AUTO FLIGHT - GENERAL Flashcards
The Flight Management Guidance System (FMGS) contains the following units:
4 items
‐ Two Flight Management Guidance Computers (FMGC)
‐ Two Multipurpose Control and Display Units (MCDU) (third MCDU optional)
‐ One Flight Control Unit (FCU)
‐ Two Flight Augmentation Computers (FAC).
The Flight Management and Guidance System (FMGS) provides predictions of
flight time, mileage, speed, economy profiles and altitude.
FLIGHT MANAGEMENT GUIDANCE COMPUTER (FMGC) is divided into two main parts:
‐ The Flight Management (FM) part controls the following functions:
* Navigation and management of navigation radios
* Management of flight planning
* Prediction and optimization of performance
* Display management.
‐ The Flight Guidance (FG) part performs the following functions:
* Autopilot (AP) command
* Flight Director (FD) command
* Autothrust (A/THR) command.
Each FMGC contains elements stored by the flight crew that enable them to create
20 waypoints,
10 runways, 20 navaids, and 5 routes.
The MCDUs allow the activation of ___ in the case of a dual FM Failure.
the back–up navigation
The FAC controls
rudder, rudder trim and yaw damper inputs.
The FAC also provides warning for low-energy and windshear detection if these functions are installed.
The thrust levers are the main interface between the
Flight Management Guidance Computer (FMGC), the Full Authority Digital Engine Control System (FADEC), and the flight crew.
An ___ (EFIS) control panel is located at each end of the glareshield and is used to control both Primary and Navigation Displays.
ELECTRONIC FLIGHT INSTRUMENTS
PRIMARY FLIGHT DISPLAYS
This centralized color display includes:
‐ Flight Director attitude guidance targets
‐ Armed and engaged modes
‐ Navigation and instrument approach information
‐ Altimeter setting
‐ Barometric altitude
‐ System messages.
NAVIGATION DISPLAYS
Five different color navigation compass displays can be selected:
‐ ARC (map mode)
‐ ROSE NAV (map mode)
‐ ROSE VOR
‐ ROSE ILS
‐ PLAN.
The FMGS has four modes of operation:
‐ Dual mode (the normal mode)
‐ Independent mode. Each FMGC being controlled by its associated MCDU
‐ Single mode (using one FMGC only)
‐ Back–up navigation mode.
FMGS MODES OF OPERATION
DUAL MODE is the normal mode. The two FMGCs are synchronized: each performs its own computations and exchanges data with the other through a
crosstalk bus.
FMGS MODES OF OPERATION
MASTER FMGC LOGIC
If one autopilot (AP) is engaged, the related FMGC is master:
It uses the onside FD for guidance
It controls the A/THR
It controls the FMA 1 and 2.
FMGS MODES OF OPERATION
MASTER FMGC LOGIC
If two APs are engaged, ___ is master.
FMGC1
FMGS MODES OF OPERATION
MASTER FMGC LOGIC
If no AP is engaged, and
- The FD1 pb is on, then ___ is master
- The FD1 pb is off, and FD2 pb on then ___ is master.
FMGC1 / FMGC2
FMGS MODES OF OPERATION
MASTER FMGC LOGIC
If no AP/FD is engaged, A/THR is controlled by ___.
FMGC1
FMGS MODES OF OPERATION
INDEPENDENT MODE
The system automatically selects this degraded mode under specific abnormal conditions (e.g.
different database validity on both FMGCs
“INDEPENDENT OPERATION” message is displayed
FMGS MODES OF OPERATION
INDEPENDENT MODE
PROCEDURES IN FLIGHT
DO NOT SWITCH the navigation databases.
MAKE the same entries on both MCDUs to have
both AP/FDs similar orders.
FMGS MODES OF OPERATION
SINGLE MODE
The system automatically selects this degraded mode when
one FMGC fails.
FMGC displays “OPP FMGC IN PROCESS”
FMGS MODES OF OPERATION
SINGLE MODE
PROCEDURES
If a transient failure triggers a single mode of operation:
- SET both NDs on the same range and mode to display the same information from the operative FMGC.
- When convenient, RESET the failed FMGC.
FMGS MODES OF OPERATION
BACK UP NAVIGATION MODE
The flight crew selects on the MCDU MENU page this degraded mode when both FMGCs fail. They recover the navigation function through the
MCDU and IRS/GPS .
The MCDU continuously memorizes the active flight plan in its memory.
If both FMGCs fail, the back up navigation provides the following functions:
‐ Flight Planning
‐ Aircraft position using onside IRS, IRS3, or GPIRS position (if GPS )
‐ F-PLN display on ND
‐ No AP/FD NAV mode
‐ Limited lateral revision
‐ F-PLN automatic sequencing.
Note: In managed guidance (lateral, vertical guidance or managed speed), the corresponding window is dashed. Turning a knob without pulling it, displays a value that is the sum of the current target and the turn action value. The display remains ___ s on the HDG/TRK and V/S windows and ___ s on the SPD/MACH window before the dashes reappear. This rule does not apply to the ALT knob/window.
45 / 10
SPD/MACH knob
Display range: between ___ for speed, between ___ for Mach number. One rotation of the knob corresponds to approximately 32 kt or M 0.32.
100 and 399 kt
0.10 and 0.99
HDG/TRK knob
Display range: between 0 ° and 359 °.
One rotation of the knob corresponds to ___
32 ° (1 ° per click).
Altitude knob (INNER AND OUTER)
Display range:
100 to 49 000 ft
V/S or FPA knob
Range (V/S) :
Range (FPA) :
One rotation of the knob corresponds to 32 clicks. One complete rotation sets: FPA = 3.2 °
V/S = 1 600 ft/min
–6 000 to +6 000 ft/min
(2 clicks = 100 ft/min, If the flight crew turns the knob slowly, each click equals 100 ft/min.)
–9.9 ° to +9.9 °
1 click = 0.1 °
Note: If the V/S or FPA mode is not engaged within ___ s after preselection, the preselected value is cancelled and the dashes reappear.
45
The characteristic speeds displayed on the PFD are computed by the
Flight Augmentation Computer (FAC), according to the FMS weight data, based on the aircraft gross weight (which is computed according to the entered ZFW and the FOB)
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
VS : Stalling speed.
VLS : Lowest Selectable Speed.
F : Minimum speed at which the flaps may be retracted at takeoff.
S : Minimum speed at which the slats may be retracted at takeoff.
O : Green dot speed.
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
VS : Stalling speed
All operating speeds are expressed as functions of this speed (for example, VREF = 1.3 VSmin).
Because aircraft of the A320 family have a low-speed protection feature (alpha limit) that the flight crew cannot override, Airworthiness Authorities have reconsidered the definition of stall speed for these aircraft.
All the operating speeds must be referenced to a speed that can be demonstrated by flight tests. This speed is designated VS1g.
Airworthiness Authorities have agreed that a factor of 0.94 represents the relationship
Airworthiness Authorities have agreed that a factor of 0.94 represents the relationship between VS1g for aircraft of the A320 family and VSmin for conventional aircraft types. As a result, Authorities allow aircraft of the A320 family to use the following factors :
V2 = 1.2 × 0.94 VS1g = 1.13 VS1g
VREF = 1.3 × 0.94 VS1g = 1.23 VS1g
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
VLS : Lowest Selectable Speed represented by the
top of an amber strip along the airspeed scale on the PFD corresponds to 1.13 VS during takeoff, or following a touch and go.
Becomes 1.23 VS, after retraction of one step of flaps.
Becomes 1.28 VS, when in clean configuration.
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
Lowest Selectable Speed
Note: If in CONF 0 VLS were 1.23 VS (instead of 1.28 VS), the alpha protection strip would
hit the VLS strip on the PFD.
Above 20 000 ft, VLS is corrected for Mach effect to maintain a buffet margin of
0.2 g.
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
F : Minimum speed at which the flaps may be retracted at takeoff.
Equal to 1.26 VS of CONF 1 + F, and limited to a minimum of
1.1 VMCA and VMCL + 15 kt.
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
F : Minimum speed at which the slats may be retracted at takeoff.
Equal to 1.23 VS of clean configuration, and limited to a minimum of
VMCL + 20 kt.
SPEEDS DEFINITION - CHARACTERISTIC SPEEDS
O : Green dot speed.
Engine-out operating speed in clean configuration. (Best lift-to-drag ratio speed).
Also corresponds to the final takeoff speed.
Below 20 000 ft equal to
2 × weight (metric tons) +85
Above 20 000 ft, add 1 kt per 1 000 ft
SPEEDS DEFINITION - LIMIT SPEEDS
VA
VMCG
VMCA
VMCL
VFE
VLE
VLO
VMO
VFE NEXT
Maximum design maneuvering speed. This corresponds to the maximum structural
speed permitted for full control deflection, if alternate or direct law is active.
Minimum speed, on the ground during takeoff, at which the aircraft can be controlled
by only using the primary flight controls, after a sudden failure of the critical engine,
the other engine remaining at takeoff thrust.
Minimum control speed in flight at which the aircraft can be controlled with a
maximum bank of 5 ° if one engine fails, the other engine remaining at takeoff thrust
(takeoff flap setting, gear retracted).
Minimum control speed in flight, at which the aircraft can be controlled with a
maximum bank of 5 ° if one engine fails, the other engine remaining at takeoff thrust
(approach flap setting).
Maximum speed for each flap configuration.
Maximum speed with landing gear extended.
Maximum speed for landing gear operation.
Maximum speed.
Maximum speed for the next (further extended) flap lever position.
SPEEDS DEFINITION - PROTECTION SPEEDS
Vα PROT, Vα MAX and VSW are computed by the FAC, based on
aerodynamic data. They are only used for display on the PFD, and not for flight control protection (the activation of the protections is computed by the ELAC).
SPEEDS DEFINITION - PROTECTION SPEEDS
Vα PROT :
Angle of attack protection speed.
Corresponds to the angle of attack at which the angle of attack protection becomes active.
Represented by the top of a black and amber strip along the PFD speed scale, in normal law.
SPEEDS DEFINITION - PROTECTION SPEEDS
Vα MAX :
Maximum angle of attack speed.
Corresponds to the maximum angle of attack that may be reached in pitch normal law.
Represented by the top of a red strip along the PFD speed scale, in normal law.
SPEEDS DEFINITION - PROTECTION SPEEDS
VSW :
Stall warning speed.
Represented by a red and black strip along the speed scale when the flight control normal law is INOPERATIVE.
SPEEDS DEFINITION - PROTECTION SPEEDS
VMAX :
Represented by the bottom of a red and black strip along the speed scale. Determined by the FAC according to the aircraft configuration.
Is equal to VMO (or speed corresponding to MMO), VLE or VFE.
SPEEDS DEFINITION - OTHER SPEEDS
VREF :
Reference speed used for normal final approach.
Equal to 1.23 × VS of CONF FULL.
Displayed on the MCDU APPR page, if landing is planned in CONF FULL (VLS CONF FULL).
SPEEDS DEFINITION - OTHER SPEEDS
VAPP :
Final approach speed.
Represents : VAPP = VLS + wind correction
The wind correction is limited to a minimum of 5 kt and a maximum of 15 kt.
flight crew may modify VAPP through the MCDU.
‐ During autoland or when A/THR is on or in case of ice accretion or gusty
crosswind greater than 20 kt, VAPP must not be lower than ___
‐ For landing in configuration 3 with ice accretion VAPP must not be lower than
VLS +5 kt / VLS +10 kt.
