Istari6 Posted January 7 Posted January 7 THE PROBLEM My group recently moved to flying "2007 era Vipers" after several Liberation/Retribution campaigns set in other eras (1986, 1996). These other campaigns allowed us to learn the DCS Viper progressively (CCIP bombing in the 80s, HTS/HARM in the 90s, etc). So we know the Viper well, but only recently started using the latest weapons like JDAM, JSOW and CBU-105. In our campaign, we found ourselves repeatedly missing targets with JSOW and CBU-105 WCMD. At first we thought it was due to mistakes in our switchology or understanding of the weapons, but we kept checking and rereading the manual, and still kept missing. This was getting quite frustrating. Finally on our 9th campaign mission when one of us launched four CBU-105s and every single one hit with a similar deviation from the target, we became convinced it must be a mod conflict or bug. RESEARCH TO DATE I've run a series of tests to try to isolate the issue. I created a test mission with flagpoles to mark distance off the target (for deviation) and flew the same approach each time for delivery. Of many variables tested, the only one that controls the behavior seems to the presence of "winds aloft". When winds aloft are blowing, JSOW and CBU-105 miss every time with consistent deviations. When winds aloft are reversed exactly 180 degrees, the weapons miss by exactly the same deviation on the other side of the target. When winds are set to zero, they impact accurately. I've repeated these results over and over to confirm them. Here are some other variables I checked and confirmed OK before submitting this bug: - GPS System Accuracy (DED) - HIGH in all cases - Area Track isn’t being commanded properly - (e.g. check TMS Right bound properly) - bound properly - Once commanded, Area Track isn’t being established - checked symbology in TGP - Once established, Area Track isn’t passing to JSOW - tested via target far off STPT - Laser ranging - done before release in all tests Here's a set of variables tested that showed no effect. - Hot Start vs In-Flight - Map: Syria vs Nevada - XRNeckSafer active vs not running - INS Drift over Time (flying >30 min to target versus start nearby) - Retribution Mission (with included mods like Splash Damage) vs Non-Retribution Mission (with baseline mods) - Single Player vs Multiplayer - Modded DCS vs Vanilla DCS (all mods removed except TacView) HOW TO REPRODUCE Use the attached test missions. - In each, fly an approach to STPT 1 at CRS 190, 24,000 ft and release CBU-105 at ~6.9-7.2nm. Observe impact deviation when winds are present using flagpoles near SA-15 at STPT 1. - Then turn and fly out beyond 20nm and fly same approach (190 CRS, 24,000 ft) and release JSOW at 19-20 nm. Observe impact deviation when winds are present using flagpoles near SA-15 at STPT 1. Track files are included: - In 1st track (Winds), 3:45 is CBU-105 missing wide of SA-15. 9:30 is JSOW missing wide of target. - In 2nd track (No Winds), 3:43 is CBU-105 impacting target, 8:30 is JSOW accurately blanketing wreck of previously hit SA-15. WINDS ALOFT USED This is the Winds Aloft settings I used. These were generated by Liberation for a mission we had those 4 CBU-105 misses in, so I used them for my testing. I don't believe the bug is restricted to these particular wind values. TEST 1 T 34C 30.34 QNH 0900 5 kts at 33 ft, 159 deg 10 kts @ 1600 ft @ 159 29 kts @ 6600 ft @ 139 37 kts @ 26000 ft @ 171 39 Turbulence TEST 2 (all same except for following) 0 kts at 33 ft, 159 deg 0 kts @ 1600 ft @ 159 0 kts @ 6600 ft @ 139 0 kts @ 26000 ft @ 171 0 Turbulence CLOSING Please let me know if there's other information that would be helpful. CBU105_JSOW_TestZeroWinds_010624.trk CBU105_JSOW_TestNormalWinds_010624.trk Nevada Hot Start_2007_JSOWTesting_NoMods.miz Nevada Hot Start_2007_JSOWTesting_NoMods_NoWind.miz 5
ED Team Lord Vader Posted January 9 ED Team Posted January 9 Hello @Istari6 I have raised this internally for analysis. Thanks. 3 Esquadra 701 - DCS Portugal - Discord
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