BLEED AIR PANEL

Question 1

DESCRIBE THE DUCT MON SYSTEM.

Answer 1

TEST – Performs a continuity check of all the loops associated with the 10th and 14th stage bleed air ducts and simulates a duct air leak. 5 Master Warnings are shown (“5 Ducts and a Goose”).
NORM – Normal operation, leak detection on loops A & B is provided.
LOOP A – Tests Loop A of the 10th stage bleed air to make sure there are no shorts or the loop is not grounded.
LOOP B - Tests Loop B of the 10th stage bleed air to make sure there are no shorts or the loop is not grounded.

Question 1

DESCRIBE THE 14th STAGE ISO SWITCH-LIGHT.

Answer 1

OPEN – Indicated the isolation valve is open. This will allow the L or R side 14th stage bleed air to cross heat the opposite wing for anti-ice operations. This will NOT allow opposite side heating of cowl anti ice.

Question 2

DESCRIBE THE 14th STAGE L/R SWITCH-LIGHTS.

Answer 2

DUCT FAIL – Indicates there is a leak in the associated Duct.
CLOSED – Associated bleed air SOV is closed. When 14th Stage bleed air SOV is closed, the use of reverse thrust and wing/cowl anti-ice is lost.
NOTE: During loss of electrical power (DC BUS 1 & 2) the 14th stage bleed SOV’s fail OPEN.
14th Stage valves are electrically controlled and pneumatically operated. They fail to the open position.

Question 3

DESCRIBE THE APU LCV SWITCH-LIGHT.

Answer 3

FAIL – APU LCV is not in the commanded position.
OPEN – Indicates APU LCV is open, the following conditions must be met:
Switchlight selected in
APU is operating
ENG 10th Stage bleeds closed

Question 4

DESCRIBE THE 10th STAGE L/R SWITCH-LIGHT / FUNCTION.

Answer 4

DUCT FAIL – Indicates there is a leak in the associated Duct.
CLOSED - Associated bleed air SOV is closed. 10th Stage bleed SOV will automatically close after:
Engine shutdown
Start cycle complete
Pack over-temp/press
On side ENG FIRE PUSH is selected
Selected manually
10th Stage valves are electrically controlled and pneumatically operated. They are also spring loaded closed.

Question 5

DESCRIBE THE 10th STAGE ISOL SWITCH-LIGHT.

Answer 5

Open - Indicates the isolation valve is open, either by 1 of 2 ways:
Manually selected
Automatically by the engine start sequence

Question 6

WHEN THE DUCT MON IS IN THE NORMAL POSITION, WHAT IS ITS FUNCTION?

Answer 6

NORM – Normal operation, leak detection on loops A & B is provided.

Question 7

WHEN THE DUCT MON IS IN THE TEST POSITION, WHAT IS ITS FUNCTION?

Answer 7

TEST – Performs a continuity check of all the loops associated with the 10th and 14th stage bleed air ducts and simulates a duct air leak. 5 Master Warnings are shown (“5 Ducts and a Goose”).

Question 8

WHEN THE DUCT MON IS IN THE LOOP A POSITION, WHAT IS ITS FUNCTION?

Answer 8

LOOP A – Tests Loop A of the 10th stage bleed air to make sure there are no shorts or the loop is not grounded.

Question 9

WHEN THE DUCT MON IS IN THE LOOP B POSITION, WHAT IS ITS FUNCTION?

Answer 9

LOOP B - Tests Loop B of the 10th stage bleed air to make sure there are no shorts or the loop is not grounded.

Question 10

HOW ARE THE 14TH STAGE VALVES OPERATED?

Answer 10

14th Stage valves are electrically controlled and pneumatically operated. They fail to the open position.

Question 11

HOW ARE THE 10TH STAGE VALVES OPERATED?

Answer 11

Selected manually

10th Stage valves are electrically controlled and pneumatically operated. They are also spring loaded closed.