skyblue CBT oil and fuel

Question 1

what does the engine oil system provide?

Answer 1

lubrication of bearings and gearboxes

supplies oil pressure for prop actuation

Question 2

what is the capacity of the main oil tank?

Answer 2

14.4L

Question 3

what is the oil system pressure maintained by the regulator?

Answer 3

55-65 psi

Question 4

where is the oil tank?

Answer 4

intergral with the rear inlet casting

Question 5

what does the single system provide oil to?

Answer 5

reducton gearbox and turbo machinery

Question 6

what are the 2 subsystems that make up the oil system?

Answer 6

presure system and scavenge system

Question 7

what does the gear pump do?

Answer 7

pressurises the system and routes it to a cooler

Question 8

what does the low temperature valve by the pressure gear pump do?

Answer 8

returns oil to the tank to prevent a pressure surge during cold start

Question 9

where is the oil cooler located?

Answer 9

the engine inlet

Question 10

how does the oil cooler cool oil?

Answer 10

inlet air, if a clog develops there is a bypass valve

Question 11

where does oil flow to from the oil cooler?

Answer 11

pressure regulating valve

pressure filter

Question 12

what does the pressure regulating valve do?

Answer 12

maintains a constant oil pressure in relation to the air pressure

Question 13

what opens if the pressure filter gets clogged?

Answer 13

bypass valve

Question 14

what 8 components is oil fed to after the pressure filter?

Answer 14

1. fuel heater
2. fuel cooled oil cooler
3. reduction gearbox
4. oil low pressure switch
5. pressure transducer

6 temp sensor

7. accesory gearbox
8. engine bearing cavitys

Question 15

what does the low pressure switch do?

Answer 15

feeds pressure info to the FWS and EWD

Question 16

when will we get a LO OIL warning?

Answer 16

when oil pressure drops below 40 psi

Question 17

when is the oil pressure switch inhibited?

Answer 17

for 30 seconds during start

Question 18

what does the pressure transducer do?

Answer 18

sends pressure info to the MFD

Question 19

when will be get a OIL TEMP L caution?

Answer 19

when temp is below 0 on the ground

or below 45 when the engine is running with PL greater than 30 degrees

Question 20

when will we get an OIL TEMP H caution?

Answer 20

temp between 125 and 140C

Question 21

when will we get an OIL OVHT?

Answer 21

oil temp greater than 140C

Question 22

what does oil flow through to get to the reduction gearbox?

Answer 22

fuel heater and the fuel cooled oil cooler into the pressurised auxiliary oil tank

Question 23

where does oil flow to after the auxiliary oil tank?

Answer 23

• reduction gearbox
• propeller valve module (PVM)
• electrical feathering pump
• reduction gear train and bearings

Question 24

where is the chip detector installed?

Answer 24

gearbox cavity

Question 25

where does the scavenge pump draw oil to?

Answer 25

anti icing front inlet case and another filter

Question 26

what engine parts are lubricated?

Answer 26

7 bearing cavitys and the engine gearbox

Question 27

how is engine oil scavenged from the engine part?

Answer 27

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)

Question 28

what does the fuel go through prior to the HMU?

Answer 28

fuel heater

Question 29

how is the fuel heated through the heater?

Answer 29

transfers heat from the oil through a heat exchanger. heat is thermostatcally controlled

Question 30

where does the fuel go after the heater and filter?

Answer 30

hp pump

Question 31

what does an ENG FUEL CLOG caution mean?

Answer 31

clog in the high pressure pump filter

Question 32

what are the 2 functions of the HMU?

Answer 32

1. deliver metered pressurised fuel to the engine 2. provide high pressure motive flow to the engine jet pump

Question 33

where is excess fuel sent back to by the HMU?

Answer 33

high pressure pump

Question 34

where is fuel flow sensed?

Answer 34

after the HMU

Question 35

what does the fuel cooled oil cooler do prior to the flow divider?

Answer 35

cools oil via a heat exchanger

Question 36

where does the fuel flow after the fuel cooled oil cooler?

Answer 36

flow divider and nozzles

Question 37

what normally schedules fuel flow

Answer 37

electronic engine control (EEC)

Question 38

what 4 inputs from the flight deck does the EEC use to schedule fuel?

Answer 38

1. power lever angle 2. power management selector 3. position of bleed air valves 4. engine sensor information

Question 39

how is ambient conditions sent to the EEC?

Answer 39

from the ADC

Question 40

what feeds info to the HMU in manual mode when the EEC is unavailable?

Answer 40

power levers through a metering valve assembly

Question 41

how does the EEC command fuel flow to the HMU?

Answer 41

through a stepper motor