Jeppesen Oral- Chapter 7 (Engine Fuel and Fuel Metering) Flashcards
Bleed air and engine lubricating oil
float-type carburetors, pressure injection carburetors and direct fuel injection systems
controls the fuel/air mixture
Excessively rich mixture
Provides immediate and brief flow of fuel flow in venturi to enrich mixture
Power enrichment system that provides richer mixture at high power settings, where the excess fuel helps in engine cooling .Functions are settings above cruise power
The engine is operating normally
To clear the engine
Engine driven fuel pump
Engine shuts off
A sealed brass aneroid capsule is connected to the fuel metering system, and expands and contracts with changes in pressure and temperature, adjusting the mixture accordingly
Less danger of induction icing Better acceleration Better fuel distribution Better fuel economy Not limited in maneuvers
They automatically meter fuel to the engine
Hydro-mechanical and electronic
power lever position, engine rpm, compressor inlet temperature, compressor inlet pressure, compressor discharge pressure, burner pressure
Electronic control unit and the hydro mechanical fuel control
Better fuel economy, improved starts, requires no engine trimming, provides constant idle speeds regardless of ambient conditions
They inject fuel into the combustion area
EPR or RPM
Fuel SPG, idle rpm, maximum rpm, max EPR
variable displacement pump
Fuel strainer
Returns excess fuel to the inlet side of the pump
rotary vane pump
Supply pressurized fuel to the fuel pump which helps prevent vapor lock and cavitation
centrifugal type
Caused by insuficne t fuel pressure, high fuel temperatures which may block fuel to the engine
Provides continous supply of fuel and proper pressure while engine is running
constant and variable displacement
Constant displacement
leaks and secure mounting
If one element seizes, a portion of the dirve shaft seizes and allows the other element to continue
Fuel filter is most likely. Fuel heaters which use oil heat heat exchanges or bleed air to warm
Allows fuel to flow to the engine when the filter becomes blocked
Discharges two different fuel patterns. The spray pattern is wider at engine start up and narrows when engine speed is above idle
Pressurizing portion provides primary and secondary fuel flow to dual-line duplex fuel nozzles Dump portion allows fuel to drain from the manifolds after engine shutdown
Allow tank and engine selection, provides means for shutting off fuel flow
