Photos Reveal Precision Of Today's Weapons
One of the truly transformational weapons in the Global War On
Terrorism has been the Joint Direct Attack Munition, or JDAM for
short. This inexpensive, precision-guided bomb can strike within a
yard of its target and usually does. Furthermore, since JDAMs come
in 500, 1,000 and 2,000 pound sizes, this is usually bad news for
the target, as seen in this remarkable picture below.
The US Army provided us this picture and a brief explanation of
the JDAM tactic used in high-value target cases like this one. The
exact circumstances of this attack, and the particular target, are
classified. While the terrain resembles certain areas in Iraq, we
can't guarantee that this was a combat drop; it may have been a
test.
JDAMs are targeted to an exact grid coordinate, a precisely
described point on the ground. This target selection can be done in
flight, by aircrew or directly by a ground controller through data
link to the aircraft.
Because even JDAMs occasionally suffer fuze failures, and very
occasionally go astray, if a target is sufficiently valuable, the
aircraft drops a pair. "When a single aircraft's drops are released
from the same aircraft at minimum release time, the second hits
first and the first release drops almost directly in the hole [made
by] the first impact," the source says. "You can really dig a deep
hole this way."
Why does the second bomb hit first? Because the carrier aircraft
is traveling towards the target, usually perpendicularly to the
ground element's line of sight on the target, which reduces the
risk of a long or short round impacting on friendlies.
The gray cloud is the blast of the first JDAM (second one
released, first one to hit). Zoom in on the top of the blast in the
photo below, where the red arrow points, and you see the
second weapon plunging in.
Over 100,000 JDAM kits have been produced by Boeing for the Air
Force, Navy, and Marines. The kit attaches to the ordinary "dumb"
bombs in the US inventory, and provides them with a dual GPS and
inertial navigation system that provides truly unprecedented
accuracy -- at five or ten percent of the cost of Vietnam-era
laser guided bombs and a fraction of the risk to aircraft, crews
and ground troops.
In addition, the JDAM can be dropped in all visibilities and all
weather, day or night, moon or none, through undercast, or from
such height and distance that the target has no opportunity to
observe or engage the drop aircraft. Fighter aircraft can drop five
or more JDAMs at once, and the B-2 Spirit bomber has been tested
with an incredible 80 JDAM drop.
Even losing the GPS signal is no big deal to a JDAM. It
automatically fails over to its inertial navigation system backup,
and while accuracy is degraded enough to make a difference to a
bullet, it's still accurate enough for a bomb.
The JDAM was first used in the 1999 Kosovo air war, but was
largely ineffective. The combination of JDAM precision and
on-the-ground targeting by special operations forces, which was
first used in the 2001 Afghan campaign, has proven to be another
matter entirely. It was this one-two punch that caused the famously
unconquerable nation to fall to fewer than 100 Americans and their
Afghan allies in less than two months from the first American's
arrival in country.
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