Bleed Air

Question 1

Which systems use bleed air?

Answer 1

Air conditioning/pressurization
Wing and Eng thermal anti-icing
Engine starting
hydraulic reservoirs pressurization
water tank pressurization
If installed, apsirated TAT probe

Question 2

The ON position for both the APU and either engine bleed air switch will open only when any of them is _______.

Answer 2

operating.

Question 3

How does the auto position of the ISOLATION VALVE work?

Answer 3

closes the isolation valve if both bleed engine air switches are ON and both air PACKS are either AUTO or HIGH. AUTO allows for opening of isolation valve if either bleed air or A/C pack is positioned off.

Question 4

BLEED TRIP OFF

Answer 4

illuminates if excessive bleed air temp or pressure or both is sensed. If this happens the bleed air valve automatically closes.

Question 5

What does the wing body OVHT TEST switch do?

Answer 5

test overheat detection circuits. The test should illuminate both WING-BODY OVERHEAT lights.

Question 6

What does DUAL BLEED mean?

Answer 6

advises crew when both engine and APU are both supplying air to pneumatic manifold.

Question 7

What causes Left WING-BODY OVERHEAT light?

Answer 7

Overheat from a duct leak in:
Left engine strut
Left inboard wing leading edge
Left air conditioning bay
Keel beam
APU bleed air duct

Question 8

What causes Right WING-BODY OVERHEAT light?

Answer 8

Overheat from a duct leak in:
Right engine strut
Right inboard wing leading edge
Right air conditioning bay

Question 9

Bleed air is supplied from which stages?

Answer 9

5th & 9th (9th is available should it be needed by demand)

Question 10

Which valve makes available 9th stage bleed air?

Answer 10

High stage valve.

Question 11

Where is the external air cart hook up?

Answer 11

underneath the plane near the forward left wing root.

Question 12

The APU bleed valve is ______ controlled and _____ operated.

Answer 12

DC controlled and pressure operated.

Question 13

When the APU is shut down, what happens to the APU bleed valve?

Answer 13

it will close automatically.

Question 14

At idle thrust, the ___ stage valve would normally be _____.

Answer 14

9th, open.

Question 15

If APU is providing bleed air at the same time as engine bleed, what happens to the 9th stage bleed valve?

Answer 15

back pressure in the duct will cause the 9th stage valve to close.

Question 16

The engine bleed air valve is _____ activated and _____operated.

Answer 16

DC activated and pressure operated.

Question 17

The engine bleed air shutoff valve acts in 2 ways:

Answer 17

acts as a shutoff valve and pressure regulator when engine BLEED switch is on.

Question 18

What powers the isolation valve?

Answer 18

AC power

Question 19

T/F: The APU BLEED air switch affects isolation valve operation.

Answer 19

false

Question 20

What power setting must the engine thrust be if a DUAL BLEED light comes on?

Answer 20

idle

Question 21

T/F: Differences between left and right duct pressure on the duct press gauge are normal.

Answer 21

True, provided there is adequate flow for cabin pressurization.

Question 22

How many overheat sensors are located at various locations throughout the aircraft?

Answer 22

8

Question 23

Where are the sensors that illuminate the LEFT WING-BODY OVERHEAT light?

Answer 23

L engine strut, L inboard wing leading edge, L air conditioning bay, Keel beam, bleed duct from the APU.

Question 24

Where are the sensors that illuminate the RIGHT WING-BODY OVERHEAT light?

Answer 24

R engine strut, R inboard wing leading edge, R air conditioning bay.

Question 25

What is the BLEED TRIP OFF non-normal checklist first step?

Answer 25

select WING ANTI-ICE off

Question 26

If a BLEED TRIP OFF light remains illuminated, what happens.

Answer 26

The pack is selected off and the other pack that works goes to high flow in flight with flaps up. Avoid icing conditions…duh!

Question 27

Use of Wing Anti-ice above ~ _____ may cause bleed trip off and possible loss of cabin pressure.

Answer 27

FL350

Question 28

T/F: The dual bleed light is a normal indication following engine start using APU bleed air and should extinguish once the APU BLEED air switch is selected off.

Answer 28

true