02 Air Systems Flashcards
The air cycle pack output is automatically reduced during which high demand periods?
Engine start and landing gear retraction after take off.
How many temperature zones does the aircraft have?
Seven. Six cabin zones and a flight deck zone.
Normal cooling circulation for the forward E & E and the flight deck instrument panels is provided by?
Cooling system supply fans.
With then EQUIP COOLING switch in OVRD, forward E and E cooling circulation is provided by?
Cabin differential pressure. The cooling air is then dumped overboard by cabin pressure.
Which system controls cabin pressurisation?
Air Supply Cabin Pressure Controllers (ASCP).
Describe the ASCPC functions at aircraft initial start up?
The ASCPCs complete a functional check which includes a check of the outflow valves. After the checks are complete the ASCPCs operate the outflows in ground mode. Ground mode commands the outflow valves fully open.
Describe then ASCPC functions during take off?
When the thrust levers are advanced for take off the ASCPC enter take off mode. In take off mode they pressurise the cabin slightly to ensure a smooth transition after take off. If the thrust levers are retarded for an RTO, the ASCPCs re enter ground mode.
What is the maximum aircraft altitude, maximum cabin altitude and maximum pressure differential?
1) 43,100 ft.
2) 8000 ft.
3) 9.4 psi.
How does the ASCPC manage the pressurisation of landing?
At TOPD the ASCPC begin to descend the cabin. The cabin is descended to 190 feet below destination altitude. After landing the ASCPCs command the outflow valves to open slowly. Once the outflow valves are open, the system operates in ground mode.
How does the pressurisation system handle a diversion?
Prior to 400nm from departure or halfway along the route, the system uses the departure elevation as the landing altitude. After reaching 400nm from departure or halfway on the route the system uses destination elevation.
