02 - Air Systems Flashcards
AIR SYSTEMS
1. What are the sources of the Bleed Air System?
- Engines
- APU
- External pneumatic air
AIR SYSTEMS
2. What is the purpose of the Air Supply Controller (ASC)?
Control of the PRSOV and HPSOV. It digitally controls the output of 4th- and 10th-stage pneumatic air in response to bleed air demands.
AIR SYSTEMS
3. What causes the engine bleed air valve to automatically close?
- High temp (254 degrees C)
or - Overpressure (170 psi for 5 sec)
AIR SYSTEMS
4. What does illumination of the BLEED light indicate?
• bleed sensor(s) have closed the associated engine bleed air valve for over-temperature
or excessive pressurization of the bleed duct, or
• a failure within the Bleed Air System that may not be resettable, or
• an incorrect bleed configuration after takeoff or go-around
AIR SYSTEMS
5. What causes the automatic closure of the APU bleed valve?
The APU being shutdown, regardless of switch position.
AIR SYSTEMS
6. What is the position of the isolation valve with the ISOLATION VALVE switch in AUTO?
Closed - with both engine BLEED switches ON and both PACK switches in AUTO or HIGH;
Open - with any engine BLEED or PACK switch in the OFF position
AIR SYSTEMS
7. What does the illumination of the DUAL BLEED light indicate?
that two sources of bleed air (engine and APU) could be pressurizing the left bleed duct. This could happen due to
the APU bleed air valve being open and Engine 1 Bleed Switch is ON, or
the APU bleed air valve open, Engine 2 Bleed Switch is ON, and the isolation valve is open
NOTE: The DUAL BLEED light monitors engine BLEED switch position and APU bleed valve position
AIR SYSTEMS
8. In the event of a single pack failure at altitude, the remaining pack is capable of
maintaining cabin pressure and comfort up to what altitude?
Max certified ceiling of 41,000’
AIR SYSTEMS
9. What causes a pack to automatically switch to high airflow?
-Pack switch in AUTO
-Failure of a pack or an engine with;
- aircraft airborne
- Flaps UP
- Both engine bleed switches ON
- Pack switch OFF in flight with Flaps UP
- EQUIP SMOKE light illuminated
AIR SYSTEMS
10. How many controllers does each pack have?
Each pack has one dual-channel pack/zone electronic controller. Digital channel is primary and analogue channel provided back up control for opposite side pack automatically.
AIR SYSTEMS
11. What does the illumination of the PACK light indicate?
- failure of both the primary and standby pack controls for the same pack
- failure of the pack valve to open when commanded
- incorrect pack switch configuration after takeoff
- pack overheat
AIR SYSTEMS
12. Do the Flight Attendants have any control of cabin temperature?
Yes, the temperature set points for the forward and aft cabin zones can be adjusted +/- 3 degrees from the Flight Attendant panel
AIR SYSTEMS
13. How is the failure of either the primary or standby pack controller indicated on the
ground?
The MAINT light and the OVERHEAD System Annunciator and MASTER CAUTION lights will illuminate after landing
AIR SYSTEMS
14. What provides cooling air for the pack systems?
The Ram Air System, controlled by a Smart Ram Air Door Actuator (SRADA)
AIR SYSTEMS
15. How is a supply duct overheat indicated?
ZONE TEMP lights
AIR SYSTEMS
19. What does the Equipment Cooling System cool?
electronic equipment in the Flight Deck and E&E Bay
AIR SYSTEMS
21. What does the EQUIP COOLING OFF light indicate?
Loss of airflow due to the failure of a fan
AIR SYSTEMS
23. How is the alternate pressurization controller selected?
Selecting ALTN on the Cabin Pressurization Panel
AIR SYSTEMS
25. What would cause the OFF SCHED DESCENT light to illuminate?
A descent beginning prior to the aircraft reaching the set FLT ALT (e.g., an air turn-back during climb). The AIR COND System Annunciator and MASTER CAUTION lights also illuminate.
AIR SYSTEMS
27. Can the cabin altitude warning horn can be silenced using the ALT HORN CUTOUT switch above 10,000 ft?
Yes
