People think that the Joint Direct Attack Munition is an excellent system. Don't get me wrong it is great when there is a point target you need to go away.
JDAMs usually land within 30 feet of their target thanks to the use of the Global Positioning System for guidance. In fact, a lot of other systems, including the Tomahawk cruise missile, use that system as their entire guidance package, or to supplement other precision systems.
But there are some things these precision-guided systems can't do so well. In fact, the cluster bomb actually can do some things that the JDAM can't – which is a reason why the United States has not signed the Oslo Treaty that bans cluster bombs.
Here's a sample of situations where it proves useful.
CBU-105 at the Textron Defense Systems's trade booth, Singapore Airshow 2008 in Changi Exhibition Centre. (Photo from Wikimedia Commons)
1. Cluster bombs can hit multiple targets
This is the big thing. One JDAM can take out one target. Bridges or bunkers are the sort of thing the JDAM specialize it killing. But let's take a look at a company of tanks. Here, we are talking anywhere from ten to fifteen vehicles.
This is the sort of target something like the CBU-87 cluster bomb was designed to handle. With 202 BLU-97 bomblets, it has a good chance of landing one or two on the thin top armor of tanks. One bomb can kill multiple tanks, or trucks, or enemy troops.
That can be very useful for an Special Forces A-Team in a fight for their lives.
When a lot of tanks are coming, You don't have time for JDAMs to kill them one-by-one. (Photo: Wikimedia)
2. Cluster munitions allow missiles to hit multiple locations
Next to the BGM-109B TASM Tomahawk anti-ship missile, the BGM-109D Tomahawk TLAM-D is often a forgotten missile. But the BGM-109D has the ability to hit multiple locations, something the latest Tactical Tomahawks can't do.
This is because the BGM-109D's BLU-97s – the same ones used on the CBU-87 – are carried in a series of packets. For instance, one missile could dump some of its bomblets on parked planes, then fly on to hit a supply base elsewhere. The BGM-109D, therefore can do the work of two TLAMs.
A ZSU-23 is hit by BLU-97 sub-munitions like those used on the BGM-109D Tomahawk. (DOD photo)
3. Cluster bombs provide multiple effects in one package
The JDAM has one warhead that can go off one time. But a cluster bomb can carry different kinds of submunitions in the same case. Perhaps the best example is the CBU-89 GATOR – it carried two kinds of mines – one was an anti-tank mile, the other was anti-personnel. The JP233 was another – it combined both a runway-cratering munition with area-denial munitions.
The other thing is that even when you have a bomb that is all one type of submunition, some bomblets can be set to go off immediately, while others could be set to wait for a period of time (the famous delayed-action bomb – or in this case, delayed-action bomblets).
The JP233 on display underneath the Panavia Tornado GR1 in the Cold War Gallery at the National Museum of the U.S. Air Force. (U.S. Air Force photo)
4. Cluster bombs can provide surprises without going bang
Some cluster bombs don't even need their submunitions to go bang. For instance, Designation-Systems.net notes that the CBU-94 and CBU-102 are "blackout bombs" that drop carbon fiber chaff over power lines. This shorts out an entire power grid.
The CBU-19, though, dispensed 528 bomblets filled with CS, better known as tear gas. If you ever saw "The Big Break" episode of the 1950s TV show "Dragnet," you saw CS in use.
The BLU-114 submunition used in the CBU-94 and CBU-102 "blackout bombs" - it doesn't go "bang," it just drops metal filaments over power lines. (Photo from Wikimedia Commons)
Finally, some cluster bombs can also be guided in, thanks to the Wind-Corrected Munitions Dispenser program. In essence, these systems can also be dropped within feet of their aiming point.