These oil filters are installed on, but not limited to Lycoming 320, 360 and 720 series engines.
This Continued Airworthiness Notice (CAN) alerts operators of aircraft fitted with Champion oil filters P/N CFO-100-1 of the difficulty of installing the flat rubber gaskets P/N CFO-203 supplied with oil filter kit P/N CFO-100-1.
This CAN is prompted by six reports of oil leaks occurring between the oil filter housing and the engine case during engine ground runs post oil change. Investigation revealed that the flat rubber gasket P/N CFO-203 had slipped inside the oil filter housing allowing oil to leak. The flat rubber gasket which is part of the latest oil filter kit P/N CFO-100-1 was found to fit loosely inside the cover plate. In comparison the gasket from the oil filter kit P/N CFO-100 was found to be a snug fit. The two gaskets were compared and placed one upon the other and the gasket from the P/N CFO-100 oil filter kit was found to be slightly larger in diameter. The situation was possibly made worse with the flat rubber gasket P/N CFO-203 from the oil filter kit P/N CFO-100-1 being coated with a very slippery silicon type grease.
The CAA is concerned that difficulty of installing these flat rubber gaskets P/N CFO-203 supplied with oil filter kit P/N CFO-100-1 may result in partially unseated gaskets on other aircraft. This could cause loss of engine oil and result in engine failure with the possibility of a forced landing.
When fitting flat rubber gasket P/N CFO-203 supplied with oil filter kit P/N CFO-100-1 install the gasket dry. The gasket should be thoroughly cleaned to remove all traces of the silicon type grease coating before fitting. Also ensure the filter screw is tightened to the torque specified by Champion. Torque values vary depending on the P/N of filter housing.
Inspect engine for oil leaks at every pre-flight. Any oil leaks require further investigation.
Alternatively, modified the aircraft and install a Champion cartridge type CH48 series filter.
All other enquires regarding this CAN should be made to:
Owen Olls
Airworthiness Specialist
Email: ollso@caa.govt.nz
Phone: 04 560 9569
