Fundamentals

M15
GAS TURBINE ENGINE
Rev.-ID: 1APR2013
Author: DaC
For Training Purposes Only
ELTT Release: Jun. 04, 2013

M15.10
Lubrication Systems

EASA Part-66
CAT B1

M15.10_B1 E
Training Manual

For training purposes and internal use only.

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Lufthansa Technical Training
GAS TURBINE ENGINE EASA PART-66 M15
LUBRICATION SYSTEMS
M15.10

M15 GAS TURBINE ENGINE

M15.10 LUBRICATION SYSTEMS
FOR TRAINING PURPOSES ONLY!

FRA US/O-5 DaC May 17, 2013 ATA DOC Page 1

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LUBRICATION SYSTEMS System Layout
M15.10

LUBRICATION SYSTEM LAYOUT

Basic Lubrication System

The lubrication system distributes oil to the engine bearing compartments and
the gearboxes.
Most gas turbine engines use a self−contained dry sump lubrication system.
The oil is re-circulated through this system by pumps. The system keeps the oil
in a fit condition to perform its tasks.
The basic lubrication system has four subsystems:
S an oil reservoir and supply system
S a scavenge system
S a vent system
S and a monitoring system.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 01|Intro|L1|A/B1 Page 2

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Figure 1 Basic Lubrication System

HAM US/F SwD 01.04.2008 01|Intro|L1|A/B1 Page 3
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LUBRICATION SYSTEMS System Operation
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SYSTEM OPERATION

Oil Reservoir and Supply System

The oil reservoir and supply system is also called the pressure oil system.
The main components of this system are:
S the oil tank
S the supply lines
S the supply pump
S and the supply filter.
The oil is stored in the oil tank and pumped by the supply pump through the
supply lines to the oil nozzles in the engine bearing compartments and the
gearboxes.
The oil is filtered before it reaches the oil nozzles.
The supply filter is located downstream of the supply pump. The filter removes
any foreign particles from the oil before it reaches the oil nozzles. This prevents
blockage of the nozzles.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 02|Oil Supply Syst|L1|A/B1 Page 4

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Figure 2 Pressure Oil System Schematic

HAM US/F SwD 01.04.2008 02|Oil Supply Syst|L1|A/B1 Page 5
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LUBRICATION SYSTEMS System Operation
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Bearing Compartments with Labyrinth Seals

Another name for bearing compartment is bearing sump.
Here you can see the bearing surrounded by the bearing compartment walls.
The walls prevent any leakage of oil from the bearing compartment.
In this example the oil is sprayed on the bearing by an oil nozzle.
The oil drips off the bearing to the bottom of the bearing compartment and
leaves the bearing compartment via the scavenge oil line. As you can see the
scavenge oil line is connected to the bottom of the bearing compartment.
Seals are used where the shaft passes through the bearing compartment walls.
These can be labyrinth type seals, as you see here, or carbon seals, which you
will see later.
The labyrinth type seals have knife edges, which rotate with the shaft and the
seal land, which is made from a soft abradable material.
The cavities outside the bearing compartments are pressurized with air. This is
necessary for sealing.
The inner seals prevent oil escaping from the bearing compartment. They are
called oil seals.
The outer seals minimize the air escaping from the cavities. They are called air
seals.
The cavity drains normally release air during engine operation. They can also
release any oil that leaks into the cavities if the oil seals are not in good
condition.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 03|Labyr. Seals|L2|B1 Page 6

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Figure 3 Bearing Compartment with Labyrinth Seals

HAM US/F SwD 01.04.2008 03|Labyr. Seals|L2|B1 Page 7
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LUBRICATION SYSTEMS System Operation
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Bearing Compartments with Carbon Seals

Carbon seals are also used to seal the gap between the bearing compartment
walls and the engine shaft.
The main components of a carbon seal are:
S the carbon ring
S the seal seat
S the seal support
S springs
S and the seal ring.
The carbon ring is a static ring of carbon which rubs against the seal seat. The
carbon ring is supported in the seal support. The gap between the carbon ring
and the bearing compartment wall is sealed by a seal ring.
The seal seat is a rotating collar on the engine shaft. The contact face of the
seal seat with the carbon ring has a polished surface. Springs are used to
maintain the contact between the seal seat and the carbon ring.
Seal wear or, for example, vibrations can give an airflow across the carbon
seals into the bearing compartment. Because of this the bearing compartments
must be vented.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 04|Carb. Seals/B1 Page 8

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Oil Nozzle

Part of
Bearing
Compartment
Wall
FOR TRAINING PURPOSES ONLY!

Figure 4 Bearing Compartment with Carbon Seal

HAM US/F SwD 01.04.2008 04|Carb. Seals/B1 Page 9
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LUBRICATION SYSTEMS System Operation
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Bearing Compartments with Carbon Seals

The contact surface of the seal seat is lubricated when the engine is running.
The lubrication of the carbon seals has a number of benefits. It reduces seal
wear leading to a longer service life, the oil removes the heat caused by
friction, and the sealing is improved.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 05|Carb. Seals|L2|B1 Page 10

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Figure 5 Bearing Compartment with Carbon Seal

HAM US/F SwD 01.04.2008 05|Carb. Seals|L2|B1 Page 11
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LUBRICATION SYSTEMS System Operation
M15.10

Scavenge System
The scavenge system is part of every dry sump lubrication system. It returns
the oil from the bearing compartments and the gearboxes to the oil tank.
This prevents the accumulation of lubrication oil in the bearing compartments
and the gearboxes.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 06|Scavenge System|L1|A/B1 Page 12

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Figure 6 Oil Scavenge System

HAM US/F SwD 01.04.2008 06|Scavenge System|L1|A/B1 Page 13
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LUBRICATION SYSTEMS System Operation
M15.10

Scavenge System cont.

The lubrication oil is returned to the oil tank via
S the individual scavenge lines
S the scavenge pumps
S the common scavenge lines
S the scavenge oil filter
S and the oil cooler.
There is a scavenge pump installed in each of the individual scavenge lines.
The scavenge pumps remove the lubrication oil at a faster rate than it is
delivered via the oil nozzles. This prevents the accumulation of oil in the
bearing compartments and the gearbox sumps.
Because of their high capacity the scavenge pumps remove air as well as oil
and therefore send an air/oil foam back to the oil tank.
The scavenge oil filter in the common scavenge line has a very fine filter
element to remove any foreign matter from the scavenge oil. This is the main
filter in the engine lubrication system.
The oil cooler is installed downstream of the filter. The oil cooler removes the
heat from the oil. The oil is ready to be re-circulated after it passes through the
filter and the cooler to the tank.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 07|Scav Sys Compon|L2|B1 Page 14

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Supply Supply
Pump Filter
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Figure 7 Oil Scavenge System

HAM US/F SwD 01.04.2008 07|Scav Sys Compon|L2|B1 Page 15
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LUBRICATION SYSTEMS System Operation
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Vent System
The vent system releases air from the lubrication system to the atmosphere.
Bearing compartments have a vent line to release the sealing air and maintain
the airflow across the seals.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 08|Vent Sys|L1|A/B1 Page 16

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Figure 8 Vent System

HAM US/F SwD 01.04.2008 08|Vent Sys|L1|A/B1 Page 17
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LUBRICATION SYSTEMS System Operation
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Types of Vent Systems

Some systems have vent lines in the engine shaft and some systems have
separate external vent lines.
The vent air leaves the shaft at the rear of the engine. The oil tank is
connected to this vent system via a vent line to the forward bearing
compartment. It is necessary to remove the air which is pumped into the oil
tank with the scavenge oil.
The vent system also supplies air from the forward bearing compartment to the
gearboxes via the radial drive shaft housing. This air is used to replace the air
which is pumped out of the gearboxes with the scavenge oil.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 09|Types of Vent Sys|L2|B1 Page 18

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Figure 9 Vent System (via Engine Shaft)

HAM US/F SwD 01.04.2008 09|Types of Vent Sys|L2|B1 Page 19
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Types of Vent Systems

The second type of vent system has external vent lines from the bearing
compartments. Like the other system the oil tank is connected to this vent
system and air is supplied from the forward bearing compartment to the
gearboxes.
A de−oiler is connected to the end of the vent line. The de−oiler is a centrifugal
air/oil separator driven by the gearbox.
The vent air goes through the de−oiler, before it is released to the atmosphere.
The oil, which is taken out of the vent air by the de-oiler, leaves via the de−oiler
scavenge line. As you can see the de−oiler scavenge line has its own
scavenge pump.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 10|Types of Vent Sy|L2|B1 Page 20

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Figure 10 Vent System (via De-Oiler)

HAM US/F SwD 01.04.2008 10|Types of Vent Sy|L2|B1 Page 21
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Oil System Monitoring

The oil monitoring system measures and indicates oil quantity, oil pressure,
and oil temperature.
The oil monitoring system provides a flight crew warning if the oil pressure
drops below the minimum level or if the scavenge filter becomes clogged.
The monitoring system needs several sensors to detect this information.
The sensors are:
S the oil quantity sensor
S the oil pressure sensor
S the oil temperature sensor
S the low oil pressure switch
S and the filter clogging switch.
Mechanical clogging indicators are used to indicate a clogged filter when the
engine is stopped. They are also called pop−out indicators.
The contamination in the oil can indicate the condition of the lubricated engine
parts. The contamination can be checked by inspecting the filters and by using
magnetic chip detectors.
Magnetic chip detectors are small magnets which are in contact with the
scavenge oil. They collect particles of magnetic metal which are passing
through the oil.
They are usually installed in the individual scavenge lines of each sump. This
makes it easy to isolate the source of the contamination.
The detectors are easily removed for inspection.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 11|Oil Monitoring System|L1|A/B1 Page 22

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Figure 11 Oil Indicating System

HAM US/F SwD 01.04.2008 11|Oil Monitoring System|L1|A/B1 Page 23
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M15.10

OIL SUPPLY SYSTEM

Full Flow System

The full flow system is the simplest type of oil supply system. This system has
no way of regulating the oil pressure.
The oil pressure changes with changes in N2 rotor speeds, changes in oil
temperature, and changes in the flow areas downstream of the supply pump.
The supply pump is driven by the N2 rotor system via the gearbox. At higher
N2 rotor speeds the supply pump produces a higher flow of oil through the
supply lines. This higher flow leads to a higher oil pressure, because the supply
lines have a given flow area. If the N2 rotor speed decreases, the oil pressure
also decreases.
Oil pressure is also influenced by oil temperature. An increase in oil
temperature leads to lower viscosity of the oil.
If we assume a constant N2 speed, then a lower viscosity gives lower flow
resistance and lower oil pressure. In the same way a decrease in oil
temperature leads to higher oil pressure.
The graph on top shows the relationship between oil pressure and N2 rotor
speed. With low oil temperatures the oil pressure is near the upper line of the
operating range, and with high oil temperatures the oil pressure is near the
lower line of the operating range.
You can see that you can have different oil pressures for a given N2.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 01|Full Flow System|L2|B1 Page 24

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Figure 12 Oil Supply Full Flow System

HAM US/F SwD 01.04.2008 01|Full Flow System|L2|B1 Page 25
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Full Flow System

A third reason for changes in oil pressure is changes in the total flow area
downstream of the supply pump.
A clogged oil nozzle, for example, can reduce the total flow area downstream
of the supply pump. This leads to an increase in the oil pressure.
A leakage in the oil system leads to an increase in the total flow area
downstream of the supply pump. This leads to a decrease in the oil pressure.
Normally when we have an external leakage, the decrease in oil pressure
comes with a decrease in oil quantity.
We can also have a special type of leakage which is hard to identify. With this
leakage there is a decrease in oil pressure but no change in oil quantity.
The oil pressure can become too high for the system components. A common
example is when we have very low oil temperature combined with high N2 rotor
speeds.
A pressure relief valve is installed between the delivery side and the suction
side of the supply pump to prevent oil pressure becoming too high.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 02|Full Flow System|L2|B1 Page 26

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Figure 13 Oil Leaks in Full Flow System

HAM US/F SwD 01.04.2008 02|Full Flow System|L2|B1 Page 27
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Constant Pressure System

Sometimes the constant pressure system is called the regulated pressure
system.
The constant pressure system has a pressure regulating valve.
The pressure regulating valve holds the oil pressure to a given design value at
all N2 rotor speeds from idle to maximum.
Changes in oil temperature also have no effect on oil pressure.
The control parameters are the oil pressure in the supply line and the vent
pressure. The difference between the supply pressure and the vent pressure
controls the position of the valve piston against the valve spring.
The position of the piston controls the spill flow of the supply pump from the
delivery side to the suction side. A change in the flow area has the same effect
on pressure as a leak in the full flow system.
The pressure regulating system holds the pressure difference between the oil
pressure and the vent pressure constant. This ensures, that we have the same
flow at all engine speeds.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 03|Constant Press. Syst|L2|B1 Page 28

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Figure 14 Constant Pressure System

HAM US/F SwD 01.04.2008 03|Constant Press. Syst|L2|B1 Page 29
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Advantages and Disadvantages

The full flow system and the constant pressure system are both suitable for the
operation of modern turbofan engines.
The advantages of one system are the disadvantages of the other.
The full flow system is the most commonly used system because of its
simplicity.
Another advantage of this system is that no adjustments are necessary during
maintenance of the engine.
There are two main disadvantages of the full flow system. The first is that this
system needs a large supply pump or a relatively high oil pressure when the
engines are at idle. This leads to very high oil pressures at higher speeds.
The second disadvantage of this system is that we have a significant rise in oil
temperature after a power reduction. The oil removes much of the heat from
the bearings. When the power is reduced, the lower flow rate of the oil causes
the oil temperatures to increase.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 04|Advantages & Page 30

Disadvantages|L2|B1
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Figure 15 Full Flow System Advantages / Disadvantages

HAM US/F SwD 01.04.2008 04|Advantages & Page 31
Disadvantages|L2|B1
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Advantages / Disadvantages cont.

In contrast to the full flow system, the constant pressure system maintains
relatively low oil pressure and has no increase in oil temperature after a power
reduction. This is because the flow rate is kept constant.
However, the constant pressure system is a more complex system and it
requires adjustments during maintenance. In addition the pressure regulating
valve is often a source of trouble.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 05|Advantages & Page 32

Disadvantages|L2|B1
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Figure 16 Constant Pressure System Advantages / Disadvantages

HAM US/F SwD 01.04.2008 05|Advantages & Page 33
Disadvantages|L2|B1
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SYSTEM COMPONENTS

Oil Tank
The oil tank is usually located on the outer surface of the fan case. Sometimes
oil tanks are mounted on the gearbox case.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 01|Oil Tank|L2|B1 Page 34

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Figure 17 Oil Tank Location

HAM US/F SwD 01.04.2008 01|Oil Tank|L2|B1 Page 35
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Oil Tank cont.

The graphic shows an oil tank, which is installed on the fan case. The tank has
three mounts − a front mount, an aft mount, and a top mount. It also has three
supply lines to the lubrication system.
The three lines are
S the pump supply line at the bottom of the tank,
S the scavenge oil line at the top of the tank, and
S the vent line also at the top of the tank.
You will also find the port for the installation of the oil quantity sensor at the top
of the tank.
An anti-siphon device is located in the pump supply line. It interrupts the oil flow
through the supply line after the engine stops. It prevents the oil from flowing
through the supply line to the lowest point in the system.
If we had no anti-siphon device, all the oil could be transferred to the accessory
gearbox.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 02|Oil Tank|L2|B1 Page 36

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Figure 18 Oil Tank and Components

HAM US/F SwD 01.04.2008 02|Oil Tank|L2|B1 Page 37
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Oil Tank cont.

Here you can see an internal view of the oil tank.
Sloshing bulkheads are installed to prevent rapid fluid movements in the tank.
A de−aerator is installed at the inlet for the scavenge oil. This de−aerator
separates the air from the incoming scavenge oil.
As the scavenge oil comes in through a spiral shaped flow path the centrifugal
force holds the oil flow at the outer wall of the tube. The air is separated from
the scavenge oil and moves up through the center of the de−aerator and then
leaves the oil tank via the vent line.
On some engines the oil tank has a pressurization valve at the vent air exit.
The pressurization valve holds the air pressure in the tank above a minimum
level to prevent foam build-up.
But a word of warning. The higher air pressure is present for up to five minutes
after engine shut down. If the tank filler cap is removed during this time hot oil
can spill out of the tank.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 03|Oil Tank|L2|B1 Page 38

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Figure 19 Oil Tank - Internal View

HAM US/F SwD 01.04.2008 03|Oil Tank|L2|B1 Page 39
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Oil Tank cont.

A drain port is located at the bottom of the tank. A screen is installed where the
oil enters the pump supply line.
The screen protects the supply pump if the oil is contaminated with large
particles.
The tank body is usually made from aluminium alloy. It is coated with a layer of
silicone to give it sufficient fire resistance.
To maintain this fire resistance, it is important that the silicone coating is not
damaged.
You can also find non−coated oil tanks. Oil tanks, which are not coated, are
made from materials which are strong enough to maintain this fire resistance.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 04|Oil Tank|L2|B1 Page 40

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Silicone
Layer

Non-coated
Oil Tank

Figure 20 Oil Tank Drain and Coating

HAM US/F SwD 01.04.2008 04|Oil Tank|L2|B1 Page 41
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Oil Tank cont.

The oil tank filler is installed at the rear face of the tank. It is closed by the filler
cap. The filler is surrounded by a scupper, which catches any oil spilled during
servicing and drains it to the engine drain mast.
A strainer and a check valve are installed below the filler cap in the filler.
The check valve prevents the discharge of air and oil through the filler when the
cap is lost during engine operation. The strainer catches any large foreign
particles during servicing.
Oil samples can be taken from the tank via a sampling tube in the strainer.
The oil quantity can be checked at a sight glass on the side face of the tank.
Some tanks use a dip stick for this purpose.
You also find remote filling connections beside the sight glass. These are a
filling port and an overflow port.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 05|Oil Tank|L2|B1 Page 42

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Figure 21 Oil Tank Filler Assembly

HAM US/F SwD 01.04.2008 05|Oil Tank|L2|B1 Page 43
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Oil Pumps
The lubrication system has a supply pump and a number of scavenge pumps.
On modern engines the pumps are usually located on the accessory gearbox.
The supply pump and the scavenge pumps may be installed in separate
housings or in a common housing called a lubrication unit.
All oil pumps are positive displacement pumps.
The main types used are:
S gear pumps,
S gerotor pumps, and
S vane pumps.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 06|Oil Pumps|L2|B1 Page 44

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Figure 22 Supply and Scavenge Pumps

HAM US/F SwD 01.04.2008 06|Oil Pumps|L2|B1 Page 45
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Oil Pumps cont.

The supply pump is usually driven from the gearbox via the drive gear.
In this example the supply pump is a gear type pump with a common housing
for
S the pump,
S the supply filter, and
S the pressure relief valve.
As you can see the oil enters the pump at the lower side and leaves the pump
at the top.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 07|Oil Pumps|L2|B1 Page 46

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Figure 23 Supply Pump

HAM US/F SwD 01.04.2008 07|Oil Pumps|L2|B1 Page 47
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Oil Pumps cont.

Here you see an example of a scavenge pump unit, which houses all the
scavenge pumps of the lubrication system.
The unit housing has connection flanges for the scavenge oil lines from the
bearing compartments, the gearbox sumps, and the de−oiler.
All the scavenge oil flows through a common scavenge line to the scavenge
filter.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 08|Oil Pumps|L2|B1 Page 48

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Figure 24 Scavenge Pump

HAM US/F SwD 01.04.2008 08|Oil Pumps|L2|B1 Page 49
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Oil Pumps cont.

Here you see a typical lubrication unit. This unit houses two filters − the supply
filter and the scavenge filter - and magnetic chip detectors.
The view of the lubrication unit from the other side shows the oil inlets from the
bearing compartments and the gearboxes.
You can also see the connections for the oil supply lines.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 09|Oil Pumps|L2|B1 Page 50

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Figure 25 Lubrication Unit

HAM US/F SwD 01.04.2008 09|Oil Pumps|L2|B1 Page 51
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Oil Pumps cont.

The gerotor type pumps are installed in a row on one shaft.
Screens are installed in the suction line of every oil pump. They remove any
large particles in the oil flowing from the individual scavenge lines to the pump.
The oil usually passes a magnetic chip detector before it reaches the screen.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 10|Oil Pumps|L2|B1 Page 52

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Figure 26 Lubrication Unit - Internal Components

HAM US/F SwD 01.04.2008 10|Oil Pumps|L2|B1 Page 53
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Oil Filter
Filters and screens are used in the lubrication system to clean the oil and to
protect the system. Screens in the suction lines are used to protect the oil
pumps.
In some lubrication systems screens are also used to protect the oil nozzles if
the supply filter is bypassed. These screens are installed in the supply lines
upstream of the oil nozzles.
They are sometimes called last chance filters.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 11|Filter|L2|B1 Page 54

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Figure 27 Last Chance Filters (Screens)

HAM US/F SwD 01.04.2008 11|Filter|L2|B1 Page 55
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Oil Filters cont.

The filters in the lubrication system and the scavenge system may be separate
components, or they may be part of the lubrication unit.
All filters have
S a filter housing,
S a removable cover,
S a filter bypass valve and
S electric clogging indicators.
The cover has a drain plug to drain the oil from the filter housing. It is removed
to take out the filter element.
A filter element with a pleated woven wire mesh is normally used in supply
filters. Some of these filter elements can be reused but they must be cleaned
first.
A filter element with paper as the filtering medium is normally used in scavenge
filters. Paper filter elements are always disposable cartridges.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 12|Filter|L2|B1 Page 56

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Figure 28 Filter Elements

HAM US/F SwD 01.04.2008 12|Filter|L2|B1 Page 57
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Oil Filters cont.

When the filter element is removed, the foreign particles can be washed out
and taken for analysis.
The element itself should be protected from dirt and dust before analysis.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 13|Filte|L2|B1 Page 58

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Figure 29 Filter Inspection

HAM US/F SwD 01.04.2008 13|Filte|L2|B1 Page 59
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Heat Exchangers
The oil cooler in a lubrication system can be installed in the supply line
downstream of the supply pump or in the scavenge line.
If it is installed in the supply line the system is called the hot tank system. The
oil from the bearing compartments is not cooled before it returns to the oil tank.
If the oil cooler is installed in the scavenge line the system is called the cold
tank system. The oil from the bearing compartments is cooled before it returns
to the oil tank.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 14|Heat Exchanger|L2|B1 Page 60

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Figure 30 Hot Tank and Cold Tank Oil Cooler System

HAM US/F SwD 01.04.2008 14|Heat Exchanger|L2|B1 Page 61
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Heat Exchangers cont.

There are two main types of oil cooler used for turbine engines:
S fuel cooled oil coolers and
S air cooled oil coolers.
Most large jet engines use fuel cooled oil coolers as the primary coolers
because they are efficient and small.
Some large jet engines use air cooled oil coolers as secondary coolers to
remove excessive heat from the oil.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 15|Heat Exchanger|L2|B1 Page 62

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Air Cooled
Oil Cooler
FOR TRAINING PURPOSES ONLY!

Figure 31 Main Types of Oil Cooler

HAM US/F SwD 01.04.2008 15|Heat Exchanger|L2|B1 Page 63
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Heat Exchangers cont.

Air cooled oil coolers are usually used on turboprop engines and APUs.
Large air coolers are necessary on these engines, because the fuel flow is low
in relation to the amount of heat to be removed from the oil and the quantity of
oil in these engines is relatively high.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 16|Heat Exchanger|L2|B1 Page 64

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Figure 32 Air Cooled Oil Cooler

HAM US/F SwD 01.04.2008 16|Heat Exchanger|L2|B1 Page 65
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Heat Exchanger cont.

The main components of a typical fuel cooled oil cooler are
S the housing,
S the cover, and
S the core.
The core contains a bundle of tubes. The fuel flows through the tubes and the
oil circulates around them.
If the passage of the oil through the core is clogged, the oil flows through the oil
bypass valve to the exit and if the passage of the fuel is clogged, the fuel flows
through the fuel bypass valve to the exit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 17|Heat Exchanger|L2|B1 Page 66

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Figure 33 Fuel Cooled Oil Cooler

HAM US/F SwD 01.04.2008 17|Heat Exchanger|L2|B1 Page 67
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De-Oiler
The de−oiler is installed in the bearing compartments.
This de−oiler has radial ducts mounted on the engine shaft.
The air/oil mist flows in a radial direction through the ducts into the vent line in
the shaft.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 18|De−oiler|L2|B1 Page 68

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De-Oiler

Figure 34 De-Oiler in Bearing Compartment

HAM US/F SwD 01.04.2008 18|De−oiler|L2|B1 Page 69
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De-Oiler cont.
On some engines the de−oiler is mounted on the gearbox and driven by the
gearbox shaft.
The air/oil mist enters the de−oiler housing and flows through the rotating radial
ducts to the center of the rotor. The oil droplets are thrown out of the rotor and
against the walls of the housing by the centrifugal force. This oil is collected at
the bottom of the housing and then returned to the oil tank via the scavenge
pump. The air from the center of the rotor is vented to the atmosphere via the
vent air outlet.
The small amount of oil released with the air represents the normal oil
consumption of the engine.
The de−oiler operates efficiently when the vent air flow is normal, and is less
efficient when the vent air flow is higher than normal.
If we have a higher vent air flow, then a lower percentage of oil is recovered
from the vent air and there is a risk that the oil consumption can increase
above the maximum limit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 19|De−oiler|L2|B1 Page 70

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Oil
Consumption Higher Range of
Vent Air Flow Leads to
Higher Oil Consumption
FOR TRAINING PURPOSES ONLY!

Figure 35 De-Oiler on Gearbox

HAM US/F SwD 01.04.2008 19|De−oiler|L2|B1 Page 71
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ENGINE OIL MONITORING SYSTEM

Oil Quantity Indication

The oil quantity transmitter in the tank sends the information via a computer,
which performs the measurement, in this example called the engine interface
unit (EIU), to the display units in the cockpit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 01|Oil Qty Indic|L1|A/B1 Page 72

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Figure 36 Oil Quantity Indicating Schematic

HAM US/F SwD 01.04.2008 01|Oil Qty Indic|L1|A/B1 Page 73
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Oil Quantity Indication cont.

The oil quantity transmitter is normally installed at the top of the oil tank.
This allows the transmitter to be changed without draining the tank.
Two types of transmitter are used
S the capacitance type transmitter and
S the reed switch type transmitter.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 02|Oil Qty Indic|L1|A/B1 Page 74

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Figure 37 Different Types of Quantity Transmitter

HAM US/F SwD 01.04.2008 02|Oil Qty Indic|L1|A/B1 Page 75
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Oil Quantity Indication cont.

Here you see the capacitance type transmitter.
The upper part has the electronic components for the capacitance
measurement and an electrical connector.
The lower part, which is immersed in the oil, has two concentric tubes. These
are the two plates of the capacitor.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 03|Oil Qty Transmtr|L2|B1 Page 76

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Figure 38 Capacitance Type Transmitter

HAM US/F SwD 01.04.2008 03|Oil Qty Transmtr|L2|B1 Page 77
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Oil Quantity Indication cont.

The reed type transmitter has a metal tube with a float inside and a multi switch
assembly.
The metal tube has holes to let the oil in from the tank so that the float can
move up and down with the oil level in the tank. The float assembly has
permanent magnets, which activate an internal switch assembly.
The multi switch assembly has a ladder of reed switches connected by
resistors. The magnet in the float always closes the switch nearest to it.
When, for example, the oil tank is full, then the float is at the upper limit of its
travel. The magnet in the float assembly causes the top switch in the ladder to
close. In this situation the resistance in the electrical circuit is at its minimum,
and this gives maximum output voltage from the transmitter.
You have seen that when the oil level falls, the float also falls. The switch
nearest to the float closes and all other switches open.
The electrical resistance in the circuit changes with the switch that is closed
and this gives a corresponding output voltage from the transmitter.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 04|Oil Qty Transmtr|L2|B1 Page 78

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Figure 39 Reed Switch Type Transmitter

HAM US/F SwD 01.04.2008 04|Oil Qty Transmtr|L2|B1 Page 79
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Oil Pressure Indication

The oil pressure transmitter is connected to the oil supply line and to the oil
tank vent line.
The transmitter senses the pressure difference between the total oil pressure in
the oil supply line and the vent pressure in the oil tank.
Oil pressure information is sent from the oil pressure transmitter to the engine
interface unit, which performs the measurement and then to the display unit in
the cockpit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 05|Oil Press Indic|L1|A/B1 Page 80

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Figure 40 Oil Pressure Indication System Schematic

HAM US/F SwD 01.04.2008 05|Oil Press Indic|L1|A/B1 Page 81
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Oil Pressure Sensor

There are two main types of oil pressure transmitters:
S the bourdon tube type and
S the strain gage type.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 06|Oil Press Sensor|L2|B1 Page 82

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Figure 41 Oil Pressure Sensors

HAM US/F SwD 01.04.2008 06|Oil Press Sensor|L2|B1 Page 83
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Low Oil Pressure Switch

An additional pressure switch is used in the engine oil system to initiate a low
oil pressure warning.
The pressure switch is also connected to the oil supply line and the oil tank
vent line.
If the oil pressure decreases below the limit, the low oil pressure switch closes,
a signal is sent to the flight warning computer, and a warning message appears
on the display unit in the cockpit.
Note also, that the engine low oil pressure warning is always accompanied by
an acoustic warning in the cockpit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 07|Low Oil Press Switch|L1|A/B1 Page 84

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Figure 42 Low Oil Pressure Switch

HAM US/F SwD 01.04.2008 07|Low Oil Press Switch|L1|A/B1 Page 85
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Low Oil Pressure Switch cont.

Here you can see the location of the oil pressure transmitter and the low oil
pressure switch on an engine.
In this example they are installed on the fan case in the ten o’clock position.
You can see where each is connected to the oil supply line and the oil tank
vent pressure line.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 08|Low Oil Press Switch|L1|A/B1 Page 86

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Figure 43 Pressure Transmitter & Low Pressure Switch Location

HAM US/F SwD 01.04.2008 08|Low Oil Press Switch|L1|A/B1 Page 87
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Oil Temperature Indication

The location of the oil temperature sensor in the lubrication system depends on
the engine type.
The sensor can be found in the scavenge system, where it senses the hot oil
temperature upstream of the oil cooler, or it can be found in the pressure
system, where it senses the temperature of the cooled oil.
Oil temperature information is sent from the oil temperature sensor to a
computer, which performs the measurement and then to the display unit in the
cockpit.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 09|Oil Temp Indic|L1|A/B1 Page 88

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Figure 44 Oil Temperature Indication

HAM US/F SwD 01.04.2008 09|Oil Temp Indic|L1|A/B1 Page 89
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Oil Temperature Indication cont.

There are two main types of oil temperature sensors:
S the thermocouple and
S the thermistor.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 10|Oil Temp Sensor|L1|A/B1 Page 90

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Figure 45 Oil Temperature Sensor Location

HAM US/F SwD 01.04.2008 10|Oil Temp Sensor|L1|A/B1 Page 91
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Oil Contamination Monitoring

As you already know, the engine oil carries particles from the bearings and the
gears to the filters in the lubrication system.
You can monitor the quantity, the size, and the type of material of these
particles to get some indication of the internal wear of lubricated engine parts.
A process called Spectrometric Oil Analysis Program, or SOAP for short, is
used to find out about internal wear of lubricated engine components.
This SOAP analysis can find particles in the oil, which are so small that they
can not be caught by the oil filters. These particles range in size from 0.001
mm to 0.02 mm.
It is important to monitor the concentration of these particles in the oil to
identify increased wear at an early stage.
Many particles indicate increased wear and knowledge of the material helps to
identify the engine part with increased wear.
Oil samples for SOAP are taken from the oil tank at regular intervals and sent
to the laboratory for analysis.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 11|Oil Contam Monitorg|L1|A/B1 Page 92

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Figure 46 Spectrometric Oil Analysis Program

HAM US/F SwD 01.04.2008 11|Oil Contam Monitorg|L1|A/B1 Page 93
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Oil Contamination Monitoring cont.

The scavenge oil filter element catches larger particles which are of a size of
more than 0.015 mm. These particles can be removed and sent for analysis.
The problem with this is that the filter element is not changed very often and
each filter inspection takes time.
Magnetic chip detectors are an easier and less time consuming method to get
information about the condition of the oil.
Magnetic chip detectors catch metal particles which are attracted to the
magnet. They can be easily removed and the condition can be checked.
The magnetic chip detectors can be manually checked at fixed intervals or on
some modern aircraft they can be electronically monitored and removed when
necessary.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 12|Oil Contam Monitorg|L1|A/B1 Page 94

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Figure 47 Magnetic Chip Detectors

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Oil Contamination Monitoring cont.

Here you see an electronically monitored chip detector, installed in the
scavenge oil line.
This chip detector has two magnets at its tip.
The resistance between the two chip detector magnets is monitored by the
electronic control unit.
The resistance decreases when particles connect with the magnets.
When the resistance between the magnets gets below the limit, the electronic
control unit sends a maintenance message for the post flight report.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 13|Oil Contam Monitorg|L1|A/B1 Page 96

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Figure 48 Electronic Magnetic Chip Detectors

HAM US/F SwD 01.04.2008 13|Oil Contam Monitorg|L1|A/B1 Page 97
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MAINTENANCE PRACTICES

System Servicing
On aircraft the oil quantity in the engines is checked at intervals specified in the
maintenance schedule for the aircraft.
The oil quantity can be checked at the sight gages on the oil tanks of the
engines, or on the ECAM or EICAS displays in the cockpit.
On most engines the oil tank is located above the level of the gearbox.
There is a slow oil flow from the tank to the gearbox due to the siphon effect.
To prevent this, an anti-siphon device is installed.
On engines without anti-siphon it is important to check the oil quantity between
5 and 20 minutes after engine shut-down when all of the oil is in the tank.
The oil can be refilled via the oil tank filler port.
Note, that you must wait at least 5 minutes after engine shut-down before you
open the oil tank filler cap.
If you don’t wait at least 5 minutes after engine shut−down, hot oil can spray
out of the filler port when you open it.
You should also observe the smell of the oil when you open the filler cap.
If you smell fuel, this indicates a leakage in the fuel cooled oil cooler. Further
troubleshooting is required.
FOR TRAINING PURPOSES ONLY!

HAM US/F SwD 01.04.2008 01|System Servicing|L1|A/B1 Page 98

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FOR TRAINING PURPOSES ONLY!

Figure 49 Oil Quantity Check

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System Servicing cont.

You can refill the oil out of oil cans, or you can use an oil servicing system.
If you use oil cans the process is called gravity filling, and if you use an oil
servicing system the process is called pressure filling.
Remember, that you should always make sure that you are using the correct
type and same manufacturer of oil before you refill the tank.
You can find details of the required oil type on a label close to the oil tank filler
cap.
The use of oil cans should be minimized for environmental reasons. If you must
use oil cans, always use new, closed cans and open them immediately before
the filling process.
You should put all empty oil cans in a special disposal container.
FOR TRAINING PURPOSES ONLY!

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LUBRICATION SYSTEMS System Operation
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FOR TRAINING PURPOSES ONLY!

Figure 50 Oil Servicing Methods

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System Servicing cont.

If the oil servicing system is used, the hoses are connected to the pressure fill
port and to the overflow port of the oil tank.
It’s an advantage to use a transparent hose for the overflow port so that you
can see directly when the tank is full.
On tanks with a sight gage, however, you fill the tank until the oil level reaches
the full mark.
You should always check the oil level on the sight gage to prevent an overfill.
An overfill is dangerous, because a large amount of oil can be pumped through
the oil tank vent line into the forward bearing compartment or the de−oiler.
It is important to monitor the oil consumption of the engine.
For this reason you must enter the quantity of oil added to the tank in the
technical log book.
FOR TRAINING PURPOSES ONLY!

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LUBRICATION SYSTEMS System Operation
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FOR TRAINING PURPOSES ONLY!

Figure 51 Oil Servicing

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LUBRICATION SYSTEMS System Operation
M15.10

Soap Sampling
Oil samples are taken from the engine oil tank for the spectrometric oil analysis
program. A plastic bottle with a hose is used to take the oil sample. The hose is
inserted through the sampling tube of the filler assembly into the oil tank.
A number of safety precautions must be observed for SOAP sampling.
S You should always use a new plastic bottle and a new hose to prevent
contamination of the oil.
S Remember to wait at least 5 minutes after engine shut-down before you
open the oil tank filler cap.
S You should wear gloves to protect your hands, because the oil can be hot.
S You must close the bottle and label it immediately after the sample is taken.
The label is necessary to prevent samples getting mixed up.
You can see that the label must have details of:
S the aircraft registration,
S the engine position,
S the engine serial number,
S the station where the sample is taken,
S the date, and
S the time of the sample.
When the label is completed, the sample can be sent for analysis.
FOR TRAINING PURPOSES ONLY!

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LUBRICATION SYSTEMS System Operation
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FOR TRAINING PURPOSES ONLY!

Figure 52 Soap Sampling

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LUBRICATION SYSTEMS System Operation
M15.10

Magnetic Chip Detector Inspection

Magnetic chip detectors are inspected at fixed intervals.
For safety reasons maintenance staff should only check the detectors on one
engine and a cross−check by a second mechanic is required. This is to
minimize the effect of working errors.
A wrong detector installation can lead to a leak in the oil system and an
in-flight shut-down of the engine.
Typically the magnetic chip detectors are designed so that they can be
removed without tools.
Note, that the detectors may be hot from the oil so you should wear gloves to
protect your hands.
You remove the magnetic chip detector by pressing it in and then by turning it
counter clockwise.
When a detector is removed, a check valve closes in the housing to prevent an
oil leakage.
You must handle the magnetic chip detectors with care. Any chips must be
removed with a sheet of paper and secured for analysis and the detector must
be cleaned before you install it again.
FOR TRAINING PURPOSES ONLY!

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LUBRICATION SYSTEMS System Operation
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FOR TRAINING PURPOSES ONLY!

Figure 53 Magnetic Chip Detector Inspection

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LUBRICATION SYSTEMS System Operation
M15.10

Magnetic Chip Detector Inspection cont.

Some chip detectors have two seals:
S a re-usable seal and
S an O−ring.
Other chip detectors just have two O−rings.
The old O−rings in the magnetic chip detectors must be replaced with new
ones to help prevent leakage.
Keep in mind that the most common work error is to forget to install the
O−rings.
You must check, that the detector has engaged correctly.
FOR TRAINING PURPOSES ONLY!

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Lufthansa Technical Training
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LUBRICATION SYSTEMS System Operation
M15.10
FOR TRAINING PURPOSES ONLY!

Figure 54 Magnetic Chip Detector Installation

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M15.10 B1 E

TABLE OF CONTENTS
M15 GAS TURBINE ENGINE . . . . . . . . . . . . . 1 MAGNETIC CHIP DETECTOR INSPECTION . . . . . . . . . 106

M15.10 LUBRICATION SYSTEMS . . . . . . . . . . . . . . . . . 1

LUBRICATION SYSTEM LAYOUT . . . . . . . . . . . . . . . . . . 2
BASIC LUBRICATION SYSTEM . . . . . . . . . . . . . . . . . . . . 2
SYSTEM OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
OIL RESERVOIR AND SUPPLY SYSTEM . . . . . . . . . . . 4
BEARING COMPARTMENTS WITH LABYRINTH SEALS 6
BEARING COMPARTMENTS WITH CARBON SEALS . 8
SCAVENGE SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
VENT SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
TYPES OF VENT SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . 18
OIL SYSTEM MONITORING . . . . . . . . . . . . . . . . . . . . . . . 22
OIL SUPPLY SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
FULL FLOW SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
CONSTANT PRESSURE SYSTEM . . . . . . . . . . . . . . . . . . 28
ADVANTAGES AND DISADVANTAGES . . . . . . . . . . . . . 30
SYSTEM COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . 34
OIL TANK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
OIL PUMPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
OIL FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
HEAT EXCHANGERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
DE-OILER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
ENGINE OIL MONITORING SYSTEM . . . . . . . . . . . . . . . 72
OIL QUANTITY INDICATION . . . . . . . . . . . . . . . . . . . . . . . 72
OIL PRESSURE INDICATION . . . . . . . . . . . . . . . . . . . . . . 80
OIL PRESSURE SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . 82
LOW OIL PRESSURE SWITCH . . . . . . . . . . . . . . . . . . . . 84
OIL TEMPERATURE INDICATION . . . . . . . . . . . . . . . . . . 88
OIL CONTAMINATION MONITORING . . . . . . . . . . . . . . . 92
MAINTENANCE PRACTICES . . . . . . . . . . . . . . . . . . . . . . 98
SYSTEM SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
SOAP SAMPLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

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TABLE OF FIGURES
Figure 1 Basic Lubrication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Figure 36 Oil Quantity Indicating Schematic . . . . . . . . . . . . . . . . . . . . . . . 73
Figure 2 Pressure Oil System Schematic . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 37 Different Types of Quantity Transmitter . . . . . . . . . . . . . . . . . . 75
Figure 3 Bearing Compartment with Labyrinth Seals . . . . . . . . . . . . . . . . 7 Figure 38 Capacitance Type Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Figure 4 Bearing Compartment with Carbon Seal . . . . . . . . . . . . . . . . . . 9 Figure 39 Reed Switch Type Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Figure 5 Bearing Compartment with Carbon Seal . . . . . . . . . . . . . . . . . . 11 Figure 40 Oil Pressure Indication System Schematic . . . . . . . . . . . . . . . 81
Figure 6 Oil Scavenge System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 41 Oil Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Figure 7 Oil Scavenge System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 42 Low Oil Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Figure 8 Vent System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 43 Pressure Transmitter & Low Pressure Switch Location . . . . . 87
Figure 9 Vent System (via Engine Shaft) . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 44 Oil Temperature Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Figure 10 Vent System (via De-Oiler) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 45 Oil Temperature Sensor Location . . . . . . . . . . . . . . . . . . . . . . . 91
Figure 11 Oil Indicating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 46 Spectrometric Oil Analysis Program . . . . . . . . . . . . . . . . . . . . . 93
Figure 12 Oil Supply Full Flow System . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 47 Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Figure 13 Oil Leaks in Full Flow System . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Figure 48 Electronic Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . . 97
Figure 14 Constant Pressure System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Figure 49 Oil Quantity Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Figure 15 Full Flow System Advantages / Disadvantages . . . . . . . . . . . 31 Figure 50 Oil Servicing Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Figure 16 Constant Pressure System Advantages / Disadvantages . . . 33 Figure 51 Oil Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Figure 17 Oil Tank Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 52 Soap Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Figure 18 Oil Tank and Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 53 Magnetic Chip Detector Inspection . . . . . . . . . . . . . . . . . . . . . . 107
Figure 19 Oil Tank - Internal View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Figure 54 Magnetic Chip Detector Installation . . . . . . . . . . . . . . . . . . . . . 109
Figure 20 Oil Tank Drain and Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 21 Oil Tank Filler Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 22 Supply and Scavenge Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Figure 23 Supply Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Figure 24 Scavenge Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 25 Lubrication Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Figure 26 Lubrication Unit - Internal Components . . . . . . . . . . . . . . . . . . 53
Figure 27 Last Chance Filters (Screens) . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 28 Filter Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Figure 29 Filter Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 30 Hot Tank and Cold Tank Oil Cooler System . . . . . . . . . . . . . . 61
Figure 31 Main Types of Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Figure 32 Air Cooled Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Figure 33 Fuel Cooled Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Figure 34 De-Oiler in Bearing Compartment . . . . . . . . . . . . . . . . . . . . . . . 69
Figure 35 De-Oiler on Gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

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