Automatic Flight Flashcards
On the ground with no AP engaged and both FD’s off. What happens when you turn on one Flight Director?
- First FD on arms the FD in the TOGA roll and pitch modes
- Second FD on displays flight direction and steering indications on the second PFD
In flight with the AP disengaged and both FD’s off, the first FD turned on activates what vertical and lateral modes?
- Vertical speed
- Heading Hold
–If bank is greater than 5 degrees lateral mode is attitude hold
In flight with the AP ENGAGED and both FD’s off, the first FD selected on activates…
the flight director in the selected AP modes
What situation would cause the flight directors to populate even if the switches were selected in the OFF position
TOGA switch is pressed when airspeed is greater than 80kts and the flaps are out of up
EX: you see the runway, kill the FD and have to go missed
Can you turn on the autopilot with the FD’s off?
Yes
Can you turn on the FD with the AP off?
yes
If you turn on the AP with the FD off, what modes would be active?
Same as FD: default modes are
1.Vertical speed
2 heading hold
–unless bank is greater than 5 degrees then Attitude hold
If either FD is on, then the AP is engaged, what happens?
The AP engages in the selected FD mode(s)
How many autopilots are there?
3
Autopilot disengage bar does what?
- disengages all three AP’s
- Prevents AP enguagement
- exposes amber strip
–must lift bar back up to enable AP engagement
What are the two basic autothrottle modes?
- THRUST: Maintains speed using thrust
- SPEED: maintains speed using elevator
What does the Auto Throttle arm switch do?
Arms the AT system for mode selection
IF AT is armed, when will the AT activate?
- when VNAV, FLCH or TOGA switch is pushed (SPEED)
- when speed switch is pushed and pitch mode is ALT, VS or G/S (THRUST)
When AT is armed but no mode is selected what will activate the AT?
Cycling AT arm switch to off then arm
AT Arm swithc off:
- Disconnects AT
2.disables AT activation
3.disables engine trim equalization
Briefly explain the purpose of the Thrust switch THR?
Dual purpose switch
1. Thrust limit function (light remains off)
–Selects Climb thrust or Continuous depending on situation
2. Changes AT mode selection to THR REF
When do the SPD and THR switches become operative?
400’ after takeoff until landing
Regarding the THR switch and its thrust limit function, when would this function be used?
- after takeoff with VNAV or FLCH selected: changes reference thrust limit to armed climb thrust limit or CON if engine inop
2.After go around: changes ref thrust limit to CLB or CON if engine inop or CON selected
NOTE: Reference thrust remains GA when flaps in landing position or pitch mode is GS
Regarding the THR switch and it’s AT mode function, when would AT mode be changed to THR REF when switch is pressed?
- Reference thrust limit is CLB, CLB1, CLB2, CRZ or CON and pitch mode is ALT or VS
- Reference thrust limit is GA and pitch mode is GS or FLARE OR pitch mode is ALT or VS and flaps are in lading position
When SPD switch is pressed what happens?
1.Selects AT mode to Speed mode (speed is controlled by elevator)
2. Displays SPD on both PFDs
3. controls thrust to maintian IAS or MACH displayed in IAS or MACH window subject to min and max speed limits
4. Inactive in VNAV XXX, FLCH SPD, or TOGA pitch modes
IAS/MACH window sets what speed when power is first applied?
200KTS
IAS/MACH display range in KTS and MACH
100-399KTS
.400-.950 Mach
When does IAS automatically change to MACH and vis versa?
- In climb, IAS to MACH approximately: .84
2.In descent Mach changes to IAS at approximately: 310KTS
What does the IAS/ MACH Select switch do?
Alternately changes between IAS and MACH
NOTE: Mach must be .4 or greater for IAS to MACH
What does the IAS/ MACH selector allow you to do?
(Knob right below IAS/MACH window)
- Allows you to select a desired speed/ MACH number
- When window is blank (speed is controlled by the FMC) and selector is pressed in, this allows for speed intervention
Regarding the LNAV switch, what are the two important requirements for LNAV to become active?
1.Aircraft must be 50’ above runway elevation
2. within 2.5 NM of Active leg
What scratch pad message would you get if LNAV is armed and you are not on an intercept heading?
NOT ON INTERCEPT HEADING
What VNAV modes are there?
VANV PTH, VNAV SPD, VNAV ALT
On departure, when can VNAV become active if armed
400’ above runway elevation
What happens when you select FLCH?
- FLCH becomes the active pitch mode
- IAS/MACH window populates commanded speed
- Fixed thrust setting(CLB or IDLE) and elevator controls speed.
Describe the HDG selector switch inner and outer knobs
Inner: sets desired heading in the heading window, if knob is pushed in HDG SEL roll mode is activated
Outer (bank limit) AUTO: varies between 15 degrees and 25 degrees depending on aircraft speed, configuration and V2
OR
Manually selecting: 5,10,15,20,25
If the heading hold switch is pressed in a turn what happens?
AFDS rolls wings level then holds present heading
What happens when Vertical speed switch is pressed
1.Vertical speed becomes the active pitch mode
2. Current VS is displayed in the window
3. VS selector is used to command vertical speed
Regarding the altitude selector, what are the different functions of punching in the selector?
- during a climb or descent with altitude constraints, each push deletes the next waypoint constraint between aircraft alt, and alt window setting
- during a climb with no alt constraints, and the alt window set above FMC cruise alt, pressing the alt selector changes the cruise altitude to what’s in the window
- During cruise, pushing the alt selector button sets whatever alt is in the window to be the new FMC cruise alt
- During cruise with VNAV PTH or VNAV ALT setting a new alt in the window and pushing the alt selector will start a climb or descent to capture the new alt
- Within 50 NM or TOD pressing will initiate descent now
If ALT hold is pressed during a climb or descent what happens
AFDS will capture and hold the altitude when the switch was pressed
For the LOC mode to become active, the aircraft must be within how many degrees of the loc corse?
120
Regarding the APP switch, what must happen first before GS can become active?
GS capture is inhibited until loc intercept is within 80 degrees
