In normal mode, the ailerons droop at a different rate and schedule than the flaperons.
When the flaps are retracted, the ailerons are at the 2 degrees TED rig position in relation to the wing fixed trailing edge. With the flaps at the takeoff position (5 to 20), the ailerons droop by 8 degrees TED. With the flaps at the landing position (25 and 30), the ailerons move to 0.6 degrees TED.
The flaperons droop to 10 degrees TED when the flaps are at the 5 position. They droop to 20 degrees TED when the flaps are at the 15 or 20 position. They droop to 31 degrees TED when the flaps are at the landing position (25 or 30).
On the ground, the PFCs remove the flaperon droop command in proportion to the speedbrake lever movement from 17 to 55 degrees. When the speedbrake lever goes back to the DOWN position, the flaperons gradually droop to the position commanded by the flaps.
Secondary and Direct Modes
In the secondary and direct modes, the flaperons droop to a constant value of 20 degrees when the flaps and slats are not retracted. The ailerons do not droop.
EFFECTIVITY BEJ ALL 27-11-00
Page 74
D633W101-BEJ Sep 05/2002
AILERON AND FLAPERON CONTROL -AILERON AND FLAPERON DROOP
EFFECTIVITY BEJ ALL 27-11-00
Page 75
D633W101-BEJ Jan 05/2002
AILERON AND FLAPERON CONTROL -AILERON LOCKOUT
Purpose
The outboard location of the ailerons and their large surface area could cause large wing torsion loads and loss of lift at high speed. To prevent this, the ailerons align (fair) to the wing surface and lock out during cruise.
Functional Description
Aileron lockout is available in normal, secondary, and direct modes.
In normal mode, the PFCs and the ACEs command the ailerons to lock out based on altitude and computed airspeed (CAS). In secondary and direct modes, the ailerons lock out only when the flaps and slats are retracted.
Normal Mode
In normal mode, the PFCs multiply the aileron command by the lockout factor. The lockout factor is based on airspeed and altitude. For low airspeeds and low altitudes, the lockout factor is one. For high airspeeds and high altitudes, the lockout factor is zero.
If the airspeed is between the zero lockout airspeed and the one lockout airspeed, then the lockout factor is proportional between zero and one. In this condition, the aileron command has reduced authority.
Secondary and Direct Modes
In secondary and direct modes, the PFCs and ACEs use FSEU flaps and slats retracted signals to command lockout. When the flaps and slats are retracted, the ailerons lock out. When the flaps and slats are not retracted, the ailerons are unlocked.
EFFECTIVITY BEJ ALL 27-11-00
Page 76
D633W101-BEJ Sep 05/2002
AILERON AND FLAPERON CONTROL -AILERON LOCKOUT
EFFECTIVITY BEJ ALL 27-11-00
Page 77
D633W101-BEJ Jan 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
THIS PAGE IS INTENTIONALLY LEFT BLANK
27-11-00
Page 78 D633W101-BEJ Jan 05/2002
AILERON AND FLAPERON CONTROL -BANK ANGLE PROTECTION
Purpose
The bank angle protection (BAP) function of the PFC helps prevent the airplane from rolling to large bank angles. However, the pilot can always override the control wheel forces and remain in full control of roll.
Functional Description
When the bank angle exceeds the nominal value of 35 degrees, BAP increases the control wheel force to the pilot.
BAP operates only in PFCS normal mode and is available in both manual operation and in autopilot.
When the BAP function is active, the ELMS prevents the operation of the aileron trim.
BAP does not operate when the pitch attitude is more than 75 degrees (positive or negative). When the airspeed is between the maximum operating speed (Vmo/Mmo) and the maximum design dive speed (Vdive/Mdive), the BAP roll activation value decreases linearly from 35 to 20 degrees.
Manual Operation
The PFCs calculate backdrive actuator commands based on:
*
Roll attitude
*
Roll rate
EFFECTIVITY
BEJ ALL
*
Mach number
*
Computed airspeed
*
Pitch attitude
*
Wheel force.
When the bank angle is more than 35 degrees, the PFC BAP function sends a backdrive command to the AFDCs. The AFDCs send this command to one of the wheel backdrive actuators. The actuator motor applies a torque to turn the control wheels proportionally as the bank angle increases from 35 to 60 degrees.
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 1(44)
