Autoflight Flashcards
Some FCU knobs can be pushed and pulled. What does each generally do?
Pull- selected guidance (a mode that doesn’t use FMS data).
Push- managed guidance (FMS controls autoflight system).
*Selected guidance always takes priority over managed guidance.
What does each column of the FMA display?
- Autothrust mode.
- Vertical flight guidance modes.
- Lateral flight guidance modes.
- Approach capabilities and enters DH/MDA.
- Status of autopilot, FD and A/THR.
What determines which FMGC is MASTER?
If AP 1 is on, FMGC 1 is MASTER.
If AP 2 is on, FMGC 2 is MASTER.
If neither autopilot is on, FMGC 1 defaults as the MASTER.
What is the limitation for engaging the AP after takeoff?
100ft AGL and at least 5 seconds after liftoff.
What is the preferred and other methods for disengaging the AP?
Preferred:
pressing red disconnect button on side stick (pressing it a second time silences chime).
Other methods:
-Pressing an illuminated AP pb.
-Applying force to sidestick or rudder pedals.
Which FMGC normally controls the A/THR system?
The FMGC that controls the engaged AP.
If no AP is engaged, FMGC 1 controls A/THR.
If the controlling FMGC fails, the opposite FMGC automatically takes over.
What is the active range of the A/THR?
Both engines running:
Just above idle up to and including CL detent.
Single engine operations :
Just above idle stop up to and including MCT detent.
What indication on FMA indicates that Fixed Thrust is active? What are the 4 possible modes?
THR CLM- fixed climb thrust available for ambient conditions.
THR IDLE- fixed idle thrust.
THR MCT- single engine ops, MCT detent.
THR LVR- thrust levers are in a position that limits autothrust’s authority.
What indications on the FMA indicate autothrust is in a variable mode? When is it used?
SPEED or MACH
Used:
-during climb/descent for a specific rate.
-as an altitude is being captured.
-during level flight.
When all flight guidance is selected off, but autothrust is still active.
How is autothrust disconnected?
-Pressing one of two pbs on thrust levers.
-retarding the thrust levers to idle.
*will also disconnect if A/THR pb pressed, however since this is not normal a Level 2 Caution is generated.
What are the default modes for AP and FD when selected on in flight?
HDG and VS
*on the ground default modes depend on the flight plan and settings of the FCU.
What colour on the PFD indicates managed modes are being performed?
MAGENTA
What is V APP speed and how is it calculated?
Reference speed flown down approach when fully configured for landing.
Automatically calculated by adding 5kts to V LS plus 1/3 of steady state winds entered into MCDU.
What does Ground Speed Mini do and how is it calculated?
Provides windshear protection by ensuring a minimum ground speed is flown during approach- ensures sudden changes in headwind do not result in airspeed dropping below V APP.
Calculated by subtracting runway headwind from V APP.
How are Open Climb and Open Descent engaged and what thrust is used?
Pulling the ALT knob.
Open Climb- thrust is fixed at climb power.
Open Descent- thrust begins at idle power.
*in both cases, constraints on flight plan are ignored and pitch is used to command airspeed.
What does EXPED pb do in climb and descent?
Climb- initiates a climb at green dot and ignores all flightplan altitude/speed constraints.
Descent- increases airspeed to 340kts/.8M knots to increase descent rate. Thrust decreases to idle.
How can EXPED be disengaged prior to reaching FCU altitude?
Another vertical mode must be engaged.
*pressing EXPED pb will have no effect.
What mode is A/THR in during vertical speed climbs/descents?
Thrust is in a variable mode, either SPEED or MACH and commanded airspeed is ignored.
*A/THR will maintain commanded airspeed unless VS becomes excessive.
What does pushing the VS knob do?
Sets VS to 0 and the aircraft levels off.
In managed descent, does flight path or airspeed have priority?
Flight path has priority, airspeed is allowed to vary.
Can a managed climb or descent be performed in HDG mode?
No- managed climbs and descents can only be performed in managed track.
What does ALT CRZ on FMA indicate?
Soft altitude hold- allows altitude to vary slightly from cruise altitude (as referenced from MCDU PROG page).
This minimises thrust variations and reduces fuel consumption.
How would you reset the flight guidance modes after an aborted takeoff?
Cycle both FDs off and then back on.
What is BIAS?
A vector from MIX IRS to radio or GPS position.
Updated continually so if either are lost BIAS can be added to MIX IRS.
What vertical mode automatically engages if lateral flight plan is lost?
OPEN CLIMB
What is DUAL MODE for FMGS?
FMGC 1 and 2 are synchronised via the cross talk bus. (One of them will be MASTER, determined by which AP is on).
Which FMGC drives the FD and FMA?
If FD 1 and 2 are on, each FMGC drives it’s own FD and FMA.
What happens if FMGS cross talk bus is lost?
INDEPENDENT MODE- each FMGC drives it’s own FG (AP/FD), EFIS and MCDU.
What happens in FMGS SINGLE MODE?
1 FMGC drives both MCDU.
ND 1 and 2 range and mode must be identically set in order for copy side to display map.
