Overview

Question 1

Bleed air is used for:

Answer 1

• Engine starting
• Engine Anti-ice
• Wing Anti-ice
• Air conditioning and Pressurization
• Water tank pressurization
• Hydraulic Reservoir Pressurization

Question 2

How is pressure controlled?

Answer 2

Pressure regulating shut off valves (PRSOVS)

Question 3

What are the sources of bleed air?

Answer 3

• Left Engine
• Right Engine
• APU
• HP external air connection

Question 4

What stage is air taken from?

Answer 4

5th (primary) LP

9th (Secondary) HP

Question 5

How is the bleed air valve controlled?

Answer 5

Electrically (DC power)

Question 6

What position is the bleed switch normally in?

Answer 6

ON

Question 7

What is the temperature when the BLEED AIR TRIP OFF light illuminates?

Answer 7

490 F

Question 8

What is the pressure when the BLEED AIR TRIP OFF light illuminates?

Answer 8

220 psi

Question 9

How is the ISOL valve operated?

Answer 9

Electrically (AC)

Question 10

When is the ISOL valve closed?

Answer 10

ISOL valve switch - AUTO
BOTH engine BLEED air switches - ON
BOTH engine PACK switches - AUTO or HIGH

Question 11

What causes the ISOL valve to open with the ISOL valve switch in AUTO?

Answer 11

Selecting any one of the PACK or engine BLEED air switches to OFF

Question 12

Is the ISOL valve affected by the APU BLEED air switch or the ground HP air supply?

Answer 12

No

Question 13

ISOL valve switch OPEN

Answer 13

ISOL valve remains open regardless of engine BLEED air or PACK switch position

Question 14

ISOL valve switch CLOSED

Answer 14

Closes ISOL valve

Question 15

Which side does the APU supply?

Answer 15

Left

Question 16

Which side does the HP ground air Supply?

Answer 16

Right

Question 17

How is the APU bleed air valve operated?

Answer 17

Electrically (DC)

Question 18

APU BLEED air switch ON

Answer 18

Controls the valve electrically and opens the valve when sufficient bleed air is available

Question 19

APU provides bleed air for how many PACKS on the ground? In flight?

Answer 19

2/1

Question 20

APU’s primary use

Answer 20

Ground pneumatic source for air conditioning PACK operation and engine starting.

Question 21

Max APU BLEED air extraction

Answer 21

17,000 feet

Question 22

How long should the APU run before BLEED air is available?

Answer 22

1 minute

Question 23

What does system logic look at to illuminate the DUAL BLEED light?

Answer 23

• BLEED air switch position

- APU bleed air valve position

Question 24

What are the 2 circumstances when the DUAL BLEED light to be illuminated?

Answer 24

1) The APU bleed air valve is open and the number 1 engine BLEED air switch is ON.
2) The APU bleed air valve is open, the number 2 engine BLEED air switch is ON, and the ISOL valve is OPEN.

Question 25

What is the restriction of thrust with the DUAL BLEED light illuminated after engine start?

Answer 25

Not above idle thrust

Question 26

The left WING-BODY OVERHEAT annunciator provides detection for:

Answer 26

• left engine strut
• left inboard wing leading edge
• left air conditioning bay
• keel beam
• bleed duct from the APU

Question 27

The right WING-BODY OVERHEAT annunciator provides detection for:

Answer 27

• right engine strut
• right wing leading edge
• right air conditioning bay

Question 28

What light cannot be reset using the TRIP RESET switch

Answer 28

WING-BODY OVERHEAT

Question 29

How does the WING-BODY OVERHEAT light extinguish?

Answer 29

Once the respective pneumatic duct cools