4. Automatic Flight Flashcards
Automatic Speed Changeover Altitude
FL260
MCP Speed Condition Symbols
- A: Underspeed limiting. Minimum speed
- 8: Overspeed limiting. Vmo/Mmo, Landing Gear Limit, Flap Limit
Strange VNAV Disengagement Criteria
- XTrack deviation exceeds twice the RNP,
- During PATH descent with a database vertical angle,
- LNAV not engaged
Manually Set N1 Caution
A/T may exceed the N1 limit
ALT HLD Switch
Commands pitch to hold uncorrected barometric altitude at which switch was pressed
ALT INTV Cruise Descent
- More than 50NM from T/D and,
- Selected MCP altitude above the first altitude restriction,
- Otherwise Early Descent is initiated
LNAV Bank Angle Limits for T/O
- 15 degrees below 200FT,
- 30 degrees above 200FT
White LNAV Armed Flashing On the Ground
Required FMC data (e.g. valid radio altitude) is not available
LNAV Engagement Criteria Inflight
If within 3NM of active route:
- With any heading,
If outside of 3NM of active route:
- On intercept course of 90 degrees or less and,
- Intercept route segment before active WPT
VOR/LOC Localizer Capture
- Not later than 1/2 dot deviation,
- When localizer frequency selected VHF NAV automatically switches from tail to nose antenna,
- If switching does not occur, LOC mode is inhibited
Bank Angle Selector Affected Modes
- HDG SEL and,
- VOR
HDG SEL Turn Direction
- Initial selection commands turn in the shortest direction toward selected heading bug,
- After engagement, roll commands are the same direction as rotation of heading selector
Latest Altitude to Engage 2nd A/P
800FT RA
APP Mode Diseangagement After LOC and G/S Capture
- Pushing TOGA switch,
- Disengaging A/P and turning off both F/Ds,
- Retuning the VHF NAV Receiver
Glide Slope Capture Point
2/5 dot below Glideslope
F/D Deviated Pitch Operation to A/P
- While Pitch Command is more than 1/2 scale from center,
- Pushing CMD switch engages the A/P in CWS for Pitch,
- Related F/D Bars retract
CWS Engage Switch
- CMD not displayed in A/P status display,
- If F/D switches ON, FD annunciates in A/P status diplay,
- A/P does not follow commands while in CWS
CWS Roll Heading Hold
- If aileron pressure released within 6 degrees or less bank,
- A/P rolls wings level and hold existing Heading
Inhibited when:
- Below 1500FT RA with Gear Down,
- After LOC capture in APP,
- After VOR capture with TAS 250KT or less
Steady Autopilot Disengage Light
- Stabilizer out of trim below 800FT RA on Dual Channel Approach,
- ALT ACQ Mode inhibited during A/P Go-Around if stabilizer not trimmed for Single A/P operation,
- Automatic Ground System tests fail
STAB OUT OF TRIM Light
- Operates only with A/P engaged,
- Means A/P not rimming stabilizer properly
AFS
- Automatic Flight System,
- Consists of Autopilot Flight Director System (AFDS) and the A/T
MCP Switch Lights and Disengagement
- If illuminated it means can be deselected,
- If not illuminated it can’t be deselected,
- All modes can be disengaged by:
-Selecting another mode and,
-Disengaging A/P and turning F/Ds OFF
A/P Automatic Disengagement
- Related IRS Failure or FAULT light,
- Loss of related electrical power,
- Loss of a sensor input,
- Loss of related Hydraulic System,
- Stick Shaker activates and persists for longer than 5 minutes
Radio Altimeter Inoperative Operation
- If failed side A/P used during ILS Approach,
- A/P will disengage 2s after LOC and GS capture
Independent F/D Operation
- APP Mode engaged with LOC and G/S captured,
- GA Mode engaged below 400FT RA,
- TO Mode engaged below 400FT RA
Generator Fail Below 800FT During Approach/Takeoff
FCC on the unaffected side positions the F/D command bars on both attitude indicators
A/T Modes
- GA: A/T maintains thrust at Reduced Go-around setting
- THR HLD: Thrust Lever A/T servos inhibited, pilots can set the thrust manually
- ARM: Difference from THR HLD = No A/T mode engaged. and Minimum Speed Protection is provided
TOGA Takeoff F/D Guidance
- 10 degrees nose down,
- Roll Command is HDG SEL,
- A/T is engaged in N1 mode,
- At 60KT, 15 degrees nose up until sufficient climb rate is acquired then to maintain MCP Speed + 20KT,
- If engine fails on the ground, Pitch target is V2 or liftoff speed whichever is greater,
- At 84KT A/T modes changes to THR HLD until 800FT AGL then changes to ARM
TOGA Guidance When F/D Switches OFF
Can be engaged by pressing TOGA switches when:
- After 80KT and,
- Below 2000FT AGL and,
- Within 150s after liftoff
TOGA Go Around Arming Criteria
- Not in T/O Mode,
- Below 2000FT RA,
- Above 2000FT with Flaps Extended or G/S captured
A/T EEC Recommendation
- Both EEC be ON or ALTN,
- This produces minimum Thrust Lever Seperation
Autothrottle Automatic Disengagement
- 2s after touchdown,
- A/T system fault,
- Thrust Levers seperated more than 10 degrees (except GA mode),
- Significant thrust difference along with control wheel roll input of 10 degrees or more (except GA mode)
Pitch Commands After T/O With OEI
- V2 if airspeed is below V2,
- Existing speed if speed is between V2 and V2 + 20KT,
- V2 + 20KT if speed is above V2 + 20KT
Second Push of TOGA During T/O
- Below 800FT AGL, N1 limit bugs increase to full GA limit but thrust levers will not move,
- Above 800FT AGL N1 limit bugs increase to full GA limit and thrust levers advance toward full GA thrust
Engaging A/P During T/O
- Pitch Mode changes to LVL CHG,
- Roll Mode changes to HDG SEL unless another mode has been selected,
- MCP IAS and airspeed cursor changes to V2 + 20KT
Terminating T/O Mode
- Below 400FT AGL: F/D switches must be turned OFF,
- Above 400FT AGL: Selecting another pitch mode, Engaging A/P
Dual Channel Approach Self Test
- After LOC and G/S captured and below 1500FT RA,
- 2nd A/P couples with the flight controls,
- ILS Deviation Monitor System test is performed (LOC and G/S display turns amber and flashes),
- FLARE armed annunciated,
- SINGLE CH extinguishes CMD illuminates,
- A/P Go-around mode arms but is not annunciated
Dual Channel Approach Important Altitudes After Test
- 400FT RA: Stabilizer trimmed an additional amount nose up,
- 350FT RA: If FLARE is not armed both A/Ps disengage automatically,
- 50FT RA: FLARE mode engages and F/D bars retract,
- 27FT RA: RETARD mode engages,
- A/T automatically disengages approximately 2s after touchdown
A/T Go Around Mode Criteria
- Below 2000FT RA (if both RA failed below 15500FT),
- With or without AFDS,
If above 2000FT RA (> 15500FT) with Flaps Extended or G/S captured:
- A/T will repond TOGA switch,
- But will engage in N1 mode and not the Reduced Go-around Thrust mode
A/P Go Around Procedure
- Armed when FLARE is armed until A/P sensing touchdown,
- A/T engages in GA, using reduced GA thrust,
- TOGA Mode initial pitch 15 degrees to achive 1000-2000FPM,
- Then commands target speed for each Flap setting based on MTOW as you retract flaps,
- Roll mode annunciation is blank but commands to hold current ground track,
- And for some aircrafts LNAV will engage at 400FT AGL
- IAS/Mach display is blank
Pressing TOGA After Touchdown
- A/P if engaged, disengages,
- A/T may command GA thrust
Second Push of TOGA During GA
- GA changes to N1,
- N1 limit increases to Full Go-around limit,
- Thrust levers advance to full go-around limit
TOGA Mode Termination From A/P Go-Around
- Below 400FT RA, disengage A/P and turn OFF F/Ds,
- Above 400FT RA, select a different Pitch or Roll Mode,
- If Roll Mode changed first: Roll mode engages in Single A/P (first selected) and Pitch mode stays in dual channel,
- If Pitch Mode changed first: 2nd A/P disengages, Pitch mode engages in Single A/P (first selected) and Roll mode changes to CWS R
A/T Go Around Mode Termination
- Selecting another pitch mode,
- ALT ACQ engages
F/D Go-Around Mode Criteria
- Below 2000FT RA,
- Not in T/O mode,
- Above 2000FT with Flaps Extended or G/S captured,
- After touchdown with wheel spin up
F/D Go-Around Procedure
- Below 2000FT RA A/T engages in GA, using reduced GA thrust (Above 2000FT N1 and full go-around limit),
- A/P disengages,
- TOGA mode initial pitch 15 degrees to achive 1000-2000FPM,
- Then commands target speed for each Flap setting based on MTOW as you retract flaps,
- Roll mode annunciation is blank but commands to hold current ground track,
- And for some aircrafts LNAV will engage at 50FT AGL
- IAS/Mach display is blank
TOGA Mode Termination From F/D Go-Around
- Below 400FT RA, disengage A/P and turn OFF F/Ds,
- Above 400FT RA, select a different Pitch or Roll Mode,
- If Roll Mode changed first: Roll mode engages in selected mode and Pitch mode stays in TOGA,
- If Pitch Mode changed first: Pitch mode engages in selected mode and Roll mode changes to HDG SEL,
- Engaging A/P automatically engages LVL CHG for Pitch
Single Engine F/D Go-Around Differences
- MCP Speed window is open,
- Initial Pitch Attitude is 13 degrees,
If engine failure occurs after Go-around, target speed depends whether 10s passed since G/A engagement:
- If within 10s: MCP Approach Speed,
- After 10s and Speed is within 5KT of G/A Engagement Speed: G/A Engagement Speed,
- After 10s and Speed is more than 5KT of G/A Engagement Speed: Present Speed
LNAV in Lieu of Track Hold
- For some aircrafts,
- If missed approach exists in the flight plan and FCC are capable of entering go-around,
- During approach with FLARE armed if LNAV armed after 400FT AGL LNAV engages,
- During approach without FLARE armed if LNAV armed after 50FT AGL LNAV engages
AFS Operation in Windshear
T/O or G/A:
- F/D commands to maintain speed until V/S decreases to +600FPM,
- Then commands 15 degrees nose-up until Stick Shaker is reached,
- Then commands intermittent activation of the Stick Shaker
APP and LDG:
- No recovery guidance unless TOGA is pressed
Command Speed Limiting
- For: Vmo/Mmo, Flap Placards, Landing Gear Placard, Minimum Speed
- Speeds greater than Vmo/Mmo cannot be selected,
- The other limit speeds may be selected,
- AFS allows acceleration or deceleration to slightly short of the limit then commands the limit speed,
- Overspeed/Underspeed symbol appears in the MCP when commanded speed cannot be reached,
- 15KT or greater speed must be selected to remove underspeed symbol
Minimum Speed Definition
1.3Vs for the current Flap Configuration
Reversion Modes
- Modes for Placard Limit and Minimum Airspeed Reversions,
- Both AFDS and A/T have reversion modes which activate slightly before reaching the limit speed
Placard Limit Reversion
- For Gear, Flap or Vmo/Mmo,
- Overspeed limiting symbol appears in the MCP,
- AFDS engaged but not in CWS or Speed mode and A/T is armed but not in Speed control: A/T reverts to SPEED,
- If AFDS or A/T is in Speed control: Speed maintained slightly below the placard limit,
- If A/T not available, no reversion for Gear or Flap placard limits
For Vmo/Mmo only:
- If A/T is engaged in a speed mode and thrust levers are IDLE and,
- If AFDS in V/S or CWS P mode, will change to LVL CHG,
- If A/T not available, AFDS reverts to speed control for Vmo/Mmo
Minimum Speed Reversion
- If actual Speed becomes equal or slightly less than minimum speed, underspeed symbol appears,
- If operating in V/S or CWS P modes, AFDS reverts to LVL CHG,
- Also reverts from VNAV PTH except flying level segment,
- AFS commands 5KT above minimum speed and when reached underspeed symbol disappears,
- If thrust levers not advanced AFDS commands nose down pitch
Minimum Speed Reversion Exceptions
- No reversion to LVL CHG when Flaps are greater than 12.5,
- When A/T is OFF and AFDS in ALT HLD or G/S mode,
- During LVL CHG climb with commanded minimum speed and minimum ROC cannot be maintained,
- Also in this case A/P disengages and F/D bars retract
