Book 3 - Lubrication Systems

Question 1

the requirements of a lubricating oil are to:

• lubricate
• cool
• prevent ________
• resist ________ at high temperatures
• possess suitable viscosity at all operating __________

Answer 1

the requirements of a lubricating oil are to:

• lubricate
• cool
• prevent CORROSION
• resist OXIDATION at high temperatures
• possess suitable viscosity at all operating CONDITIONS

Question 2

gas turbines use ___ viscosity synthetic oil that is produced entirely in a factory

Answer 2

gas turbines use LOW viscosity synthetic oil that is produced entirely in a factory

Question 3

viscosity of an oil is its _________ to flow

Answer 3

viscosity of an oil is its RESISTANCE to flow

Question 4

due to low viscosity oils, GTE starts are possible at -__ celsius

Answer 4

due to low viscosity oils, GTE starts are possible at -40 celsius

Question 5

there are two types of oil system, re-________ and total ____

of the re-circulatory type, there are two systems:

• the pressure ______ valve system
• the full ____ system

the main difference between the re-circulatory systems is the control of oil flow to the bearings

temperature and oil pressure readings will be displayed in the _______ for both re-circulatory systems

Answer 5

there are two types of oil system, re-CIRCULATORY and total LOSS

of the re-circulatory type, there are two systems:

• the pressure RELIEF valve system
• the full FLOW system

the main difference between the re-circulatory systems is the control of oil flow to the bearings

temperature and oil pressure readings will be displayed in the COCKPIT for both re-circulatory systems

Question 6

in a pressure relief valve oil system, the oil flow to the bearings is controlled by limiting the max _______ in the feed line

this is achieved using a system ______ valve

when a specific engine speed is reached, feed oil pressure will overcome the spring and spill excess oil back to ____

this maintains a constant pressure and flow to the bearings at _______ engine speeds

in some systems, including a FCOC, a PMV is fitted to ensure oil pressure is always ______ than fuel pressure

Answer 6

in a pressure relief valve oil system, the oil flow to the bearings is controlled by limiting the max PRESSURE in the feed line

this is achieved using a system RELIEF valve

when a specific engine speed is reached, feed oil pressure will overcome the spring and spill excess oil back to TANK

this maintains a constant pressure and flow to the bearings at HIGHER engine speeds

in some systems, including a FCOC, a PMV is fitted to ensure oil pressure is always HIGHER than fuel pressure

Question 7

in a full flow oil system, the oil flow to the bearings is determined by the speed of the pressure ____, the size of the oil jets and the pressure in each bearing housing

also, a ________ spill of oil back to the tank, which together with the oil jets, is _________ to match pump output. this ensures that the oil flow requirements of the bearing are met at all engine _______

instead of a pressure filter by-pass valve, this system has a __________ pressure switch which senses the pressure ____ across the filter and gives _______ warning of a blocked filter in the cockpit

Answer 7

in a full flow oil system, the oil flow to the bearings is determined by the speed of the pressure PUMP, the size of the oil jets and the pressure in each bearing housing

also, a METERED spill of oil back to the tank, which together with the oil jets, is METERED to match pump output. this ensures that the oil flow requirements of the bearing are met at all engine SPEEDS

instead of a pressure filter by-pass valve, this system has a DIFFERENTIAL pressure switch which senses the pressure DROP across the filter and gives ADVANCED warning of a blocked filter in the cockpit

Question 8

total loss oil systems are only used for engines that run for _____ periods, e.g. _______ lift and booster engines

the system is ______ and of low weight because it requires no oil ______, scavenge pump or filters

oil flow can be ________ or delivered in shots

oil is then ejected into the main gas stream via an ejector nozzle

Answer 8

total loss oil systems are only used for engines that run for SHORT periods, e.g. VERTICAL lift and booster engines

the system is SIMPLE and of low weight because it requires no oil COOLER, scavenge pump or filters

oil flow can be CONTINUOUS or delivered in shots

oil is then ejected into the main gas stream via an ejector nozzle