Bleed Air Systems

Question 0

Within the Compartment Temp Controls and Indicators, what does the OFF mode do?

Answer 0

Closes the compartment trim air valve, the compartment temperature INOP light illuminates. (Vol 2/2.10)

Question 1

Within the Compartment Temp Controls and Indicators, what does the AUTO mode do?

Answer 1

Provides automatic compartment temperature control. (Vol 2/2.10)

Question 2

On the 767 only, within the Compartment Temp Controls and Indicators, what does the MAN mode do?

Answer 2

Provides manual control of compartment trim air valve, spring loaded to the 6 o’clock position. (Vol 2/ 2.10)

Question 3

What does an amber engine bleed OFF light mean?

Answer 3

Engine bleed air valve is closed:

• automatically due to a system fault,
• the switch is OFF,
• the engine is not running. (Vol 2/ 2.10)

Question 4

What are the indications of a dual auto pressurization controller failure?

Answer 4

AUTO INOP light illuminates amber, AUTO 1 and AUTO 2 cabin altitude control functions are inoperative. (Vol 2/ 2.10 and 2.20)

Question 5

On a 767, what does an amber cargo heat OVHT light mean?

Answer 5

Cargo compartment temperature is above standard control range, and the shutoff valve signaled closed. (Vol 2/ 2.10)

Question 6

What does the trim air system do?

Answer 6

• adds warm air to the pack output air.
• the pack controllers regulate the pack output air temp to satisfy the temp requirement of the compartment requiring the coldest air.
• if the trim air system is off or INOP, the packs attempt to maintain all compartments at an average temperature. (Vol 2/ 2.10 and 2.20)

Question 7

What does the TRIM AIR switch do?

Answer 7

ON- the trim air valve is commanded open.
Off (ON not visible)- the trim air valve is commanded closed.

(Vol 2/ 2.10 and 2.20)

Question 8

What does the Trim Air OFF light mean?

Answer 8

When illuminated amber, the TRIM AIR switch is off. (Vol 2/ 2.10 and 2.20)

Question 9

How does the gasper system work?

Answer 9

It draws air from the forward cabin overhead air conditioning ducts and discharges it from gasper outlets in the passenger service units located above each passenger seat. Gasper air is controlled by the GASPER fan switch. (Vol 2/ 2.20)

Question 10

When must the landing altitude on the pressurization panel be reset?

Answer 10

During a destination change. (Vol 1/NP 20 Vol 2/2.20)

Question 11

What is the purpose of the recirculation fans?

Answer 11

They maintain overall cabin circulation while allowing a reduction of cabin air ventilation, permitting the packs to be operated at a reduced flow. This reduced bleed air demand from the engines, reducing fuel burn. On the 757, the left recirculation fan should not be turned off because of its equipment cooling function. (Vol 2/2.20)

Question 12

How do you manually control the cabin altitude?

Answer 12

Place the cabin altitude mode selector in MAN and rotate the cabin altitude MANUAL control to climb or descend. (Vol 2/2.10)

Question 13

Where is the Bulk Cargo Heat Selector located?

Answer 13

It is located on the accessory panel (only on 767’s)

Vol 1/NP 20, Vol 2/2.10

Question 14

What are the switch positions for the bulk cargo heat selector?

Answer 14

NORM- standard cargo heating range

VENT- provides a warmer compartment temperature than NORM, activates a fan in the bulk cargo compartment. (Vol 1/NP 20, Vol 2/2.10)

Question 15

For all Delta operations, what is the preflight position for the BULK CARGO HEAT selector?

Answer 15

Vent. (Vol 1/NP 20 Vol 2/2.10)

Question 16

In the 767, what does the AUTO position do on the equipment cooling selector?

Answer 16

Automatically controls equipment cooling system.

Vol 2/2.10 and 2.20, QRH/2

Question 17

In the 767, what does the STBY position do on the equipment cooling selector?

Answer 17

Positions equipment cooling system for inboard air flow.

Vol 2/2.10 and 2.20, QRH/2

Question 18

In the 767, what does the OVRD position do on the equipment cooling selector?

Answer 18

Positions equipment cooling system for reverse air flow and arms the NO COOLING light.

(Vol 2/2.10 and 2.20, QRH/2)

Question 19

What does an amber illuminated PACK OFF light mean?

Answer 19

The pack valve is closed, and the pack is off. (Vol 2/2.10 and 2.20)

Question 20

What does an amber illuminated pack INOP light mean?

Answer 20

Either the pack is overheated, or there’s a fault in the automatic control system.

Question 21

What does an amber illuminated gasper OFF light mean?

Answer 21

The gasper fan switch is on, but the gasper fan is not operating. (Vol 2/ 2.10)

Question 22

What does an amber illuminated recirc fan INOP light mean?

Answer 22

Either the recirculation fan is failed or not operating, or the RECIRC FAN switch is off. (Vol 2/ 2.10)

Question 23

On a 757, what does an amber illuminated equipment cooling OVHT light mean?

Answer 23

Insufficient airflow due to:

• either supply fan is inoperative, or
• overboard exhaust valve is closed, with the left recirc fan failed or switched off. (Vol 2/ 2.10)

Question 24

On a 767, what does an amber illuminated equipment cooling OVHT light mean?

Answer 24

High temperature or low airflow in the equipment cooling system. (Vol 2/ 2.10)

Question 25

What does the OFF position on the pack control selector do?

Answer 25

Closes the pack valve. (Vol 2/ 2.10)

Question 26

What does the AUTO position on the pack control selector do?

Answer 26

The pack is automatically controlled. (Vol 2/ 2.10)

Question 27

What do the STANDBY positions on the pack control selector do?

Answer 27

N (normal)- regulates the pack outlet temp to a constant, moderate temperature. C (cool)- sets the pack to full cold operation. W (warm)- sets the pack to full warm operation. NOTE: the automatic controller is bypassed in the standby position.

Question 28

What does a red CABIN ALTITUDE light on the overhead panel or a red CABIN ALT light on the center forward (discrete) panel signify?

Answer 28

Cabin altitude exceeds 10,000ft. Extinguishes when cabin altitude descends below 8,500ft. (Vol 2/ 2.10)

Question 29

How does the cabin altitude auto rate control work?

Answer 29

-only functions if AUTO 1 or AUTO 2 selected -rotating sets limit for cabin altitude rate of climb/descent during auto control -the index mark is the proper preflight position (+500fpm/-300fpm) (Vol 2/ 2.10)

Question 30

On a 767, what does an amber illuminated NO COOLING light mean?

Answer 30

Light is only active when the switch is in OVRD mode. Signifies that there is no reverse airflow through the E/E compartment avionics. (Vol 2/ 2.10)

Question 31

What does an amber illuminated compartment temperature INOP light mean?

Answer 31

-fault in the zone temperature controller -the compartment temperature control is selected OFF -the trim air switch is selected OFF (Vol 2/ 2.10)

Question 32

Why is the center isolation (C ISLN) switch on the 767 guarded?

Answer 32

To protect the air source to the Air Driven Pump (ADP). (Vol 2/ 2.10)

Question 33

What does an amber illuminated DUCT LEAK light mean?

Answer 33

A high temperature bleed air leak is detected. (Vol 2/ 2.10)

Question 34

What does an illuminated BLEED light mean?

Answer 34

"Bleed air malfunction." (Vol 2/ 2.10) The engine bleed air temperature is excessive.

Question 35

What does an illuminated HI STAGE/ OVHT light mean?

Answer 35

"Bleed air malfunction." (Vol 2/ 2.10) The engine bleed system pressure is excessive. The engine high pressure bleed air valve is automatically closed.