PNEUMATICS
AIR CONDITIONING
AND PRESSURIZATION
AIRPLANE
O
PERATIONS
MANUAL
2-14-15
Page
8
Code
02
REVISION 41
Copyright © by Embraer. Refer to cover page for details.
AUTOMATIC INCREASED RATE OF DESCENT SEQUENCE
This sequence is initiated when the airplane descent rate is greater
than 200 ft/min for at least 10 seconds, in order to satisfy all airplane
rapid descent cases. The cabin altitude rate of change limits may be
accordingly increased, depending on the remaining flight time which is
calculated considering the airplane operating altitude, airplane vertical
speed and the selected landing altitude.
Therefore, the cabin altitude rate of descent limit may be increased to
a value between –450 ft/min and –1300 ft/min (for EMB-145 models
Pre-Mod. SB 145-21-0006) or –450 ft/min and –500 ft/min (for
EMB-145 Post-Mod. SB 145-21-0006 or S/N 145.050 and on and
EMB-135 models).
AUTOMATIC DEPRESSURIZATION SEQUENCE ON GROUND
This sequence is initiated when the airplane is on the ground and the
engine 1 thrust lever is in the IDLE position.
To avoid a cabin bump during the landing, it is necessary that the
airplane land with the cabin being submitted to a small differential
pressure. For that reason, the automatic mode always controls, for
landing, a cabin altitude equal to the selected landing altitude minus
300 ft. This sequence cancels this differential pressure corresponding
to 300 ft, as well as reduces cabin bump when the air conditioning is
turned off or the main door is open.
Cabin depressurization is controlled at a rate of climb equal to
650 ft/min, up to the full opening of the outflow valves.
In automatic mode, the rapid cabin depressurization is commanded by
the Dump Button.
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