TM 1-1520-238-T-4
4–7
4–2.
LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont)
4–2
(6) Engine Power Controls.
The major components of the engine power controls are the pilot power
quadrant, CPG power quadrant (fig. 4–6), control cables, the power available spindle gearbox, the load demand
spindle (LDS) gearbox, the grip control collar switch, the hydro–mechanical unit (HMU) and the turbine speed
control box (fig. 4–7).
BAT OVRD
PWR
PWR
LEVERS
TRIGGER
RELEASE
CPG POWER QUADRANT
FRICT
POWER
LEVER
PILOT POWER QUADRANT
M58-078
Figure 4–6.
Power Quadrants
(a) Power Quadrants.
The pilot and CPG power quadrants contain two power levers. The left PWR
lever operates engine NO 1. The right PWR lever operates engine NO 2. The PWR levers have four positions:
OFF, IDLE, FLY, and LOCKOUT. A trigger release on each of the power levers release the stops. The pilot’s
power quadrant has a FRICT (friction) power lever, a MASTER IGN (master ignition) switch, and a RTR BK (rotor
brake) switch. The pilot power quadrant has mechanical stops that lock the position of the levers. The CPG’s
quadrant has a EMER HYD PWR (emergency hydraulic power) switch and BAT OVRD (battery override) switch.
The stop release levers on the CPG quadrant are connected to a solenoid.
(b) Control Cables.
The control cables (fig. 4–7) link the power levers and collective control sticks to
the HMU. There are six sections of control cables located between the power levers and the power available
spindle gearboxes. There are four sections of control cables located between the collective bellcrank and the LDS
gearboxes. The cables are composed of balls, ball guides and outer and inner races inside of a flexible stainless
steel tubing covered by plastic. The center element of the race is the action element that travels on the balls to
reduce friction.
(c) Power Available Spindle and LDS Gearboxes.
The power available spindle and LDS gearboxes
are on the HMU for each engine. They are linked to the pilot and CPG power levers, collective pitch servocylinder,
and the turbine speed control unit. The power available spindle and LDS gearboxes are simple rack and pinion
and are interchangeable with their respective gearboxes on the opposite engine.
