Air Filter Maintenance

Dust or some form of dirt is frequently the principal factor in premature piston ring, ring groove and cylinder wear. If a worn or poorly fit air filter allows as much as a tablespoon of abrasive dirt material into the cylinders, it will cause wear to the extent that an overhaul will be required. Evidence of dust or other dirt material in the induction system beyond the air filter is indicative of inadequate filter care or a damaged filter.

One recommendation is keeping ground running to a minimum. It is also recommended that the air filter be cleaned daily when operating in dusty conditions. Otherwise, the filter should be inspected daily and cleaned as required. If there are any holes or tears in the filter or if it shows signs of deterioration, it should be replaced immediately.

To prevent undesirable combustion chamber wear, follow the instructions outlined in the Aircraft and Engine Operator Manuals on filter maintenance procedures. They will stress such recommendations as inspecting the entire air induction system to preclude the introduction of unfiltered air between the filter and fuel injector or carburetor. The manual also recommends inspecting the carburetor heat door, or the alternate air door, to ensure that they are operating correctly and sealing properly. Any accumulation of dirt and dust in or near the entrance of the alternate air door or carburetor heat door, will be drawn into the engine if the above doors are opened. Subsequently, aircraft parked or stored in dusty areas should have the unfiltered section of the induction system ahead of the air door examined and cleaned, if dirty, before use.