Should a GBU-12 be able to hit a moving tank?

I watch a documentary on smart bombs last night, all about laser guided bombs. I totally got how they worked and so I thought I would put it into practice in this sim. The documentary showed a laser bomb been used against a moving tank and it had no problem taking the tank out.

I first tried to use a GBU 12 against a moving tank, but they just kept on missing? I target them using CCRP form about 5000ft and press the laser with about 12 seconds to go, but they all just missed by some distance?

I then had the JTAC laser the target for me. I released the GBU-12 using the same code as the JTAC 1688, but again though the GBU-12 missed? I used CCIP this time to release the bombs!

So, first question. Why does the GBU-12 have problems hitting moving targets and would this be the case in real life? The documentary showed them to be quite accurate at this.

Second question. How come when I release the GBU-12, while in CCiP, and the JTAC lasering the target...Does the GBU-12 miss the target? I thought the bomb just followed the flash at the end of the laser? Again this was with a moving tank.

Have you tried from a higher altitude? I think 5000' might be a bit low. Try to go 10k feet and see if the same happens.

In order to help you, it's better to post a track to see what you're doing.

And perhaps experiment with a shorter lasing time - 8-10 sec for example. The longer you lase, the more energy is spent early for maneuvering - which could now be lacking during the last couple of meters before impact.

Have you tried from a higher altitude? I think 5000' might be a bit low. Try to go 10k feet and see if the same happens.

In order to help you, it's better to post a track to see what you're doing.

I agree. It should definitely work and I've done it many many times, but I would also drop closer to 10k than 5k. You might also consider turning auto lase on and setting the lase timer to 10.

Also, are you holding the lase button if you're doing it manually? Without changing the latch setting it will turn off instantly if you release it, so you'd be effectively just lasing the target for a split second.

I haven't had much luck with 5000 ft. Go for a higher height. Should give better results.

LGBs need 8 seconds of lasing time to guide properly.

Also to be accurate you should lase until the target is hit. If you stop lasing the LGB could pick up another laser source (if coded the same) or guide off the target through it's own kinetic energy.

I always try to drop from altitudes greater than 6,000'. I also use CCRP so you can keep a nice steady release platform (while staying away from threats).

You even should be able to hit a Helo!

(like in real life a F-15E Pilot did with a GBU-10 in Iraq 1991 but that´s another story... http://www.f-15e.info/joomla/stories/182-tim-bennetts-war )

I always set autolase to 10sec. and made some good experiences. Altitude better more than 5k.

But can remember times when i run into similar issues with the GBU12. But don´t ask me why i had those? I assume: human error :joystick:

Were you doing LSS from the JTAC's laser prior to releasing?

I have no problem hitting moving vehicles, generally stay above 7,000 ft AGL (check elevation of target), approach the vehicle within 30 degrees from behind. Make sure either autolase is on and/ or latch is on and allow for 8-10 seconds of laser time.

I've had problems where I have the target set as SPI in my TGP, I call 10 seconds, laser on, then go to LSS (JTAC says lasing) I pick up the spot, exit LSS and drop and had failure to guide using it that way, even while I lase in the target. I go to the F7 view and the bomb clearly hasnt picked up any laser as its not doing the bang bang dance.

Also, how fast is this tank moving? I know IRL pilots have rules of thumb for leading the target with a laser (x number of feet per mph target speed, wind correction, etc.)

I will take all what has been said into account and let you know how it all goes. I'm just learning to do stuff with JTAC atm, so it's more then likely I am doing something wrong. I'm going to try dropping the bombs from height without using the JTAC and see how that goes.

@Mike - I clicked on LSS once I asked JTAC to laser the target which they did. I then thought I could use the JTACS laser and all I had to do was drop the bomb. I was in CCIP mode and just dived for the target from about 6000 FT. I did watch the bomb and noticed it made no attempt to head towards the target, it just acted like a dumb bomb.

One other thing I found quite annoying is that sometimes when I ask them to laser the target, the laser can suddenly jump off the target and go to the mark point. I'm not sure what that is all about, but it's happened a couple of times now.

I had the very same problems when I was starting off. It's height that's the key. 5000ft is way too low.

It's tricky, you need to attack like using dumb bombs, and depending on how fast you go, it's only 1-2 sec lasing, mostly to stop it from overshooting. Not sure this would work in real world.

GBU-12 at 5000.trk

Also- just double check you are actually making the vehicle your SPI (not just tracking it in point).

If they keep missing, I'd try using a _longer_ lase time. The CCRP solution does not care about a target's movement. Essentially, you're dropping the bomb into the area where the target is at the time of the drop, not where it will be on impact.

Therefore, the target might be out of the 'visible area' of the bomb's laser detector by the time the laser fires.

Another factor you need to think about is the direction of the target. While falling down, the bomb's nose will be facing forward and so will the laser detecor. That means, if a target is heading towards you, it might pass below the bomb, never giving it the chance of picking up the laser.

Also, LGBs are (purposely) dropped long (behind the target) to give it some extra energy for maneuvering, increasing the effect mentioned above with oncoming targets. This is something you can change in the profile under 'solution', which is very useful if you want to use LGBs like unguided bombs.

Also- just double check you are actually making the vehicle your SPI (not just tracking it in point).

You will miss anyway, if you try. Unless you also do it like a dumb bomb, and lase just to adjust the impact.

Edit; Trying to do this repetedly seem to fail, using 'Taking Control' after drop I can't repeat it so good. On my Track, above.

@Mike - I clicked on LSS once I asked JTAC to laser the target which they did. I then thought I could use the JTACS laser and all I had to do was drop the bomb. I was in CCIP mode and just dived for the target from about 6000 FT. I did watch the bomb and noticed it made no attempt to head towards the target, it just acted like a dumb bomb.

Note that the laser code settings in the TGP do not configure the bomb as far as I know. If you/JTAC use a code different from the default, you will have to reconfigure the bomb's laser code in the DSMS inventory page.

I never have problems hitting moving targets.

If at low altitude , all i can sugest is pitching down before release so the laser seeker is pointed down already and will pick up the laser beam faster

I think I might have found where I'm going wrong apart from height been one factor. I think the other reason is because I'm not setting up for the target correctly. I'd really appreciate someone filling in the blanks for me on this subject.

Once I have called IP what distance in nautical miles should I be from the target when calling in the other commands? Like how many miles from the target when I ask JTAC for laser on? Then for calling over the radio things like "in" etc? If someone could just list the commands after I give the IP call and then the miles you need to be from the target when calling each one in it would be great.

Also, what page of the manual does it explain what I am asking for above because I cant seem to find it.

Thanks for the help!

It all depends on your speed and altitude for the minimum distance you should make the calls. Also whether or not you're dropping CCIP or CCRP. The higher and faster you are, the longer out you will need to set up for the calls. Though 7-8 miles should be sufficient to start your IP inbound call.

I try to get the calls over with asap so I can call IN when the CCRP timer starts it's countdown. If it's a single player campaign where there's a crap ton of radio traffic, I would just call in even further out than the countdown timer.

I just tried having a JTAC lase the target for me. Indeed, the SPI is removed from the TGP and sets to the nearest (or current activated?) steerpoint while doing LSS. I don't know however, if when you exit LSS if the TGP stays slaved to the last detected laser spot or the last coordinates it was anchored on before LSS. If it stays on the last laser spot, you could easily exit LSS, set TGP as SPI and line up for release.

I wish in DCS you had the option to request laser on anytime during the sequence. Often a JTAC IRL will mark with a laser prior to the aircraft starting an attack.....not for teminal guidance, only for acquisition. On the flip side, it would allow for a delayed lase as well.

You even should be able to hit a Helo!

(like in real life a F-15E Pilot did with a GBU-10 in Iraq 1991 but that´s another story... http://www.f-15e.info/joomla/stories/182-tim-bennetts-war )

Ganesh. Thanks for the article url. I had read it before and lost it. It is really a "Good Read" for anyone who is interested in our genre. Thanks again.

One thing you might consider is how you select the weapon in the first place. If you select it directly with the corresponding OSB on the MFCD, you lose your setting, including lease time and autolase. You need to select it with DMS left or right. Either on your joystick or keyboard. (NumPad delete or PageDown).

Bill

I generally drop from over 10k, mostly like 15k feet and I start lazing right after pickle. I never have any issues with bombs missing. The worst miss was on a fast moving Shark that was bobbing and weaving from the laze and because I already bombed him 2x before in the same day.

Here you can see it miss but still be close enough for a kill.

Realistically, the lazer guided bombs are designed for moving targets so they definitely should hit in real and in simulation.

Nice, but in your youtube video description should be :

I hit a airborne shark with a LGB instead of JDAM ;)

One thing you might consider is how you select the weapon in the first place. If you select it directly with the corresponding OSB on the MFCD, you lose your setting, including lease time and autolase. You need to select it with DMS left or right. Either on your joystick or keyboard. (NumPad delete or PageDown).

 

Bill

Why is this, it seems a bit odd?

Why is this, it seems a bit odd?

The general concept is, that every weapon is selected by activating a weapon profile (which holds all the relevant parameters). You do this either by going to the profile page and selecting an existing profile (the appropriate weapon stations will be selected automatically) or you select a weapon station directly. But in that case, the DSMS creates a temporary, "manual" profile with the default parameters. You can change these parameters, but they are still held in that temporary profile. When you select a different weapon station or a different predefined profile, your changes to the temporary profile are lost.

You can see what kind of profile you are using at the HUD (lower left corner, iirc). It either states the selected predefine profile name, or ,in case of a temporary profile, the weapon name prefixed with "M/".