AUTOFLIGHT, CAT I
Operation
Aircraft Operations Manual
3.2
S
PAGE
19
Apr 01/15
CONDITIONS
ABNORMAL PROCEDURES
3.5
ALTITUDE
PRESELECTOR
ALERTER
FAILURE TO
CAPTURE SET
ALTITUDE
If it is evident that the system is not responding correctly to capture the selected
altitude, disconnect the autopilot and manually fly the aircraft onto the altitude
disregarding Flight Director command. Select ALT mode, verify mode annunci-
ation on EADI and re
−
engage autopilot.
When a mode data source fails to a flagged condition, the FD command bars will disappear from view, the
red FD flag will appear. In such an event, the pilot is responsible for evaluating the situation and taking
proper action such as disengaging the autopilot or changing flight director modes.
Other failure modes can occur which will provide different cues such as aircraft attitude or flight path
changes and it is always the pilots responsibility to monitor system operation against raw data and other
sources. However, the following paragraphs (3.6 and 3.7) describe two important situations more in detail.
3.6
LOC/GS
GROUND
STATION
INTERRUPTION
When flying in APPR or NAV mode and LOC and/or GS capture. Loss of LOC
and/or GS radio signals due to ground station interruption will cause the follow-
ing on the EADI:
−
Flight Director command bar disappears replaced by FD red flag.
−
LOC and/or GS indication disappears replaced by LOC and/or GS red flag.
−
Captured LOC and/or GS annunciation remain in capture (green).
−
APPR or NAV mode remains selected.
−
The FD/AP will maintain short term dead reckoning (not announced on the
EADI) until other modes are selected.
ACTIONS
−
Perform GO
−
AROUND.
