FMA Flashcards
AT
IDLE
AT is reducing or has reduced thrust to flight Idle. It may engage in a VNAV descent. It will engage after FLARE is engaged.
AT
SPD
Autothrottle controlling thrust to maintain speed selected in IAS/Mach, or if VNAV engaged, the speed as programmed by the FMC.
AT
THR HOLD
Thrust levers remain in existing position or where manually placed
AT
EPR
Autothrottle controlling to the selected EPR ref thrust
AT
FLCH
Autothrottle controlling to a maximum of the selected mode reference thrust during climb and to a minimum thrust during descent
AT
GA
Autothrottle controlling to a maximum reference thrust to maintain a climb rate of 2000’ per min
PITCH
TO
On ground TO annunciation by selecting either FD switch on when both switches are off. The flight director pitch bar an initial pitch of approx 8 degrees up.
PITCH
GA
AFDS system commands pitch to maintain existing speed or selected speed whichever is the greater.
PITCH
VNAV SPD
VNAV provides pitch commands to maintain the FMC computed airspeed / path
VNAV SPD - the AFDS maintains the FMC speed displayed on the CDU climb or descent pages. The speed can be manually set by speed intervention.
PITCH
VNAV PTH
The AFDS maintains FMC altitude or descent path with pitch commands. If the MCP altitude window is set to current cruise altitude, as the a/c approaches the TOD the CDU scratchpad message RESET MCP ALT displays.
2 AP FMA MODES
FD
CMD
8 ROLL FMA MODES
LNAV. TO
LOC. ATT
HDG HOLD. GA
HDG SEL. ROLL OUT
RALLGHHT
12 PITCH MODES
TO. GA. ALT HOLD. G/S
VNAV PATH. FLARE. VNAV SPD. V/S
ALT CAP. SPD. SPD LIM. FLAP LIM
9 AT MODES
THR HOLD. FLCH. SPD. GA
EPR. IDLE. ALPHA. FLAP LIM. SPD LIM
PITCH
FLARE
Flare (armed) during AUTOLAND displays below 1500ft RAD ALT.
Flare (active) during AUTOLAND flare activates at 50’ rad and deactivates at touchdown
PITCH
ALT CAP
Transient manoeuvre entered automatically from
V/S FLCH VNAV CLB or descent to selected MCP altitude.
ROLL
ATT
ATT -active. When the AP is first engaged or the flight director is first turned on in flight AFDS holds a bank angle between 5 and 30 degrees and will not roll to wings level.
When the bank angle is less than 5 degrees. AFDS returns to wins level HDG HOLD
When the bank angle is greater than 30 degrees. AFDS returns to 30 degrees of bank.
PITCH
ALT HOLD
Activated by pushing the MCP ALT HOLD switch or capturing the selected altitude from V/S FLCH climb or descent.
What are the 5 switch selections on MCP which will engage the AT.?
SPD EPR FLCH VNAV GA
Pushing the EPR switch does what? 4 things
Selects AT EPR MODE
EPR annunciates on each FMA
Autothrottle holds ref thrust value displayed on EICAS subject to maximum speed limits
Updates FMC position to takeoff runway threshold position when selected for takeoff
SELECTABLE ROLL MODES ON MCP
LNAV
HDG SEL
HDG HOLD
Heading Bank Angle limits
High Speed 15 degrees
Low Speed 25 degrees
When is NOT ON INTERCEPT HEADING displayed on ADI ?
If AC is not heading towards an active leg and more than 2.5 miles away
SELECTABLE PITCH MODES ON ADI ?
ALT HOLD
VNAV
VS
Is there automatic Speed Protection in VS ?
No
During a FLCH climb what does the AT command and what does the AFDS Pitch channel command ?
AT commands THRUST
AFDS commands SPEED
Hence ADI displays
FLCH
SPD
The AFDS alters pitch to maintain current speed.
The AT applies thrust up to a max ref thrust in climb- full ref thrust for a large climb and less thrust for a small climb
What happens at level off following a FLCH climb?
FMAs indicate :
SPD
ALT CAP then ALT HOLD
What will be the INITIAL. AT and AFDS mode indications during a FLCH descent ?
FLCH
SPD
During a protracted FLCH descent what will be the AT and AFDS FMAs ?
THR HLD
SPD - AFDS pitching to maintain the speed.(you can move the Thrust lever to alter rate of descent)
What are the FMAs for a VNAV climb ?
EPR
VNAV SPD
eg when VNAV first selected at Acceleration Altitude.
IAS window blanks and the FMS positions the speed bug. It also positions the Magenta bug (Ref EPR ). The FMS positions both speed and EPR bug (emphasise)
AFDS uses pitch to maintain speed
AT applies thrust to maintain EPR
In a VNAV climb what happens to the FMAs if an intermediate ( not cruise level) altitude is captured?
SPD
ALT CAP then ALT HOLD
When will you get DRAG REQUIRED ?
In a VNAV descent with a stronger than forecast tailwind
IDLE
VNAV PTH
PATH will initially be maintained at the expense of speed . When it’s more than 15 kts increase DRAG REQUIRED will be displayed
What will happen in VNAV descent in PATH if speed is not kept under control ?
The path will be lost and
IDLE
VNAV SPD
will display
In a VNAV descent if stronger than expected headwind ?
Initially path will be maintained and speed will reduce below bug
IDLE
VNAV PTH
more than 15 kts slow
SPD
VNAV PTH
Here AT recovering the speed
Then
IDLE
VNAV PTH
will resume
What happens when DES NOW is pressed?
This is only time
EPR
VNAV SPD
is shown in the descent. This shows at the initial stages of descent until 1000ft per min is attained
1 EPR
VNAV SPD
2 THR HOLD
VNAV SPD
3 IDLE
VNAV PTH
Thinking about the MCP which 2 modes are AT ONLY ?
EPR
SPD
Which 3 push buttons on the MCP selected AT and AP?
GA (not on MCP)
VNAV
FLCH
With LNAV engaged what provides the steering signals ?
FMS
If VS is selected during a VNAV or FLCH climb what does AT mode change to ?
SPD
VS will be the pitch mode
FLCH climb
What do the A/T and AP do?
FLCH
SPD
AT applies thrust to up to REF thrust
AFDS pitches to maintain speed at time of engagement (window)
Is a FLCH climb or descent stopped when approaching…..
MCP selected altitude
FMS cruise altitude
FMS constraint altitude ?
YES
NO
NO
FLCH mode will ignore any FMS programmed profiles
What does it mean if the Amber AUTO PILOT light and message are displayed with an amber line through the mode annunciation ?
Failure affecting the active mode only
AP will stay connected in an attitude stabilising mode
Which TWO conditions arm GO-around ?
Flaps out of up
GS capture
What is the lowest point at which GA can be engaged?
2 secs after 5’ radio
When a Go-around is initiated what do the three FMA modes achieve?
AT GA thrust to 2000’ per min
AFDS pitch maintains current speed or MCP speed
ROLL mode maintains RWY track
What is the TMSP?
THRUST MODE SELECTOR PANEL
- sets selected thrust mode reference
TO. GA. CLB CRZ CON
- selection of fixed and assumed temperature derated reference thrust values
