4.000 AUTOMATIC FLIGHT Flashcards
(38 cards)
- What is the function of the Flight Control Unit?
The FCU located on the glareshield is the short-term interface between the Flight Crew and the FMGC. It is used to select any flight parameters or modify those selected in the MCDU. The autopilots and autothrust functions may be engaged or disengaged. Different guidance modes can be selected to change various targets (speed, heading, track, altitude, flight path angle, vertical speed).
- What do dashes in the FCU display windows along with the adjacent white dot indicate?
When the aircraft uses target quantities from the FMGS (managed guidance), the FCU windows display dashes and the white dots next to those windows light up. When the aircraft uses target quantities, entered by the Flight Crew (selected guidance), the windows display the selected numbers and the white dots do not light up.
- How is Selected Guidance engaged?
By pulling SPD, HDG, ALT, or V/S on the Flight Control Unit (FCU).
The FMGS then guides the aircraft to the target value of this parameter that they have selected. This type of guidance is said to be “selected.”
- Does Selected or Managed Guidance have priority?
Selected guidance always has priority over managed guidance
- Will the FCU Altitude window ever display dashes?
No. The altitude window always displays an altitude selected by the Flight Crew (never dashes).
- What are the main components of the FMGS?
The Flight Management Guidance System (FMGS) contains the following units:
• Two Flight Management Guidance Computers (FMGC)
• Two Multipurpose Control and Display Units (MCDU)
• One Flight Control Unit (FCU)
• Two Flight Augmentation Computers (FAC)
- What are the functions of the Flight Management Guidance Computers?
• The Flight Guidance part performs the following functions:
- Autopilot (AP) command
- Flight Director (FD) command
- Autothrust (A/THR) command
- What are the 4 modes of FMGS operation?
• The Flight Management part controls the following functions:
- Navigation and management of navigation radios
- Management of flight planning
- Prediction and optimization of performance
- Display management
- How does autopilot selection influence master FMGS logic?
Master FMGC Logic
• If one autopilot (AP) is engaged, the related FMGC is master. It uses the onside FD for guidance and controls the A/THR. It also controls FMA 1 and 2.
• If two APs are engaged, FMGC1 is master.
• If no AP is engaged, and the FD1 pb is on, FMGC1 will be the master. If the FD1 pb is
off, and the FD2 pb is on, FMGC2 will be the master.
• If no AP/FD is engaged, A/THR is controlled by FMGC1.
- If an amber SELECT OFFSIDE RNG/MODE message is displayed on the ND, what action should the crew take?
The Flight Crew will notice on the ND (usually associated with the failed FM), that if the NDs are not both in the same mode or range, the associated ND displays the message “MAP NOT AVAIL” and “SET OFFSIDE RNG/MODE.” This should be an indication to the pilot with the failed FMGC to change the range scale or mode on the EFIS control panel to match the other side ND.
- What is the difference between the large and small fonts utilized in the MCDU?
Small and large fonts are displayed according to the following rules:
• The title line and the scratchpad are displayed in large font
• Data fields are usually displayed in large font
• Label lines are displayed in small font
• Flight Crew entries and modifiable data are displayed in large font
• Defaulted/computed and non-modifiable data are displayed in small font
- What do amber box prompts on the MCDU indicate?
Mandatory Data (Boxes) - Flight Crew Action Required
- What is VLS?
Lowest Selectable Speed proving an appropriate margin to the stall speed. Represented by the top of an amber strip along the airspeed scale on the PFD.
Computed by the FAC and corresponding 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.
In approach mode, it is equivalent to VREF
- What are the 2 modes of flight guidance?
Two types of autopilot and flight director modes (Managed and Selected) are available to guide the aircraft
- What is the Managed mode of flight guidance used for?
Managed modes are used for commanding long-term lateral, vertical, and speed profiles via the MCDU.
- What is the Selected mode of flight guidance used for?
Selected modes are used for commanding short-term lateral, vertical, and speed profiles via the FCU.
- Can both autopilots be engaged during any phase of flight?
No. Two APs may be engaged at a time (AP1 active, AP2 in standby), when the localizer/glide- slope, roll out or go-around mode is armed or engaged. Only one AP can be engaged at a time in all other cases.
- What is Ground Speed Mini?
During the approach, the flight guidance (FG) portion of the FMGC continuously computes the managed speed target in order to account for gusts or wind changes. The magenta target airspeed triangle can therefore increase above VAPP on approach due to wind changes.
The GS mini function is active when the speed is managed and the FMS flight phase is the approach phase.
- What does it mean when you see the magenta target airspeed triangle above VAPP on approach?
The magenta target airspeed triangle can increase above VAPP on approach due to wind changes.
- Is the Ground Speed Mini function available in selected speed?
No, GS mini function is active only when the speed is managed and the FMS flight phase is the approach phase.
- What are 3 ways to disconnect the A/THR?
Standard A/THR Disconnection:
1) Pushing the instinctive disconnect pb on the thrust levers or;
2) Setting both thrust levers to IDLE detent.
Non-standard A/THR Disconnection:
1) Pushing the A/THR pb on the FCU while A/THR is active/armed, or;
2) The system loses one of the arming conditions.
- How do you disconnect the A/THR for the remainder of the flight?
Push and hold one instinctive disconnect pb for more than 15 seconds. The A/THR system is then disconnected for the remainder of the flight. All A/THR functions including ALPHA FLOOR are lost, and they can be recovered only at the next FMGC power-up (on ground).
- What would you lose if you held down the Instinctive Disconnect Pushbutton for more than 15 seconds?
All A/THR functions for the remainder of the flight
- What happens to thrust and what annunciates on the FMA when you reach Alpha Floor?
ALPHA FLOOR is a protection that commands TOGA thrust, regardless of the thrust levers’ positions. A. FLOOR will be displayed in the A/THR FMA. This protection is available from lift-off to 100 ft RA on approach.
