CBU-105

[Dragan]

Hello, I have a small problem with the use of cluster bombs, specifically the CBU-105, when I create some of my missions I set a minimum wind, literally a breeze, when I get to the target area I drop the 105 on the targets, from a height between 11/12,000 feet, it happens that they totally fail, sometimes I drop only one, sometimes two, but very often it happens that they don't hit a group of vehicles at all, what's wrong or where am I wrong? However, as for the CBU-97, they are much more deadly, I use them even from 10,500 feet and they usually destroy all targets in one or 2 passes...

I forgot to write that I eject them in CCRP mode.

Edited May 24 by Dragan

[ASAP]

Without a track file or more detail its hard to say.

Are they missing downwind? The CCRP solution puts the bomb at the desired point of function. Maybe you are aiming them to the wrong spot.  Once the canister functions the sensor fused weapons drifts down under a parachute until the weapon activates when it sees a target. If you are aiming them right above the target the canister might open and then the wind pushes the sub munitions off target. Try aiming up wind maybe?

[EricJ]

Yeah that's I agree with what you suggest, or find out the wind in a mission (if possible). I used a CBU-105 I believe and while it impacted, it only hit a few targets, but I'm guessing that was due to spread of the targets rather than any issue with any wind (which I believe there was none).

EDIT: i just came back from a training scenario and it seemed to work fine for me. I mean if there's wind it's not affecting the bomb or munitions significantly.

Edited May 24 by EricJ

[Dragan]

I didn't pay too much attention to aiming upwind or crosswind, I simply threw them at a group of vehicles that were lined up in a diamond formation, so the group of vehicles wasn't scattered either, I fired them as I wrote and in CCRP mode when I get a countdown of 10 and hold the button, I know that of course, but I was never satisfied with their killing, as is the case with the CBU-97, and I mentioned that, their killing proved to be very deadly, at least for me,compared to 105..

[EricJ]

I'll try the -97 sometime, may just be how the system works or a bug or some other reason it's doing that. I think at the altitude I drop it at is reasonable for engagement of multiple vehicles, though they're spread out more than your formation, so that may be a factor too.

[Dragan]

I set the wind to 3/6/9/12 m per second ( From the ground to 8000) the average altitude is 11 to 12,000 feet, is this altitude enough for the CBU-105, is there a problem with the wind, I assume it is not because they have wind correction + sensors that indicate it

Edited May 24 by Dragan

[EricJ]

Well I looked up the definition (Okay it was Wikipedia), but didn't mention any notion of it correcting for wind. I don't know off the top of my head if it does, or it just is messed up by the wind or not.

[Yurgon]

4 hours ago, ASAP said:

If you are aiming them right above the target the canister might open and then the wind pushes the sub munitions off target.

That shouldn't be the case, as far as I can tell.

It used to be DCS made WCMD activate right over the target, so that the CBU-105's ballutes were getting drifted off target by the surface winds. Which, for a wind corrected munitions dispenser, always seemed a fairly odd thing to do. IIRC several forum users said that's not how the system works in real life and that the IFFCC should account for wind so that the submunitions have the best possible chance of hitting the targets, with the aimpoint being the targets themselves.

I don't recall the exact version, but there was a DCS update that made WCMD do exactly that. I tested that with an aimpoint right over a group of targets with a ridiculous crosswind of something like 50 knots on the surface, and the CBU-105 wreaked havoc on that target group.

If it no longer works like that, it would indicate a change and possibly a bug in DCS.

Without a track, it's hard to tell why OP's CBU-105 missed, though.

[Dragan]

I don't know if the CBU-105 has a problem with DCS, I have a problem with them, compared to the CBU-97 with which I am satisfied. I will test them these days and try to add a save track so we will see, it is very possible that they need ideal conditions, whatever that may be...

[Dragan]

I completed one night mission with a combination of CBU-105, with minimal wind, the effect was solid, Shilka and T-55 were attacked, perhaps the effect could have been better given the circumstances, but in addition to 4 CBU-105s that were dropped individually, I had to operate with my wingman with AGM-65, GBU-12/38 bombs, but also with M 151 APKWS in order to completely kill all vehicles in the area of action...

LastMissionTrack.trk

[Yurgon]

Is that a 2 hour track?

When reporting a problem in DCS, it really is up to you to make the report short, concise, to the point. If you can generate a 1 minute track to showcase the issue, that's perfect. It it absolutely needs to be 5 minutes long, no worries.

2 hours? Good luck finding anyone who'll even try to watch it. Plus, the longer a track runs, the higher the odds of the replay showing something completely different from what you experienced in it.

I thought this was something that had come up numerous times in the past. Tracks need to be short in order to analyze bugs and issues.

[Dragan]

Somehow, logically, I send complete missions for a detailed analysis of everything in the mission.That's the only reason, it's not a bad intention.Sorry

[Yurgon]

2 hours ago, Dragan said:

Somehow, logically, I send complete missions for a detailed analysis of everything in the mission.

Sure, if the question was "Can you critique my approach to this mission and give me a debrief", then a track of the full flight would be perfectly sensible.

That's just not the question you asked. Always try to isolate the one issue that is pertinent to this question, and try to create a short track that shows this issue. In other words, a track should be as long as necessary and as short as possible.

[Dragan]

I completed another mission. With minimal wind, CBU-105 was fired, only one on a group of 12 tanks, destroying 9, new passage, another cluster fired, destroying the remaining 3 tanks, height 11000 feet, I will test with increased wind for all 4 parameters, I will report the result, for the first time I am satisfied with the achieved effects..

Lest I forget, every pass was in the direction of the wind strictly before the bomb was dropped.

Edited Monday at 08:50 PM by Dragan

[A10Yoda]

Sorry for the late response as I have been missing from the forums for a bit.

The CBU 105 

HOF is a key factor to the weapon.  DCS unfortunately does a poor job of altitude sourcing for QFE in the A10.  Not saying that's your problem, just stating it's a small part of the problem.  Sourcing your current QFE at the altitudes you listed will help with this problem so you can adjust your MSL.  HOF is for function over target.  Anything over 3000 AGL you are risking the disks to be blown way off target.  While the CCRP attempts to correct for WIND (If Tabled correctly), if the HOF is also off because your QFE is wrong, it will add to the severity of them being blown off target.

At the altitudes listed, the computer has no RADAR altimeter to Delta the elevation area and get a mixed QFE.  

While you are missing with the 105 and hitting with the 97 would likely be due to HOF being way out of parameters to get you over the intended target.  Proper Ingress/Egress keyholing would also help the wind blow your disks over the target area.  Allowing the disks more time to identify targets in the area.

Changing your ALT SRC switch likely to delta won't help with this issue as I still believe it has yet to be modeled properly to my knowledge and again too high for Radar altitude sourcing anyways.

Edited Thursday at 04:29 AM by A10Yoda

[Dragan]

Hello, I have never adjusted the HOF for either the CBU-105 or 97, I simply went with the default setting, I still have to try with stronger wind at least in the lower levels to the ground, so far the wind has mostly been weaker, I will try adjusting the HOF as well, I know about those settings.With the action of a weaker wind, the performance is solid, but for bombs of this purpose that have wind resistance, I assume it has to be much, much better.

Edited Thursday at 11:08 AM by Dragan

[Yurgon]

9 hours ago, A10Yoda said:

DCS unfortunately does a poor job of altitude sourcing for QFE in the A10.

I was under the impression that A-10Cs work with QNH pretty much exclusively, because all IFFCC calculations assume the pressure in reference to MSL, not AGL. Is that not correct, or did it maybe change over the last couple of years?

Also, in what regard does DCS do a bad job here? I can't say that it's correct as is, I'm just not aware of an existing issue.

[EricJ]

I don't find it a problem as the targets I practice on are dispersed, so effects vary depending on where I drop it (I don't do anything special either, I just use the default setting). So I don't know if it's an issue to look at, or intended behavior. I can do what Dragan did and put some targets together and see if anything spectacular happens though.

EDIT: I hit the majority of targets (like 5 or six with eight grouped together. Some of the disks either missed or hit so I guess it worked? This was against eight vehicles parked beside each other, and I guess the expectation that the whole CBU-105 would have killed them, but five or six out of eight isn't bad.

Edited Thursday at 03:31 PM by EricJ

[Dragan]

42 minutes ago, EricJ said:

I don't find it a problem as the targets I practice on are dispersed, so effects vary depending on where I drop it (I don't do anything special either, I just use the default setting). So I don't know if it's an issue to look at, or intended behavior. I can do what Dragan did and put some targets together and see if anything spectacular happens though.

EDIT: I hit the majority of targets (like 5 or six with eight grouped together. Some of the disks either missed or hit so I guess it worked? This was against eight vehicles parked beside each other, and I guess the expectation that the whole CBU-105 would have killed them, but five or six out of eight isn't bad.

Each of the 8 targets had 5 or 6 hits, excellent job, can you provide wind data, all parameters, whether you were flying into the wind or sideways, and of course the height from which the bombs were dropped.Was only one bomb dropped or two?

Edited Thursday at 03:43 PM by Dragan

[EricJ]

1 hour ago, Dragan said:

Each of the 8 targets had 5 or 6 hits, excellent job, can you provide wind data, all parameters, whether you were flying into the wind or sideways, and of course the height from which the bombs were dropped.Was only one bomb dropped or two?

I can just give you the mission I use (no wind that I know of, it's an old mission that I've used for practice). I can't give you much of that data because I don't concentrate at it, I may do a short track and give you the data that way, but I don't think drop height makes a difference if it's pre-programmed to disperse the submunitions at a specific height, which was default, and it was just one (I carry one only on my preferred loadout). But I did do an East-West approach if that matters. Overall the vehicles are parked in a formation (you'll see on the mission, the island above Kobeleti.

Flying.miz

Edited Thursday at 04:59 PM by EricJ

[Dragan]

Wind should always be taken into account, mostly because of reality and everything else, I often add wind between 15 and 20 km per hour at 2000 meters, for example today the wind at my house is about 20 km per hour.And it's unbelievable that it's easier for me to fly with stronger wind than with minimal, maybe it's just become a habit for me.I especially love cloudy and bad weather, it's phenomenal in DCS, the low clouds are a challenge for avoiding SAM missiles.All of this together that I mentioned is not a problem for the CBU-97, they kill without a second thought in all conditions.That's why I don't like risk with 105..

Edited Thursday at 05:34 PM by Dragan

[EricJ]

Ahh gotcha, but I consciously (or subconsciously) don't add wind to any of my missions. It's not an oversight, just something I don't feel the need to do for missions. I mean I could fly in them, but it's not a worry of mine to add it.