skyblue CBT oil and fuel Flashcards
what does the engine oil system provide?
lubrication of bearings and gearboxes
supplies oil pressure for prop actuation
what is the capacity of the main oil tank?
14.4L
what is the oil system pressure maintained by the regulator?
55-65 psi
where is the oil tank?
intergral with the rear inlet casting
what does the single system provide oil to?
reducton gearbox and turbo machinery
what are the 2 subsystems that make up the oil system?
presure system and scavenge system
what does the gear pump do?
pressurises the system and routes it to a cooler
what does the low temperature valve by the pressure gear pump do?
returns oil to the tank to prevent a pressure surge during cold start
where is the oil cooler located?
the engine inlet
how does the oil cooler cool oil?
inlet air, if a clog develops there is a bypass valve
where does oil flow to from the oil cooler?
pressure regulating valve
pressure filter
what does the pressure regulating valve do?
maintains a constant oil pressure in relation to the air pressure
what opens if the pressure filter gets clogged?
bypass valve
what 8 components is oil fed to after the pressure filter?
- fuel heater
- fuel cooled oil cooler
- reduction gearbox
- oil low pressure switch
- pressure transducer
6 temp sensor
- accesory gearbox
- engine bearing cavitys
what does the low pressure switch do?
feeds pressure info to the FWS and EWD
when will we get a LO OIL warning?
when oil pressure drops below 40 psi
when is the oil pressure switch inhibited?
for 30 seconds during start
what does the pressure transducer do?
sends pressure info to the MFD
when will be get a OIL TEMP L caution?
when temp is below 0 on the ground
or below 45 when the engine is running with PL greater than 30 degrees
when will we get an OIL TEMP H caution?
temp between 125 and 140C
when will we get an OIL OVHT?
oil temp greater than 140C
what does oil flow through to get to the reduction gearbox?
fuel heater and the fuel cooled oil cooler into the pressurised auxiliary oil tank
where does oil flow to after the auxiliary oil tank?
- reduction gearbox
- propeller valve module (PVM)
- electrical feathering pump
- reduction gear train and bearings
where is the chip detector installed?
gearbox cavity
where does the scavenge pump draw oil to?
anti icing front inlet case and another filter
what engine parts are lubricated?
7 bearing cavitys and the engine gearbox
how is engine oil scavenged from the engine part?
by gravity from the accesory gearbox and bearing cavitys (cavity 2 is assisted by a jet pump, 6,7 is driven by a scavenge pump)
what does the fuel go through prior to the HMU?
fuel heater
how is the fuel heated through the heater?
transfers heat from the oil through a heat exchanger. heat is thermostatcally controlled
where does the fuel go after the heater and filter?
hp pump
what does an ENG FUEL CLOG caution mean?
clog in the high pressure pump filter
what are the 2 functions of the HMU?
- deliver metered pressurised fuel to the engine
- provide high pressure motive flow to the engine jet pump
where is excess fuel sent back to by the HMU?
high pressure pump
where is fuel flow sensed?
after the HMU
what does the fuel cooled oil cooler do prior to the flow divider?
cools oil via a heat exchanger
where does the fuel flow after the fuel cooled oil cooler?
flow divider and nozzles
what normally schedules fuel flow
electronic engine control (EEC)
what 4 inputs from the flight deck does the EEC use to schedule fuel?
- power lever angle
- power management selector
- position of bleed air valves
- engine sensor information
how is ambient conditions sent to the EEC?
from the ADC
what feeds info to the HMU in manual mode when the EEC is unavailable?
power levers through a metering valve assembly
how does the EEC command fuel flow to the HMU?
through a stepper motor
