-
The distribution of signals for the FMGC control laws
-
The protection of the flight envelope in automatic flight (speed limits for the FMGC, alpha-floor for the autothrust)
-
The display of the flap/slat maneuver speed
-
The windshear warning (pin program activation)
-
The low energy warning
-
The display of the positions of the control surfaces.
The FAC therefore computes:
-
The weight and the center of gravity
-
The characteristic speed data
-
The aerodynamic flight-path angle and the potential flight-path angle
-
The alpha-floor protection
-
The position of the rudder trim for the ECAM system.
R **ON A/C 106-149, 301-399, 401-499,
The Flight Augmentation Computer (FAC) fulfills several functions
independently of the engagement status of the FLT CTL/FAC pushbutton
switches.
These functions are necessary for:
-
The control of the speed scale on the Primary Flight Displays (PFDs).
-
The adaptation of gains of the Flight Management and Guidance Computer (FMGC) and Elevator Aileron Computer (ELAC).
-
The distribution of signals for the FMGC control laws
-
The protection of the flight envelope in automatic flight (speed limits for the FMGC, alpha-floor for the autothrust)
-
The display of the flap/slat maneuver speed
-
The windshear warning (pin program activation)
-
The low energy warning
-
The display of the positions of the control surfaces.
The FAC therefore computes:
-
The weight and the center of gravity
1EFF : ALL 1 22-64-00Page 1 1 1 Aug 01/05 1 1 1CES 1
-
The characteristic speed data
-
The aerodynamic flight-path angle and the potential flight-path angle
-
The alpha-floor protection
-
The position of the rudder trim for the ECAM system
-
The position of the rudder travel limiter for the ECAM system.
**ON A/C ALL
2. System Description
__________________
A. Presentation of Characteristic Speed Data (Ref. Fig. 001) The characteristic speed data are presented on the PFDs through the Display Management Computers (DMC). In normal operation:
-
The FAC1 transmits data to Captain's PFD
-
The FAC2 transmits data to First Officer's PFD.
The transmitted data are validated from:
-
The status matrices of the transmitted labels
-
The FAC HEALTHY hard-wired discrete.
If a failure affects at least one label or the computer itself, the
associated DMC is automatically switched to the opposite FAC.
In the event of a DMC failure, the associated PFD is switched to the
DMC3.
In addition to that, the indication ADC DISAGREE appears on the display
unit of the ECAM system when the ADC source used in the FAC is not the
one selected by the pilot.
Since the FAC specifically processes ADIRS data (Ref. 22-65-00), this
ensures that the characteristic speed data remain displayed:
-
At first detected or undetected failure of the ADIRS by the same FAC
-
At second detected failure of the ADIRS by the FAC associated with the
remaining ADIRS. The FAC processes the display logic of the various speed data mainly through the positioning of the label status matrices:
-F/W : source-change order
-NCD : cancellation order for the considered label.
The information transmitted to the FMGC (speed data, weight, center of
gravity, flight-path angle, alpha-floor) is processed from:
-
The validity of the status matrices
-
The FAC HEALTHY hard-wired discretes.
Interconnections Between FAC and Users
Figure 001
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1 B. Definition and Symbols
(1) Definition and presentation of speed data on PFD
(Ref. Fig. 002, 003)
-------------------------------------------------------------------------------| SPEED | DEFINITION | PRESENTATION | PRESENTATION ON PFD | |--------|---------------------|------------------|---------------------------| | VSW | According to ELAC | After lift-off | Red checkered tape at | | | Alpha Protection | in direct law | the bottom of the scale | | | | only | | |--------|---------------------|------------------|---------------------------| |VALPHA | Speed corresponding | After lift-off | Amber and black strip at | |PROT | to ELAC Alpha | in Normal Law | the bottom of the scale | | | Protection | | | |--------|---------------------|------------------|---------------------------| |VALPHA | Minimum Speed | After lift-off | Red strip at the bottom | |LIM | corresponding to | in Normal Law | of the scale | | | ELAC Alpha | | | | | Protection | | | |--------|---------------------|------------------|---------------------------| | | 1.13 Vs 1g takeoff | | Amber strip at the | | VLS | 1.23 Vs 1g elsewhere| Ditto | bottom of the scale | | | 0.2 g/buffeting | | | | | 1.28 Vs 1g in clean | | | | | configuration | | | |--------|---------------------|------------------|---------------------------| | | Drift Down Speed | Clean configura- | O | | VMAN | | tion | Green dot | |--------|---------------------|------------------|---------------------------| | V3 | 1.18 Vs 1g of 18/10 | Flaps extended | F | | | | except full | | | V4 | 1.18 Vs 1g of 0/0 | Only slats | S | | | | extended | | |--------|---------------------|------------------|---------------------------| | VFE | Max flap and slat | Flaps or slats | Red checkered tape at the | | | extended speed | extended | top of the scale | | VLE | Max landing gear | Landing gear | | | | extended speed | extended | | |--------|---------------------|------------------|---------------------------| | VC | Airspeed tendency | After | Pointer initiating in | | TREND | | lift-off | computed airspeed symbol | |--------|---------------------|------------------|---------------------------| | VM0 | VM0 + MM0 | Ditto | Red checkered tape at the | | | | | top of the scale | |--------|---------------------|------------------|---------------------------| | VMAXOP | 0.2 g with respect | Ditto except if | Not presented | 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：A320飞机维护手册 AMM AUTO FLIGHT 自动飞行2(30)
