IPAS

Question 1

What IPAS systems are not temperature regulated?

Answer 1

APU
Starter (Cross Bleed + APU)
Engine cooling louvers
Engine Anti-ice
Utility Receptacle

Question 2

When does the SP command the Engine PRSOVs open?

Answer 2

80% Ng (SP will not override crew selection)

Question 3

When does the SP command Engine PRSOVs close

Answer 3

Engines transition to 80% Ng or APU is on. (SP will override crew selection)

Question 4

Describe manual bleed air control.

Answer 4

SP (receives signal via DP/MUX) - sends command to ELC1/2 (ENG1/2) - monitors ELC - returns fault or sends to DP for MPD

Question 5

How is the engine PRSOV monitored

Answer 5

two position electrical switch monitored by ELC

Question 6

Inlet Anti-Ice Valve operation

Answer 6

solenoid energized closed. failed open 8 psi

no power and no pressure valve is closed.

Question 7

Fuel Boost Pump valve operation

Answer 7

28vdc
electrical position indicator
energized open
failed closed

Question 8

Fuel system pressure regulator psi? Location?

Answer 8

19 +/- 3

On the deck near the low pressure manifold

Question 9

3 components of the ice detector system?

Answer 9

Ice detector sensor
Ice detector signal processor
Ice detector air shut off valve

Question 10

Engine PRSOV psi?

Answer 10

45 - 55 psi

Question 11

Explain engine PRSOV operation.

Answer 11

2 solenoids (on/off and start)
normal ops - both energized
cross-bleed ops - only on/off is energized (27.5 - 35 psi)
28 Vdc switch for on/off monitoring
Downstream (flow sense) pressure connection
operates pneumatic actuator to maintain pressure.

Question 12

Describe ATS starter function.

Answer 12

28 Vdc energizes a solenoid that off seats a ball allows pressurized air through a check valve and reference valve for constant pressure to actuator (butterfly valve)
Single stage axial turbine