Honda Aircraft Company
HA-420
SYSTEMS
POM
DESCRIPTION
HJ1-29000-005-001
October 30, 2016
1-147
c.
The aircraft is in flight at an aircraft altitude less than 24,500feet,
the cabin pressure altitude is above 8,000 feet, and the aircraft
has taken off from an elevation of greater than 8,000 feet.
In addition to revising the pressurization schedule to accommodate the
high field operation, the normal cabin altitude alerting threshold is raised
from 10,000 feet to 15,000 feet in the high field mode. The allowed cabin
rate of change is also increased from +575 / -485 feet per minute to
+1,740 / -1,500 feet per minute.
Cabin Dump
Selecting the CABIN DUMP switch to DUMP depressurizes the cabin.
Cabin altitude will be limited to 13,500 ±500 feet by the cabin altitude
limiters.
Cabin Altitude Hold Mode
If the pressurization control signal from the aircraft avionics system fails,
the CPCS will automatically enter a Cabin Altitude Hold Mode (Hold
Mode). Hold Mode maintains the current cabin altitude and regulates
cabin pressure within the positive and negative differential pressure
limits. Hold Mode is also activated by selecting the CONTROL MODE
switch to HOLD.
Indications
Cabin altitude, cabin altitude rate and differential pressure are displayed
in green color full-time on the ASI. LFE is displayed in magenta when
derived from the flight plan destination, and in cyan if entered manually.
Cabin altitude and differential pressure changes color from green to red
if a limit is exceeded. If the cabin altitude limit is exceeded a “
CABIN
ALTITUDE
” aural alert is played in addition to the visual indications.
The alert cannot be cancelled while the condition is true but the repeat
rate is reduced after the alert is acknowledged.
FOR TRAINING PURPOSES ONLY
