A_M15.10_2008.10.21

Fundamentals eJAMF Module 15.10 Gas Turbine Engine/Lubrication ATA 79

EASA Part-66

A EJAMF M15.10 A E

Issue: 21.10.2008 Author: SwD For Training Purposes Only  LTT 2006

Training Manual

For training purposes and internal use only. by Lufthansa Technical Training (LTT).

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g n i n i a r T l a c i n h c e T a s n a h t f u L

L N O S E S O P R U P G N I N I A R T R O F

M15 GAS TURBINE ENGINE

EJAMF Gas Turbine Engine

MODULE 15

M15.10 LUBRICATION LUBRICATION SYSTEMS SYS TEMS


M15.10 LUBRICATION SYSTEMS BASIC LUBRICATION SYSTEM

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BASIC LUBRICATION LUBRICATION SYSTEM S YSTEM INTRODUCTION 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:  an oil reservoir and supply system  a scavenge system  a vent system  and a monitoring system.

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M15.10 LUBRICATION SYSTEMS BASIC LUBRICATION SYSTEM


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Figu Figure re 1

Bas Basic Lub Lubri rica cati tion on Sy Syste stem


LUBRICATION SYSTEMS BASIC LUBRICATION SYSTEM

MODULE 15 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:  the oil tank  the supply lines the supply pump 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.






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Figure 2

Pressure Oil System Schematic





MODULE 15 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.




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Figure 3

Oil Scavenge System





MODULE 15 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.




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Figure 4

Vent System



MODULE 15 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:  the oil quantity sensor  the oil pressure sensor  the oil temperature sensor the low oil pressure switch 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. ! Y L N O S E S O P R U P G N I N I A R T R O F





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Figure 5

Oil Indicating System



LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM


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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.




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Figure 6

Oil Quantity Indicating Schematic



MODULE 15 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  the capacitance type transmitter and 



the reed switch type transmitter.




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Figure 7

Different Types of Quantity Transmitter





MODULE 15 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.




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Figure 8

Oil Pressure Indication System Schematic



MODULE 15 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.






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Figure 9

Low Oil Pressure Switch





MODULE 15 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.




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Figure 10

Pressure Transmitter & Low Pressure Switch Location





MODULE 15 OIL TEMPERATURE INDIC ATION 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.




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Figure 11

Oil Temperature Indication





MODULE 15 Oil Temperature Indication cont. There are two main types of oil temperature sensors:  the thermocouple and  the thermistor.




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Figure 12

Oil Temperature Sensor Location



MODULE 15 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.






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Figure 13

Spectrometric Oil Analysis Program





MODULE 15 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.




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Figure 14

Magnetic Chip Detectors





MODULE 15 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.




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Figure 15

Electronic Magnetic Chip Detectors


LUBRICATION SYSTEMS MAINTENANCE PRACTICES

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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.






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Figure 16

Oil Quantity Check



MODULE 15 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.






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Figure 17

Oil Servicing Methods



MODULE 15 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.






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Figure 18

Oil Servicing



MODULE 15 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.  You should always use a new plastic bottle and a new hose to prevent contamination of the oil.  Remember to wait at least 5 minutes after engine shut-down before you open the oil tank filler cap.  You should wear gloves to protect your hands, because the oil can be hot.  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:  the aircraft registration,  the engine position,  the engine serial number,  the station where the sample is taken, the date, and the time of the sample. When the label is completed, the sample can be sent for analysis.  






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Figure 19

Soap Sampling





MODULE 15 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.




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Figure 20

Magnetic Chip Detector Inspection



MODULE 15 Magnetic Chip Detector Inspection cont. Some chip detectors have two seals:  a re-usable seal and  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.






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Figure 21

Magnetic Chip Detector Installation

EJAMF M15.10 A E

TABLE OF CONTENTS

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

1

BASIC LUBRICATION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OIL RESERVOIR AND SUPPLY SYSTEM . . . . . . . . . . . SCAVENGE SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VENT SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OIL SYSTEM MONITORING . . . . . . . . . . . . . . . . . . . . . . .

2 2 4 6 8 10

ENGINE OIL MONITORING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . OIL QUANTITY INDICATION . . . . . . . . . . . . . . . . . . . . . . . OIL PRESSURE INDICATION . . . . . . . . . . . . . . . . . . . . . . LOW OIL PRESSURE SWITCH . . . . . . . . . . . . . . . . . . . . OIL TEMPERATURE INDICATION . . . . . . . . . . . . . . . . . . OIL CONTAMINATION MONITORING . . . . . . . . . . . . . . .

12 12 16 18 22 26

MAINTENANCE PRACTICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SYSTEM SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SOAP SAMPLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MAGNETIC CHIP DETECTOR INSPECTION . . . . . . . . .

32 32 38 40

TABLE OF CONTENTS

EJAMF M15.10 A E

TABLE OF FIGURES Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Basic Lubrication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure Oil System Schematic . . . . . . . . . . . . . . . . . . . . . . . . . Oil Scavenge System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vent System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Indicating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Quantity Indicating Schematic . . . . . . . . . . . . . . . . . . . . . . . . Different Types of Quantity Transmitter . . . . . . . . . . . . . . . . . . . Oil Pressure Indication System Schematic . . . . . . . . . . . . . . . . Low Oil Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure Transmitter & Low Pressure Switch Location . . . . . Oil Temperature Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Temperature Sensor Location . . . . . . . . . . . . . . . . . . . . . . . Spectrometric Oil Analysis Program . . . . . . . . . . . . . . . . . . . . . Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electronic Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . . Oil Quantity Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Servicing Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soap Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnetic Chip Detector Inspection . . . . . . . . . . . . . . . . . . . . . . Magnetic Chip Detector Installation . . . . . . . . . . . . . . . . . . . . .

3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43

TABLE OF FIGURES

TABLE OF FIGURES

A_M15.10_2008.10.21

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