4.000 AUTOMATIC FLIGHT Flashcards
- 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.