LGB missing target: Please have a look at track

[Sylle]

Hi guys,

 

I'm relatively new to this sim and very much enjoying the learning. :thumbup:

 

I ran into an issue with the laser-guided GBU12.

Using 12sec auto-lase and dropping them in CCRP mode they still miss the target although I see the bomb making track adjustments in external view (F6) after release.

The target is a non-moving truck in the instant action scenario (to practice LGB dropping).

Am I wrongly setting up the A-10 systems or are my expectations about the LGB accuracy/maneuverability set too high??

 

I was wondering if some experts could have a look at my attached track file to see what the issue is here... :joystick:

 

Looking forward to your replies!

Thanks in advance...

 

Regards,

Sylvain

GBU12_fail.trk

[Weltensegler]

Hi, I can't check cuz I'm at work but maybe instead of auto lasing (or in addition for trouble shooting) try it with "latch on".

In your TGP view on your MFD push OSB1 ("ctrl") and then middle right you see latch (I guess osb8 ); when this is on and you push the laser button the laser stays on until you push it again.

 

Also of course try to fly over the target steady and leveled until the hit so you don't mask the laser by breaking away before that.

 

Hope that helps

[159th_Viper]

Is your SPI set correctly, ie on your target?

[Harzach]

Looks like you released far too low - @4430 and 10 degrees nose down - so the bomb falls well short of the target because it doesn't have enough fall time to get there. Time of fall was just over ten seconds, in fact.

 

What's the correct way? Everyone will probably give a different answer, and a lot of them will probably be right. I prefer to drop LGBs from 12K+ and no more than 5 degrees nose down. An 8-10 second lase time is enough to get on target from that altitude. You really don't want to get above 12-15 seconds, though, or you'll increase your chances of missing due to loss of energy (but that's a different topic.)

Edited July 11, 2012 by Harzach

[Weltensegler]

You really don't want to get above 12-15 seconds, though, or you'll increase you chances of missing due to loss of energy (but that's a different topic.)

 

GBUs don't go pitbull do they?

So if you drop from 15-20ft on a moving target you won't get a good hit with 10sec lasing when the bomb is dropping >30sec or am I wrong?

Maybe you could lead the target on a fix estimation and then turn on it 10sec before impact (regarding energy efficiency)?

I guess in this case its a static target and your energy efficiency point might be valid though I never missed with laser all the way on.

At least I never noticed inaccuracy.

[Harzach]

Maybe you could lead the target on a fix estimation and then turn on it 10sec before impact (regarding energy efficiency)?

 

That is what auto lase does. A 10-second lase time means "turn laser on 10 seconds before estimated impact," not "turn laser on for 10 seconds on release."

 

The problem with long lase times is that rather than optimizing its ballistic trajectory, the LGB guides straight to the target:

 

 

Dumping that much energy right after release can often mean not having enough left to get to the target.

[WildBillKelsoe]

Looks like you released far too low - @4430 and 10 degrees nose down -

 

Harz, I concur. 8 K is usually sufficient to allow for corrections IMHO. Watch for manpads though.

[Sylle]

Hello guys,

 

Thanks for all the replies!

 

Harzach, your drawing made it crystal clear to me.

A picture says a thousands words indeed ;)

It also explains why after climbing to 12000ft to drop the bridge at waypoint 4 and stay clear of the AAA positioned next to it I had no problems using the same technique.

 

Cheers,

Sylvain

[Weltensegler]

I learned something too! Thanks! Just surprised I never had that problem with constant lasing

[JCamel]

The simple solution is to use a JDAM on stationary targets.

[Harzach]

Of course, it all boils down to the situation - threats in the area, weather, whatever. Don't take anything I say as gospel! And if you can put enough energy into the LGB on release (that is, drop at high airspeed), you should theoretically be able to overcome that long-lase problem. There is certainly enough anecdotal evidence to support that in this forum.

Edited July 11, 2012 by Harzach