PRESSURIZATION MENU Normal operation 1/18 PRESSURIZATION MENU Normal operation 2/18 We will now look at the normal operation of the pressurization system. As part of your Pre-flight walk around you should visually check the outflow valve for damage and obstruction. PRESSURIZATION MENU Normal operation 3/18 As part of your pre flight cockpit scan, verify on the Cabin Pressure Panel that the Mode selector switch is in the AUTO position, lights out. PRESSURIZATION MENU Normal operation 4/18 Confirm that the Landing Elevation Selector is set to AUTOMATIC. Landing elevation is then provided by the FMGS based upon elevation of the destination airport. PRESSURIZATION MENU Normal operation 5/18 Also confirm that the DITCHING sw is in the OFF position, lights out. PRESSURIZATION MENU Normal operation 6/18 On the ECAM CAB PRESS Page confirm that the Landing Elevation Indication is AUTO. Once the destination airport has been entered into the FMGS the destination landing elevation is displayed. PRESSURIZATION MENU Normal operation 7/18 Notice that there are no amber indications. PRESSURIZATION MENU Normal operation 8/18 So that you can get a better understanding of how the pressurization system works we will go through a normal flight profile paying particular attention to the ECAM indications. PRESSURIZATION MENU Normal operation 9/18 When the aircraft is on the ground before the flight, the outflow valve is fully open and there is no pressure differential. This can be seen on ECAM CAB PRESS page. PRESSURIZATION MENU Normal operation 10/18 PRESSURIZATION MENU Normal operation 11/18 Observe that: • the outflow valve is fully open, • the differential pressure is zero, • there is no vertical speed, • the cabin altitude is indicating the field elevation of the departure airfield. PRESSURIZATION MENU Normal operation 12/18 During the Take off roll the system controller signals the outflow valve to close slightly in order to pre-pressurize the aircraft. This is to avoid a pressure surge at rotation. Take off PRESSURIZATION MENU Normal operation 13/18 Climb Phase At Lift Off the controller initiates the climb phase and cabin altitude varies according to a fixed law taking into account the actual rate of climb of the aircraft. The outflow valve will move as required to achieve this. PRESSURIZATION MENU Normal operation 14/18 Cruise at 35000ft Once established in cruise the cabin altitude and differential pressure will remain steady. The outflow valve will move as required to maintain the cabin altitude. In the example shown the aircraft is in cruise at 35000 feet. Notice the values of differential pressure and cabin Altitude. PRESSURIZATION MENU Normal operation 15/18 While in flight we can monitor all the major pressurization indications on the ECAM CRUISE Page. PRESSURIZATION MENU Normal operation 16/18 Descent During the descent phase the pressure rate is optimized so that the cabin reaches landing field pressure just prior to landing. Note: for passenger comfort the automatic function will limit the rate of cabin descent to a maximum of approximately 750 feet per minute. PRESSURIZATION MENU Normal operation 17/18 Landing At touchdown the cabin altitude should be at the airfield elevation, and there should be no differential pressure. To ensure this, just after landing, the outflow valve is fully opened by the system controller. PRESSURIZATION MENU Normal operation 18/18 Once the outflow valve is fully opened there is an automatic change over of the system controllers in preparation for the next flight. This happens so that both systems are used equally. SYS 2 NEXT MMoodduullee ccoommpplleetteedd PRESSURIZATION MENU Normal operation 19/18 LLIISSTTOOFFSSUUBBJJEECCTTSS CCOOCCKKPPIITTCCHHEECCKKSS EECCAAMMIINNDDIICCAATTIIOONNSS FFLLIIGGHHTTEEXXAAMMPPLLEE EXIT AUDIO GLOSSARY FCOM RETURN作者: bocome 时间: 2011-7-31 10:06:31