AIR CONDITIONING Flashcards
How many packs do we have and what are called?
Main pack and Emergency pack
In the air with wing anti ice not in use, which engines provide bleed air?
1 and 3
In the air with wing anti ice in use, which engines provide bleed air?
All 3
On the ground, what provides bleed air for air conditioning?
On the ground: APU or engine bleed air (if both are available, APU bleed air takes
precedence) or ground cart
In normal operation, hot bleed air is cooled by which pack?
Main pack
In the event of partial or total failure of the main pack, or AMSAC, which pack cools the hot bleed air?
Emergency pack
Which are the different ECS operating modes?
NORMAL, PAX OFF, CREW OFF, BACKUP or EMERG
In BACKUP ECS mode, which pack supplies cold air?
Emergency pack
In NORMAL, CREW OFF and PAX OFF modes, cold air is supplied by which pack?
Main pack
How many Air Cycling Machines do we have?
1
How many heat exchangers in the ACS system?
2.
Primary and Secondary
Is air conditioning available on take off?
To maximize engine performance, there is no air conditioning during the first part of take-
off when at least 2 throttles are in take-off position and weight on wheels
When does air conditioning come back after take off?
Air conditioning is available again:
- When all engines are operating and weight off wheel,
- Or after one or two engine failures (N1 below flight idle) and:
Throttles are retarded from take off position,
Or airplane altitude exceeds 15,000 ft.
What is the function of the ACM fan?
On the ground and during low altitude flight, the ACM fan induces the airflow used to cool
the bleed air in the heat exchangers
What is the main source of cooling air flow for the heat exchangers?
In flight, the cabin air jet pump accelerates the external air (the static air inlet is located behind engine 3 pylon leading edge). The induced airflow is the main source for cooling the heat exchangers and the ACM fan only assists the cabin air jet pump. The cabin air jet pump uses the air evacuated through the baggage outflow valve
Which valves are closed when the ECS mode is selected to PAX OFF?
Cabin cold valve and Cabin hot valve
What are reasons why PAX OFF mode would have to be selected?
The PAX OFF mode is selected if control of the hot and/or cold air supply to the cabin is lost due to a valve or sensor failure. Crew members are alerted through a CAS message and the
selector must be turned to PAX OFF.
What valve allows the flow of cockpit air into the cabin?
Cabin/Crew isolation valve