Fuel Flashcards
Foreward Fuel Cell capacity
156 gal
1045 lbs
Aft Fuel Cell capacity
220 gal
1474 lbs
Primary fuels used in the helicopter
JP-4, JP-5, and JP-8
Internal fuel cell total capacity is?
376 gal, 2519.2 lb.
What are the fuel cells made of?
The internal fuel cells are crash resistant and self-sealing. The outer and inner layers are made of multiple layers of rubber-impregnated nylon. The intermediate layer consists of uncured rubber that forms the sealant material. The uncured rubber reacts with the fuel whenever the cell is punctured, causing the rubber to swell and seal the hole.
Breakaway valve
The breakaway valves reduce fire hazards by sealing fuel cells and lines in the event of a high-impact landing.
Four Way Check Valves
The four-way check valve, located in the aft fuel cell, provides the following functions:
a) Permits fuel to bypass the boost pump when it is off
b) Allows fuel to flow to the boost pump when it is on
c) Prevents draining of the fuel lines after APU and/or engine shutdown
Nitrogen Inerting System
reduces fire hazard by filling cells with oxygen-depleted air
a. NIU - purges 70% of oxygen from IPAS air, unable to combust
b. Nitrogen Check Valve - allows air to pass from NIU to fuel cells, not fuel back
c. NIU Test Panel - Aft avionics bay, checked on preflight
What does the MP do for the fuel system?
Serves as the primary processing center for the Fuel System management control. Is fully redundant, only one processor is in control at any one time.
Fuel Crossfeed Subsystem
The Fuel Crossfeed Subsystem allows both engines to draw fuel from either internal fuel cell.
Shutoff Valve (SOV)
The crossfeed SOVs are three-way, four-position ball valves that are controlled by the MP based on inputs from the MPD Fuel page, Engine Fire pushbuttons, or Engine Start switches
During engine start, the crossfeed mode for that engine is automatically set to what mode?
AFT
FUEL BOOST PUMP
fuel boost pump (aft fuel cell) provides pressurized fuel and used to increase fuel pressure when manually selected on. The pneumatically driven boost pump pressurizes the fuel line out of the aft cell. Under normal operation, fuel is drawn out of the fuel cells by the main engine fuel pumps.
FUEL TRANSFER Subsystem
The fuel transfer subsystem allows for the transfer of fuel between the internal fuel cells, from the internal auxiliary fuel cell to the internal fuel cells and from the external fuel tanks to the internal fuel cells.
APU FUEL Subsystem
consists of an electrically driven APU boost pump which draws fuel from the aft fuel cell and provides pressurized fuel to the APU. The APU shut-off valve controls the flow of fuel from the aft cell to the APU via the boost pump.
