GBU-38's inaccurate or is it me?

[Scrim]

I don't get what your problem is. You said, JDAMs don't use laser for guidance, but laser helps to determine the correct slant distance. But on the other hand you claim that the simhq tutorial is bad because it encourages the use of the laser.

 

Then Yurgon illustrated why determining the correct distance is important (or at least, is not a bad habit at all).

 

There was nothing taken out of context!? What context? And what arguments? You both basically said the same!? JDAM = not laser guided but GPS guided to hit a target coordinate. Using laser with JDAM = more precise target coordinate ... but still not laser guided ... --> more precise JDAM.

 

I said that the laser can be somewhat useful for getting distance exact, not much more. Overall it's such a trivial thing the guide could as well have mentioned not crashing on your way to the target.

 

Yurgon thought he illustrated why it was useful because he had a bad understanding to say the least, of how TGP designated SPIs work, to the extent where he didn't even know that they were continuous. That alone says a lot, considering that even I knew that in less than a week of taking up flying the A-10C, and I'm not by far an expert.

 

When he's told he's wrong by me and others, and proven to be wrong, he won't even acknowledge that I told him that. Instead he starts nitpicking exact words and phrases, probably because he's still trying to act like he's right and I'm wrong.

 

And what my problem is, is that someone who's wrong turns up, acts like an arrogant teacher, and then can't even be mature enough to keep schtum after he's acknowledged he was wrong.

 

 

And to reiterate: Using a laser does not make JDAMs dropped on TGP designated SPIs more accurate, unless it's done by a pilot so lazy he can't even be bothered to adjust the position of the SPI by moving his TGP back on target if he sees that it has strayed off course. Only in that very particular, ridiculously unlikely scenario would a laser make a JDAM drop any more accurate.

Edited February 10, 2014 by Scrim

[NoCarrier]

Addendum: Try making the IFFCC the SPI...

I'm pretty sure you're confused.

[Eddie]

I'm pretty sure you're confused.

 

Why? What about his post made him appear confused. His suggestion perfectly illustrates how the SPI works.

[Flagrum]

Using a laser does not make JDAMs dropped on TGP designated SPIs more accurate

Correct, but for my understanding that was not said by anyone in this thread. What was said is, that using the laser makes your SPI more accurately representing your intended target. (And that is not nitpicking ...? :o)

 

, unless it's done by a pilot so lazy he can't even be bothered to adjust the position of the SPI by moving his TGP back on target if he sees that it has strayed off course. Only in that very particular, ridiculously unlikely scenario would a laser make a JDAM drop any more accurate.

I am not sure what that simhq tutorial actually said, i.e. if it was just about "how to put a JDAM on your SPI" or if it was meant broader. Like for usefull cases when you set up several targets (markpoints, flight plans) in advance and from further out.

[NoCarrier]

Why? What about his post made him appear confused. His suggestion perfectly illustrates how the SPI works.

Because the Integrated Flight and Fire Control Computer is not a sensor by itself, and so cannot generate a SPI. Unless he meant something like the "SPI to Steerpoint" function?

[Eddie]

Ah but it can. TMS aft short with a weapon profile selected and CCIP aiming active.

 

The SPI will be latched to the IFFCC computed impact point for the selected weapon. Be careful you know of what you speak before so hastily jumping to claim someone else is wrong or confused. ;)

[Supersheep]

Anyways, the result of doing the above will be that the SPI is constantly re-computed to where the CCIP pipper is, and the TGP is constantly slewing (better. trying to slew) to that point. The slightest movement on the stick has the SPI all over the place, the TGP spinning equally fast, and you'll always see where your weapon would hit if fired in that instant (and where the Mark Z would be set).

 

Manual pages for reference:

88 and 400, Set SPI submode is the item of relevance for this finger exercise.

[NoCarrier]

The SPI will be latched to the IFFCC computed impact point for the selected weapon

Now I understand, he was talking about one of the HUD submodes. I just never knew the HUD actually said IFFCC as the SPI generator.

[Supersheep]

Correct, I was :) BTW: I encourage everyone to try the above

[Yurgon]

Don't mean to derail the thread but how did you get 6 jdams on an A-10? I though it could carry 4 at most.

 

I wasn't sure about it, but in the ME they can be mounted on 3, 4, 5, 7, 8 and 9.

 

I just looked it up in the manual which confirms the ME is correct:

 

IAMs can only be mounted on the six 1760 smart stations of the A-10C: 3, 4, 5, 7, 8, and 9 on single ejector racks.

[JayPee]

GBU-38's inaccurate or is it me?

 

Since this topic took a turn towards SPIs and Mark Points anyway, here's a million dollar question:

 

I'm 12 nm out

TGP as SOI

TGP generates SPI

Point Track mode set

The side of a BMP3 is perfectly fitting in the Square at the centre of the targetting cross

Laser on

Make MK

Laser off

Make MK STP

Slave TGP to STP

 

Why is my MK set 10 metres on the other side of the BMP3 on the ground?

 

As far as I'm concerned the TGP should not look through the vehicle when I set an MK with the laser on.

 

The only situation in which using the LASER would have helped is if you had made a mark point from your TGP generated SPI

Edited February 11, 2014 by JayPee

[Eddie]

At 12NM you're outside the effective range of the LASER. Both in reality and in DCS.

 

Counter question for you, in that situation why are you using point track? Had you just used area track centered on the base of the intended target everything would have worked fine.

[JayPee]

Because I am under the assumption that per definition point track should be used for vehicles and other things reasonably defined as objects.

[Eddie]

Not at all. The only time point track is required is if you want the pod to track a moving object. Otherwise area track or, subject to a few limitations, inertial rates are fine. Area track is actually preferable in most cases.

 

I can't go into detail on how the different track types work as I'm at work and typing long replies on the phone is not easy.

[JayPee]

OK so for now it is area track unless tracking a moving object.

 

Nice to have a confirmation on the procedure tho.

[Glamdring]

Since this topic took a turn towards SPIs and Mark Points anyway, here's a million dollar question:

 

I'm 12 nm out

TGP as SOI

TGP generates SPI

Point Track mode set

The side of a BMP3 is perfectly fitting in the Square at the centre of the targetting cross

Laser on

Make MK

Laser off

Make MK STP

Slave TGP to STP

 

Why is my MK set 10 metres on the other side of the BMP3 on the ground?

 

As far as I'm concerned the TGP should not look through the vehicle when I set an MK with the laser on.

 

Try having the laser on before making the SPI.

[JayPee]

Why? SPI's constantly updated so when new info's fed, new info's taken into account. If all goes well...

[Eddie]

Try having the laser on before making the SPI.

 

Perhaps he should try closing his left eye and hopping on his right leg while shouting "I am a potato" in mandarin?

 

It would be just as effective.

[JayPee]

GBU-38's inaccurate or is it me?

 

Hmm, guess my Mandarin sucks cause the 38 still landed long of the parked BMP...

[kontiuka]

I played around with this last night and the laser does seem to make a difference. I was attacking stationary tanks. Without lasing, the bomb fell several feet from the tank. With lasing, the bomb either hit the tank or fell close enough to destroy it. FYI, I set the SPI from my targetting pod and then turned on the laser. Once the bomb released, I turned off the laser. I was probably around 10,000 ft.

 

Oh, and I was shouting "I am a tomato" in Swahili.

Edited February 11, 2014 by kontiuka

[Supersheep]

That is in line with the mechanics, but not within the expected accuracy intervals that have been discussed here.

LOL @ #69, btw.

[NineLine]

Hmm, guess my Mandarin sucks cause the 38 still landed long of the parked BMP...

 

Perhaps post a track?

[JayPee]

I'll try again during one of the upcoming evenings and if I still encounter the problem I'll post a track. When ingressing from the IP in Mission Hideout I was trying to tag all four stationary BMPs with a Mark Point to drop four 38s in the same first pass from 20,000 MSL.

[ENO]

38s are part of my normal loadout and I have dropped a lot of them. Since this last update or perhaps the transition to 1.2.7 I have noticed they miss more often than they used to. I don't know why, or how... but it's definitely more noticeable.

Edited February 11, 2014 by ENO

[Supersheep]

(I haven't dropped one in a couple of months)

Do they miss, do they hit some other point, or do they show decreased accuracy?