Page 5 D633W101-BEJ Sep 05/2002
TRAILING EDGE FLAPS -GENERAL DESCRIPTION
As the flaps move, the flap position sensors send feedback
signals to the FSEUs. The FSEUs command the relays to stop
the electric motor when the flaps are at the commanded
position.
The FSEUs use the flap skew sensors to shutdown the
secondary mode if there is a flap skew or asymmetry.
Alternate Mode
The alternate mode has an open-loop control system. The pilot uses the switches on the alternate flaps panel to command the flaps. An arm switch sends a discrete signal to the FSEUs to disengage the primary and secondary modes. This switch also energizes one of the secondary/alternate control relays. This relay energizes the bypass solenoid in the flap primary control valve and the clutch in the electric motor unit. This stops hydraulic power to the hydraulic motor and lets free flow through it. the electric motor clutch connects the motor shaft to the PDU gearbox.
The alternate flaps selector sends commands through the flap limit switch to energize the other secondary/alternate control relays. These relays control electrical power to the flap electric motor in the PDU. The electric motor then moves the flap mechanisms.
The flaps move until the pilot moves the alternate flaps selector to the OFF position or the flap limit switch stops the motor when the flaps are at the limit.
There is no automatic shutdown of the alternate mode if there is a flap skew or asymmetry.
EFFECTIVITY BEJ ALL 27-51-00
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TRAILING EDGE FLAPS -GENERAL DESCRIPTION
EFFECTIVITY BEJ ALL 27-51-00
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D633W101-BEJ Jan 05/2002
TRAILING EDGE FLAPS -GENERAL DESCRIPTION -FLAP DRIVE SYSTEM
General
These are the components of the flap drive system:
*
Flap PDU
*
Torque tubes
*
Torque tube supports
*
Position sensor gearboxes
*
Angle gearboxes
*
Transmission assemblies
*
No-back brakes.
Flap PDU
The flap PDU receives hydraulic power through the primary control valve and electric power through the flap extend/retract relays. Hydraulic and electric motors on the PDU move the flap drive system.
Torque Tubes
The torque tubes transmit power from the PDU to the transmission assemblies.
Torque Tube Supports
The torque tube supports hold the torque tubes.
Position Sensor Gearboxes
The position sensor gearboxes contain the flap position sensors and limit switch. The sensors send flap position signals to the FSEUs. The limit switch removes electrical power from the electric motor when the flaps move to their limit during operation in the alternate mode.
Angle Gearboxes
The angle gearboxes connect torque tubes that are at different angles to each other.
Transmission Assemblies
The transmission assemblies receive power from the torque tube to move the flap surfaces. There are two transmissions for each flap surface.
No-back Brakes
The no-back brakes prevent air loads from backdriving the flap mechanisms. There is one no-back brake on each wing. The no-back brakes attach to the torque tubes between the two transmission assemblies for the outboard flaps.
EFFECTIVITY BEJ ALL 27-51-00
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TRAILING EDGE FLAPS -GENERAL DESCRIPTION -FLAP DRIVE SYSTEM
EFFECTIVITY BEJ ALL 27-51-00
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D633W101-BEJ Jan 05/2002
TRAILING EDGE FLAPS -COMPONENT LOCATIONS -1
Flight Deck Controls
The flap lever and the alternate flaps panel are on the P10 control stand. The flap lever position sensor is inside the control stand. 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(31)
