The U.S. played a
supporting role in the recent French-led effort to drive al Qaeda out
of Mali. One critical bit of support was KC-135 aerial tankers, which
have so far delivered nearly 500 tons of fuel to French warplanes,
allowing for these aircraft to spend hours more in the air, waiting for a
request from troops below for a smart bomb or missile. Despite having
nearly 400 of these tankers in service, about a quarter of them are
sidelined because of maintenance, much of it brought on by advanced age.
As these tankers are also used for many training exercises and the
movement of air cargo, it is not easy for the air forced to collect some
for an emergency like Mali. This will become more of a problem over the
next decade because of the delays in finding a replacement.
The four engine KC-135 carries 90 tons of fuel and can
transfer up to 68 tons per sortie. Typically, aerial tankers have to
service B-52s, which carry over 140 tons of jet fuel, and fighters like
the F-15 (over five tons). The KC-135 has also made itself useful
carrying cargo and passengers, as well as fuel. But the elderly KC-135s
are difficult to keep running, and many of them still have to serve
another twenty years, until completely replaced by the new KC-46A.
Operating aircraft this old is unexplored territory, because this is the
first time in history that so many large, and fast, aircraft have gone
on flying for so long. Commercial freighter aircraft fly more frequently
than their military counterparts, putting more strain on them, and
forcing their operators to develop new maintenance techniques the air
force can use. The KC-135s are the oldest transports the air force is
still using, and keeping them working is proving to an expensive and
challenging effort.
The basic problem is that, despite constant maintenance and
careful monitoring unexpected failures still occur with elderly
aircraft. Nothing that is cause for alarm, but it is more expensive to
keep them flying and problems are more difficult to predict. Older
aircraft are grounded if any unexpected failure seems imminent. While
that just about eliminates these aircraft having fatal failures while in
the air, it also makes older aircraft less available for service. For a
long time it was considered more cost effective to keep the old birds
flying, than to buy new ones. Eventually advanced age made replacement a
necessity, not an option.
Thus after over a decade of effort the U.S. Air Force managed
to finally select a replacement two years ago. The air force procurement
process has been cursed with corruption, incompetence, meddling
politicians and litigious suppliers, all combining to prevent the
acquisition of a new tanker. One was finally selected and the initial
order was for 18 aircraft (at about $150 million each), to be delivered
within six years. That initial order also comes with about a billion
dollars for development work. The air force might order over a hundred
KC-46As, but the exact number depends on what kind of future aircraft
the air force will be using. If there are a lot of unmanned aircraft
(UAVs), fewer tankers will be needed (because UAVs are smaller, and need
less fuel). There is, however, a lot of resistance in the air force and
Congress to any further squabbling over who should build the
replacement for the KC-135.
The KC-46A is based on the Boeing 767-200 airliner, which
sells for about $120 million. The 767 has been in service since 1982,
and over 800 have been manufactured so far. Boeing developed the KC-767,
at a cost of nearly a billion dollars, on its own. Boeing also
developed the original KC-135 tanker in the 1950s, and has since built
over 2,000 of these.
The KC-46A was selected partly because it is about the same
size as the KC-135 (wingspan is 50.3 meters/156 feet, 6.8 percent larger
than the KC-135). Thus the new tanker can use the same basing and
repair facilities as the 135. The KC-46A can carry up to 94 tons of
fuel. It can also carry up to 114 passengers or 18 cargo pallets or 58
patients (24 on litters).
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