BRU-55 with 2x AGM-154A ignores TOO2 coordinates

[vilson.farias]

Hi there.

I want to report a possible bug on the JSOW/JDAM, when we have two bombs on the same store and we are using the target of opportunity (TOO) option. 

In that scenario, the TOO2 coordinates are ignored and the second bomb is always using the TOO1 coordinate, even when they clearly have different coordinates assigned.

I added a step-by-step below and also included a track file demonstrating the issue. 

Scenario

• Have 4 BRU-55 with 2x AGM-154A each (8 missiles total)
• Have ASQ 228 AFLIR or AAQ-28 Litening 
• Create 8 vehicles on the ground
• Assign a waypoint for each vehicle, which will later be used as waypoint designators
• Make sure every waypoint has the altitude at ground level

Steps

• Go to the stores page and select JSC
• For every station STA, set “target of opportunity” TOO
• Set fuse to instantaneous
• Set launching to manual
• Go to MSN
• Make sure the TOO1 is selected
• On another screen, select the HSI
• On the HSI, select the first waypoint point to a ground target.
• Still on HSI, select WPDSG. You will see the coordinates for that waypoint will appear on the stores/MSN page
• On the MSN screen, then select the next missile in the BRU-55, using the TOO2.
• For the second missile, select the next waypoint on the HSI and repeat the process of WPDSG
• After the second missile has the new coordinates, select STEP to go to the next BRU-55.
• Repeat the process for the next 2 missiles, then go to the next BRU-55. Repeat until all 8 missiles have coordinates.
• After all the missiles have coordinates, navigate one by one and make sure every missile's coordinates is pointing to a different ground target.
• Continue flying until you are in range for the launching
• When in range, press the bomb release button over and over until all the missiles have been launched

 

Expected

• All 8 targets should be hit.

Seen

• For every BRU-55, the second missile (TOO2) is always ignoring its own coordinates, hitting the same target designated for the missile 1 (TOO1)
• Targets 1, 3, 5, and 7 are hit twice (TOO1 targets). Targets 2, 4, 6, and 8 are ignored (TOO2 targets).

Notes

• I see the same behavior on JDAMs mounted in pairs.

TOO2_bug.trk

TOO2_bug.trk

[Harker]

Sounds like correct behavior. TOO1 and TOO2 (as well as PP1-6) refer to the station, not to the individual munitions on that station. The JSOWs will go "wherever the station says they should", at the time of launching.

Also, TOO1/2 and PP1-6 are station specific and are not shared between stations (using QTY or otherwise).

For example, if you select to TOO1 on STA2, and fire the first JSOW, then you must manually switch to TOO2, if you want to use the TOO2 coordinates for the second JSOW on STA2.

[Zahnatom]

1 hour ago, Harker said:

Sounds like correct behavior. TOO1 and TOO2 (as well as PP1-6) refer to the station, not to the individual munitions on that station. The JSOWs will go "wherever the station says they should", at the time of launching.

Also, TOO1/2 and PP1-6 are station specific and are not shared between stations (using QTY or otherwise).

For example, if you select to TOO1 on STA2, and fire the first JSOW, then you must manually switch to TOO2, if you want to use the TOO2 coordinates for the second JSOW on STA2.

is there a "per weapon" designation planned or will it just be like this forever

[bfr]

26 minutes ago, Zahnatom said:

is there a "per weapon" designation planned or will it just be like this forever

If my memory serves it sort-of worked like that for a while (might've been per station rather than per individual weapon) originally in DCS and then it was changed to the current behaviour because that is how it works in real life and the original behaviour was wrong. So in answer to your question, it'll stay like this unless someone provides conflicting proof that it works differently in real life.

[vilson.farias]

2 hours ago, Harker said:

Sounds like correct behavior. TOO1 and TOO2 (as well as PP1-6) refer to the station, not to the individual munitions on that station. The JSOWs will go "wherever the station says they should", at the time of launching.

Also, TOO1/2 and PP1-6 are station specific and are not shared between stations (using QTY or otherwise).

For example, if you select to TOO1 on STA2, and fire the first JSOW, then you must manually switch to TOO2, if you want to use the TOO2 coordinates for the second JSOW on STA2.

Thanks for the explanation.

If I understand it correctly, would this procedure be possible instead?

- HSI/WPDSG 4 targets into TOO1 (targets 1, 3, 5, and 7 )

- HSI/WPDSG 4 more into TOO2 (targets 2, 4, 6, and 8 )

- Reselect TOO1 for all stations

- Select the stations under QTY

- Launch ( They will hit targets 1, 3, 5 and 7 )

- Reselect TOO2  for all stations

- Select the stations for QTY again

- Launch ( They should hit targets 2, 4, 6 and 8, right? )

 

 

 

[Harker]

Thanks for the explanation.
If I understand it correctly, would this procedure be possible instead?
- HSI/WPDSG 4 targets into TOO1 (targets 1, 3, 5, and 7 )
- HSI/WPDSG 4 more into TOO2 (targets 2, 4, 6, and 8 )
- Reselect TOO1 for all stations
- Select the stations under QTY
- Launch ( They will hit targets 1, 3, 5 and 7 )
- Reselect TOO2  for all stations
- Select the stations for QTY again
- Launch ( They should hit targets 2, 4, 6 and 8, right? )
 
 
 

Yes, all steps look correct. As long as you remember to select TOO1 for each station, launch from each station, then change each station to TOO2, and launch, you should be able to hit all eight targets.
(Correct on the QTY use as well: QTY will just allow you to drop from multiple stations, the weapons will still go to their respective targets.)

[vilson.farias]

Thanks a lot @Harker, I finally figured out that TOO1 and TOO2 are just station's memory slots and have nothing to do with the missiles/bombs itself. 

[MarkyMark]

I think this thread inadvertently solved a problem I’ve been having, where if I drop multiple JSOW or jdams, I sometimes get 2 hits on 1 target instead of getting proper spread out hits. Perhaps as the weapons are dropped and stepped to the next station it works fine, but the next target designate on the flir doesn’t update when it cycles back to station 1 (that is to say, the memory doesn’t update for some reason, even though I update and redesignate in flir when the release sequence cycles back to station 1 after 1-2-3-4.

Not sure what I’m doing wrong when it cycles back to an already used station, but I think that’s it.