IPAS Flashcards
What does the advisory BLD AIR1 on the EUFD indicate?
The mission processor commanded the engine 1 bleed PRSOV OPEN or CLOSED, and it did not move as directed.
What does the advisory BLD AIR OFF indicate?
Engine one and engine two bleed air have been manually shut off.
What does the advisory BLD AIR HOT indicate?
Mission processor has detected a bleed air overtemperature (> 490°F).
Where are the bleed air controls located?
Aircraft Utility Page or HITT Page
When one or both engines are at 101% Np and the APU is still operating, what supplies pressurized air to the low-pressure manifold?
The APU
When does air from the low-pressure manifold pressurize the primary and utility hydraulic reservoirs?
During APU only operations (no engines running).
Which components control the pressure of high-pressure air?
The Primary and Utility Hydraulic Reservoir Pressure Regulators.
What is the purpose of the Engine No.1 and Engine No. 2 high-pressure check valves?
Backflow of the 5th stage bleed air from engine to engine.
The primary and utility hydraulic reservoir pressure regulators reduce high-pressure bleed air to what pressure?
31± 3 psig.
What does the Environmental Control System (ECS) use IPAS air for?
Heating the crewstations and Air Particle Separator.
What does the Nitrogen Inerting Unit (NIU) do with IPAS air?
The NIU cools, dries, and removes oxygen from IPAS air then routes it to the fuel cells to inhibit explosive vapor build up.
What does the fuel system pressure regulator valve reduce IPAS pressure down to?
19± 3 PSIG.
Which components maintain the pressure of low pressure IPAS air?
Engine bleed air Pressure Regulator and Shutoff Valves (PRSOV)
Which component limits maximum normal bleed air supply temperature to 450ºF (231ºC)?
The bleed air precooler limits maximum normal bleed air supply temperature to 450°F (232°C) by utilizing a 115 Vac vane-axial fan to provide cooling air flow across the heat transfer surface.
When does the APU load control valve open during APU starts?
Closed during the initiation of the APU start sequence and opens when the ECU determines that the APU has reached 95% speed.