For Training Purposes Only
Sept 04
2-41
P I L O T T R A I N I N G G U I D E
AUTOMATIC FLIGHT CONTROL SYSTEM
AUTOMATIC EMERGENCY DESCENT MODE
The “Cabin Altitude” aural warning is enunciated when cabin altitude exceeds 9000
feet. The EDM mode is automatically entered anytime the following criteria is met:
•
The autopilot is engaged
•
The airplane pressure altitude is above 25,000 feet
•
The cabin altitude exceeds 14,500 feet
Once the above conditions are met, then:
•
The aural warning “Emergency Descent” is enunciated
•
An EMERGENCY DESCENT red CAS message is annunciated
•
EDM is displayed in red in the PFDs vertical flight director mode area. HDG is
displayed in green as the lateral flight director mode
•
The ALT preselector is automatically set to 15,000 feet or 4500 meters
•
The HDG bug is automatically set to 90 degrees left of current heading
•
The IAS/Mach digital readout displayed on the PFDs is displayed in red
•
The selected airspeed bug is the manual speed bug
•
The manual speed bug is placed at a position corresponding to the airspeed target
and displayed in red while EDM is active
•
The speed target is not manually selectable through the speed knob on the
guidance panel while EDM is active. Changing the FMS/MAN switch position of
the speed knob on the guidance panel has no effect while EDM is active. The FMS
speed bug is indicated by a magenta, triangular symbol, displayed on the outside of
the airspeed tape
•
The HDG bug and ALT preselector are changeable by the flight crew while in the
emergency descent mode
•
The airspeed target continuously synchronizes to Vmo -10. The selected IAS/
Mach digital readout displayed on the PFDs remains the selected airspeed type. If
Mach is the selected airspeed type, the display automatically transitions from
Mach to IAS when descending through 32,400 feet
•
The speed target is set to 250 kts upon ASEL becoming the active FD mode
•
Selection of any lateral or vertical FD mode while in EDM results in the EDM
annunciation flashing for five seconds
•
The FD flies a HDG/FLC descent to 15,000 ft. The FD performs a normal
transition to ASEL and then ALT mode upon leveling at 15,000 ft. The EDM
annunciation flashes for five seconds upon transitioning between modes. The FD
vertical mode annunciation remains EDM until the mode is exited
•
The FD system remains in EDM until the autopilot is disengaged. This is the only
way to cancel the emergency descent mode