Tuesday, August 18, 2009
Kaman's Kooler K-Max
Enter the Kaman K-Max.
This is a pure work helicopter employed to transport and set
bulky and heavy objects. It's got a centerline winch and the
fuselage is extra narrow so that the pilot can stick his head out
the sides to look down. The K-Max has a long tailboom so it
doesn't need as much fin area as the Huskie has, but like the
Huskie it doesn't need a tailrotor either. As a direct
consequence, a lot more horsepower is available for lifting.
In fact, 6000lb at sea level, impressive for a 5100lb helicopter.
Another neat design feature shared by all Kaman helicopters,
eggbeater and conventional alike, is the blade control flap.
On other helicopters, the blade pitch is controlled by pitching
it directly at the hub. This requires hydraulic controls on any
helicopter of size. With the blade control flap, the flap is
actuated in the opposite direction and this causes the blade to
twist in the desired direction, Just like the elevator on a
conventional airplane. This means the control input required is
much lighter, [no horsepower robbing hydraulic pump needed]
and because the blade is being controlled out where lift is
created instead of at the hub, the blade trim is more precise
and reactive to the airflow around it on a per blade basis.
This spells greater efficiency and reduced vibration. The
simplified rotor hub also reduces mechanical friction losses,
and reduced aerodynamic drag in forward flight.
Kaman has utilized the K-Max's light and easy main rotor
control and the lack of a squirrely tail rotor to produce a
dual function version that can be remotely controlled as well
as piloted. As far as I know, this is the first full size
helicopter to be flown unmanned. The fact that it can still
be flown manned as well makes it quite versatile.
Kaman has partnered with Lockheed Martin, called Team
K-Max to modify and demonstrate the UAV K-Max for military
operational testing. These modifications are at least the minimum
needed to turn a civilian bush aircraft into one that's integrated
with the 21st century US Navy and Marines.