I keep encountering a recurring belief among
observers/commenters that the F-35 is some kind of miracle, broad area maritime
surveillance (BAMS) platform and I don’t know where this comes from. I suspect it’s a case of F-35 proponents
latching on to anything they can to justify the aircraft.
This is an important claim because the F-35 in the BAMS role
is claimed to be the foundation of the distributed lethality concept, the
savior of carrier groups, the guidance system for attacking missiles, and the
key to achieving total victory over China – all due to its claimed ability to leisurely
cruise through enemy air/water space completely undetected while using its
radar to search an entire hemisphere of the world with 100% detection of all
enemy assets. If that’s true, China
stands absolutely no chance against us.
Is it true?
Well, there is zero authoritative public domain information
on the subject, that I’m aware of. That
makes drawing any definitive conclusions difficult, to say the least. However, we have unlimited logic available to
us so let’s apply some and see where it leads.
Detection Range. The F-35 with its APG-81 radar is claimed to
have nearly unlimited detection range with 100% detection and target
identification. Of course, this is
ridiculous. Without getting into the
math, physics, and software of radar function, the simplistic truth is, ‘more
power equals greater range’. Thus, the
larger, higher powered radar has better range and resolution than the smaller,
lower powered one. So, a fighter size
radar, for example, has less range than an AWACS.
The only hint of range data for the APG-81 that I’m aware of
is a claim of 150 km (90 miles) or so and that claim has occasionally been associated
with a 1 sq.m. target which implies an aircraft target and aerial detection
mode. How applicable that is to the
broad area maritime surface search we’re discussing is an open question.
Any manufacturer’s claim, which is, presumably, what the 90
mile claim is, is based on non-stealthy targets under ideal conditions, at
best, or, far more likely, it’s just based on someone’s theoretical
Let’s consider the nature of the targets that are the
subject of BAMS. We’re looking for
stealthy warships of various sizes.
China, for example, has their versions of the Burke although, visually,
they appear to be a bit more stealthy.
They also have stealth missile boats (the Type 22 is a good example),
corvettes, and frigates. These stealth
ships have reduced radar signatures. The
only data we have on ship stealth is vague statements that the ship (whichever
ship) has a radar signature of a ‘fishing boat’. Oddly, almost every ship of whatever size and
degree of stealth seems to have the same claimed ‘fishing boat’ radar
signature. Obviously, the claim is very
generic and utterly useless. Still, it
gives us some sort of very general idea of the reduction in radar signature.
What this means for our F-35 BAMS mission is that whatever
the claimed range of the APG-81 radar might be, the effects of wave clutter,
weather, and ship stealth combine to greatly reduce the actual detection range.
We also need to recognize the difference between detection
and identification. Let’s say we detect
a ‘fishing boat’ at x-miles. Okay,
that’s nice but what is it? Is it an
actual fishing boat? We’d hate to launch
a maximum effort naval strike only to find out that the target was, indeed, a
fishing boat! That would be a lot of
wasted missiles. That means we have to
identify the target in addition to detecting it. That, in turn, means we have to get much
closer – to the point where we can either visually identify it or our radar
provides sufficient resolution that we can identify the signature. So, our effective identification range is
much shorter than our detection range which, we’ve already noted, is much
shorter than the manufacturer’s claimed maximum range (which we don’t have for
the APG-81 in surface mode). So, our
detection range is a mere fraction, and not a big one, of the maximum range.
Thus, the notion that a small, low power, fighter size radar
can ‘see’ vast areas of ocean with 100% detection and identification is
1. An F-35 APG-81 radar is going to
provide a very limited view – the soda straw analogy.
2. Effective targeting is a two part
challenge. Detection is only half the
problem and it’s the easy half.
Identification is the other half and requires that the F-35 approach the
target much closer. Thus, the suggestion
that an F-35 can provide targeting from hundreds of miles away is utterly
3. Ship stealth will greatly reduce the
Survivability. In order for the F-35 to be an effective BAMS
platform, it needs to be survivable long enough to find a target and track it
to provide mid-course guidance for an attack.
That could, and likely will, require flying in enemy controlled air
space for hours. All the while, the
enemy will be diligently searching the air space for just such activity. Our F-35 will have to evade a multitude of
all manner of sensors: airborne patrols,
ship radars, ESM, land radars, IRST, optical sensors, etc. Yes, the F-35 is stealthy (from the front
aspect – the sides and rear, not so much) but stealth isn’t magic. Worse, the F-35 will be operating its own
radar which further increases the chance of detection. The odds on being able to loiter undetected
in the vicinity of an enemy force in enemy air space are poor.
Detection is a simple matter of statistics. To illustrate, let’s say that a stealth
aircraft has only a 1% chance of being detected in any given minute. Hey, that’s great! We have a 99% chance of not being detected. Those are great odds, aren’t they? However, over the course of an hour (sixty
1-minute intervals, each with a 1% chance of detection), that 1% chance of
detection means a 46% chance of detection.
Oops. Make it two hours and the
chance of detection goes up to 71%.
Yikes. Admittedly, this is a
simplistic treatment of stealth and detection but it is, essentially,
conceptually correct. There is always a
chance of detection and the longer the stealth aircraft loiters, the greater
the chance of being found. Thus, the
idea that an F-35 can loiter and track targets and guide missiles is
fundamentally suspect. And, of course,
the closer the F-35 loiters to the target, the greater the momentary odds of
4. Stealth aircraft WILL be found and
the odds of being found increase with loiter time and proximity to the target.
Low Probability of
Intercept (LPI) Radar. The magic
solution to detection and survivability, according to F-35 fanboys, is the
fairy dust LPI radar. F-35 proponents
would have us believe that the LPI radar is undetectable while retaining
maximum range and resolution. Of course,
this is simply untrue.
LPI radars use a variety of methods to reduce the chance of
the signal being intercepted (recognized in the background noise – the signal
will always be intercepted). These
include frequency agility, pulse rate variation, etc. and, mainly, power
reduction. However, hand in hand with
power reduction goes decreased detection range.
Make no mistake, LPI radars do, indeed, lower the chance of
intercept (recognition) but do so at the expense of range and resolution. Thus, our F-35, operating its APG-81 radar in
LPI mode, will have the effective detection range (which we previously noted
would be only a small fraction of the manufacturer’s claimed range) reduced
even further. This further reduction in
detection range also means that the F-35 must get even closer to a target
which, we previously noted, further decreases the F-35’s survivability.
Logical Conclusion 5. LPI radar is not magic and will decrease
detection range and survivability.
Area Search. The key characteristic of BAMS is that it is
a large area search function. As such,
the searching aircraft must, simplistically, pass back and forth repeatedly (a
euphemism for whatever search pattern is employed) in order to effectively
cover the desired area. As we noted,
given that detection range for targets of interest is going to be only a
fraction of the claimed range, the searching aircraft will have to cover very
small increments of the search area as opposed to sweeping vast areas in a single
radar pulse, as F-35 proponents would have us believe. This continual and extended back and forth
searching, all the while with the radar broadcasting, is going to still further
increase the chance of the F-35 being detected.
As noted in a Wiki article on LPI radar, a searching aircraft with LPI
radar active will always be pointing its main lobe at some radar receiver. (1)
Having considered and applied all the preceding logic, it is
logical to conclude that the F-35 cannot be an effective BAMS asset. There is, in addition, one final bit of evidentiary
logic that disproves the F-35 fanboy’s claims of effective BAMS and the simplicity
of the logic is so self-evident that it needs no additional analysis:
Conclusion. If all the claims for the
F-35 broad area maritime surveillance capability were true, we’d have already
eliminated AWACS, Triton, BAMS, E-2 Hawkeyes, etc. in favor of the F-35 with
its APG-81 radar.
So, does the preceding mean that an F-35 is incapable of
finding a target? Of course not. It just means that the F-35 is not a magical
BAMS asset as so often claimed. The F-35
is not the magical answer to the distributed lethality sensor problem. The F-35 is not the magical answer to some
notional sea control concept. The F-35
is not a substitute for a carrier’s E-2 Hawkeye.
What can the F-35 do?
It can provide search over a limited area if we’re willing to risk the
detection and loss of the aircraft. Is
it worth risking a $100M aircraft to do limited area search? Well, that’s an operational question whose
answer depends on what the potential benefits are in relation to the potential
Where this can work best is when we have an idea where the
target is and the search area – and risk - is, therefore, limited. This is not as unlikely as it might
sound. Naval forces usually have at
least a general idea of where the enemy is. This was true throughout WWII and is true
today. A shared understanding of our own
and the enemy’s strategies and objectives combined with various other sensor
reports and intelligence are sufficient to offer general locations of enemy
naval forces. Thus, we do not need to
search the entire ocean, we just need to search a moderately constrained area
although prudence dictates sending search assets out in all directions just to
be safe (the WWII carrier dawn 360 degree search by SBD Dauntlesses).
We see then, that the F-35 is NOT a BAMS platform and would
not be effective as such. It can,
however, be effective as a search/confirmation asset when we have a general
idea of where to find enemy targets.
(1)Wikipedia, “Low-probability-of-intercept radar”,