Gas Turbine Engine Oil Systems

GAS TURBINE ENGINE OIL SYSTEMS:Lubricating oils for gas turbine engines are usually of the synthetic type low viscosity oils. There are special precautions to be followed when handling synthetic lubricants. As they have high pertinent characteristics. Do not allow the oil to remain in contact with skin for longer time as it may result in physical injury and also do not spoil them on aircraft structure as they dissolve paints, enamels and other materials easily. If synthetic oil is spoiled, it should be cleaned immediately by washing or cleaning with a suitable agent. When changing pr adding oil to a gas turbine engine system, it must be ensured that correct type and grade lubricant is used. Safety precautions given in the aircraft maintenance manual should be adhered strictly.

GAS TURBINE ENGINE LUBRICATION SYSTEM COMPONENTS: i)oil tank ii) Oilpresssure pump iii) Oil filter iv) Magnetic chip detector v)oil scavenge system consists of scavenge pumps vi)oil coolers vii)oil pressure indicator viii)oil temperature indicator ix)oil pressure warning x)oil temperature warning MAINTENANCE PRACTICES ON GAS TURBINE OIL SYSTEMS:Periodic changes of oil are not necessary for gas turbine engines using synthetic lubricants.however,to ensure continued effectiveness of the engine lubricant,two procedures are employed i)filtering of oil ii)oil analysis

I) FILTERING OF OIL: In a typical turbo fan engine oil is filtered every 250 hours of engine operation. Remove the main oil filter and install a filter adapter. The adapter provides inlet and outlet connections by which a 15 micron filter is connected externally to the engine. When the filter has been connected, the engine is operated at medium speed for about 5 minutes. This causes all the engine oil tube passed through the filter, thereby removing even the smallest particles of suspended material. After the filtering operation is completed, install back the system filter which is 40 micron filter.

II) OIL ANALYSIS:

It is an analytical process which when used within certain limits, can be used to identify some engine problems before major problem or damage occurs. The analysis of the oil condition can be divided into two basic areas. The first test determines the amount of weariness in the oil, whereas the second test determines the larger contaminant. The quantity of wear metals in the oil is measured in parts per million. Wear metals are generally smaller than 1 micron. During processing of oil sample, it can be determined whether the metal wear is excessive and what part of engine it has came from. Oil analysis is a good example of preventive maintenance. It is important to take samples frequently and the continuous used of collecting of oil should be absolutely clean and dry. Whenever oil samples are taken, it is necessary to top up the oil tank to make up the loss. Oil sampling records are maintained for a particular engine throughout its operating life.