787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Automatic Flight -
System Description
Copyright © The Boeing Company. See title page for details.
4.20.14 D615Z003-TBC
Automatic Flight Approach and Landing
The AFDS provides autopilot guidance for Instrument Landing System (ILS),
GPS Landing System (GLS) and approaches utilizing Integrated Approach
Navigation (IAN).
ILS approaches are flown in the G/S and LOC modes with the approach path
deviation data from the localizer and glideslope transmitters.
GLS approaches are also flown in the G/S and LOC modes, but the approach path
deviation data is from the Ground Based Augmentation System (GBAS).
[Option – GS capture inhibited before LOC capture]
Pushing the APP switch arms the pitch and roll modes after an approach procedure
selection is made in the FMC. Glideslope/glidepath capture is inhibited until the
localizer is captured.
Pushing the LOC/FAC switch arms the AFDS to capture and maintain an
approach lateral flight path to a runway using an ILS localizer beam or a lateral
path provided by the FMC. Descent on the localizer or final approach course can
be accomplished using VNAV, V/S, FLCH, or FPA pitch modes. The LOC or FAC
mode cannot capture if the intercept angle exceeds 120º.
With a command speed of VREF+5 knots and landing flaps, there is sufficient
wind and gust protection available with the autothrottle active. The autothrottle
adjusts thrust quickly when the airspeed decreases below the command speed. The
autothrottle decreases thrust slowly when the airspeed is more than the command
speed. In turbulence, the result is that the thrust average is higher than necessary
to keep the command speed. This causes the speed average to be more than the
command speed.
Integrated Approach Navigation
Integrated Approach Navigation allows the use of consistent procedures for all
types of instrument approaches. Any approach that has a Flight Path Angle (FPA)
published in the navigation database can be flown using procedures, indications
and alerts similar to those used for an ILS approach.
Approaches flown with IAN procedures always use FMC computed glidepath
(G/P) for vertical path guidance. Depending on the type of approach flown, lateral
guidance can come from the FMC or localizer.
February 15, 2010
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