LUBRICATION SYSTEMS

Question 1

What type of lubrication System do most gas turbine engines use?

Answer 1

Self contained Dry slump lubrication

Question 2

What sub-systems does the basic lubrication system consist of?

Answer 2

• oil reservoir and supply system
• scavenge System
• vent system
• monitoring system

Question 3

What is the oil reservoir system also know as?

Answer 3

Pressure oil system

Question 4

What components are contained within the pressure oil system?

Answer 4

• oil tank
• supply lines
• supply pump
• supply filter

Question 5

Where is the supply filter located and what is its purpose?

Answer 5

Downstream of supply pump.

- removes foreign particles from oil before it reaches oil nozzles.

Question 6

What is a scavenge System for?

Answer 6

Returning oil from bearing and gearbox components to the oil tank, to prevent accumulation of lubrication.

Question 7

Why is a vent system used?

Answer 7

Releases air from system into the atmosphere.

• air pumped into the forward bearing and gearbox to replace air pumped out by the scavenge System.

Question 8

Why would bearing compartments have a vent system?

Answer 8

Release sealing air and maintain airflow across the seals.

Question 9

What is required when air is pumped into the oil tank by the scavenge System?

Answer 9

Removal of the air.

Question 10

What is the oil monitoring system?

Answer 10

Measures oil quantity, oil pressure and oil temp.

Sends signals to cockpit if pressure low or scavenge filter is blocked

Question 11

What sensors does a oil monitoring system require?

Answer 11

• quantity
• pressure
• temp
• low pressure switch
• clog switch

Question 12

How can contamination in the oil be inspected?

Answer 12

Magnetic chip detectors, inspecting filters

Question 13

Where are magnetic chip detectors located?

Answer 13

Usually on individual scavenge lines to make the source of contamination finding easy.

Question 14

What are the types of quality transmitters and where are they usually located?

Answer 14

• capacitance
• reed

(On top of oil tank so it can be changed without draining the tank)

Question 15

What is the low oil pressure switch warning accompanied with in the cockpit?

Answer 15

An acoustic warning

Question 16

What are the two main types of temperature sensor?

Answer 16

• thermistor

- thermocouple

Question 17

What is Spectrometric Oil Analysis Programme (SOAP) for?

Answer 17

Find about internal wear of lubricated engine components.

Particles between 0.001mm - 0.02mm

Question 18

What size particles does the scavenge oil filter collect?

Answer 18

Larger particles (more than 0.015mm)

Problem with this is that filter does not get changed very often and each inspection takes time.

Question 19

What is an easier and less time consuming method of gaining information about the condition of oil?

Answer 19

Magnetic chip detectors.

Question 20

When does the resistance of the magnetic chop detector decrease?

Answer 20

When particles connect with the magnets.

Electronic control unit sends maintenance message when resistance is too low.

Question 21

Why is there a slow flow of oil from the tank to the gearbox?

Answer 21

Siphon effect (anti-siphon device installed)

Important to check oil quantity between 5-20 mins after engine shutdown.

Question 22

Why is an oil overflow dangerous?

Answer 22

Oil can be pumped into forward bearing compartment of de-oiler.

Question 23

What must always be replaced when removing magnetic chip detectors?

Answer 23

O rings

Or use the reusable seal