(6) Engine Power Controls

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.