曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
A 3000 psi hydraulic power augmentor system provides elevator control for additional nosedown capability in extreme, high angle-of-attack flight conditions. Supplied by the left hydraulic system, the power augmentor system activates during an extreme stall condition after elevator control tabs have been displaced approximately 10 degrees airplane nosedown with respect to the elevator surface. This augmentor action will restore positive column elevator control. A light on the annunciator panel (ELEVATOR POWER ON) is provided to indicate when hydraulic pressure is used to drive the elevator.
Aerodynamic load feel forces are supplemented by a variable load feel system consisting of a mechanical ratio changer attached between the First Officer’s control column and the elevator load feel and centering spring. The variable load feel mechanism is connected by cables to the longitudinal trim system. Control column force will vary with stabilizer movement and will decrease with forward center-of-gravity conditions.
A Mach trim spring is also connected to the First Officer’s control column. The Mach trim spring is controlled by a Mach trim compensator that provides corrective Mach trim at high Mach number conditions. Operating on a Mach schedule, the Mach trim compensator pulls the First Officer’s control column aft as Mach number increases. As the control column moves aft, an indicator rod on the left side of the First Officer’s control column extends, giving visual indication of Mach trim operation. Mach trim can be selected or overridden by a switch on the overhead panel.
Directional Control System
Directional control is obtained through rudder pedals that control rudder movement. The rudder is normally powered by the right hydraulic system.
Powered Rudder Operation
During powered rudder operation, the rudder control tab is locked hydraulically, and rudder pedal movement activates the entire rudder. Hydraulic power to the rudder may be shut off by placing the rudder power control handle in the manual position. When hydraulic power to the rudder control unit is shut off, or when right hydraulic system pressure drops to approximately 950 psi, the rudder automatically reverts to manual operation, unlocking the rudder control tab. A light on the annunciator panel comes on to indicate manual rudder operation.
The maximum rudder deflection in the powered mode is approximately 22 degrees to either side of neutral.
Manual Rudder Operation
During manual rudder operation, rudder pedal movement operates a control tab on the rudder. Aerodynamic force on the control tab moves the rudder.
Due to the aerodynamic operation of the rudder control tab, maximum rudder deflection in the manual mode is expected to be approximately 17 degrees to either side of neutral.
Each set of rudder pedals is individually adjusted. The Captain’s and First Officer’s rudder pedal systems are connected by a torque tube forward of the pedals.
Rudder Trim
Trim is accomplished by turning a trim knob on the pedestal. Movement of the trim knob will cause the rudder pedals to displaced accordingly. Whether the rudder is operating in the powered or manual mode, the trim will operate. In the powered mode, the trim will cause the entire rudder to be hydraulically displaced. In the manual mode, the trim will cause the rudder control tab to be displaced.
Rudder Throw Limiter
A rudder throw limiter is installed to protect the empennage from overload in case of inadvertent application of excessive rudder control. The limiter operates (in either powered or manual modes) by ram air pressure from the pitot tube on the leading edge of the vertical stabilizer. The higher the airspeed, the more ram pressure, resulting in proportional restriction of rudder movement. The throw limiter is scheduled to vary the maximum available rudder throw from –22° (unrestricted) to –2.5°.
On acceleration, rudder throw is unrestricted to 180 KIAS (200 KIAS MD-83), then will gradually reduce until reaching –2.5° at 300 KIAS. On deceleration, the throw will increase until reaching –22° at 144 KIAS (165 KIAS MD-83).
A blue RUDDER TRAVEL UNRESTRICTED light on the annunciator panel comes on during unrestricted rudder throw operation. This light must be on for takeoff and should be on for landing. If it is not on for landing, an Abnormal Procedure is accomplished by the crew.
The rudder limiter pitot tube is normally electrically heated to prevent ice by use of the pitot heat selector switch on the cockpit ice protection panel.
Continental
Rev. 12/01/00 #29 Flight Manual
Yaw Damper
An electrically operated yaw damper is installed in the rudder system to provide automatic damping of any lateral directional oscillation. Yaw damper operation is selected by a switch on the overhead panel. A light on the annunciator panel comes on when the damper is turned off or the yaw damper becomes inoperative.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：MD-80 Flight Manual 麦道80飞行手册 2(131)
