Bleed Air

Question 1

What is Bleed Air used for?

Answer 1

A - Air Conditioning
H - Hyd Reservoir
E - Engine Start
A - Anti Ice
P - pressurization

Question 2

Light: Wing Body Overheat

Answer 2

A - Air conditioning Bay (R/L)
L - Leading edge of the inboard wing (R/L)
E - Engine strut (R/L)
A - APU ducting (L only)
K - Keel beam (L only)

Question 3

Light: Pack Trip off

Answer 3

• Pack overtemp
• pack valve closes
• Mix valves drive full closed
• requires reset

Question 4

Simple fault (recall)

Answer 4

G - GPS
S - Speed Trim
P - PSEU
A - Auto slat
M - Mach trim
+800 - Pack
+800 - Zone temp

Question 5

What does the recirc fan do?

Answer 5

Takes pressure off of the pack by recirculating air from the passenger cabin to the mix air manifold to cool the pack with conditioned air

Question 6

Light: Pack (800 only)

Answer 6

• Pack overtemp (requires reset)
• both packs controllers failed
• SRADA failed closed

• light illuminates only on recall when:
- single pack controller fault
- SRADA fault

Question 7

Pack switches

Answer 7

Auto:
- with both packs operating, regulates to low flow
- operating pack regulates to high flow if other pack not operating

• switching to high flow is inhibited:
-on the ground
- in flight with flaps extended

•bleeds off takeoff
- with both engines bleeds off, and APU bleed feeding one pack
•operating pack regulates to high flow
• on the ground and in flight

Question 8

Isolation valve switch

Answer 8

Auto: valve closed unless:
- right pack off
- left pack off
- right engine bleed off
- left engine bleed off

• 4 corner switches off •

Question 9

Overheat test

Answer 9

• tests wing body overheat detector circuits
• illuminates both “wing body overheat” lights along with “master caution” and “air conditioning” panel annunciator

Question 10

Recirc Fan (700)

Answer 10

Auto: Fan will run, unless either pack switch is in high (both pack’s operating’

Question 11

L Recirc Fan (800)

Answer 11

In flight
- fan runs unless either pack is in high
Ground
- fan runs unless both packs are in high

……………………….

                         800 - auto L Recirc fan.                                    R recirc fan
 1…………………….flight………………..  2  (Unless 1 pack in high).         (Runs u less both packs in high)

2………………….ground………………. Runs (Runs unless both packs in high). (Alway runs on ground)

Question 12

Light: Ram Door full open

Answer 12

• ram door full open
  • ram door in full open position
• Will be illuminated
  • on the ground
  • slow flight with flaps extended

Question 13

Light: dual bleed (800)

Answer 13

• Possible back pressure
  • monitors, engine, bleed SWITCH position
  • monitors APU and ISO VALVE position

Left side: left bleed and apu bleed
Right side: right bleed, APU ISO, and ISO valve

Question 14

Light: Duct overheat (700)

Answer 14

• over temperature in distribution duct
• Air max valves drive full cold
• Requires reset (trip reset)

Question 15

Temperature selectors (800)

Answer 15

• automatic temperature control
  • cont cabin: flight deck
  • FWD cabin; forward cabin
  • PASS cabin: passenger cabin

Off

• turns off associated trim air
• temperature selector is ignored by temperature control system

(Hose analogy)

Question 16

Light: zone temp

Answer 16

• light illuminates for:
  •duct overtemp (associated trim air valve closed)
  • requires reset (trip reset)
  • failure of both Cont control cabin primary and standby controllers (dual channel light)
• illuminates on recall only:
  • either cont cabin controller fail (dual channel light)
  • FWD cabin OR aft cabin controller failure