Fuel & IPAS Flashcards
What does the Fuel System do?
Provides fuel and fuel management provisions to operate both engines and the APU
What is the capacity (gallons/pounds) of the forward fuel cell?
156 gallons
1045 pounds
What is the capacity (gallons/pounds) of the aft fuel cell?
220 gallons
1474 pounds
What is the capacity (gallons/pounds) of the Internal Auxiliary Fuel Cell (Robby Tank)?
100 gallons
670 pounds
The fuel cells and fuel lines are self-sealing against up to what caliber projectile?
Within the 30 minute reserve?
- 5-mm projectile
14. 5-mm projectile (30 min reserve)
Fuel Cell Internal Components
What is the purpose of the Breakaway Valve?
Reduce fire hazards by sealing fuel cells and lines in the event of a high-impact landing.
Fuel Cell Internal Components
How does the fuel cell equalize pressure within the fuel cells; vent contents due to thermal expansion, and/or prevent fuel leakage in the event the helicopter rolls over?
Air Vent / Pressure Release Valve
Fuel Cell Internal Components
If not using pressurized fuel, how can the fuel cells be filled?
Gravity Filler Port
Fuel Cell Internal Components
What is the purpose of the Fuel Level Control Valve Assembly?
Automatically shut off fuel flow into the FWD/AFT cell when full
Fuel Cell Internal Components
How many Fuel Quantity Transmitters are there?
Where is the quantity signal sent to?
Three. Two FWD (due to shape); One AFT
Signal sent to the SP
Fuel Cell Internal Components
What is the purpose of the Four-Way Check Valve?
- Permits fuel to bypass boost pump when it is off
- Allows fuel to flow to boost pump when it is on
- Prevents draining of the fuel lines after APU and/or ENG shutdown
Fuel Cell Internal Components
What component relieves excessive pressure buildup in the fuel lines due to thermal expansion and prevents draining of the fuel lines after engine shutdown?
Check / Thermal Relief Valve
Fuel Cell Internal Components
What is the purpose of the Sump Drain Assembly?
Allows access to obtain fuel samples
How often are fuel samples required?
Before the first flight of the day
What is the maximum airspeed with symmetrically loaded (two or four) external fuel tanks?
130 KTAS
What is the maximum G load factor with symmetrically loaded (two or four) external fuel tanks?
2 G’s
What is the purpose of the Nitrogen Inerting System (NIS)?
Reduces fire hazards by filling the ullage with oxygen-depleted air that will not support combustion.
Where does the NIU receive air from?
IPAS Pressurized Air
What is the indication that the NIU has failed?
NIU Monitor Panel - Black and Three White Triangles
What is the purpose of the Fuel Transfer Subsystem?
Allows for the transfer of fuel between the internal fuel cells (internal) and from the auxiliary fuel tanks to the internal fuel cells (external).
Fuel Transfer Subsystem Components
What controls IPAS pressurized air to the fuel transfer pump?
Fuel Transfer Air Valve
Fuel Transfer Subsystem Components
The IPAS powered, bi-directional fuel transfer pump will move fuel from one cell to the other at a rate of not less than ___ gallons per minute.
4 gallons per minute
How many round-magazine does the 100 gallon combo tank hold?
242 rounds. 58 in the chute for a total of 300 rounds on board
[CAUTION] - FUEL XFER FAIL
What occurred?
One of the following:
- FWD or AFT Fuel SOV Fail
- XFER Pump Air Valve Fail
- XFER Pump Fail
[Advisory] - L EXT XFER FAIL
What occurred?
LH external fuel transfer was commanded to ON or OFF and did not respond to the command.
What are the two fuel transfer modes?
Automatic (SP Control) or Operator Selectable
What is the purpose of the Fuel Crossfeed Subsystem?
Allows both engines to draw fuel from either internal fuel cell. It also provides a positive fuel shutoff during maintenance and emergencies.
The Crossfeed SOVs are ___-way, ___-position ball valves that are controlled by the SP based on inputs from the _____ page, ________, or _______ switches.
The Crossfeed SOVs are 3-way, 4-position ball valves that are controlled by the SP based on inputs from the MPD Fuel page, ENG Fire pushbuttons, or ENG START switches.
Under Normal crossfeed valve position, which engine draws fuel from which tank?
ENG 1 - FWD
ENG 2 - AFT
What will happen to the crossfeed SOV when an ENG 1 or 2 FIRE pushbutton is pressed?
The SP will command the respective Crossfeed SOV to close and cut off fuel.
What is the warning associated with CROSSFEED button selection?
The CROSSFEED button shall be set to NORM position at all times while in flight, unless executing an for FUEL PSI ENG 1 or 2.
[CAUTION] - XFEED 1 VALVE FAIL
What occurred?
The ENG 1 crossfeed valve has been commanded to move and it did not go to the commanded position.
During engine start, the crossfeed is set to what? Why?
Crossfeed is set to AFT for that respective engine because only the AFT Fuel Cell contains a boost pump.
How much fuel is remaining in the FWD tank when the Low-Level Indication is displayed?
240 lb
How much fuel is remaining in the AFT tank when the Low-Level Indication is displayed?
260 lb
[CAUTION] - AFT FUEL LOW
What occurred?
The aft fuel cell level has been detected as less than 260 lb or the analog sensor returns a low indication to the SP.
[CAUTION] - FWD FUEL LOW
What occurred?
The FWD fuel cell level has been detected as less than 240 lb or the analog sensor returns a low indication to the SP.
What is the purpose of the Fuel Quantity Subsystem?
Measures remaining fuel and detects low levels in the internal fuel cells.
What is the purpose of the Fuel Boost Subsystem?
Provide pressurized fuel to the engines.
How is the fuel boost pump powered?
IPAS pressurized air is applied to a motor which drives the pump
When is the fuel boost pump turned on?
1) Auto during ENG START sequence by the SP
2) Manually by operator selection on Fuel Page
[CAUTION] - BOOST PUMP FAIL
What occurred?
The pump was commanded on and it has been detected as off, or commanded off and detected on.
Where does the fuel boost pump draw fuel from?
AFT Fuel Cell
Where does the APU Boost Pump draw fuel from?
AFT Fuel Cell
What drives the APU Boost Pump?
Electrical Power from the battery
[CAUTION] - APU FUEL VALVE
What occurred?
The APU fuel shutoff valve has failed to go to the commanded position.
What is the note associated with radio transmissions during refueling?
Radio transmissions will be limited to emergencies only until refueling has been completed
What is the maximum psi for refueling?
55 psi
What warning is associated with fuel servicing and weather conditions?
Fuel servicing will not be performed during thunderstorms or possible lightning conditions.
[CAUTION] - REFUEL VALVE OPEN
What occurred?
The refuel valve has been detected as open.
Turning the Boost Pump on will command the SP to do what?
- Apply IPAS air IOT power the boost pump
- CROSSFEED AFT
What is the primary IPAS air source when both engines are operating?
Bleed Air from both engines (approx. 50% from each)
Is either engine capable of supplying 100% of the IPAS pressurized air requirement?
Yes
Other than the engines, what are other sources of IPAS air when on the ground?
APU
AGPU
IPAS Low-Pressure Components
The _________ limits the flow of bleed air to 6.5% of the total engine compressor core flow in the event of an IPAS leak.
Low-Pressure Venturi
IPAS Low Pressure Components
Where is the Engine Bleed Air PRSOV located?
Downstream of the fifth stage low-pressure air outlet of each engine
IPAS Low PSI Components
What is the purpose of the Low Pressure Venturi?
In the event of an IPAS leak, it limits the flow of bleed air to 6.5% of the total engine compressor core flow
IPAS Low PSI Components
The _____________ reduces the 45-55 pasig air pressure from the engines and maintains a constant / normal air pressure of 25 +/- 3 psig.
Bleed Air PRSOVs
IPAS Low PSI Components
The ___________ interconnect the PRSOVs to ensure that both engines are supplying an equal amount of bleed air.
Flow Share Sense Lines
IPAS Low PSI Components
Each engine and the APU have ____________ located downstream of the PRSOVs IOT prevent back flow of pressurized air.
Bleed Air Check Valve
IPAS Low PSI Components
The _____________ receives low pressure bleed air from the engine(s) / APU / AGPU and distribute it to the using system and components.
Primary Manifold / Low Pressure Manifold
IPAS Low Pressure Components
The __________ limits max temp of bleed air to 450*C before supplying to components.
Bleed Air Precooler
IPAS Low PSI Components
True / False - When ON, the APU supplies all pressurized air to the IPAS system even when one or both engine(s) are running
TRUE
IPAS Low Pressure Components
When does the APU Load Control Valve open?
When the APU reaches 95% speed
IPAS Low PSI Components
The Bleed Air Over-temperature Switch closes at ___*C, which causes the displays a BLEED AIR HOT advisory to be displayed on the UFD.
490*C
What (8) components are driven by low-pressure IPAS?
ECS, ATS, Fuel System Components, Ice Detector Probe, NIU, Engine Firewall/Cooling, Utility Receptacle, Canopy Defog
What does the ECS use IPAS air for?
Heating crew stations and the Air Particle Separator (APS).
What does the Nitrogen Inverting Unit (NIU) use IPAS air for?
To cool, dry, and remove oxygen from the pressurized air which is then routed to the fuel cells.
What does the fuel system pressure regulator valve reduce IPAS pressure down to?
19 +/- 3 psig
IPAS High PSI Components
What supplies regulated High Pressure IPAS air to the hydraulic system reservoirs?
Hight Pressure Manifold
IPAS High PSI Components
The __________ prevent back flow of high pressure IPAS air to the engines or APU.
High Pressure Check Valves
IPAS High PSI Components
The _________________ reduce high-pressure bleed air to 31 +/- 3 psig for the primary and utility hydraulic reservoirs.
PRI/UTILITY Hydraulic Reservoir Pressure Regulators
Once one or both engines are running, the __________ manifold is pressurized by the engine diffuser. The ___________ manifold is still pressurized by the _____ until it is shut down.
High-Pressure Manifold
Low-Pressure Manifold, APU
When does air from the low-pressure manifold pressurize the primary and utility hydraulic reservoirs?
When only the APU is operating.
When one or both engines are at 101% Np and the APU is still operating, what supplies pressurized air to the low-pressure manifold?
APU
[Advisory] - BLEED AIR HOT
What occurred?
SP detects a bleed air over temperature condition (>490*C)
[Advisory] - ENG 1(2) BLD AIR FAIL
What occurred?
SP commands ENG 1(2) Bleed Air PRSOV OPEN or CLOSED, and it did not move as directed
[Advisory] - BLEED AIR OFF
What occurred?
Bleed Air sources have been manually shut off
