Unrestricted SATNAV option incorrectly affects BLUFOR JF-17s

[tae.]

Hello,

After many, many (way too many) hours of trying to figure out why it felt like the JF-17 GPS guided weapons seemed to break at complete random in my sorties, I have finally found the issue.

Summary

The "Unrestricted SATNAV" option does not work as intended for the JF-17. As I understand it, the intended functionality for the "Unrestricted SATNAV" option for missions is supposed to deny REDFOR the capability to use GPS, limiting it to BLUFOR coalition aircraft only. Unfortunately it seems that in the current patch, if "Unrestricted SATNAV" is false, ie. no GPS for REDFOR, this will actually also affect all JF-17s on BLUFOR too. I have tried many countries within BLUFOR and none seem to provide the JF-17 with GPS functionality, not even USA, unless "Unrestricted SATNAV" is enabled and enforced. If this is intended then obviously this report can be discarded, but I don't think it is intentional based on how this mission option is supposed to work, and how it works with other aircraft in DCS.

How to Reproduce / Check

1. Edit the "Unrestricted SATNAV" option of any mission to False and make sure it is enforced by the mission. Alternatively, head to Settings>Gameplay and untick "Unrestricted SATNAV", and play a mission where "Unrestricted SATNAV" is not enforced to true.

2. Create/spawn/play as a BLUFOR JF-17 in the mission as a hot or air start (HNS set to INS+GPS automatically). Alternatively cold start but ensure HNS is turned on during start (set to INS+GPS).

3. GPS will be unavailable - JF-17 seems to INS drift and GPS guided munition drops will be inaccurate (observing LS6 weapon drops is a quick way to test).

Workaround / Comments

The issue can be easily worked around by ensuring that "Unrestricted SATNAV" is enforced to true in any mission featuring BLUFOR JF-17s. However, this is not an ideal situation for missions where REDFOR should have the restriction, but BLUFOR should not. Additionally, it is possibly enforced off for many online servers, missions and end users accidentally, leading to ambiguous issues with weapons that aren't immediately clear - I personally spent many hours unable to reproduce this issue (everything working fine), and an equal amount puzzled as to why I suddenly missed everything I dropped following the same procedures, due to flying many different missions and servers in my DCS playtime - some presumably having the option enforced off, and others having it enforced on.

 

Track Files

Please see attached track files, and short description of each one below:

jf17_USA_unrestricted_satnav_off: BLUFOR/USA JF-17 dropping 2xLS6-500 and 4xLS6-250 on 6x BTR-80s, in TOO mode via. WMD-7 point tracks. All 6 weapons are inaccurate/miss indicating limited/no GPS and/or INS drift.

jf17_USA_unrestricted_satnav_on: BLUFOR/USA JF-17 dropping 2xLS6-500 and 4xLS6-250 on 6x BTR-80s, in TOO mode via. WMD-7 point tracks. All 6 weapons are pinpoint accurate indicating GPS is available.


Cheers

jf17_USA_unrestricted_satnav_off.trk jf17_USA_unrestricted_satnav_on.trk

[sylkhan]

On 8/20/2024 at 11:35 PM, tae. said:

As I understand it, the intended functionality for the "Unrestricted SATNAV" option for missions is supposed to deny REDFOR the capability to use GPS, limiting it to BLUFOR coalition aircraft only.

No, redfor has GPS but with reduced accuracy.

I did some test and i confirm that unrestricted satnav affect the blue JF-17 :

Blue JF-17 unrestricted satnav off --> accuracy reduced ?
Blue JF-17 unrestricted satnav on --> good accuracy

Red JF-17 unrestricted satnav off --> good accuracy ?
Red JF-17 unrestricted satnav on --> good accuracy

it seems that DCS has turned the tables for the JF-17, red is blue, and blue is red :)

 

Edited September 17, 2024 by sylkhan

[tae.]

2 hours ago, sylkhan said:

No, redfor has GPS but with reduced accuracy.

I did some test and i confirm that unrestricted satnav affect the blue JF-17 :

Blue JF-17 unrestricted satnav off --> accuracy reduced ?
Blue JF-17 unrestricted satnav on --> good accuracy

Red JF-17 unrestricted satnav off --> good accuracy ?
Red JF-17 unrestricted satnav on --> good accuracy

it seems that DCS has turned the tables for the JF-17, red is blue, end blue is red :)

 

 

Oh, interesting. Thanks for helping confirm and the extra testing!

[SpecteRED]

I think its major bug. This bug block to use any gps bombs on almost all servers. @uboats

[Bigity]

Wonder if ED has even acknowledged the problem.