Reducing friction losses in an engine is done by taking into consideration circumstances as engine usage, ambient temperature, time of year, location, engine design and selecting the correct oil. The engine manufacturer usually recommends a certain type of oil to use under different circumstances.
Lubricating oil plays an important part in the life of the engine and during maintenance it will be replaced, on certified aircraft the pilot can only replenish it. Without oil the engine would fail within minutes, keeping a watchful eye during flight is therefore important.
This book contains information on the characteristics and specifications of these products and offers guidance on their application.
Detailed specifications in this Aeroshell book on aviation oils.
Excerpt from the document:
Under this heading the more important and known representative aviation uses have been named for each AeroShell Grade, and these are intended to serve as a general indicator of the type of application for which the grade is normally suitable. Further consultation with the component manufacturer is recommended in case of doubt. Whenever an aircraft is certified, all of the oils, greases and hydraulic fluids used on that aircraft are specified for each application point on the type certificate.
The Type Certificate will specify, either by specification number or by specific brand names, those grades which are qualified to be used. The U.S. Federal Aviation Administration (FAA) regulations state that only grades qualified for specific applications can be used in certified aircraft. Therefore it is the responsibility of the aircraft owner or designated representative to determine which grades should be used.
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