cannot reproduce CDU-99 with FMU-140 not working

[Dsaniel]

I tried a million configurations, but, no matter what, the fuse is never triggered and the bomb never opens (VT1).

 

cbu99.trk

[BIGNEWY]

Hi Dsaniel

We ran your track and we are observing the bomblets deploy and explode. Perhaps you are not seeing it because the way you set it up they explode off target.

 

[Dsaniel]

They don’t deploy in my computer, I’ll upload another track with a video next week

[SloppyDog]

Maybe the bomblets are not having time to arm. The canister may be opening but the bomblets are not arming in time. Depending on the altitude you are releasing the bombs, they need time to open and arm the submunitions. You cannot release the bombs from a high altitude and set the burst altitude too low, otherwise you are not giving enough time for the bomblets to arm. Refer to the following thread: 

Also, I attached a spreadsheet showing the calculated height above ground that the bomblets will armed.

Line 36 of the spreadsheet refers to your first run. You released from 19,000 feet with a VT1 of 700 feet AGL.  The problem with this setting, considering a standard ARM Delay of 1.2 seconds, is that the bomb will open 33.73 seconds after release and be armed at 34.93 seconds. It gives an altitude of -625.36 feet AGL, meaning that the bomblets will hit the ground before being armed.

For the other bombing runs, with the burst setting at 2,200 feet AGL, it gives the bomblets enough time to arm, being able to arm at around 1,000 feet AGL over the target (lines 33 to 35 of the spreadsheet).

However, the problem I noticed is that with CBU-99 you need to be right on the money when attacking the target. As precise as you should be using Mk-82s, for example. If you hit a little bit off, the bomblets won't have much effect, or none at all. And by releasing them from altitude, the bombs miss by a little and the bomblets cannot have an impact on target. 
See the attached track file. I make one run from altitude with no effect, and the another at low level, with much success. From my testing, CBU-99 and Mk20 work way better at low level, from 1,000 to max 5,000 feet over the target. 

 

CBU-99 Height of Function.xlsx F-18 - CBU 99 - FMU-140 High and Low.trk