CBU 97 nothing

[Lobo_63]

I'm sorry, but I don't find not lasing to be an adequate explanation for the behavior exhibited in my no-hit tracks.

 

MagnumHB have you watched this great vid by ExcessiveHeadspace?

 

[159th_Viper]

I'm sorry, but I don't find not lasing to be an adequate explanation for the behavior exhibited in my no-hit tracks...

 

Herewith your custom mission flown with no laser utilized, in both instances 6 out of 7 kills:

 

105 High Altitude - no laser.trk

 

105 High Altitude #2 - no laser.trk

[Crescendo]

They do not open early - they open at the set HOF, ie 1800ft AGL: It is the altitude at release that is a factor. If released too low, the 97 does not have sufficient 'falling' time to complete a satisfactory ballistic trajectory onto the target.

 

It's clear from external view: Had the 97's dispenser skin not been severed, it would have impacted on target at the trajectory it was travelling at. The submunitions are then arrested mid-flight by the parachutes which bring the munitions up short. Had the 97 had more time to travel, it's ballistic trajectory would have brought it over the targets at the moment the skin was severed as opposed to the result when releasing at too low an altitude. This of course accords with your findings as in your above post, with the added comment illustrated by the tracks attached that a High-Altitude drop will completely mitigate the behaviour you experience, as illustrated in the following tracks:

 

Thanks for the reply, Viper.

 

I do understand that releasing CBU-97s at higher altitude will typically promote a more 'normal' ballistic trajectory, as I mentioned in my first post (which you acknowledged above). I personally only flew as high as 10000ft MSL in the "Easy - East Georgia - Spring" mission, so perhaps that explains my issue.

 

However, it is my experience — at least around the Kobuleti Target Range — that CBU-97s do not follow a ballistic trajectory at low altitudes. I have always assumed that this is normal IFFCC behaviour designed to specifically mitigiate the problem of BLU-108s falling short of the target at low altitudes. In these circumstances, it is my understanding that the CBU-97 trajectory is similar to the "Optimal" trajectory of a laser-guided GBU-12, only more exaggerated. That is, the impact point is calculated somewhere ahead of the target such that the CBU-97 has sufficient energy to ensure that the 1800ft AGL HoF release point occurs directly over the target.

 

This is illustrated in the following track, where I release a CBU-97 using CCRP at ~2700R and ~250KIAS over the Kobuletic Target Range:

 

CBU-97 - Kobuleti Target Range - 2700R.trk

 

As demonstrated in the above track, the CBU-97 is clearly on an "Optimal"-esque trajectory. It then detonates above the targets such that the BLU-108s parachute down directly on top of them.

 

Now, consider the following track, where I release a CBU-97 using CCRP at ~2700R and ~250KIAS in the "Easy - East Georgia - Spring" mission:

 

CBU-97 - Abisi-Psta - 2700R.trk

 

Note in the above track that the CBU-97 does not have an "Optimal" trajectory and thus releases its submunitions short of the target. The difference between it and the Kobuleti example is quite stark. Also note the radar altimeter after the pickle point: The terrain is essentially flat, so the CBU-97 radar altimeter HoF over 'bumpy' terrain does not appear to be the culprit.

 

What is going on here? :huh:

[Crescendo]

This looks like the same problem I was having: http://forums.eagle.ru/showthread.php?t=84124 . Releasing the bombs from a high altitude compensates for the problem because the trajectory is much closer to vertical when they reach the HOF.

 

Thank you for posting that link. Your experiences correlate with the tracks I posted above.

 

The Abisi-Psta region in my second track is 1000ft+ above sea level, and the CBU-97 falls short.

[159th_Viper]

 

What is going on here? :huh:

 

That is what we need to figure out :)

 

It probably appears as if I sometimes come across as argumentative.......definitely not my intent. I (or any other tester for that matter) just need to narrow/hammer the issue down to it's smallest possible parts before we submit an issue as a bug-report, hence the to-and-fro discussions/tracks flying about etc etc. Sort of making 100% sure you got your sh*te straight before confronting the missus regarding a potential PC upgrade. Same with a bug report - Devs are demanding and a stickler for details.

 

That said, does disabling the radar altimeter of the CBU have any effect on the outcome? I have not looked at that myself.

 

Edit: Just followed Rotareneg's link - it appears as if the issue is already known to the Devs. Will teach me to follow links prior to posting :)

[MagnumHB]

MagnumHB have you watched this great vid by ExcessiveHeadspace?

Yes, and the differences in lasing vs. non-lasing accuracy described in that video are negligible in the scenario being discussed here.

 

Herewith your custom mission flown with no laser utilized, in both instances 6 out of 7 kills:

I haven't watched the tracks yet since I'm at work, but I'm very interested to see why your results are better than mine.

 

Edit: Just followed Rotareneg's link - it appears as if the issue is already known to the Devs. Will teach me to follow links prior to posting

I also had not seen that thread. I look forward to future developments in the next patch.

[159th_Viper]

I haven't watched the tracks yet since I'm at work, but I'm very interested to see why your results are better than mine.

 

I suspect it's altitude. The thought occurred to me and the only thing different is our release parameters, ie I am higher. Now why that would influence the behaviour of the skeets, ie to target or ignore based on a coupla thousand feet is the next question that needs answering.

 

In any event, it seems as though it's a separate issue from the one Crescendo/Rotareneg has been describing. I'll tinker some more and report.

[Crescendo]

It probably appears as if I sometimes come across as argumentative.......definitely not my intent...

 

Viper, no offence taken on my end! Hashing things out like this is often inevitable when picking nits.

 

That said, does disabling the radar altimeter of the CBU have any effect on the outcome? I have not looked at that myself

 

If this is acheived by toggling "FZU39" to "No", then no, I don't believe it has any noticable effect. I don't have track evidence at this time, but from memory the BLU-108s still fell short in the "Easy - Spring" mission, and behaved normally in the "Kobuleti Target Range" mission.

 

Right now I'm going to bed, but I can post some tracks tomorrow if you haven't already done so yourself.

[MagnumHB]

I suspect it's altitude. The thought occurred to me and the only thing different is our release parameters, ie I am higher. Now why that would influence the behaviour of the skeets, ie to target or ignore based on a coupla thousand feet is the next question that needs answering.

This is what I don't understand either. It seems to me that radar altimeter burst fuzing and dispenser parachute deployment should negate any effects of differing (reasonable) drop altitudes by placing the skeets in roughly the same place in 3D space, in the same attitude.

[159th_Viper]

This is what I don't understand either. It seems to me that radar altimeter burst fuzing and dispenser parachute deployment should negate any effects of differing (reasonable) drop altitudes by placing the skeets in roughly the same place in 3D space, in the same attitude.

 

Agreed.

 

I'll run further tests on the current tester's build and report the issue if still present.

[chardly38]

This thread went bigger than i thought. I dont play A10c alot compared to BS2 thats every day. Im using that mission to learn. I have no idea how to set up the cbu 97s. I wish i had the 9. version to install to see if the problem goes away.

Edited February 6, 2012 by chardly38

[159th_Viper]

I wish i had the 9. version to install to see if the problem goes away.

 

The problems that exist at present are capable of being 'circumvented', so to speak. As such nothing is preventing you from deploying CBU's - they do work :)

[ergn]

I have previously made my own tests and noticed the 'falling short' behavior, though when I watched from other camera angles, the ballistics seemed correct as if it was a non-cluster bomb.

After the tests, I always drop CBU with that in mind (target a little away from the target). It is even more fun with moving tank formations :). You align yourself with the movement line and try to estimate the offset distance.

[MagnumHB]

Agreed.

 

I'll run further tests on the current tester's build and report the issue if still present.

Any updates Viper?

[159th_Viper]

Any updates Viper?

 

I'll get back to you in the morrow.

 

 

Edit: OK - earlier than planned, but as per the current build it would appear as if all the issues have been resolved.

 

Test conducted with your altitude mission provided earlier to ensure conformity, with satisfactory results. The dispenser skin severs at an appropriate AGL with a trajectory that deposits the BLU-108's down the throat of the intended target, which IIRC was cause for concern #1.

 

Cause for concern #2 was the apparent inability of the BLU-108 to dispense the skeets/skeet behaviour, dependant on drop-altitude, resulting in them not firing/deactivating without targeting, also solved at current build. Test mission scored 6 kills at top-right target, dropped at 18000ft, whilst target at centre-right got 3 kills, which if you have regard to the target location, ie sitting on the side of an almost 45 degree incline of a cone-shaped mountaintop is probably to be expected, said drop from 16000ft.

 

So yeah, in conclusion I am happy to report that at this stage in proceedings it seems as if both issues have been adequately addressed.

Edited February 10, 2012 by 159th_Viper

[Jona33]

When you say current build do you mean the latest testers build?

[MagnumHB]

Sounds great, thanks.

[159th_Viper]

When you say current build do you mean the latest testers build?

 

Yes.

[EinsteinEP]

IIRC, after being dispensed, the BLU-108 skeets will detonate when they find a target (each skeet has a coning search pattern, so there's no assurance of 100% coverage or that multiple skeets won't go after the same target), or when they stop spinning (i.e, hit the ground).