BK90 after latest Viggen update

Just returned to the Viggen after the last update.

I noticed the Mjolnir (type 2 anti armour) is consistently dispensing wide of the targets. Targets are simple BTR column with a few T80's, on a road, stationary. Entering the target waypoint either in cockpit via computer, or via pre loaded mission planner plan, the result is the same. Submunitions are dispensed 400 meters (approx) east of the target. No targets are hit. It's as if the guidance units in the weapon are ignoring the target coords?

Code is 91100 (100m) and 921(long) or 922(wide).

Anyone else experiencing any errors with the Mjolnir? Or is this just my error?

It's an awesome weapon in DCS. I last flew the Viggen back in March and found the Mjolnir worked flawlessly with a simple vehicle column target.

Just to answer my own question and perhaps help anyone else with this issue...

The problem was wind! I had 12 Knots at 270 degrees over the target. So the sub munitions were drifting off target.

Using the "Vind Ruta Mal" setting on the CK37 computer appeared to solve the off set targeting issue.

I inputted 27012 or 270 degrees at 12 Knots into the target waypoint and saw that the munitions were released from the Mjolnir at the correct off set. The MJ2, anti armour, munitions parachuted down right onto the column!

I have attached the CK37 input code sheet for anyone who's interested!

I am not certain the take off wind display is correct though? I saw ninety degrees at 10 Knots for take off, but the mission planner was set to 270 at 10? Possibly something getting reversed?

Happy holidays!

Just to answer my own question and perhaps help anyone else with this issue...

 

 

The problem was wind! I had 12 Knots at 270 degrees over the target. So the sub munitions were drifting off target.

 

 

Using the "Vind Ruta Mal" setting on the CK37 computer appeared to solve the off set targeting issue.

 

 

I inputted 27012 or 270 degrees at 12 Knots into the target waypoint and saw that the munitions were released from the Mjolnir at the correct off set. The MJ2, anti armour, munitions parachuted down right onto the column!

 

 

I have attached the CK37 input code sheet for anyone who's interested!

 

 

I am not certain the take off wind display is correct though? I saw ninety degrees at 10 Knots for take off, but the mission planner was set to 270 at 10? Possibly something getting reversed?

 

 

Happy holidays!

Thanks! Interesting. I also experienced the same drift when I tried out the BK-90 some time ago. Corrected with taking new coordinates but probably had the same issue with wind as you.

Did you just input the wind and strength and instead of confirming with LS/SKU you confirmed with the target waypoint (e.g. B3)?

Just to nitpick, it's 12km/h and not knots.

Regarding the wind directions, I know there is some discrepancies between ME, mission briefing, ATC and possibly kneeboard. Some are correctly giving the direction FROM where the wind is coming from (ATC I think), while others give the direction TO where it is blowing (ME). Just learn who is giving what (I haven't) and you will be fine.

The problem was wind! I had 12 Knots at 270 degrees over the target. So the sub munitions were drifting off target.

 

 

Using the "Vind Ruta Mal" setting on the CK37 computer appeared to solve the off set targeting issue.

Thanks for the pointer! I was under the impression that the wind parameters would already be stored in the CK37 or that the Doppler unit would take care of it. Apparently the automatically determined wind speed/direction does not match the actual parameters?

Thanks! Interesting. I also experienced the same drift when I tried out the BK-90 some time ago. Corrected with taking new coordinates but probably had the same issue with wind as you.

 

Did you just input the wind and strength and instead of confirming with LS/SKU you confirmed with the target waypoint (e.g. B3)?

Hi chaps.

I inputted the wind strength based upon what I had set in the weather parameters in the mission planner. the LS/SKU originally showed a one eighty degree discrepancy?

Its still not firm in my mind what to set the wind to, but setting it to the MP wind certainly helps with the drifting of the chutes on the sub munitions.

Strangely, if I use no wind at all, there is still a poor result. The skeets seem less effective?

I see that the effects are not as nice as back in April, when I did my Mission Not Impossible mission. The double explosions from the Anti personnel vs the armour skeets are gone now? Their effectiveness seems to have been dumbed down also. I am only hitting 2 or 3 vehicles in a 10 vehicle column?

The A.I are useless and wont drop the Mjolnir at all?

There is something definitely wrong with wind input on the viggen, after several tests i'm sure about this : ck computer Works the opposite to bk90, in order to hit with the bk90 u need to input to where the wind is blowing, ur hud Will be showing wrong wind correction but atleast u'll be able to hit your target.

Feel free to try the same :D

Edit : As long as u fly low with ternav on u should have no problems with drift, even with heavy winds

Just returned to the Viggen after the last update.

 

Code is 91100 (100m) and 921(long) or 922(wide).

If the winds are high, reducing your programmed altitude would be advisable unless terrain features are in the way. 100M is pretty high and will significantly drift. Likewise, if using the MJ2 munition you will get better effect the lower altitude the BK90 releases (of course you will get a much smaller impact area). If you approach on axis with the threat's vector and use long area attack (921) two BK90s at 50m-30m the wind will have less chance possibly however I am noticing in testing that regardless the settings (and even the default 60m) the altitude isn't changing - though no wind issues noted on my part.

I was under the impression that the value input into address 91xxx is only for the ingress altitude. I believe it states somewhere that the final attack altitude of the BK-90 is always 60m.

--- Confirmed:

Pg. 343 of the manual:

"The attack altitude is always 60m."

The address 91 is for the ingress (approach) altitude.

There is something definitely wrong with wind input on the viggen, after several tests i'm sure about this : ck computer Works the opposite to bk90, in order to hit with the bk90 u need to input to where the wind is blowing, ur hud Will be showing wrong wind correction but atleast u'll be able to hit your target.

 

Feel free to try the same :D

 

Edit : As long as u fly low with ternav on u should have no problems with drift, even with heavy winds

I think that the wind direction in game, is in fact reversed 180 degrees.

For example, in my video, I set 270 a 12, in the mission editor. I use 270 @ 12 in the ck 37 wind input page. However if you look at the drift on the parachute sub munitions. They appear to be drifting 090 @ 12??? This is before ck 37 wind input. After the wind correction, the submunitions are released more easterly and the hits are a bit more accurate. Despite the input of 270@12 as the ck37 input? Inputting 090@12 just makes the error worse!

The AI wingmen won't release BK90 though, so I deploy them with 75's.

Anyway, as you may see, the second, wind corrected pass seems better?

Wind direction has always been pretty confusing in DCS, all the way back to the release of the A-10C.

Take a look at this 8 year old thread for example: https://forums.eagle.ru/showthread.php?p=1857496#post1857496

Wind direction has always been pretty confusing in DCS, all the way back to the release of the A-10C.

Take a look at this 8 year old thread for example: https://forums.eagle.ru/showthread.php?p=1857496#post1857496

Agreed!

I think that if we stick to entering the mission planner values into the ck 37, then we will get the wind "in game" correct! Even though "in game" it's actually blowing the opposite direction i.e. 090 v 270?

Is it just me, or do the A.I. wingmen not use the BK90?

Happy new year:)

Wind in DCS is incorrect from the ME and briefing page. It's a near decade old issue that has not yet been fixed. in game, all info for wind, as observed by the platforms that can give the info, such as the Viggen, Ka-50, ATC, etc, will give it you correctly. You can easily test this by setting up some smoke markers in the ME, setting your wind and starting the mission. The wind will blow in the opposite direction from where you've set it.

I.e. the wind will be reported the direction where it is blowing FROM. The ME and brief sets the wind where it is blowing TO. Heaven only knows why ED has not fixed this.