Fuel System Flashcards
What are all of the Components of the Engine Fuel System?
- Fuel Pump
- FCU
- TT2 Temperature Sensor
- Fuel Filter
- Fuel Filter Bypass
- Start Fuel Nozzle
- Fuel Slinger
- Fuel Control Shutoff
Break down the Fuel pump into more detail as described by the AFM.
- 110 - 150 psi out to FCU from 6 - 8 psi input from ejector pump
- 10 micron outlet filter protects high pressure gear element
Filter will bypass at 10 PSID - Part of its fuel outlet is bypassed from the FCU to drive primary ejector pump
What are the five parameters sensed in the FCU?
- p3 or compressor discharge pressure
- Pressure Altitude or ambient pressure TT2
- Compressor inlet temperature
- N2 RPM
- Throttle position
Break down the TT2 Temperature Sensor into more detail as described by the POH.
- Located in bypass duct
- Monitors air temperature and adjusts fuel schedule to optimum levels at maximum N2 setting
Break down the Fuel Filter Bypass into more detail as described by the POH.
- Bypass imminent, 4.5 PSID illuminates Fuel FLTR Bypass annunciator light
- Bypass will occur at 10 PSID
Break down the Start Fuel Nozzle into more detail as described by the POH.
- Receives fuel from FCU
- Continuous 9 PPH whenever engine is running
- Monitored by fuel flow indication system
Break down the Fuel Slinger into more detail as described by the POH.
- Part of HP rotary group
- Fuel supplied to underside of slinger by fuel manifold
- Ejected radially by high pressure and centrifugal force through a series of holes/slots in slinger
Break down the Fuel Control Shutoff into more detail as described by the POH.
- 0.05 rearward stretch of N1 shaft causes FCU to shut off fuel at manifold
- Fuel Flow will terminate within 300 milliseconds
- Will not self reset, maintenance reset only
At what psi is the Fuel pump sending fuel to the FCU?
110-150 psi
What psi is the ejector pump sending fuel initially to the EDFP?
6-8 psi
Why does the fuel transfer valve fail closed when losing all DC power?
Why it fails closed:
Fuel crossfeed is designed so the pilot has full positive control over fuel balance.
If DC power is lost, the valve defaults to closed to prevent unintended fuel transfer that might cause a dangerous fuel imbalance.
