LGBs veering off at last minute

[Capn kamikaze]

I've been trying to learn the A-10C recently and I've encountered a problem, I've completed the LGB/JDAM training mission with no problems, but on a mission I have built I am dropping a GBU-12 on a BRDM and when it gets within about 2 seconds to impact it just veers off, I have tried using the auto laser mode and the manual one, and on the auto laser one I've set the timer to 60 seconds, to make sure it is on.

 

My question is does the BRDM have a laser jammer or something?

[fltsimbuff]

I've been trying to learn the A-10C recently and I've encountered a problem, I've completed the LGB/JDAM training mission with no problems, but on a mission I have built I am dropping a GBU-12 on a BRDM and when it gets within about 2 seconds to impact it just veers off, I have tried using the auto laser mode and the manual one, and on the auto laser one I've set the timer to 60 seconds, to make sure it is on.

 

My question is does the BRDM have a laser jammer or something?

 

Are you turning in such a way that your laser on your TGP gets masked just before impact? Note that it can be masked while the video is not. The flashing L will change to something else when it is masked (I can't remember what, possibly an M)

[Yurgon]

[...] and on the auto laser one I've set the timer to 60 seconds' date=' to make sure it is on.[/quote']

 

Well that is pretty much guaranteed to result in a miss. :)

 

There are some very nice explanations around here. To put it shortly: LGBs should fall ballistic and only engage guidance a few seconds before impact. If you lase 60 seconds (from most altitudes that would be right at release), the bomb will actively steer towards the laser spot as soon as it picks it up and will bleed all its energy trying to follow/chase it (this applies regardless of moving or static target).

 

You should lase anywhere between 8 to 15 seconds prior to impact. I usually use 10 seconds and the hit rate is very good.

 

If that doesn't solve your problem, you should post a track.

[Deezle]

I don't think the GBU-12s even begin tracking the laser until ~15 seconds before impact, they certainly don't appear to be anyways.

 

Make sure your TGP is SPI, if you're releasing where your steer point is and not where the TGP is pointing, you'll never hit your target.

 

Yes, SPI, not SOI, brainfart.

Edited December 19, 2015 by Deezle

[fenderplayer946]

Further to Deezle's post, make sure TGP is set as the SOI.

 

This is confirmed by the appearance of TGP in the bottom left area of the HUD. (normally it will read TAD for steerpont guidance)

 

Edit: This is done via TMS forward long :)

 

Enjoy

 

Jord

Edited December 18, 2015 by fenderplayer946

[Yurgon]

Small correction to the previous posts: It's SPI (or SPI generator), not SOI.

 

When releasing LGBs, the Sensor of Interest is actually of little interest. :P

 

The important thing is the Sensor Point of Interest, and the sensor that currently generates this SPI is what's written in the lower left corner of the HUD. :thumbup:

 

And yes, it's a common problem to have a target beautifully tracked in the TGP, and then release the bomb - but with SPI still set to STPT... let's just hope this won't turn out to be a blue-on-blue situation... :music_whistling:

[fenderplayer946]

Small correction to the previous posts: It's SPI (or SPI generator), not SOI.

 

Doh, thats the fella!

 

Thanks

 

Jord

[Capn kamikaze]

Are you turning in such a way that your laser on your TGP gets masked just before impact? Note that it can be masked while the video is not. The flashing L will change to something else when it is masked (I can't remember what, possibly an M)

 

Nope, a nice gentle 15 or so degree bank to the left, the laser is flashing, and i'm dropping in CCRP mode.

[Capn kamikaze]

Well that is pretty much guaranteed to result in a miss. :)

 

There are some very nice explanations around here. To put it shortly: LGBs should fall ballistic and only engage guidance a few seconds before impact. If you lase 60 seconds (from most altitudes that would be right at release), the bomb will actively steer towards the laser spot as soon as it picks it up and will bleed all its energy trying to follow/chase it (this applies regardless of moving or static target).

 

You should lase anywhere between 8 to 15 seconds prior to impact. I usually use 10 seconds and the hit rate is very good.

 

If that doesn't solve your problem, you should post a track.

 

That would explain them falling short, but they're not, they're suddenly flying off to the side, the bombs clearly have enough speed that energy isn't a problem, the target is static, and I am doing everything that I do in the training mission, the only difference is instead of shipping containers on a runway it's a BRDM, according to the training mission you can set the laser to be on from release.

 

Correction, it's a BTR-80

Edited December 18, 2015 by Cap'n kamikaze

[fenderplayer946]

Ey up Cap'n,

 

Just another thought, is your laser latch set to on? If its not and the laser stops emitting that could explain the deviation of the weapon, such as suddenly loosing track mid-course adjust.

 

cheers,

 

Jord

[Yurgon]

Square one, we meet again.

 

If that doesn't solve your problem, you should post a track.

[Capn kamikaze]

I'll do a track, I've just ran through the training mission again, and scored 4/4 hits with 2 GBU-12's and 2 GBU-38's, I'm setting up everything as I have in the training mission, and all four times now the bomb has done this weird thing.

 

I'll have to leave it until tomorrow to post the track though.

[Yurgon]

In 1.5 OpenBeta, I also just created a test mission with different types of enemy APCs/IFVs, including a BTR-80, and scored 4 out of 4 with GBU12, no problems.

 

I think a track is really going to help narrow it down. BTW, which version of DCS are you running?

[Capn kamikaze]

1.5, and I can get them to guide if I manually las the target, what it seems to be doing is the laser is turning off about two seconds before impact no matter what I set the timer to.

[Mike5560]

After an LGB release, you can turn left 30 degrees (If TGP is mounted on the right wing) engage alt/hdg autopilot and not have to worry about the TGP becoming masked. I've been able to go up to a 50 degree left turn at higher altitudes <13,000ft.

 

That's for self lasing, JTAC terminal guidance or a buddy lase on multiplayer it's different. If you drop, then turn where you please.

[Capn kamikaze]

I've uploaded a track to the DCS server, as soon as it is approved I'll post a link here.

[Harzach]

I've uploaded a track to the DCS server' date=' as soon as it is approved I'll post a link here.[/quote']

 

You can just attach it to your post.

[Capn kamikaze]

Laser turning off.trk

 

Ok this is a bit weird, I've built a completely separate mission, and it works fine in that, the only major difference is the location of the targets has a much better contrast with the ground, but I don't see why that would matter to a laser seeker.

[Capn kamikaze]

You can just attach it to your post.

 

Thanks, didn't know that. :)

[FUgaijin]

i set the laser to 30 sec and it never misses. altitudes range from 5-18k. just make sure you have the L and its flashing.

[Deezle]

I watched your track. You never set the TGP to be your SPI generator, therefore you dropped the bomb over the steerpoint which is the SPI by default.

[Capn kamikaze]

Right I'll try again.

[Capn kamikaze]

That doesn't seem to be making any difference, the vehicles are not moving, and as long as the pod is pointing at the target that should be what is getting lased.

 

Anyway, I've managed to get a hit there now, but in doing so and playing about with the mission editor I've noticed something very strange in that part of the map, it looks like the map in the editor does not line up with the map in the game, as part of trying to figure this out I set a few waypoints right on top of the targets so I could just point my sensor right at the waypoint and it should be pointing right at the vehicles, and I tried this in another mission in another part of the map and it worked perfectly, well until the pod failed "autolase fail", they were right in the cross hairs, but in the area of the map of this mission they're out by about a thousand ft, the waypoint in the game is further than it is in the editor, I don't know if there is something weird about this area of the map, maybe it's distorted and doesn't line up with the ME map.

[Yurgon]

That doesn't seem to be making any difference' date=' the vehicles are not moving, and as long as the pod is pointing at the target that should be what is getting lased.[/quote']

 

I watched your track. You dropped the GBU12 on the steerpoint, which was way short of the target you lased. If you don't understand why that's a problem, sorry, you didn't do your homework.

[Blackeye]

To elaborate further your SPI (sensor point of interest) is -among other things- the place where the computer assumes you want drop your bombs on and the CCRP is given for that point.

 

The place where your (current) sensor is pointing to might be different and it usually is if you start moving your TGP around.

So after you have found a target you need to tell the computer that the point your SOI (sensor of interest) is currently looking at should be your new SPI.

Once you've done that all calculations will be updated to reference the new SPI.

 

Here's what the TAD looked like when you released the GBU (left) and what it should look like (right)

 

 

In the left picture the green diamond (TGP) is pointing to your target, however the SPI (white wedding cake) is still at its default position, i.e. the current steer point.

Pressing TMS up long (LCtrl up?) will set the SPI to your SOIs target and the cake is on top of the green diamond(right).

Edited December 19, 2015 by Blackeye