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SPOILER AND SPEEDBRAKE CONTROL -FUNCTIONAL DESCRIPTION -SPOILER LOCKOUT
Purpose
To prevent tail buffet at cruise speed, spoilers 5 and 10 fair to the wing surface and lock out during cruise.
Functional Description
The PFCs and the ACEs command spoilers 5 and 10 to lock out based on altitude and computed airspeed (CAS).
Spoiler lockout is available in normal, secondary, and direct modes.
Normal Mode
In normal mode, the PFCs control the lockout of spoilers 5 and 10 based on airspeed and altitude. For high airspeeds and altitudes, the spoiler panels are locked out. For low airspeeds and low altitudes, the spoiler panels are commanded to move.
There is a range of reduced authority as the airspeed increases. The PFCs use airspeed input to decrease the amount of spoiler pick-up from full authority to lock out.
Secondary and Direct Modes
In secondary and direct mode, the PFCs and ACEs lockout spoilers 5 and 10 at all times.
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SPOILER AND SPEEDBRAKE CONTROL -FUNCTIONAL DESCRIPTION -SPOILER LOCKOUT
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777 AIRCRAFT MAINTENANCE MANUAL
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27-62-00
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AUTO SPEEDBRAKE CONTROL -GENERAL DESCRIPTION
General
The auto speedbrake controls the automatic movement of the speedbrake lever during airplane operation on the ground. The pilots use the auto speedbrake during landing and refused takeoff (RTO). Extension of the auto speedbrake causes all spoilers to deploy to their maximum position.
Auto Speedbrake Control
The PFCs control the automatic extension and retraction of the speedbrake lever. The PFC logic requires that a series of conditions be met to command the auto speedbrake actuator to operate.
When the pilot moves the speedbrake lever out of its DOWN detent to the ARM position, the speedbrake lever transducer supplies a signal to the PFCs through the ACEs. When the pilot operates the engine thrust reverser, the auto speedbrake thrust reverse switch supplies a signal to the PFCs through the AIMS cabinets.
The main landing gear truck tilt sensors supply signals to the proximity sensor electronic units (PSEUs). The electronic engine controls (EECs) supply signals through the engine data interface units (EDIUs) to show the position and validity of the thrust resolver angles. The hydraulic interface module (HYDIM) cards supply signals about the hydraulic pressure status of the truck tilt actuators. The weight-on-wheels (WOW) cards supply signals that the airplane is on the ground. The radio altimeters supply the airplane altitude near the ground. All these signals go through the AIMS to the PFCs.
When the extension or retraction conditions are met, the PFCs send command signals to the ACEs. The ACEs then control the auto speedbrake relays which control power to the auto speedbrake actuator. This causes the auto speedbrake actuator to extend or retract.
The auto speedbrake clutch transmits the movement from either the speedbrake lever or the auto speedbrake actuator to the speedbrake lever transducer. The auto speedbrake clutch permits the pilot to move the speedbrake lever and override the commands of the auto speedbrake actuator at anytime.
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AUTO SPEEDBRAKE CONTROL -GENERAL DESCRIPTION
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AUTO SPEEDBRAKE CONTROL -COMPONENT LOCATIONS
General
The auto speedbrake components are on the left side of the control stand in the flight deck. These components include:
*
The auto speedbrake clutch
*
The auto speedbrake actuator
*
The RTO speedbrake mechanism.
Remove the left panel of the control stand to access the auto speedbrake components.
The two auto speedbrake relays are on a bracket below the control stand. Access to the relays is through the forward equipment access door.
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AUTO SPEEDBRAKE CONTROL -COMPONENT LOCATIONS
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AUTO SPEEDBRAKE CONTROL -INTERFACES
General
The electrical interfaces with the PFCS for the auto speedbrake go through the ACEs. The ACEs have interfaces with these components: 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：777 AMM 飞机维护手册 飞行操纵 Flight Controls 2(56)
