SWA B737 - Air Conditioning

Question 1

(Air Conditioning) What are the sources of Conditioned Air for the cabin?

Answer 1

• Airplane’s Air Conditioning PACKS

* Preconditioned Ground Air Source

Question 2

(Air Conditioning) True or False: You can operate both PACKS from one engine at any time.

Answer 2

False - Never operate both PACKS from one engine. (One PACK can control the aircraft temperature and pressurization up to the maximum certified ceiling)

Question 3

(Air Conditioning) How are PACK Valves controlled/operated?

Answer 3

Electrically controlled - Pneumatically operated.

Question 4

(Air Conditioning) When will the PACKS regulate a low flow?

Answer 4

If both PACKS are in the AUTO position and both PACKS operating.

Question 5

(Air Conditioning) When the PACK Switches are in the AUTO position, when will a PACK automatically go to High Flow?

Answer 5

• With only one PACK operating while in flight with the flaps retracted.
• Both engine BLEED air switches are OFF and the APU BLEED air switch is ON

Question 6

(Air Conditioning) When is automatic switching to High Flow inhibited?

Answer 6

• On the Ground
• In flight with the Flaps extended

(This is done in order to reduce demand on the Engine and ensure adequate engine power for single engine operation)

Question 7

(Air Conditioning) What does an illuminated PACK TRIP OFF light in the Overhead Panel indicate?

Answer 7

The PACK temperature has exceeded its limits.

Question 8

(Air Conditioning) What happens to the PACK once the PACK TRIP OFF light illuminates?

Answer 8

The corresponding PACK Valve automatically closes and the mix valve drives to the full cold position.

Question 9

(Air Conditioning) Once the PACK is sufficiently cooled, is there a way to reset the light in flight?

Answer 9

Yes - by pressing the TRIP RESET button on the overhead panel

Question 10

(Air Conditioning) When do the RAM AIR INLET doors move to the full open position?

Answer 10

• On the ground

* In flight with the flaps extended

Question 11

(Air Conditioning) If the RAM DOOR FULL OPEN light is extinguished does that mean the Ram Air Door is closed?

Answer 11

No (just not full open - they are still modulating as required to provide the necessary airflow to the heat exchangers.

Question 12

(Air Conditioning) Where does the Mix Manifold get its air from?

Answer 12

• Both PACKS (L/R) or an external low pressure conditioned air source.
• That air is mixed with recirculated cabin air, supplied by the recirculation fan.

Question 13

(Air Conditioning) What does the Recirculation fan do?

Answer 13

Helps maintain overall cabin air circulation while reducing Engine Bleed Air and Air Conditioning PACK demand.

Question 14

(Air Conditioning) With the Recirculation (RECIRC) Fan seitch in AUTO (its normal position), when would the RECIRC fans turn OFF?

Answer 14

Both PACKS are operating and one of the switches is in HIGH.

Question 15

(Air Conditioning) True or False: While in the MANUAL range, the temperature selector is spring-loaded to the OFF (neutral) position?

Answer 15

True

Question 16

(Air Conditioning) What does an illuminated DUCT OVERHEAT light on the Overhead Panel indicate?

Answer 16

There is an overheat sensed in the Distribution Duct. (Air mix valves will automatically drive to the full cold position)

Question 17

(Air Conditioning) When the overheat in the Distribution Duct is no longer present (caused the DUCT OVERHEAT light to illuminate) how do you set the mix valves back to a position based on selected temperature?

Answer 17

Pressing the TRIP RESET button on the Overhead Panel.

Question 18

(Air Conditioning) What does an illuminated OFF light on the EQUIP COOLING PANEL on the Overhead Panel indicate?

Answer 18

There is not sufficient airflow and the respective fan (Supply or Exhaust) has failed. (Selecting the ALTERNATE fan should restore airflow and extinguish the light within 5 seconds)

Question 19

(Air Conditioning) What are the functions of the Overboard Exhaust Valve?

Answer 19

• Controlling Air Volume

* Smoke Removal

Question 20

(Air Conditioning) When performing a Smoke/Fumes Removal Non-Normal checklist, what can you do to increase ventilation?

Answer 20

Selecting either PACK switch to HIGH and the RECIRC switch to OFF. (This causes the overboard exhaust valve to be driven open)