Chapter 4: Automatic Flight

Question 1

Explain the meaning of a green light illuminated in any MCP Mode Selector Switch.

Answer 1

The switch illuminates to indicate mode selection and that the mode can be deselected by pushing the switch again.

Question 2

Explain the meaning of a Master (MA) F/D indicator light.

Answer 2

The master FCC is indicated by illumination of the respective master (MA) F/D indicator light. The master FCC is determined as follows:
- with neither A/P engaged in CMD, the FCC for the first F/D turned on is the master
- with one or both A/Ps engaged in CMD, the FCC for the first A/P in CMD is the master FCC, regardless of which F/D is turned on first.
Note: Independent F/D operation is indicated by illumination of both MA lights.

Question 3

Explain which roll modes are affected by the bank angle selector.

Answer 3

• HDG SEL.

- VOR.

Question 4

Describe the manual methods for Autothrottle engagement

Answer 4

Autothrottle Engagement:
Moving the magnetically held A/T ARM switch to ARM, arms the A/T for engagement while in the following pitch modes:
-LVL CHG
-ALT ACQ
-V/S
-VNAV 
-ALT HLD
-G/S capture
-TO/GA

Question 5

Describe the manual methods for Autothrottle disengagement.

Answer 5

Autothrottle Disengagement:
Any of the following actions will manually disengage the A/T:
-Moving the A/T Arm switch to OFF.
-Pushing either A/T Disengage switch.
Note: A/T disengagement is followed by A/T Arm switch releasing to OFF and flashing red A/T Disengage lights on the forward panel. The A/T Disengage lights do not illuminate when the A/T automatically disengages after landing touchdown.

Question 6

When do Autothrottles automatically disengage

Answer 6

• two seconds have elapsed since landing touchdown.
• Thrust levers become separated more than 10 degrees, except during takeoff.
• Significant thrust difference along with control wheel roll input of 10 degrees or more throughout the entire flight envelope.

Question 7

Explain what the color green represents in the FMA.

Answer 7

Engaged or Captured mode.

Question 8

Explain what a green box represents in the FMA.

Answer 8

A mode change highlight symbol (rectangle) is drawn around each pitch, roll, CWS, A/P status, and thrust engaged annunciation for a period of 10 seconds after each engagement.

Question 9

Explain what the color white represents in the FMA.

Answer 9

Armed modes are shown in smaller white letters at the bottom of the flight mode annunciation boxes.

Question 10

Explain the different meanings of the AFDS Autopilot Status Annunciations: CMD, FD, CWS P, CWS R, SINGLE CH, SINGLE CH and AUTOPILOT.

Answer 10

The following AFDS status annunciations are displayed in the A/P
status display located above the attitude indicator:
CMD – one or both autopilots are engaged.
FD – the flight director is ON and the autopilot is either OFF or engaged in
CWS.
CWS P – pitch mode engaged in CWS.
CWS R – roll mode engaged in CWS.
SINGLE CH (Amber) – For single A/P ILS approach, annunciates after localizer capture and remains on for entire approach. For dual
A/P ILS approach, annunciates after localizer capture and extinguishes after pitch monitor confidence test is successfully completed. (Then goes to CMD)
SINGLE CH (Green) – For an IAN approach, annunciates after FAC capture and remains on until AP disengaged or 100 feet RA.
AUTOPILOT (Flashing Amber) – Autopilot remains engaged below 100 feet RA for an IAN approach).

Question 11

Explain what conditions must be met before a second autopilot can be engaged.

Answer 11

• Both VHF NAV receivers tuned to the ILS frequency.
• Approach Mode (APP) selected.
• Second A/P engaged in CMD prior to 800 feet RA.

Question 12

Explain the function of the A/P DISENGAGE bar.

Answer 12

Pull down:
 - Exposes yellow background.
- Disengages both A/Ps.
- Prevents A/P engagement.
Lift up:
- Conceals yellow background.
- Enables A/P engagement.

Question 13

Explain the meaning of an illuminated Amber A/P Autopilot Disengage light on the forward panel.

Answer 13

A/P Illuminated (amber) and flashing: Autopilot reverted to CWS pitch or roll while in CMD.
Reset by P/RST (push to reset) either light or selecting another mode.

Question 14

Explain the meaning of an illuminated Red A/P Autopilot Disengage light on the forward panel.

Answer 14

A/P Illuminated (red) and flashing
- flashes and tone sounds when autopilot
has disengaged.

A/P Illuminated (red) and steady

• stabilizer out of trim below 800 feet RA on dual channel approach or,
• ALT ACQ mode inhibited during A/P go–around if stabilizer nottrimmed for single A/P operation or,
• automatic ground system tests fail.
• Reset by pushing P/RST (push to reset) either light or either A/P disengage switch

Question 15

Explain the indications of a disengaged Autothrottle.

Answer 15

• flashing red A/T P/RST light on the Forward Panel.

Question 16

Explain the meaning of the amber STAB OUT OF TRIM light on the left forward panel.

Answer 16

-Autopilot not trimming stabilizer properly.

Note: Operates only with A/P engaged.

Question 17

Explain what will happen on approach when TO/GA is selected below
2000 feet RA.

Answer 17

• No A/P or single A/P engaged: Disconnects autopilot (if engaged) and requires manual F/D go around.
• Both A/Ps engaged (with FLARE armed on the FMA): A/P goaround mode is activated. A/Ps remain engaged.

Question 18

Know the difference in commanded thrust when selecting TO/GA once versus twice during a go-around.

Answer 18

• First push: A/T provides reduced go-around N1 to produce 1000 to 2000 fpm rate of climb.
• Second push: A/T advances to the full go around N1 limit.

Question 19

Specify the AFDS Flight Mode Annunciations and their location.

Answer 19

The flight mode annunciations are displayed just above the attitude indicator on the PFD. The mode annunciations, from left to right, are:

• autothrottle,
• roll,
• pitch.

Question 20

Explain the meaning of the AFDS FMA Autothrottle Modes.

Answer 20

N1 – the autothrottle maintains thrust at the selected N1 limit displayed on the thrust mode display, including full go-around N1 limit.
GA – the autothrottle maintains thrust at reduced go–around setting.
RETARD – displayed while autothrottle moves thrust levers to the aftstop.
FMC SPD – the autothrottle maintains speed commanded by the FMC.
MCP SPD – the autothrottle maintains speed set in the MCP
IAS/MACH display.
THR HLD – the thrust lever autothrottle servos are inhibited; the pilot can set the thrust levers manually.
ARM (white)– no autothrottle mode engaged. The thrust lever autothrottle servos are inhibited; the pilot can set thrust levers manually. Minimum speed protection is provided.

Question 21

Explain the meaning of the AFDS FMA Pitch Modes.

Answer 21

TO/GA – (Takeoff) Engaged for takeoff by turning both F/D switches ON and pushing either TO/GA switch.
TO/GA – (Go–around) Engaged for go–around by pushing the
TO/GA switch under the following conditions:
- in flight below 2000 feet radio altitude, or
- in flight above 2000 feet radio altitude with flaps not up or G/S captured
- not in takeoff mode
- either F/D ON or OFF.
VNAV SPD – the AFDS maintains the FMC speed displayed on theairspeed indicator and/or the CDU CLIMB or DESCENT pages.
VNAV PTH – the AFDS maintains FMC altitude or descent path withpitch commands.
V/S (engaged) – commands pitch to hold selected vertical speed.
V/S (armed) white – V/S mode can be engaged by moving Vertical Speed Thumbwheel.
ALT ACQ – transition maneuver entered automatically from a V/S,
LVL CHG, or VNAV climb or descent to selected MCP altitude. Engages but does not annunciate during VNAV transition.
ALT HOLD – commands pitch to hold MCP selected altitude oruncorrected barometric altitude at which ALT HOLD switch waspushed.
MCP SPD – pitch commands maintain IAS/MACH window airspeed or Mach.
G/S (armed) white – the AFDS is armed for G/S capture.
G/S (engaged) – the AFDS follows the ILS glideslope.
FLARE (armed) white – during a dual A/P ILS approach, FLARE is displayed after LOC and G/S capture and below 1500 feet RA. The second A/P couples with the flight controls and A/P go–around mode arms.
FLARE (engaged) – during a dual A/P ILS approach, flare engages at 50feet radio altitude. FLARE accomplishes the autoland flare maneuver.
G/P (armed) white– the AFDS is armed for G/P capture.
G/P (engaged) – the AFDS follows the IAN glide path.

Question 22

Explain the meaning of the AFDS FMA Roll Modes.

Answer 22

LNAV (engaged) – the AFDS intercepts and tracks the active FMC route.
LNAV (armed) white– the AFDS is armed (prior to takeoff) to engage
LNAV at 50 feet RA.
LNAV (armed) white – in the approach phase and a missed approach exists in the flight plan.
HDG SEL – the airplane is turning to, or is on the heading selected in the MCP Heading Display.
VOR/LOC (armed) white– AFDS is armed to capture selected VOR or LOC COURSE.
VOR/LOC (engaged) – AFDS tracks selected VOR course or tracks selected localizer course along the inbound front course bearing.
FAC (armed) white – the AFDS is armed to capture the IAN final approach course.
FAC (engaged) – the AFDS tracks the IAN final approach course along the inbound course bearing.
B/CRS (armed) white – the AFDS is armed to capture the localizer final approach back course.
B/CRS (engaged) – the AFDS tracks the localizer final approach course along the inbound back course bearing.

Note- Delta does not use Back Course approaches on 737

Question 23

Explain how to arm/engage the Integrated Approach Navigation (IAN) modes and their meaning.

Answer 23

The Integrated Approach Navigation (IAN) modes are armed/engaged by selecting the APP button on the AFDS Mode Control Panel (MCP). Once armed, the autopilot/flight director will capture and track the localizer/final approach course and glide/slope or glide path.

The following roll and pitch mode control annunciations of the FMA will be displayed for each type of approach:
- ILS approach – VOR/LOC and G/S will be the displayed roll and pitch modes.
- FMC IAN approach – FAC and G/P will be the displayed roll and pitch modes.
- ILS approach with G/S selected off or a localizer only approach
– VOR/LOC and G/P will be the displayed roll and pitch modes.

Question 24

Describe the Go-Around Roll Mode – LNAV in Lieu of Track hold.

Answer 24

• When a missed approach exists in the flight plan and the FCCs are capable of entering go-around, LNAV arm will be annunciated on the FMA. Track hold will automatically transition to LNAV during a missed approach.
• During autoland operations with FLARE arm or FLARE engage displayed, if TO/GA is pressed, LNAV will engage when the airplane is above 400 feet. Below that altitude the roll mode will be track hold.
• During an approach without FLARE arm or FLARE engage displayed, if TO/GA is pressed, LNAV will engage when the airplane is above 50 feet. Below that altitude the roll mode will be track hold.

Question 25

Explain the function of the SPEED Switch on the MCP

Answer 25

Push – (light not illuminated)
-engages A/T in SPEED mode if compatible with engaged AFDS
modes.
-illuminates SPEED switch light.
-maintains speed in MCP IAS/MACH display.
Push – (light illuminated)
-deselects speed mode and extinguishes switch light.
-engages A/T in ARM mode.

Note: Normally Autothrottle SPEED modes are automaticallyengaged with the selection of compatible pitch modes without making a separate selection with this switch. It is also possible to use this switch to deselect the SPEED mode while the light is illuminated to temporarily put the A/T system in ARM.

Question 26

Explain the function of the Speed Intervention (SPD INTV) Switch on the MCP.

Answer 26

Push (only when VNAV engaged)

• IAS/MACH display alternately shows selected IAS/Mach and blanks.
• when IAS/MACH display is unblanked, FMC speed intervention is active, FMC target speed is displayed, and IAS/MACH Selector may be used to set desired speed.
• when IAS/MACH display is blank, FMC computed target speed is active and displayed on the airspeed indicator.

Question 27

Explain the function of the VNAV Switch on the MCP.

Answer 27

Push –

• VNAV switch light illuminates.
• pitch mode annunciates VNAV SPD, VNAV PTH.
• A/T mode annunciates FMC SPD, N1, RETARD, or ARM (white).
• IAS/MACH display blanks and airspeed cursors positioned to FMC commanded airspeed.

Question 28

Explain the function of the Level Change (LVL CHG) Switch on the MCP.

Answer 28

Push –

• LVL CHG switch light illuminates.
• pitch mode annunciates MCP SPD for climb or descent.
• autothrottle mode annunciates N1 for climb or RETARD followed by ARM (white) for descent.
• IAS/MACH display and airspeed cursors display target speed.

Question 29

Explain the function of the Altitude Hold (ALT HLD) Switch on the MCP.

Answer 29

Push –

• engages ALT HOLD command mode.
• commands pitch to hold uncorrected barometric altitude at which switch was pressed.
• annunciates ALT HOLD pitch mode and illuminates ALT HLDswitch light.

Question 30

Explain the function of the Vertical Speed (V/S) Switch on the MCP.

Answer 30

Push –

• arms or engages V/S command mode.
• commands pitch to hold vertical speed.
• engages A/T in speed mode to hold selected airspeed.
• annunciates V/S pitch mode and illuminates V/S switch light.

Question 31

Explain the function of the Altitude Intervention (ALT INTV) Switch on the MCP.

Answer 31

Allows manual deletion of next FMC altitude constraint via altitude SEL and ALT INTV switch.
Push – (during VNAV climb)
-lowest FMC altitude constraint below selected MCP altitude is deleted.
-if airplane is currently at an FMC altitude constraint, deletion allowsairplane to resume climb. MCP altitude must be set above current altitude.
-for each press of switch, one deletion occurs.
-if MCP altitude is set above current FMC altitude, FMC cruise altitude resets to MCP altitude. FMC cruise altitude cannot be decreased using ALT INTV switch.
Push – (during VNAV cruise)
-if MCP altitude is set above current FMC cruise altitude, FMC resetscruise altitude to MCP altitude and initiates a cruise climb.
-if MCP altitude is set below current FMC cruise altitude, an early descent is initiated. Lower FMC cruise altitude cannot be entered using ALT INTV switch.
Push – (during VNAV descent)
-the highest FMC altitude constraint above MCP altitude is deleted.
-if airplane is currently at an FMC altitude constraint, deletion allowsairplane to continue descent. MCP altitude must be set below currentaltitude.
-if all FMC altitude constraints are deleted during VNAV path descent, an automatic transition to a VNAV speed descent is made.

Question 32

Explain the function of the LNAV Switch on the MCP.

Answer 32

Push –

• commands AFDS roll to intercept and track the active FMC route.
• annunciates LNAV as roll mode and illuminates LNAV switch light.

Question 33

Explain the function of the VOR Localizer (LOC) Switch on the MCP.

Answer 33

Push –
-commands AFDS roll to capture and track selected VOR or LOC
course.
-annunciates VOR/LOC armed or engaged as roll mode.
-illuminates VOR LOC switch light.

Question 34

Explain the function of the Heading Select (HDG SEL) Switch on the MCP.

Answer 34

Push –

• engages HDG SEL command mode.
• commands roll to follow selected heading.
• annunciates HDG SEL as FMA roll mode.
• illuminates HDG SEL switch light.

Question 35

Explain the function of the Command Engage (CMD ENGAGE) Switch (A or B) on the MCP.

Answer 35

Push –

• engages A/P.
• enables all command modes.
• displays CMD in A/P status display.
• pushing an engage switch for second A/P, while not in approach mode, engages selected A/P and disengages first A/P.

Question 36

Explain the function of the Control Wheel Steering Engage (CWS ENGAGE) Switch (A or B) on the MCP.

Answer 36

Push –

• engages A/P.
• engages pitch and roll modes in CWS. Other pitch and roll modes not enabled.
• displays CWS P and CWS R in A/P status display.
• A/P pitch and roll controlled by pilot with control wheel pressure.

Question 37

Explain the function of the Altitude Selector (SEL) on the MCP.

Answer 37

Rotate –

• sets altitude in ALTITUDE display in 100 foot increments.
• arms V/S (white) mode if rotated while in ALT HOLD.

Question 38

Explain the meaning of the Speed Condition Symbols on the MCP.

Answer 38

Overspeed or Underspeed Limiting Symbol appears when commanded
speed cannot be reached.
-Underspeed Limiting (flashing character “A”)
- minimum speed.
-Overspeed Limiting (flashing character “8”)
- Vmo or Mmo limit.
- landing gear limit.
- flap limit.

Question 39

Explain the function of the Changeover (C/O) Switch on the MCP.

Answer 39

Push –

• changes IAS/MACH display between IAS and MACH.
• automatic changeover occurs at approximately FL260.

Question 40

Explain the function of the N1 Switch on the MCP.

Answer 40

Push – (light not illuminated)
-engages A/T in N1 mode if compatible with AFDS modes already engaged.
-illuminates N1 switch light.
Push – (light illuminated)
-deselects N1 mode and extinguishes switch light.
-engages autothrottles in ARM mode.
Note: Normally N1 mode is automatically engaged with the selection of compatible pitch modes without making a separate selection with this switch. However, it is possible to use this switch to deselect the N1 mode while the light is illuminated to temporarily put the A/T system in ARM.