Low Oil Pressure During Flight - Lycoming IO-390-D Series Installation And Operation Manual

IO-390-D Series Engine Installation and Operation Manual

Low Oil Pressure During Flight

Circumstances which cause loss of oil pressure are many and varied. Therefore, it is difficult to
make a prediction of the extent of damage to the engine or its future reliability. In case of oil
pressure loss or engine operation with oil below the recommended minimum operating level
(identified in Table A-1 in Appendix A), the most conservative action is to remove and
disassemble the engine and completely examine all engine components per instructions in the
IO-390-D Series Engine Maintenance Manual.
NOTICE: Very often a sudden loss of oil pressure also shows a sudden increase in oil
temperature.
Any time oil pressure falls below the minimum level, complete a safe landing of the aircraft as
soon as possible. Identify the root cause of sudden loss of oil pressure according to the
progressive steps identified in Chapters 05-50 and 12-30 of the IO-390-D Series Engine
Maintenance Manual.
NOTICE: Any decision to operate an engine that had a loss of oil pressure without an
inspection must be the responsibility of the agency who is putting the aircraft back
into service.
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March 2020
Engine Conditions
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