737 Flight Crew Operations Manual
Automatic Flight -
Controls and Indicators
Boeing Proprietary. Copyright © Boeing. May be subject to export restrictions under EAR. See title page for details.
D6-27370-866-EGP 4.10.5
Climb –
• autothrottle holds FMC thrust limit
• AFDS holds FMC target speed
• automatic level-off occurs at MCP altitude or VNAV altitude,
whichever is reached first
• MCP constrained altitude annunciates VNAV ALT
• VNAV constrained altitude annunciates VNAV PTH.
Cruise –
• autothrottle holds FMC target speed
• AFDS holds FMC altitude
• selecting a lower MCP altitude arms FMC to automatically begin
descent upon arrival at FMC top of descent point.
Descent –
• VNAV SPD descent
• autothrottle holds idle
• AFDS holds FMC target speed.
• VNAV PTH descent
• autothrottle holds idle but can command FMC SPD mode if ground
speed becomes too low to maintain FMC vertical path
• AFDS tracks FMC descent path.
• automatic level-off occurs at MCP altitude or VNAV altitude,
whichever is reached first
• MCP constrained altitude annunciates VNAV ALT
• VNAV constrained altitude annunciates VNAV PTH.
Inhibited below 400 ft RA or if performance initialization not complete.
VNAV mode is terminated by any one of the following:
• selecting another pitch mode
• glideslope capture
• reaching end of LNAV route
• transition of glideslope intercept waypoint if G/S is armed
• crosstrack deviation exceeds twice the RNP value during PTH descent
for an active leg with a database vertical angle and LNAV not engaged
In the event of glideslope intercept waypoint transition, VNAV can be re-engaged.
September 27, 2012
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