Precision with Mk82s and CBUs

[Oznerol256]

Hi everybody!

 

I always miss with Mk82's. I have stopped taking them into combat since i dont manage to hit anything with them. Do you know any trick or technique to make using them more precise?

 

I also miss with CBUs. I usually pick the CBU-105 to get the Wind Corrected Dispenser. However, the CBU submunitions always drift off the target quite far. So i dont really hit the way it is intended with CBU.

 

If somebody out there is able to get some precision with CBUs or Mk82s would like to see you post a track, video, tutorial or something like that to show how its done correctly. I want to get somewhat useful with these weapons

[Settingz85]

Mk82´s are dumb bombs. Try to engange at a lower altitude. CBU´s always drift away because of wind effects. Set HoF to a lower value, like 500feet.

[Oznerol256]

Thanks. Ill try that.

[PhoenixBvo]

If you want to do it right, read this thread: 476th vFG, 76th vFS "Battle Book". It's all there and there is really no way around it for unguided bombs.

 

EDIT: If you find yourself asking what all the acronyms mean, have a look at post 14 and post 36.

Edited April 8, 2013 by PhoenixBvo

[WildBillKelsoe]

Mk82´s are dumb bombs. Try to engange at a lower altitude. CBU´s always drift away because of wind effects. Set HoF to a lower value, like 500feet.

 

I beg to differ. Mk-82 are indeed dumb, but if you're releasing them while doing 300+, they are like throwing knives.... OP: INCOMING!!!!

[Furious]

In CCIP I always drop the 82s a bit long, just fater the pipper has gone over targets, seems to do the trick.

In CCRP, I often have to drop one, see where it splashes, and come back for a second run, compensating with the tgp for drift. (if first one was long/right, I aim second short/left). Usually works

[Zenra]

I'm no expert and PhoenixBvo already referred you to the battle book from the 476th which is awesome, but for me using CCIP and dive bombing ( as opposed to toss bombing ) is the way to go with the 82's.

 

Experiment with the HOF setting for CBU's, and set your SPI to a location upwind of your intended target. As with a lot of things in the A-10C it's not all about switchology - practice and experience count for a lot.

[Oznerol256]

I'm no expert and PhoenixBvo already referred you to the battle book from the 476th which is awesome, but for me using CCIP and dive bombing ( as opposed to toss bombing ) is the way to go with the 82's.

 

Experiment with the HOF setting for CBU's, and set your SPI to a location upwind of your intended target. As with a lot of things in the A-10C it's not all about switchology - practice and experience count for a lot.

 

How low do you release the Mk82s when dive bombing?

 

And this upwind setting of the SPI...I thought that would be the sense of my IFFCC to calculate the wind in CCRP bombings. Addtionally, im using the CBU-105 which handles like a JDAM and should automatically correct the wind. Why would it else be called "Wind Corrected Ammunitions Dispenser"?

 

However, this doesnt seem to work as advertised. Now i have to know in what direction the wind blows to set the SPI somewhat upwind. I think i get that information somewhere in the CDU?

[Nealius]

I think the problem with the CBU-105s is that the the bomb casing's trajectory is wind corrected. The BLU-108 submunitions that come out of the casing are not wind corrected and they hang by parachutes. The higher your HOF the longer the BLU-108s will float around and the farther off target they will drift due to wind. In one of my little training missions I have set up I will drop two CBU-97s in CCIP from 9,000 feet with a HOF of 800 and spacing of 300. Even dropping in the middle of the tank column the wind will push the submunitions so far that I only kill 3 or 4 tanks at the very end of the column.

Edited April 8, 2013 by Nealius

[Oznerol256]

I think the problem with the CBU-105s is that the the bomb casing's trajectory is wind corrected. The BLU-108 submunitions that come out of the casing are not wind corrected and they hang by parachutes. The higher your HOF the longer the BLU-108s will float around and the farther off target they will drift due to wind.

 

I already thought something like that. So i have to set the SPI upwind according to the HOF.

 

Still cant believe that. I mean the bomb knows everything! The current wind can be calculated while the bomb is in flight or even be digitally sent to the bomb prior to release. The bomb knows the HOF it is gonna use and the bomb knows the current radar altitude. Why the hell isnt this $360,000 thing calculating the wind if it is even called "Wind Corrected Ammunitions Dispenser" and "precision-guided weapon" ?

[Ich666]

In CCRP, I often have to drop one, see where it splashes, and come back for a second run, compensating with the tgp for drift. (if first one was long/right, I aim second short/left). Usually works

 

This might be a dangerous habit in RL, coming back to drop a second bomb because the first one didnt hit leaves the enemy plenty of time to defend properly the next time you arrive on the scene.

[Nealius]

I already thought something like that. So i have to set the SPI upwind according to the HOF.

 

I guess that's the best way to do it. I know there is a CDU page somewhere that gives current wind direction/speed, but I can't remember where it is.

 

If at all practical I would roll in on the target with a tailwind.

[Mt5_Roie]

I found that with the CBU-103 you need to drop them around 6,000ft and watch for wind. As for the MK82 and MK82 Air you have to be flying pretty low to get accurate. I would say around 3000 ft as the least. Just my experience though and yes I do need to practice more. I've been doing the Dragon's training missions for JTAC and just loading it with bombs each time.

[Nealius]

How well does the Mk82AIR work at 3,000? The last time I tried anything above 500ft they drifted in the wind...so I went lower and got so shot up my cannon, ILS, and CDU were knocked out.

[Mt5_Roie]

Works alright, I would not say dead on. I did manage to hit two trucks at that altitude. You really have to make sure there isn't any crazy wind, and don't descend too fast. But I was using CCRP because that's what Dragon's training had it on and it would not change to CCIP mode.

[PhoenixBvo]

Again, read the other thread guys. The battlebook contains proper release altitudes in combination with dive angle, speed and base alt.

After I practiced that I hit a BMP on its head using one MK82 with a high altitude profile (base 14000ft and release at 9000ft). Now I won't tell you that happens every try, but I do get pretty good results.

[Nealius]

I've looked at the battlebook, but there's one thing that it doesn't explain: How the hell do you know that you are 1.3nm away from the target without putting a steerpoint right on it? The only answer I got was "use canopy cues" which helps a little, but it is still impossible to get exactly 1.3nm (or whatever the profile calls for) using nothing but your eyeballs.

[Eddie]

The only answer I got was "use canopy cues" which helps a little, but it is still impossible to get exactly 1.3nm (or whatever the profile calls for) using nothing but your eyeballs.

 

You don't need to be "exactly" at 1.3 NM. 1.25 or even 1.2 will work fine, you just might end up with your dive angle being a bit off. Likewise +/- 5 degrees from your planned dive angle won't cause major issues.

 

The point of CCIP, as opposed to old school manual bombing, is that CCIP adjusts so that minor errors in your attack profile will not prevent accurate weapon delivery.

 

That said, if you are at the proper base altitude and you have the target on the correct canopy reference (and therefore at the correct angle below you) you will be at the correct distance. If two parameters of the triangle are correct, the others will be too. It's just simple trigonometry.

 

It's the base alt, base speed, and the quality of your roll in that most impact your delivery.

[Sierra99]

And this upwind setting of the SPI...I thought that would be the sense of my IFFCC to calculate the wind in CCRP bombings.

 

"CCRP MODE.

The CCRP Mode adds the capability for weapons deliveries out- side the HUD FOV by using SPI. The CCRP Mode adds a CCRP, which allows a delivery of rockets and bombs over larger en- velope of release conditions than with the CCIP and also al- lows the use of flares. The CCRP Mode display includes a Pro- jected Bomb Release Line (PBRL), Solution Cue, Time-To-Re- lease Numeric, Release Angle Numeric, Azimuth Steering Line (ASL), and Rocket Steering Line.

The CCRP function is not available when the navigation mode displayed on line 1 of the CDU is GPS-only (G). Refer to TO 1A-10C-34-1-1 for detailed description of CCRP operations.

(TO 1A-10C-1)

 

 

Addtionally, im using the CBU-105 which handles like a JDAM and should automatically correct the wind. Why would it else be called "Wind Corrected Ammunitions Dispenser"?

 

The key word is "Dispenser".

 

JDAMS are "Dumb" bombs with parts added to guide the bomb to the Desired Point of Impact DMPI coordinates are feed to the JDAM guidance kit when you set SPI telling the bomb exactly where you want it to Land...

 

CBUs are guided the same way, But in the case of a CBU, you are only guiding the "Dispenser" to the point in the sky where it can deploy its submunitions. Submunitions aren't dumb, But they aren't guided. (If you set a CBU to function at 0 feet it will hit right where you aim it.... And make a hole.) The lower you set the function altitude the more accurate your drop because the wind will have less effect on the submunitions.

(Which leads to the discussion of submunitions coverage, weapon effectiveness... Blah blah blah:smilewink:)

 

However, this doesnt seem to work as advertised. Now i have to know in what direction the wind blows to set the SPI somewhat upwind. I think i get that information somewhere in the CDU?

 

CDU waypoint page... Not sure if that's surface wind or winds a loft though.

[Oznerol256]

Quite right. Good explaination.

 

However, it isnt that hard to calculate the expected wind drift if you know the parameters of the wind. So the IFFCC or the guidance module on the dispenser could apply the offset automatically (maybe this functionality could be turned off in the DSMS profile). It is not going to be precise to the inch but it doesnt need to. It is a cluster bomb. But ignoring the wind drift completely doesnt lead to errors as small as the bomblets can compensate.

 

Sadly, this precision guided weapon doesnt account wind after the dispenser lets the submunitions fly.

 

Wait...if you drop dump bombs, the wind is calculated by the IFFCC right? CBU-97s are dropped as if they were dump bombs. I think here again we have a similar problem than the problem with the CBU-105: IFFCC isnt using the data that is available. AFAIK, IFFCC is not accounting for the fact that CBUs separate and open parachutes. This means the bomb is always released wrong since it will fly much longer than the IFFCC thinks.

 

After all, with all the CBUs you have to guess how far they are going to drift with the wind. Not that 21th-century-style that the CBUs are advertised to be.

[Eddie]

Given that when properly employed there isn't enough time for the BLU-108s to drift any significant distance before releasing the skeets ideally don't see the problem.

 

Reduce your HoF to an appropriate value.

 

HUD symbology and a few DSMS functions/options aside, WCMDs are correctly implemented, as are un-corrected CBUs.

[Oznerol256]

HUD symbology and a few DSMS functions/options aside, WCMDs are correctly implemented, as are un-corrected CBUs.

 

I didnt say that CBUs are wrongly implemented, i just said that it is a poor precision system. As they are closely modeled, they must have the same problems in reality.

 

Given that when properly employed there isn't enough time for the BLU-108s to drift any significant distance before releasing the skeets ideally don't see the problem.

 

There are two different HoFs on the CBU-97. The first one says on what height the BLU-108s should be released. The seconds says when the BLU-108s should release the skeeds. The drift of the bomb mainly occurs while the BLU-108s are hanging on the chutes. So basically i want to reduce the time the chute is used. On the other hand, this time allows the BLU-108s to drift away from each other, making the effective area of the cluster bomb bigger. What does the HoF in the DSMS really specify?

[Nealius]

 

That said, if you are at the proper base altitude and you have the target on the correct canopy reference (and therefore at the correct angle below you) you will be at the correct distance. If two parameters of the triangle are correct, the others will be too. It's just simple trigonometry.

 

 

I guess the main thing I need to work on is getting myself in the right base position. It seems to be much easier if you are going after a point target rather than lining up on a column.

[Sierra99]

Quite right. Good explaination. Sadly, this precision guided weapon doesnt account wind after the dispenser lets the submunitions fly.

 

Well, yes and no... It really doesn't need to if you set it up properly.

 

Watch this video:http://m.youtube.com/#/watch?v=AKdFCsycYm8&desktop_uri=%2Fwatch%3Fv%3DAKdFCsycYm8

 

 

As you can see, the bomblets cover a wide area...

 

Wait...if you drop dump bombs, the wind is calculated by the IFFCC right?

 

No. Wind is not factored by IFFCC

 

CBU-97s are dropped as if they were dump bombs.

 

Because they are unguided free fall bombs. (Just like adding a JDAM guidance kit to a MK84 turns it into a "smart bomb" adding the WCMD turns a CBU 97 into a CBU 105)

 

I think here again we have a similar problem than the problem with the CBU-105: IFFCC isnt using the data that is available. AFAIK, IFFCC is not accounting for the fact that CBUs separate and open parachutes. This means the bomb is always released wrong since it will fly much longer than the IFFCC thinks.

 

I'm going to differ to the propeller heads who actually designed the IFFCC to comment on weather or not its operating properly or weather it's making use of the data available.

 

After all, with all the CBUs you have to guess how far they are going to drift with the wind. Not that 21th-century-style that the CBUs are advertised to be.

 

If you're dropping a CBU, you obviously aren't looking for pinpoint accuracy...if you were, you'd be dropping a GBU Or LGB

[Oznerol256]

No. Wind is not factored by IFFCC

 

It is not!? What unit calculates the wind instead?