resupply problem. Given the demand for
helicopters in Afghanistan already, using a
UAV for such jobs also should ease the burden on manned Marine Corps rotorcraft
that can be used to deliver supplies but are
needed for a variety of other missions, too.
“There also could be some other areas
where it may potentially be a game-chang-er,” Heffern said. “There may be situations
where the risk of ground fire or weather
may be so elevated that we’re unable to take
manned aviation into particular areas.” The
Marines “may be more willing to assume
that risk with an unmanned system,” he
continued. The Marines got at least three
responses to their RFP, with major differences among the entries.
K-MAX
Lockheed Martin Corp.’s Systems Integration division at Owego, N. Y., partnered with
Kaman Helicopters of Bloomfield, Conn.,
to offer the beefiest entry, an “optionally
manned” version of Kaman’s K-MAX. The
manned version of the K-MAX has been
used since the 1990s for logging and other
medium-lift jobs, but Kaman has sold only
a few. The K-MAX’s empty weight is 6,000
pounds, and with its two intermeshing “
syn-chropter” rotors, which cancel out torque,
and no tail rotor to bleed power from its
single engine, Kaman boasts that the aircraft
can lift its own weight in payload.
Hummingbird
Boeing Co. also bid on the Marine Corps
contract with its A160T Hummingbird, a
35-foot-long helicopter UAV whose claim to
fame up until now has been its ability to stay
aloft for long periods — 18. 7 hours in a 2008
test. The Hummingbird was developed by
the ever-inventive Abe Karem, who also
devised the fixed-wing UAV that evolved
into the Predator. The Hummingbird uses
Karem’s rigid Optimum Speed Rotor, whose
revolutions per minute can be adjusted for
maximum efficiency at different altitudes
and cruise speeds. DARPA and the Army
funded the development work and Boeing
took over Hummingbird when it bought
Frontier Systems Inc. in 2004. Designed for
endurance, the Hummingbird is light —
about 2,500 pounds empty — and according
to Boeing can carry up to 2,500 pounds of
cargo in addition to its fuel.
Game On
Going into the competition, Lockheed
and Kaman officials were confident the
K-MAX’s superior lifting ability would
give their entry the edge needed to win the
Marine Corps contract. “They require that
you have to deliver 20,000 pounds of cargo
over a 24-hour window,” said Dan Spoor,
vice president for rotary wing programs at
Lockheed’s O wego division. “That’s the key
requirement. We can handily meet that
requirement.” The K-MAX also has a carousel cargo hook that allows it to carry four
separate loads and drop them at four locations, said Salvatore Bordonaro, president
of Kaman Helicopters. “We actually call it
the ‘aerial truck,’” Bordonaro explained.
The companies tested a K-MAX flying
autonomously in June 2008 for the Army,
whose Aviation and Missile Research,
Development and Engineering Center at
Redstone Arsenal, Ala., is very interested
in the optionally manned K-MAX, though
that service has no plans as yet to buy a helicopter UAV for cargo hauling. The Army
tests were flown with a “safety pilot” aboard
because Federal Aviation Administration
regulations severely limit unmanned aircraft flights in domestic airspace.
In those tests, Lockheed and Kaman
proved that an operator on the ground
using a ruggedized laptop computer with a
joystick could control the K-MAX through
a data link. Team K-MAX, as the companies
are calling their partnership, also showed
that the aircraft could take off autonomously, pick up and deliver a 3,000-pound
sling load, and change its preplanned route
in flight. For the Marine Corps competition, Lockheed is installing a satellite communications system in the K-MAX to allow
ground operators to control the aircraft
when it gets beyond line of sight.
A typical mission for the Marines, Spoor
said, might be to deliver food, water, ammunition and medical supplies to a FOB located 75 miles or so from a hub base. A ground
operator at the hub would put the aircraft
into a hover at around 50 feet and hold it
there while Marines hooked cargo loads
to the K-MAX. The aircraft then would fly
a preprogrammed route autonomously at
12,000 to 15,000 feet to one or more FOBs.
At each FOB, a Marine on the ground with a
handheld control station would take control
of the K-MAX as it approached, put it into
a hover, release one or more of the cargo
loads, then return control to the aircraft’s
mission management computer.
“They can proceed back to other FOBs
or to the hub with a series of ground controllers operating it along the way,” Spoor said. “It
has the full capability to be flown unmanned
autonomously,” he added, but because the
K-MAX has a cockpit, “if you want to ferry it
between locations with a pilot, you could do
that. You kind of get the best of both worlds.”
Boeing officials said they were confident
their Hummingbird could do what the
Marine Corps wants. The requirement,
observed Boeing’s Mike Lavorando, A160T
deputy program manager, breaks down to
delivering at least 2,500 pounds and ideally
5,000 pounds of cargo every six hours, and
the 150-nautical-mile round-trip requirement is no problem for an aircraft that has
shown it can fly literally all day and much of
the night, on one tank of gas.
The Hummingbird, Lavorando added,
offers its own advantages. Should the
Marines decide they want their UAV to
carry cargo faster than 70–80 knots, the top
speed most any helicopter would be able to
fly hauling a sling load, he said, the A160T
can be fitted with an aerodynamic cargo pod
that would let it fly as fast as 140 knots. Lavorando said the company was still designing
a system to carry sling loads but already had
flown the A160T with a cargo pod, though
not to 140 knots. A 40 x 48-inch pallet loaded with 750 pounds of cargo won’t fit into
the pod, but in principle “the Hummingbird
offers the faster podded resupply capability,”
Lavorando said. “Getting cargo delivered in
half the time, basically, that you could do
with a sling load would be a big advantage.”
The Hummingbird has flown a mission
profile such as the Marine Corps wants
autonomously, but as the competition
began, Boeing was still working to equip
it with handheld and beyond line-of-sight
control systems. John Groenenboom, Boeing’s A160T program manager, said the com-
