CSP-HE/HS-1
ROTORCRAFT FLIGHT MANUAL
General
MD 500
(Models 369HE/HS/HM
)
Revision 6
1-12
The main rotor transmission is mounted on the basic airframe structure above
the passenger/cargo compartment. The transmission is lubricated by its own
internal lubrication system.
The main rotor static mast is non−rotating and is rigidly mounted to the mast
support structure. The rotor hub is supported by the rotor mast.
Torque is transmitted independently to the rotor through the main rotor drive
shaft, thus lifting loads are prevented from being imposed onto the main trans−
mission eliminating thrust loading of transmission parts.
The tailboom is a monocoque structure of aluminum alloy frames and skin.
The tailboom is the supporting attachment structure for the stabilizers, tail ro−
tor transmission and tail rotor. The tailboom also houses the tail rotor trans−
mission drive shaft; the one piece dynamically balanced shaft requires no inter−
mediate couplings or bearings. Metallic diaphragm shaft−end−couplings are
used.
The tail rotor transmission is mounted on the aft end of the tailboom and has
a self contained lubrication system. The tail rotor is mounted on the output
shaft of the transmission and consist of two variable pitch blades.
The helicopter utilizes a four bladed, fully articulated main rotor assembly
with unique features. While contemporary helicopters use torsion tension
straps in lieu of thrust bearing stacks to contain blade centrifugal loading and
allow feathering, the MDHI strap pack arrangement goes three steps further.
First, the strap configuration (while secured firmly to the hub) actually allows
the centrifugal load exerted by one blade to be countered by the force exerted
by the opposite blade. Thus, very light centrifugal loads are sensed by the hub.
Second, the V−legs of the strap pack rotate as driving members to turn the
blades. Finally the straps are configured to allow feathering and flapping of
the blades. The main rotor blades are secured to the hub with quick release
lever type pins.
Cyclic, collective, and adjustable pedal controls are provided at the left crew
position (right position, military only). Adjustable friction devices, which may
be varied to suit the individual pilot, are incorporated in the cyclic, collective
and throttle controls. In addition, electrical cyclic trim actuators allow flight
loads to be trimmed out. Since stick control forces are low, a hydraulic boost
system is unnecessary. An optional dual control system may be easily removed
to provide room for passengers or cargo.
The landing gear is a skid−type attached to the fuselage at 12 points and is
not retractable. Aerodynamic fairings cover the struts. Nitrogen charged land−
ing gear dampers act as springs and shock absorbers to cushion landings and
provide ground resonance stability. Provisions for ground handling wheels are
incorporated on the skid tubes.
