cannot produce and mssing track file JDAMS falling off target

[Sting_Array]

Hello - since the update, GPS Guided JDAMS no longer hit their target. By way of procedure, I have used the DCS Route Tool (in the F10 map) to place a waypoint over the target (when fully zoomed in). Elevation is set to 0 AGL. The resulting waypoint is then loaded into the F16 on next start - and with the ordnance powered on, and the aircraft fenced in, I fly directly to the target - releasing the weapon once the timer has reached 0 and the carat is 'in zone'. The bombs consistently fall off target (between 50 and 100 m would be my estimate.)

I have tried the same bombing run in the Hornet - and the same ordnance is accurate. This suggests a bug in the Viper (perhaps the return of an old bug involving the INS?).

Hoping this can be fixed - and, in the meantime, does anyone happen to know of any workaround?

Thanks

[rob10]

47 minutes ago, Sting_Array said:

Hello - since the update, GPS Guided JDAMS no longer hit their target. By way of procedure, I have used the DCS Route Tool (in the F10 map) to place a waypoint over the target (when fully zoomed in). Elevation is set to 0 AGL. The resulting waypoint is then loaded into the F16 on next start - and with the ordnance powered on, and the aircraft fenced in, I fly directly to the target - releasing the weapon once the timer has reached 0 and the carat is 'in zone'. The bombs consistently fall off target (between 50 and 100 m would be my estimate.)

I have tried the same bombing run in the Hornet - and the same ordnance is accurate. This suggests a bug in the Viper (perhaps the return of an old bug involving the INS?).

Hoping this can be fixed - and, in the meantime, does anyone happen to know of any workaround?

Thanks

Please post a (short as possible and preferably on Caucus map) track file.  You can save a track file from the debriefing window when you close the mission.  That will allow people to check that you're not missing a step somewhere or reproduce the bug.  ED devs also have additional tools that allows them to use a trackfile for more deeper debugging.

[Sting_Array]

Travelling for the coming week. Will post track file in about seven days. I mention this in case the lack of an immediate response is taken to indicate a lack of commitment to resolving this issue. S

[Pyrocumulous]

I am not experiencing any issue with F16C JDAM accuracy in 2.9.18.12722. For best accuracy, use targeting pod to refine actual target position and use laser ranging, adjust the impact angle to near vertical, release near the center of the launch window.

[Sinclair_76]

Bomb on coordinate or pre-planned JDAM (or JSOW ftm) is still borked. ED chose to implement JDAM relative mode but not (yet, if ever) absolute mode. Plenty of discussion regarding this matter in the past. 

On 7/27/2025 at 5:08 AM, rob10 said:

Please post a (short as possible and preferably on Caucus map) track file.  You can save a track file from the debriefing window when you close the mission.  That will allow people to check that you're not missing a step somewhere or reproduce the bug.  ED devs also have additional tools that allows them to use a trackfile for more deeper debugging.

Various tracks regarding this matter have been submitted and issue has been deisgnated as WIP by ED.edit ED pulled a 180 and are just going to leave it. They changed the tag from WIP to procedure revised. 

 

Further reading

 

https://forum.dcs.world/topic/349982-jdam-pre-mode-not-working/#findComment-5446118

Edited Wednesday at 09:19 PM by Sinclair_76

[RogueSpecterGaming]

On 7/26/2025 at 7:19 PM, Sting_Array said:

Hello - since the update, GPS Guided JDAMS no longer hit their target. By way of procedure, I have used the DCS Route Tool (in the F10 map) to place a waypoint over the target (when fully zoomed in). Elevation is set to 0 AGL. The resulting waypoint is then loaded into the F16 on next start - and with the ordnance powered on, and the aircraft fenced in, I fly directly to the target - releasing the weapon once the timer has reached 0 and the carat is 'in zone'. The bombs consistently fall off target (between 50 and 100 m would be my estimate.)

I have tried the same bombing run in the Hornet - and the same ordnance is accurate. This suggests a bug in the Viper (perhaps the return of an old bug involving the INS?).

Hoping this can be fixed - and, in the meantime, does anyone happen to know of any workaround?

Thanks

If you are putting 0 for the elevation then that is your problem. I also think you are misunderstanding what AGL means and how to use it. If you set the altitude for a Stpt in the F16 to 0 that is completely wrong.

 

Say you have a tgt and coords X, Y, and the ground is 1850 MSL. You wouldn't put 0 into the DED, because if you did then you are telling the system that at X,Y the elevation of the ground is at sea level. Doing this will move your stpt "under" the ground which would translate to your bombs hitting far away. The number you should put into your DED is the MSL of the ground, so in this case 1850. Now you are telling the system that at X,Y the ground is 1850 above MSL. I've never had a problem with GBU falling that far from a target. 50-100 meters pretty far outside the CEP. 

Go ahead and place a stpt and put the number you see for Altitude on the F10 map into the DED and try again.

And don't compare the Hornet's system with the Viper's. You will just further confuse yourself and others. 

[Sinclair_76]

2 hours ago, RogueSpecterGaming said:

On 7/27/2025 at 4:19 AM, Sting_Array said:

 

If you are putting 0 for the elevation then that is your problem. I also think you are misunderstanding what AGL means and how to use it. If you set the altitude for a Stpt in the F16 to 0 that is completely wrong.

That's the fastest way in ME to get AGL. The ME doesn't accept an altitude below AGL so it defaults to AGL in the altitude window.

 

Furthermore the F-16 is the only system in the DCS world that has location uncertainty introduced in it's INS/GPS (except for the F-15E, but they had JDAM relative and absolute mode figured out as well). Therefore it's the only system in the DCS world that can't deploy JDAM or JSOW preplanned effectively. 

Because the F-18 does not have a location error it can drop preplanned effectively.

 

Edited 23 hours ago by Sinclair_76

[RogueSpecterGaming]

2 hours ago, Sinclair_76 said:

That's the fastest way in ME to get AGL. The ME doesn't accept an altitude below AGL so it defaults to AGL in the altitude window.

 

Furthermore the F-16 is the only system in the DCS world that has location uncertainty introduced in it's INS/GPS (except for the F-15E, but they had JDAM relative and absolute mode figured out as well). Therefore it's the only system in the DCS world that can't deploy JDAM or JSOW preplanned effectively. 

Because the F-18 does not have a location error it can drop preplanned effectively.

 

He said route tool though. And ngl I've never used the route tool, so does it function the same way as the ME? Where if you put 0 it will auto adjust to MSL??

And correct. The JDAMs on the F-16 only uses Relative Mode (which the HUD should indicate but there is no indication currently). It also only uses the INS portion and not GPS. Hopefully sometime this year or next year we will see it get that. When we do get that we should get absolute mode at the same time. But this is also why we should not bring other aircraft into this discussion as the JDAMs on the other jets do not suffer from the same thing as the F-16 does. This is also a topic that has been brought up and talked about countless times. A quick search would get OP all his answers about this.