JDAM test

[28270]

I have observed in various JDAM tests that the last bombs dropped are the first to hit sequentially. This goes beyond logic, as when you drop the next bombs, the previous ones should already have traveled a few seconds.

As an example, the first bomb dropped to the east hits after a subsequent bomb falls to the west ten seconds apart at the same distance.

I suspect that somehow the sequence has been reversed.

I think this should be checked internally for a bug, as I don't know how the actual Hornet works.

[pocketedition]

It could be the speed at which your traveling.

If your direction is toward the target, the last bomb dropped has less distance to reach the target.

[28270]

hace 1 minuto, pocketedition dijo:

It could be the speed at which your traveling.

If your direction is toward the target, the last bomb dropped has less distance to reach the target.

Drop bomb 1 to the east. Ten seconds later, drop bomb two to the west.

First hit bomb 2 to the west, second hit bomb 1 to the east.

inverted sequence.

 

But you're right, the second bomb can gain more speed by gaining more vertical descent closer to the target.

[oldcrusty]

6 minutes ago, 28270 said:

Drop bomb 1 to the east. Ten seconds later, drop bomb two to the west.

First hit bomb 2 to the west, second hit bomb 1 to the east.

inverted sequence.

 

But you're right, the second bomb can gain more speed by gaining more vertical descent closer to the target.

and... if the target to the West was closer, the bomb would guide at a steeper angle, faster, so, it depends.

[Tholozor]

Exactly, the last weapon dropped has more retained energy due to reduced slant range as you move towards the target.

The JDAM's INS guidance system is active pretty much at all points in the flight, with the GPS correction kicking in after about 30 seconds from separation. If the weapon is released at maximum range, it may be commanded to use a pseudo-gliding approach to reach above the target then turn down to respect the terminal attack angle, which can lead to an increased TOT versus a weapon that was dropped at a closer range.

[28270]

Indeed, it has to do with my speed. I have been stupid. The first bombs dropped are left behind and the last bombs dropped have less travel and higher vertical speed.

Please don't be cruel to me =(

[pocketedition]

28270

Not knowing something is not being stupid.
You are clever enough to have noticed this effect with bomb drops, and you were smart enough to ask the question regarding that on this forum.
You had a question, asked, and hopefully got an answer.

That's being clever. Well done

[BuzzLine]

Hear, hear !

Sharing this classic : https://m.xkcd.com/1053/

 

Sorry for the off-topic comment but it'd be nice if more people shared in this philosophy.  

 

[Foka]

On 4/10/2022 at 9:50 PM, Tholozor said:

with the GPS correction kicking in after about 30 seconds from separation

What happens with bombs dropped from low altitude, close to target with fly time lower then 30 secs?

[Tholozor]

They fly INS-only, which is still quite accurate since it has less time to drift. DCS doesn't simulate the same degradation problems that real-world GPS suffers from, so as far as the weapon is concerned, it knows exactly where it is at the moment of separation until impact. If for some reason GPS is not available in the mission, the JDAM will only suffer from an increased CEP.