Airworthiness Directives; Aviat Aircraft Inc. Airplanes

We are adopting a new airworthiness directive (AD) for certain Aviat Aircraft Inc. Models A-1C-180 and A-1C-200 airplanes equipped with a Rapco part number RA1798-00-1 fuel vent check valve installed on either wing or both. This AD was prompted by a report that the fuel tank vent check valves are sticking in the closed position causing fuel starvation to the engine. This AD requires revision of the airplane flight manual (AFM) to add a pre-flight check of the fuel vent check valves for proper operation and replacing any inoperative fuel vent check valve with an airworthy part. We are issuing this AD to address the unsafe condition on these products.