SWA B737 - Bleed Air

Question 1

(Bleed Air) What does an illuminated DUAL BLEED light on the BLEED AIR PANEL on the Overhead Panel indicate?

Answer 1

That the APU Bleed Valve is open, so it is to remind you a back pressure of air to the APU could occur.

Question 2

(Bleed Air) What are the different sources that can provide Bleed Air to the aircraft?

Answer 2

• Engines
• APU
• HP Ground Air Source

Question 3

(Bleed Air) What sources supply Bleed Air into the Left Pneumatic Duct?

Answer 3

• Left Engine

* APU

Question 4

(Bleed Air) What sources supply Bleed Air into the Right Pneumatic Duct?

Answer 4

• Right Engine

* External Air Source

Question 5

(Bleed Air) What is Bleed Air used for?

Answer 5

• Engine Starting
• Engine Anti-Ice
• Wing Anti-Ice
• Air Conditioning and Pressurization
• Water Tank Pressurization
• Hydraulic Reservoir Pressurization

Question 6

(Bleed Air) What is the primary source of Engine Bleed Air?

Answer 6

5th Stage (Low Pressure Stage)

Question 7

(Bleed Air) If the 5th Stage Air from the Engines is insufficient for the Bleed Air System requirements, what helps maintain adequate pressure?

Answer 7

9th Stage (High Pressure Air) Valve modulates open to maintain adequate pressure

Question 8

(Bleed Air) What controls the Engine Bleed Air Valve?

Answer 8

Electrically controlled (DC Power) - Pneumatically operated.

Question 9

(Bleed Air) What does an illuminated BLEED TRIP OFF light on the BLEED AIR PANEL on the Overhead Panel indicate?

Answer 9

The Engine Bleed Air temperature or pressure has exceeded a predetermined limit. (The Engine Bleed Air Valve will automatically close to reduce the amount of Bleed Air Outflow in response)

Question 10

(Bleed Air) How do you reopen the Engine Bleed Air Valve once the over temperature/pressure (that caused the BLEED TRIP OFF light to illuminate) is corrected?

Answer 10

Pressing the Trip Reset button on the BLEED AIR PANEL

Question 11

(Bleed Air) During normal operations, where should the L/R Duct Pressure needles be?

Answer 11

Approximately Equal. (Differences between the two is normal as long as there is sufficient air for cabin pressurization)

Question 12

leed Air) How are the Left and Right Bleed Air Ducts connected?

Answer 12

Isolation Valve

Question 13

(Bleed Air) What powers the Isolation Valve?

Answer 13

AC Transfer Bus 1

Question 14

(Bleed Air) With the Isolation Valve Switch in the AUTO position, what would cause the Valve to open?

Answer 14

Placing any one of the Engine Bleed switches OFF or selecting either PACK switch OFF. (The Valve position is NOT affected by the APU BLEED Air Switch or the Ground HP Air Supply)

Question 15

(Bleed Air) What powers the APU Bleed Air Valve?

Answer 15

Electrically powered (DC) - Pneumatically operated.

Question 16

(Bleed Air) How much Bleed Air can the APU provide?

Answer 16

• 2 Packs (Ground)

* 1 Pack (In Flight)

Question 17

(Bleed Air) How long after APU start should you wait to start using the APU Bleed Air?

Answer 17

2 minutes

Question 18

Bleed Air) What does an illuminated DUAL BLEED light on the BLEED AIR PANEL on the Overhead Panel indicate?

Answer 18

That there is a POSSIBILITY that a back pressure of air to the APU can occur.

Question 19

(Bleed Air) What are the two circumstances that would cause the DUAL BLEED light to illuminate?

Answer 19

• The APU Bleed Air Valve is open and the Number 1 Engine Bleed Air Switch is ON.
• The APU Bleed Air Valve is open, the Number 2 Engine Bleed Air Switch is ON and the Isolation Valve is OPEN.

Question 20

(Bleed Air) What does an illuminated WING-BODY OVERHEAT light on the BLEED AIR PANEL on the overhead panel indicate?

Answer 20

A Bleed Air Leak is detected

Question 21

(Bleed Air) What does the Left WING-BODY OVERHEAT light provide detection for?

Answer 21

• Left Strut
• Left Inboard Wing Leading Edge
• Left-Hand Air Conditioning Bay
• Keel Beam
• APU Bleed Duct

Question 22

(Bleed Air) What does the Right WING-BODY OVERHEAT light provide detection for?

Answer 22

• Right Engine Strut
• Right Inboard Wing Leading Edge
• Right-Hand Air Conditioning Bay

Question 23

(Bleed Air) Can the WING-BODY OVERHEAT light be reset by pressing the Trip Reset Button the the BLEED AIR PANEL?

Answer 23

No (the light will only extinguish once the respective pneumatic duct is cooled).