PGM Tactics
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This is probably opening a can much larger than can be addressed in a forum thread, but I wanted to ask a few questions about PGM selection and employment. On a typical strike mission I’m carrying two large (2000 lb class) GBUs, i.e. Either GBU31 or GBU10/24. It seems like most targets can be flattened with just one of these large bombs. With JDAMs, I feel like employment is pretty straight forward. If I have loiter time I can two pass and hit two DMPI, if I need to one pass/haul ass I can still usually hit two DMPI with some pre-planning. LGBs are different. When I can hang around I can pick two targets, but if I need to get out quick I only get one DMPI. Is it realistic to drop both on the same target? If I only use one (which is often enough to flatten the target), then I’m egressing with excess drag and weight that I didn’t need to bring. If I drop both, the second one is hitting a crumbling target (assuming they don’t impact each other going for the same laser spot… Is that a real concern?).
Anyone have insight on how this works in the real world? The Case Study on Deliberate Force (available from the Air University, a good read) cites a rate of 2.7 PGM/DMPI destroyed. It also mentions needing more time above targets for weapon effect deconfliction, so it looks like often those 2.7 were not dropped on the same pass. This also includes misses, but does that mean dropping a pair of GBU24s on the same depot is the right way to do it? What about runways? Is the CEP of a JDAM tight enough to crater the centerline? Can I space out two LGBs enough to cover more of the runway?
And this doesn’t even get into dumb bombs. Are there good answers for these questions? Do I just need to get a textbook on weaponeering and hole up all weekend?
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Depending on the target and the weapons available, I think its not unrealistic.
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Multiple simultaneous LGBs have been delivered from one aircraft’s pass in the past so there’s some validity to doing it. That being said, I would have several concerns about doing so:
They can hit each other.
One bomb can occlude the other. A trailing Paveway II with interrupted laser will jam its control fins 100% in the direction of the last correction and has no provision to reacquire the laser. Delivering at longer times or with an angle offset would encourage LOS deconflict. Given the dimensions of the bomb and a ~2m laser splotch one could calculate at what spacing the bombs would cover no more than 50% of the splotch area/energy even if they did line up (and even then, it would probably be highly fleeting).
The impact cloud of the first bomb could degrade the laser guidance of the subsequent. The closer together the impacts the less time this problem has to develop, outside of sympathetic detonation range/timing.
A ripple release of 2 with maybe 500ms interval sounds quite safe. If the campaign allows it and the target is confidently requiring only one good weapon there’s also the secondary target(s) to utilize the other weapon and/or any the wingman is carrying for backup. I would factor in threat level, performance need, collateral risk, secondary target avail., reattack risk, target sturdiness and maybe some more.
JDAM is suitable for runways. You’d try to align your attack for good GPS conditions to shrink your CEP but I think the average 13m or so is more than enough. Statistical analysis can tell you how much to over plan for a desired confidence level.