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MAINTENANCE MANUAL
2) GUN 051; heading select mode acquires and maintains the heading selected on the MCP. It has two selectable bank angle limits: NORM and 30°. The NORM position selects a B/A based on true airspeed and heading error with a maximum angle of 30 degrees. The heading select mode can be manually called by pushing the HDG SEL switch on the MCP.
(j)
Lateral Navigation Mode (LNAV)
1) The LNAV mode responds to FMC lateral steering commands to acquire and track selected flight plan paths. It is manually selected by pressing the LNAV switch/light on the MCP.
(k)
Localizer Active Mode
1) The LOC active mode provides aileron commands to acquire and track the centerline of the localizer beam during all phases of single or multi-channel ILS approach. The A/P yaw channel provides rudder commands during multi-channel approaches to maintain runway alignment during rollout.
(l)
GUN 001-050, 052-999; Backcourse 1) The B/CRS switch operates independently of A/P or F/D to
control ILS displays on the ADI except after LOC capture. After LOC capture, the roll channel provides commands to track the B/CRS LOC centerline. The pitch channel provides commands to track the G/S centerline if G/S is available. The pitch channel will stay in the previously engaged mode after the B/CRS switch is pushed.
(m)
GUN 001-050, 052-999; Backcourse Localizer Mode 1) The B/CRS LOC mode provides corrected A/P and F/D commands
to acquire and track the centerline of the backcourse localizer beam. It is automatically initiated whenever the airplane is within the computed capture band and the B/CRS LOC ARM state has been activated in the HDG HLD, HDG SEL or LNAV modes.
(3) Roll Flight Director Operation (Fig. 8)
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MAINTENANCE MANUAL
SWITCH/LIGHT NAVIGATION LATERAL SWITCH/LIGHT SWITCH DIRECTOR
MODE CONTROL PANEL
(EXAMPLE)
INSTR SOURCE SEL
FLT DIR
L
LEFT FLIGHT DIRECTOR SWITCH
(RIGHT SWITCH IS EQUIVALENT)
COMMAND BARS
HORIZON LINE
PITCH MODE ANNUNCIATION (ARMED - WHITE) (ENGAGED - GREEN) AIRPLANE SYMBOL
ROLL MODE ANNUNCIATION (ARMED - WHITE) (ENGAGED - GREEN)
ELECTRONIC ATTITUDE DIRECTOR INDICATOR
Flight Director Controls and Displays
Figure 8
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MAINTENANCE MANUAL
(a)
The Flight Director (F/D) permits the pilot to fly the airplane without engaging the autopilot (A/P). The FCC computes F/D commands and displays these on the EADIs. The pilot controls the airplane by control column and control wheel movements in response to these commands.
(b)
When on the ground, the F/D automatically engages into the takeoff-wings level mode when it is first switched on. It changes to the takeoff-track hold mode when the airplane reaches five feet radio altitude. During flight, if the A/P is engaged when the F/D is first switched on, the F/D engages into the current A/P mode.
(c)
Manually selectable F/D modes are:
1) Heading Select (HDG SEL)
2) Heading Hold (HDG HLD)
3) Lateral Navigation (LNAV)
4) Localizer (LOC)
5) Approach (APP)
6) Go-Around (G/A)
7) GUN 001-050, 052-999;
Backcourse Localizer (B/CRS LOC)
(d)
Flight Director Controls and Displays
1) Flight Director operation and mode selection are accomplished by switches and switch/lights on the Mode Control Panel. The captain's and first officer's F/D switches are paralleled, so either can be used to turn the F/D on. Both must be off to disable the F/D. Each F/D switch, however, independently controls the F/D displays on the corresponding EADI. The L, C, or R FCC may be selected as data source for the captain's or first officer's F/D displays by the respective FLT DIR switch (P1-1 or P3-3 panels).
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