DAILY INSPECTION ENGINE COOLING HOSES O
wners/Operators, Pilots and Maintenance personnel should make themselves aware that It is a requirement under RAAus Airworthiness Notice AN270810-1 that all engine cooling hoses are inspected at each daily inspection. If this means taking the cowls off to perform this inspection then please do so. Loss of coolant whilst in-flight can be a hazard to flight safety. RAAus Airworthiness Notices are MANDATORY and are available on-line via the Members Portal under the “Maintenance� menu. We encourage everyone to review them all to determine if they affect you, your aircraft or your operation. Recently, during the 3rd Pre-flight inspection of the day, a student identified a coolant leak from
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the #4 Cylinder head, upper coolant hose mating inlet fitting. The o-ring was replaced and an EGR carried out with no leak evident. Following a short test flight, the fitting was again inspected and found to be weeping. The seat of the cylinder head that houses the o-ring was inspected with a magnifier and a crack was found on the inner shoulder. The aircraft was removed from service and a serviceable cylinder head assembly was obtained from Bert Flood Imports. Cylinder Head replaced IAW the Rotax Maintenance manual and test flown serviceable. So what went wrong?? Hard to say but possibly in the history of this aircraft, we think that someone may have removed the o-ring with a screwdriver or some
