Viper GBU-12 Bombs not following TGP laser guidance - Dawn raiders

[scotth6]

Hi,

I've been flying DCS for quite a few years, on and off, but mostly flying the A-10C and the F/A-18, with some shorter time in the F-16, F-14 and other older jets.

I have just started getting into the F-16 properly, but am having some issues getting the GBU-12s to follow laser guidance.  They just seem to come off the jet and fly their default trajectory, despite the TGP having a point track/lock on a target, and the laser firing.  I am just using the default 1688 code and have not changed that on the bombs or the TGP.  I have mostly been flying the Dawn Raiders mission over and over trying to correct my mistakes, but I can't figure out what mistakes I'm making to not get the bombs to follow the laser.  It is firing, I have the targets (launchers) in view in point track but the bombs just miss by a mile.  I am dropping from about 27000 feet and have the laser firing time set to 18 seconds.  I will attach a track from the last flight if that can provide insight into what I am doing wrong.  Thanks.

laser gbu12 miss.trk

[buceador]

This track is from a MP server and is huge!  Can you create a simple SP mission to demonstrate the problem?

[greenmamba]

stupid question ... is the laser on ? Do you see the L flashing ?

[BIGNEWY]

20 minutes ago, scotth6 said:

Hi,

I've been flying DCS for quite a few years, on and off, but mostly flying the A-10C and the F/A-18, with some shorter time in the F-16, F-14 and other older jets.

I have just started getting into the F-16 properly, but am having some issues getting the GBU-12s to follow laser guidance.  They just seem to come off the jet and fly their default trajectory, despite the TGP having a point track/lock on a target, and the laser firing.  I am just using the default 1688 code and have not changed that on the bombs or the TGP.  I have mostly been flying the Dawn Raiders mission over and over trying to correct my mistakes, but I can't figure out what mistakes I'm making to not get the bombs to follow the laser.  It is firing, I have the targets (launchers) in view in point track but the bombs just miss by a mile.  I am dropping from about 27000 feet and have the laser firing time set to 18 seconds.  I will attach a track from the last flight if that can provide insight into what I am doing wrong.  Thanks.

laser gbu12 miss.trk 43.45 MB · 4 downloads

Hi, 
I have not checked the track yet, but have been using GBU-12 without any issue and can not reproduce. 

if you can reproduce the issue in single player or a shorter MP track it would help. 

thank you 

[_SteelFalcon_]

Is the laser code in the jet the same as the bomb code indicates on the first page of your Kneeboard? if not, adjust the laser in the jet.

[scotth6]

No idea why the track is so large, but I only use single player.  This track is from the Dawn Raiders mission so maybe it's large because of that?

[scotth6]

I only seem to have this problem in the mission "Dawn raiders".  I have created a  few practice missions in the mission editor, and the GBU-12 is hitting target designated with the TGP.  In Dawn raiders, which I just flew again, the laser is firing, the code is set to 1688, but the bombs just free fall.

laser gbu12 miss 2.trk

[_SteelFalcon_]

58 minutes ago, scotth6 said:

the code is set to 1688

The code in the jet on the DED and on the first kneeboard page are identical? If not, set DED codes to the same as you find on kneeboard.

[scotth6]

1 hour ago, _SteelFalcon_ said:

The code in the jet on the DED and on the first kneeboard page are identical? If not, set DED codes to the same as you find on kneeboard.

 

Yes, as far as I can tell they are identical.  I haven't touched the kneeboard codes, and they show 1688.  Also haven't touched the TGP codes previously, but they showed 1688.  Tonight I did go into Laser settings during startup to set time for laser firing, and those codes originally showed 1688 but then changed to 0.  I went to set them back to 1688, but then they reset themselves to 1688.  May have just been something that happens during startup.  In any case, as far as I can tell, codes match up.  Next step is to try different codes I suppose .

[scotth6]

Update - After flying Dawn Raiders again tonight, I FINALLY got the LGB to guide onto target.  I did change a whole heap of things, so not sure which helped, if any.  Instead of using pairs I used a single LGB on the Scud launchers (although I then successfully dropped a pair of GBU-12s on to the building at the airfield).  Before startup I set a completely different code in the kneeboard (1521) and then changed to that code on the TGP.  I set lase time to 15 seconds instead of 18.  I bypassed the hold at WP1 and headed straight to the target.  I flew directly over the target instead of orbiting.  Will report back if I narrow down any issues.  Now I just need to figure out why the TACAN isn't working and the EHSI won't show direction or range, although I think I just read why on another post (not confirming L/L during alignment).

Edited March 27, 2024 by scotth6

[scotth6]

OK, issue solved, in a way.  Flew the entire mission again today, and after hitting enter on the DED on each Lat/Lon field and altitude during alignment, the navigation issue was solved, range and distance was showing on the EHSI, datalink was working, and bombs hit targets.  I can't say that solved the original issue though, because as written in the above post, I had successfully guided the bombs on target with the TGP before I had figured out I needed to confirm the Lat/Lon during alignment.  So, still not sure why the guidance wasn't working the first 6 times I flew the mission.  It's probable that I forgot to hit a button somewhere, but can't be sure what.  In any case there is no issue now.

[Willie Nelson]

I remember reporting that in this mission the altitude of one of the targets is spuriously set at 18,000 feet. It is still the case I believe.