A New AAW

Anti-air warfare (AAW) is the backbone of the Navy.  You’d think the backbone would be some sort of offensive capability, wouldn’t you?  But, I digress …  We’ve discussed how the Navy has lost its offensive focus and become defensive oriented (see, "The Best Defense Is A Good Offense").  Our frontline ships, the Burkes, are primarily defensive platforms with only a modest and limited capability for Tomahawk strikes.  Anyway, given the importance the Navy attaches to AAW, let’s take a closer look at it.

We’ve already discussed the relative value of active (hard kill) versus passive (soft kill) defenses and the track record of each (see, "AAW - Hard Kill Or Soft Kill?").

Let’s look a bit closer at the hard kill side of the issue.  A few things jump out:

Effectiveness – The historical data shows that AAW missiles are only marginally effective with success rates of 1% - 25%.  Against modern supersonic aircraft and missiles supported by ECM and decoys the success rate will probably be in the 1%-10% range.

Engagement Density – The speed of modern aircraft and missiles makes for very short engagement windows which means that the number of missiles (the density) that can be launched per target is very small.

Cost – The Navy’s Standard missile costs $1M+ each and the more advanced versions (SM-3 & SM-6) are more than that.

What do these factors mean?

The marginal effectiveness means that you need more missiles per target to ensure a kill.  That’s straightforward but the limited engagement density precludes increasing the number of missiles to compensate for marginal effectiveness.  Worse, when the marginal effectiveness is combined with the cost, the desire for more missiles per engagement leads to skyrocketing costs even if we could increase the engagement density.  This is a self-limiting path.

The preceding suggests that the Navy’s emphasis on long range, hard kill missile-based AAW will be only marginally effective and exceedingly expensive.  Compounding this is the Navy’s neglect of short range AAW defense.  The Burkes, for example, typically carry a single Phalanx CIWS (some ships carry two).  That’s hardly adequate.

 

It’s easy to project the ultimate result of the Navy’s current path.  AAW missiles are getting bigger and more expensive.  As the Navy attempts to build ever faster, longer ranged, smarter AAW missiles they will be able to afford fewer and fewer.  Missile size will soon exceed the Mk 41 VLS cell size and have to switch to the Mk 57 Peripheral VLS system of the Zumwalt with the attendant decrease in cell numbers.  Thus, we can foresee a path of increasing costs and decreasing numbers.

We’re already able to see a dilemma involving enemy UAVs.  Do we really want to spend $1M+ to shoot down a $5K or $50K UAV?  If not, what’s the alternative?

So what’s the solution?

Conceptually, we can engage at greater distances to increase the engagement density.  The further out we begin the engagement, the more time we’ll have and the more AAW missiles we can throw at the target.  That’s expensive but would be effective.  The problem is targeting.  Modern anti-ship missiles are generally sea skimming high-subsonic or supersonic which is difficult to detect especially in an ECM environment.  Thus, attempting to engage at greater distances won’t work unless we come up with a breakthrough advance in detection technology.

Conceptually, we can engage at the same, or closer, distances but with much greater engagement density.  The greater number of weapons would compensate for the marginal effectiveness.  The problem is that we’re limited in terminal guidance and target detection and discrimination once missiles start exploding in the target’s vicinity.  Thus, greater numbers are only going to result in untargeted or incorrectly targeted AAW missiles being wasted at $1M+ each.

So, conceptually we can increase our AAW hard kill chances but there are significant problems.  Now what?

Well, this is where we reach the point of this post.  The following is a conceptual missile-based hard kill AAW system patterned after the CIWS.  Imagine a missile that is medium to short ranged (we aren’t going to detect anti-ship missiles beyond that range anyway! – ballistic missiles notwithstanding), cheap, and doesn’t require precision guidance.  We could fling large numbers at targets and increase our overall effectiveness.  

Such a missile system is based on the CIWS concept.  The missiles are fragmentation types that are intended to explode in the path of the incoming target, creating a “wall” of debris for the target to fly through.  As such, precise targeting and guidance is not required since skin-to-skin contact is unnecessary.  A salvo of several missiles thrown in the approximate path of the target ensures a “hit”.  As with CIWS, the missiles can be continually launched until a kill is achieved.

The missiles would be relatively cheap since they would be short to medium ranged and would not need a sophisticated seeker.  In essence, a proximity fuze is all that’s required.  The missiles would not be guided but would simply be launched at a calculated intercept point.  Of course, they would need to be high speed to minimize the amount of maneuvering the target could accomplish before the missile’s arrival.

An added benefit is that massively capable radar systems like Aegis/AMDR are not really necessary since very long distance, precise targeting and guidance is not needed.

In essence, this is a CIWS missile with a much greater range than a conventional CIWS gun.

On an interesting, related note, occasional attempts were made to do something similar to this in WWII using large caliber battleship guns which would fire shells into the water in front of low flying, incoming aircraft with the hope that the planes would fly through the resulting water spouts and be knocked down.  It wasn’t tried often and I’ve never heard of any success with the technique but it is an interesting parallel.

You'll note that I've left out any specific discussion of ESSM.  This is because it falls under the same cost and capability path of diminishing returns and because it has some severe problems to the point that it may not even be functional on a practical basis.  Admittedly, I'm drawing somewhat suspect conclusions about this from various reports.  Regardless, it doesn't change the premise of the post.

This is one of those conjectural posts that ComNavOps comes up with from time to time.  It’s offered as an interesting discussion point and an outside-the-box idea.  Would it work?  Who knows?  It’s worth a few minutes thought, though.  Feel free to offer alternatives that would address the hard kill AAW issues because the current AAW path is unsustainable.

On a related note, I think the Navy recognizes the unsustainable path they’re on and are responding by trying to develop lasers and railguns.  Unfortunately, those technologies are still decades away from practical use.  The approach in this post offers a shorter term alternative.