LOFT with Target Find integration troubleshooting

[MBot]

I have been trying to get LOFT working with the Target Find integration in order to enjoy WCRS enhanced LABS lofting (target insert with offset on IP, then the WCRS will guide you precisely to the loft location). But I am having troubles with the bombs landing consistently long. I don't think it is a general accuracy issue of the system, as on repeated tries all bombs land consistently on a similar spot 1.5 NM behind the target. I would appreciate if someone could help me troubleshoot this. An example is in the attached track.

This is the attack plan. IP is a railroad bridge, target is 170°/8.78 NM from IP.

This are the offset calculations using the bomb table. Offset as mode of delivery is used here only to calculate the N/S and E/W WRCS values which are entered in the WSO cockpit by hand. All other values to be ignored.

These are the calculations for the actual loft. Only Loft Angle and Release Range are used and entered manually in the WSO cockpit. All other values are ignored (not needed when LOFT is combined with Target Find).

This is the state of the pit before release. Note TGT FIND is in HOLD, TGT INS has been pressed on IP overflight (with hotkey from front pit) and ACTIVATE has been turned on after TGT INS.

Then steering cues provided by WRCS to the loft point are followed. When the loft begins, ADI pull up cues are followed and pickle is held to release (in WRCS supported LOFT you only press pickle after pull-up begins). In general the attack works mostly as intended.

The bombs lands 1.5 NM long. I noted in the instance of this track I was about 30 kts fast at release (580 instead of 550), but according to the bomb table that would only account for about 2'000 ft long and not 9'000 ft. In other attempts when I was slow the bombs still tend to land equally long.

Has anyone been able to get this to work consistently?

LOFT_WCRS.trk

 

---------------------------

The manual suggest that 1 second prior to pullup, a 0.38 sec beep is heard to signal AJB-7 activation. This is not happening in DCS and pullup is signaled without warning. Can Heatblur please comment on this?

https://f4.manuals.heatblur.se/stores/air_to_ground/bombs/employment/lofting_tossing.html

Edited Tuesday at 08:43 PM by MBot

[ldnz]

Hi, wouldn't you use pull-up range from your loft calculation as release range in the WRCS? Its the distance at which the WRCS will trigger the pull-up timer. I believe the weapons delivery manual calls for adding 1s pull up timer so you have a moments notice - so need to add 1s worth of distance to release range. 

also, aural tone volume is now set to zero on cold start, not sure if that is the source of the beep?

Edited Tuesday at 08:33 PM by ldnz

[MBot]

Lastly, I was really hoping to use LABS LOFT with Target Find integration to loft laser-guided bombs. The idea was that since this whole process generates a WCRS target (Target Insert with offset), Pave Spike could be put in WRCS acquisition mode and be pre-aligned with the target when coming out of the weapon delivery maneuver.

To my huge disappointment, Pave Spike WCS integration is unavailable in the LOFT weapon mode:

null

@Heatblur: Is this correct behaviour, even when LOFT weapon mode has been connected to Target Find with the TGT FIND switch in HOLD?

[Zabuzard]

Lastly, I was really hoping to use LABS LOFT with Target Find integration to loft laser-guided bombs. The idea was that since this whole process generates a WCRS target (Target Insert with offset), Pave Spike could be put in WRCS acquisition mode and be pre-aligned with the target when coming out of the weapon delivery maneuver.
To my huge disappointment, Pave Spike WCS integration is unavailable in the LOFT weapon mode:
null
@Heatblur: Is this correct behaviour, even when LOFT weapon mode has been connected to Target Find with the TGT FIND switch in HOLD?

FYI you can also do a LOFT for LGBs automatically out of the bombing mode TGT FIND with the Pave Spike.
It works trivially, similar to CCRP. Pod on target, hold bombing button, pull up, bombs auto-release at the right moment.

[MBot]

15 minutes ago, ldnz said:

Hi, wouldn't you use pull-up range from your loft calculation as release range in the WRCS? Its the distance at which the WRCS will trigger the pull-up timer. I believe the weapons delivery manual calls for adding 1s pull up timer so you have a moments notice - so need to add 1s worth of distance to release range. 

My understanding is that pullup range is the distance from IP to pull-up initiation, and release range is the distance from pull-up initiation to target. The sum of both therefore is the distance from IP to target. This seems to match up. Since WRCS just needs to know at what distance from the target it needs to start the LABS maneuver, I think the Release Range from the Bombing Table needs to be entered.

[MBot]

Just now, Zabuzard said:

FYI you can also do a LOFT for LGBs automatically out of the bombing mode TGT FIND with the Pave Spike.
It works trivially, similar to CCRP. Pod on target, hold bombing button, pull up, bombs auto-release at the right moment.

Yes have tried this extensively and it is somewhat successful:

 

The problem I have with it is that it is a bit unreliable. To get the release cues you have to put the pod into tracking mode first. When coming in at ground level for a loft, the angle to the target is very flat which can lead to gross errors in target distance. This affects both the precision of the initial ballistic trajectory of the laser-guided bomb and the positioning of Pave Spike at the end the delivery maneuver. It is often the case that pulling down from the bomb release and transitioning to the designation phase, the target is outside the field of view of Pave Spike and cannot be found. Because when the pod was put into track mode initially before (or during) the pull-up, the pod's sight line to the target was just too flat and it ends up tracking a point way ahead or beyond the target.

I can get this attack type to work in training and with multiple tries. But I would not trust it to work with just one chance after a 1 hour flight to target.

I was therefore hoping that LABS LOFT could be used together with a WCRS target. This way, the pod would not be needed for the actual weapon delivery portion of the attack and could be kept aligned with the WCRS target until the laser designation phase of the attack begins.

[MBot]

@Heatblur: Is the Release Range output in the Bombing Table for Loft taking into account the distance covered by the aircraft during the pullup or is this just the bomb ballistic range? The latter would explain pretty much match the error I am seeing.

[MBot]

Ok sorry guys, I think I have found my mistake. Indeed @ldnz was correct. Pull-Up Range in the Bombing Table is indeed measured from target and is the sum of the Release Range plus the distance covered by the pull-up maneuver. This can be double checked by inserting a loft angle of 90° in the Bombing Table, then Release Range becomes 0 and the Pull-Up Range is something like 7'000 ft. And with a loft angle of 0°, Release Range = Pull-Up Range. It didn't help that the respective WRCS input is also described as "Release Range Control" in the manual...

With this I am able to put bombs into the target area using LABS LOFT with Target Find/WRCS integration.

Now the only question I have left is whether WRCS mode for Pave Spike should remain unavailable in LABS LOFT even when this delivery mode is integrated with Target Find.

[Zabuzard]

7 hours ago, MBot said:

Now the only question I have left is whether WRCS mode for Pave Spike should remain unavailable in LABS LOFT even when this delivery mode is integrated with Target Find.

WRCS integration with the pod is only available with the weapon release in TGT FIND or DIRECT and the TGT FIND switch on the WRCS panel in NORM not HOLD. Further, the pod must be unstowed, ready for use and integrated with the INS.

In your case you have the weapon release mode in LOFT, not TGT FIND or DIRECT and further you have the WRCS switch TGT FIND in HOLD, not in NORM. So WRCS integration with the pod is not available and the WSOs Antenna Hand Control is instead integrated with the radar system.

See TO 1F-4E-2-38, p. 2-9, 2-14, 2-31, 2-33, 2-41, 2-45, further a direct explanation for NORM/HOLD at 2-48 and the electric wiring diagram for the WRCS panel towards the pod in Figure 2-11.

And also the normal Weapon Delivery manual TO 1F-4E-34-1-1, p. 1-99, 1-100, 1-103.

(If you can and have the docs available, please check the manuals before you question something to save us the time digging and verifying, thank you )

Edited Wednesday at 06:02 AM by Zabuzard

[MBot]

Thanks for your feedback. I have been using the in-game manual exclusively, which is a little bit sparse on the integration of LABS modes with WRCS.

I guess my quest continues to find a tactically sensible way to use laser-guided bombs in a high-threat low-level environment such as Cold War Germany. Probably the best way will be to just use Direct (as usual...), hand-fly a loft maneuver guided by the values for a loft from the Bombing Table and have Pave Spike pre-aligned with the WRCS target.

[MBot]

13 hours ago, MBot said:

I guess my quest continues to find a tactically sensible way to use laser-guided bombs in a high-threat low-level environment such as Cold War Germany. Probably the best way will be to just use Direct (as usual...), hand-fly a loft maneuver guided by the values for a loft from the Bombing Table and have Pave Spike pre-aligned with the WRCS target.

Ok, so I tried this out. Hand tossing the LGBs in Direct actually turns out to be surprisingly easy. I can easily get the bomb close enough on target without guidance. But here is the catch with Pave Spike:

When in Direct, Target Insert doesn't work correctly. The button doesn't illuminate but something happens none the less. Pave Spike in WRCS acquisition mode, by default looking straight down, now moves to align with a point in the distance. But it is not the point at the entered offset. It seems to be a point far away. A laser designation after bomb release is therefore impossible.

When in Direct and additionally putting the TGT FIND switch in the WSO pit into HOLD, on Target Insert a WRCS target at the selected offset is created correctly and the aircraft provides steering to it. So far so good. But now WRCS acquisition for Pave Spike is no longer available with the WRCS OUT light illuminated! Therefore the pod can again not be pre-aligned with the target.

This is so extremely frustrating. All the avionics elements for easy LGB lofting are available, but they are not all available at the same time.

Edited Wednesday at 08:28 PM by MBot

[Dragon1-1]

Keep in mind that the Pave Spike was a bit of a crock IRL. At least we have the updated software version which doesn't hopelessly lock the pod up when you fat finger your switchology. The original version would go into "idiot mode" and stop responding to commands if it wasn't operated exactly right.

[MBot]

I would be really interested how for example the 86th TFW in Ramstein intended to use laser-guided bombs with their Pave Spikes. Because I don't really see them doing medium-altitude level deliveries over East Germany.