Check altitude preselection as follows:
Altitude selector knobs (altitude selector control panel)
- Set test altitude.
Establish a climb or descent as appropriate.
Flight director (FD) switch (autopilot mode controller) -
Autopilot (AP) switch (autopilot mode controller) - ON.
Arm switch (altitude selector control panel) - Depress.
Check that ALT ARM annunciator on the autopilot
annunciator panel is illuminated, and that the ARM
annunciator light on the altitude selector panel is
At 1,000 feet prior to reaching selected altitude, the
ALERT annunciator on the altitude selector panel
should illuminate, and a two second aural tone should
At 300 feet prior to reaching selected altitude, the
ALERT annunciator should extinguish.
The aircraft should smoothly level itself off at the
selected altitude, the aural alert tone should sound,
the ALT ARM annunciator should extinguish, and the
ALT HOLD annunciator should illuminate.
Autopilot NAV operation - Check as follows:
Desired navigation aid - Set as required and select as
pilot's HSI signal source.
Fly aircraft so as to intercept desired radial or