....from that high altitude, there is plenty of windmilling to help. The engine rises to 40 some rpm and then cuts back to around 20 and remain stuck there.

 

 

That airplane design can also go between 50000 to 60000 feet. In-fact, even in DCS encyclopedia it states its altitude is like 20000 meter capable. So far it cant even reach 40000 feet without the AB giving out.

Link to comment
Share on other sites

Is this with a clean aircraft?

 

 

A curious test of mine to see if the AJS Viggen can hold at least close with its JA 37 version of max alt of 590000 feet service ceiling. Design is same...so started with 70 percent fuel and zero loadout.

 

Seems like it struggles from 30000 feet in full mil power....strange!

Link to comment
Share on other sites

AJS 37 Viggen afterburner issue.

 

A curious test of mine to see if the AJS Viggen can hold at least close with its JA 37 version of max alt of 590000 feet service ceiling. Design is same...so started with 70 percent fuel and zero loadout.

 

Seems like it struggles from 30000 feet in full mil power....strange!

 

 

From the charts I’ve looked at you should be able to accelerate from 657km/h at 0km to M0.9 at 10km, it should take about 13 minutes to get there according to the charts.

So you should at least be able to hold M0.9 at 10k. There is a chart for “engine control” values that show what the engine values should be at 13km and M0.9.

 

The afterburner issue is more complex, it’s a combination between speed alt and AB zone.

If you go M1.2 and Zone3 you should be able to climb over 16k without it cutting off.


Edited by outbaxx
Link to comment
Share on other sites

Engine performance and behaviour is on the to-do list.

 

 

 

 

 

 

I see...So it was a bug after all...

 

 

Thanks for the reply!

 

 

 

 

Will await for the fix to come.

 

 

So far, I have no idea what the manual fuel regulator and manual afterburner regulator does. Yes, I tried those too at such altitudes and Viggen certainly "looks" well designed enough to hold higher altitudes. It should at least hold level flight at 25-30k altitudes without relying on AB.

 

 

 

 

 

Also the external drop tank release button cover and the switch is not switchable.

Link to comment
Share on other sites

  • 2 months later...

just had this happen to me today too. i did full afterburner on a clean bird up to 35,000ft and the afterburner shut off. i descended, and the engine was working fine in mil power, but the afterburner would never come on again. all the way to landing.

 

it clicked and the stage lights appeared in the cockpit, but nothing ever happened. completely dead ABs. this thread was from September, so assuming this hasn't been addressed yet?

Acer Predator Triton 700 || i7-7700HQ || 512GB SSD || 32GB RAM || GTX1080 Max-Q || FFB II and Thrustmaster TWCS Throttle || All DCS Modules

Link to comment
Share on other sites

Did you check your error panel on the right side?

I also flew at 30000+ yesterday at full AB and had the same time happen, and I had a error on the panel. Can't remember exactly what it said, something like pjx24y, I figured it was something about the AB no longer working. Didn't pay too much attention to be honest, I knew I was playing with danger by going that high and that fast (M1.7 something).

Link to comment
Share on other sites

I've always wondered about the AB behaviour in the Viggen. Does the AB not work at altitude in real life? If so, why is that?

 

They did change the engine for the JA-37 (RM8B), think they added one compressor stage (and some length to both the engine and plane body) for it to work better at high altitudes. Not sure how it's connected to the afterburner on the AJ, or if it's correctly modeled the way it behaves in DCS or not.

 

Wiki doesn't mention anything about high altitude problems for the RM8. So I might just be wrong on a connection to high altitude. https://en.wikipedia.org/wiki/Volvo_RM8

Link to comment
Share on other sites

Did you check your error panel on the right side?

I also flew at 30000+ yesterday at full AB and had the same time happen, and I had a error on the panel. Can't remember exactly what it said, something like pjx24y, I figured it was something about the AB no longer working. Didn't pay too much attention to be honest, I knew I was playing with danger by going that high and that fast (M1.7 something).

Sounds more like a low fuel warning to me ;)

Intel i7-4790K @ 4x4GHz + 16 GB DDR3 RAM + Nvidia Geforce RTX 2080 (8 GB VRAM) + M.2 SSD + Windows 10 64Bit

 

DCS Panavia Tornado (IDS) really needs to be a thing!

 

Tornado3 small.jpg

Link to comment
Share on other sites

  • 2 years later...

Just tested it and seems fixed to me. In my test the afterburner stopped working at 48,000 ft, so I descended down to 15,000 ft and tried to relight the afterburner and it worked.

  • Thanks 1

Intel i7-4790K @ 4x4GHz + 16 GB DDR3 RAM + Nvidia Geforce RTX 2080 (8 GB VRAM) + M.2 SSD + Windows 10 64Bit

 

DCS Panavia Tornado (IDS) really needs to be a thing!

 

Tornado3 small.jpg

Link to comment
Share on other sites

  • RagnarDa changed the title to [FIXED] AJS 37 Viggen afterburner issue.
  • 3 weeks later...

Guys, just for your information, because it was forgotten to be said:

 

In the current DCS version (OB 2.5.6.61527) you have to pull your throttle to idle before re-engaging the afterburner when below the altitude it initially went out.

Note that this might blow out the engine depending on conditions, so be careful with the throttle movements.

 

The question about why the AB is going off in that altitude was IMHO not answered by someone / any manual / any real Viggen driver.

If sources exist, please post a link or leave comments, thanks!

 


Edited by TOViper

my channel: https://www.youtube.com/channel/UC_Yx920L1ezoWQkYKCGYB9w

my PC: CSL | i7 6700 @ 4.4 GHz | NVIDIA GTX 1080 Ti OC 11GB | 40 GB 3000 MHz DDR4 | 256 GB SDD SYS + 500 GB SSD DCS + 1 TB HDD | Win10 Pro

my controls: A-10 Warthog Stick + Throttle | Rift CV1 | ViaComPro

my mods: FC3 | AJS-37 | F-14 | F-16C | F/A-18 | F-5E-3 | L-39 | (HAWK) | MiG-21 | UH-1 | Mi-8 | Mi-24 | Combined Arms | Nevada | Syria | Persian Gulf

 

Link to comment
Share on other sites

1fb3fa6c8c34e1342095af635bebdde0.jpg
Green zone: AB zone 1-3 should work normal.
Yellow zone: only zone 3, and not possible to re-ignite.
Red Zone: no zone work.

So it according to the chart it depend on speed too, the chart only show up to 16km, but I would guess you could extend those lines a bit without being completely wrong.

But speed is important at those heights too.

  • Like 3
Link to comment
Share on other sites

 Share

  • Recently Browsing   0 members

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