Engine Flashcards
The oil system is divided into
Oil pressure and scavenge system
Total loss lubrication system
Oil pressure and scavenge system provides lubrication for
Front bearing
Accessory gearbox
Reduction gearbox
The total loss lubrication system provides lubrication for
Center bearings and rear bearings, through the use of 2 metered pumps.
Oil is then discharged in the atmosphere
OIL PRESS light might appear in normal operations during
Zero or negative g flight
Oil system contains
11pints
Oil tank dimension
13.5pints
Oil qty contained in oil tank
9.5pints
Usable oil qty
6.5pints
Unusable oil qty
3pints
Max and min oil consumption
1.25pint/h and 0.9pint/h
The oil system is capable of ensuring correct engine lubrication for how long?
4h 50min
Oil qty must be checked within ____ from engine shutdown
20mins
The oil pump is connected to the engine via
The accessory gearbox
What does the oil pressure system do?
It lubriacates the front bearings, accessory gearbox and reduction gearbox
What does the oil scavenge system do?
It takes oil used from the pressure system to lubricate, and brings it back to the oil tank
OIL PRESS comes on when
Pressure drops below 0.4bar or above 2.4bar
What is the correct procedure to apply in case of OIL PRESS light?
85% RPM
If OIL PRSS is less than 0.4, then advance throttle 95%RPM for 10 sec, if it doesn’t reach at least 0.3bar, bring it back and maintain 85%RPM
Engine name
Rolls-Royce Viper MK632-43
Viper engine nominal thrust
17.8kN (at sea level under ISA)
BOV blows air when and from where
At low altitudes mainly, from 4th stage of the compressor
In what direction does the engine rotate?
Left (counterclockwise viewed from the back)
Max engine RPM
13760
The Viper is a pure turbojet based on what cycle?
Brayton Cycle
What is the peculiarity of Brayton Cycle?
It is an open cycle (since the engine is open)
With the engine windmilling, what is the only system attached to the gearbox still providing enough pressure?
The hydraulic pump
What are the utilities attached to the accessory gearbox?
GEN1
GEN2
HYD PUMP
High pressure fuel pump
Oil pump
Tachometer generator
What is the function of the nose bullet at the early stage of the compressor?
To let the air smoothly flow into the engine, and not becoming turbulent (otherwise compressor stall)
Describe Viper structure
Air intakes
Nose bullet
Airflow stabilizers (3)
8 stages compressor
Annular combustion chamber
2 stages turbine
Exhaust cone
Jet pipe
How many trimmers are there in the exhaust cone? What is their function?
6
Their function is to stabilize the air going out of the turbine and not become turbulent
Viper compression ratio
5,9:1
In the engine fuel system the RRV (Rate Reset Valve) function is to
Prevent fuel pressure variation coming out from high pressure fuel pump
Describe engine fuel system operation
Booster pump
LP filter
Engine Driven pump (RPM governor, RRV)
BFCU (EPC)
AFRC
Fuel flow transmitter
Pressure increase valve
6 atomizers
12 burners (24 nozzles)
What does the BFCU do?
- It controls the fuel pressure and qty to deliver to the AFRC according to:
- Engine Throttle position
- EPC - It regulates engine idling
- It incorporates the 2 fuel cocks connected to the throttle
The JPT LMTR system consists of
4 thermocouples (also used for JPT indicator)
JPTLA
EPC