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WCMD CBUs don't compensate for wind.

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    WCMD CBUs don't compensate for wind.

    When using CBUs like the CBU-105 (which is only CCRP), instead of compensating for the wind, the CBU would fly and deploy above the SPI, instead of a location which should compensate for wind.

    As long as the LASTE system has the needed wind data, using CBU-87s and 97s with CCRP will result in the expected behavior, i.e... the CBU will fly in a location into the wind, so when it deploys, the parachute cartridges will be blown right on target. Meanwhile the wind corrected munition will not do that and act as if you dropped a non WCMD munition without wind data.

    This makes the CBU-105 useless in wind conditions, where it should be better.

    I dive down so the LASTE can enter wind data for all altitudes.

    You can see that the CCRP solution does give a lead into the wind when releasing, but on release, the WCMD munition immediately steers its self towards the SPI
    Attached Files
    'Shadow'

    Everybody gotta be offended and take it personally now-a-days

    #2
    Bump !
    'Shadow'

    Everybody gotta be offended and take it personally now-a-days

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      #3
      I thought the wind correction of the WCMD in real life only applies to the dispenser, not for the submunitions.
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        #4
        That is true, but not the issue I am reporting.

        Every other system compensates for the wind, so the dispensers flies to a point in the air, where when it opens, the wind will fly the sub-munition to the target.

        The WCMD munition right now, when released will steer back towards your target point and when it opens, the sub munition will be blown away from the target
        'Shadow'

        Everybody gotta be offended and take it personally now-a-days

        Comment


          #5
          This is correct behaviour, submunitions drift is not accounted for. You need to account for any submunitions drift by adjusting the desired impact point, attack profile, and weapon settings accordingly.
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            #6
            Doesn't this make it kinda useless ? How are you to know what the wind is and compensate for it ?

            If I can fly trough the target area low and get the wind data in the LASTE, well might as well use a -97 with CCRP which will put the bomb in the correct place in the air for the sub-munition to be blown over the target.

            Can you share how should the -105 be used ?

            Well, I guess it kinda does make sense if you are attacking a big field of armored vehicles where a little bit of offset won't hurt much
            Last edited 04-03-2020, 04:37 PM.
            'Shadow'

            Everybody gotta be offended and take it personally now-a-days

            Comment


              #7
              If detailed weather information is not available, adjust the aim point up wind slightly and set the HoF to the lowest practical value. With a 500ft HoF there is minimal drift. HoF does not chance the submunitions footprint for the BLU-108, they always function at the same altitude, it only impacts how long they spend drifting on the parachute. Higher HoF is only required in terrain with large elevation variations.
              476 vFighter Group Public Discord Channel | 476 vFG Website

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                #8
                Originally posted by Eddie View Post
                If detailed weather information is not available, adjust the aim point up wind slightly and set the HoF to the lowest practical value. With a 500ft HoF there is minimal drift. HoF does not chance the submunitions footprint for the BLU-108, they always function at the same altitude, it only impacts how long they spend drifting on the parachute. Higher HoF is only required in terrain with large elevation variations.

                Although HoF (meaning when the canister "pops") should change the footprint (i.e. the area covered.) More time in the wind=more dispersal.

                Then yes, the submunitions function at the same altitude, but if the canister pops at 2000ft (AGL, we're always talking AGL, right?) and you have a 30knots wind the area covered (thus the density per sq. km, so to speak) should be different than canister popping at 500ft and no wind THEREFORE the chance to hit varies a lot.



                I would think that the current implementation of the CBU-105 (IDK what's a BLU-108 is) is faulty... but knowing how the government procures things, that's probably how it works in real life (as in: it sucks).
                Last edited 04-04-2020, 04:40 PM.

                Comment


                  #9
                  I am still puzzled by this and I know that I will not be able to find any public information to back this up, I still find the way the 105s are done to be illogical.

                  I talked with an WSO, I know different platforms and so on, but what he told me is that on the platform in question, 105s acted as I expected and not how they are on the DCS A-10. They would compensate for wind in such a way, that their shutes will hit over the designated target, unlike with the DCS A-10, where the canister will guide to the designated target and you have to manually compensate for the wind....

                  It is so illogical, that you might as well go with CBU-97, with wind data present, the computer will compensate automatically, so the shutes hit the target
                  Last edited 05-20-2020, 02:50 PM.
                  'Shadow'

                  Everybody gotta be offended and take it personally now-a-days

                  Comment


                    #10
                    Originally posted by SPAS79 View Post
                    Although HoF (meaning when the canister "pops") should change the footprint (i.e. the area covered.) More time in the wind=more dispersal.

                    Bigger HoF wont result in more dispersal. 105 submunition is released so relatively close together (they wont have a mile spread between each other where difference in wind speed/direction might have an effect on individual drift), there is not much difference in wind for each single one. Theyll just drift downwind further as a closed group with little to no change in distance in between.


                    Hence you choose lowest possible HoF so you minimize drift if your targets are pretty much at the same height level.


                    If you got a group of targets on a slope or rugged terrain with (for example) 500ft difference in height between targets, increase HoF (to probably 1000ft) and compensate SPI a bit for additional drift (judge this distance by experience -> direction and speed by weather data, looking at smoke or dust drift or other indicators for direction/speed etc.).
                    Gone for good.

                    Comment


                      #11
                      Health Warning- the following is all speculation and not based on real world experience.
                      The wordage of 'wind corrected' might be misleading. The tail kit is potentially only guiding the weapon to the target point and correcting for that, not for the spread of submunitions once deployed. This leads me to my main point-
                      I wouldn't mind betting that a lot of people are not employing the weapon correctly. If dropped from high altitude the ballistic trajectory will reduce the footprint. People are compensating for this by raising the HoF. Instead it should be employed in a relatively threat free environment at low level and high speed. The design itself is a tactically limiting one in terms of how it is most effectively employed in terms of sticking them in the face of the target. I did a quick test and obtained good results with a low level run. Ive attempted to include the track.. The following article explains it better I think.. of course the 97 would do a cheaper job.. Textron have stopped producing the 105- there was a bit of bad publicity after a load of bomblets drifted downwind in Yemen and killed civilians, so our problem does have real world counterparts.
                      https://www.globalsecurity.org/milit...ns/cbu-105.htm
                      Attached Files
                      Last edited 06-11-2020, 08:09 PM.

                      Comment


                        #12
                        Originally posted by Shadow KT View Post
                        I am still puzzled by this and I know that I will not be able to find any public information to back this up, I still find the way the 105s are done to be illogical.

                        I talked with an WSO, I know different platforms and so on, but what he told me is that on the platform in question, 105s acted as I expected and not how they are on the DCS A-10. They would compensate for wind in such a way, that their shutes will hit over the designated target, unlike with the DCS A-10, where the canister will guide to the designated target and you have to manually compensate for the wind....

                        It is so illogical, that you might as well go with CBU-97, with wind data present, the computer will compensate automatically, so the shutes hit the target
                        I agree with Shadow KT.
                        What it seems is that the CBU-97 falls upwind, and when the case is opened, the chutes will drift over target.
                        With the CBU-105, the bomb opens up right over the target, then the chutes will drift away.
                        What I see is that CBU-105 is guided like a JDAM (that's the purpose of the WCMD kit), thus opens up exacly over the target area. It makes sense with a normal JDAM, that must be guided to the target point, regardless of the wind. But makes no sense with a cluster bomb.

                        Anyway, the only way I got to make CBU-105 work satisfactorily is by reducing Height Of Function to 700-900 feet.
                        This is an amazing sim! 'Nuff said!

                        YouTube: SloppyDog

                        Comment


                          #13
                          Originally posted by Sunscreen View Post
                          Health Warning- the following is all speculation and not based on real world experience.
                          The wordage of 'wind corrected' might be misleading. The tail kit is potentially only guiding the weapon to the target point and correcting for that, not for the spread of submunitions once deployed. This leads me to my main point-
                          I wouldn't mind betting that a lot of people are not employing the weapon correctly. If dropped from high altitude the ballistic trajectory will reduce the footprint. People are compensating for this by raising the HoF.
                          Exactly that. The WCMD compensates for drift BEFORE the bomb opens and only guides the bomb to the target area. It does not compensate for chute drift. So, the only way it worked for me is by reducing HoF to 700-900 feet. This way the bombs opens very close to the ground and the submunitions act faster, not drifting too much away from the target.
                          Last edited 10-19-2020, 07:09 PM.
                          This is an amazing sim! 'Nuff said!

                          YouTube: SloppyDog

                          Comment


                            #14
                            Originally posted by RodBorza View Post
                            Exactly that. The WCMD compensates for drift BEFORE the bomb opens and only guides the bomb to the target area. It does not compensate for chute drift. So, the only way it worked for me is by reducing HoF to 700-900 feet. This way the bombs opens very close to the ground and the submunitions act faster, not drifting too much away from the target.
                            This.

                            Afaik the WCMD are INS guided. That means they actively steer towards the designated tgt - even if wind tries to blow them off course. But once they released the submunitions, there is no INS anymore, only dumb bomblets.
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