Airworthiness Directives; Cessna Aircraft Company 170, 172, 175, and 177 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to all Cessna Aircraft Company (Cessna) 170, 172, 175, and 177 series airplanes. This AD requires replacing certain fuel selector valve cams or fuel selector valves that Cessna shipped from December 6, 1998, through May 10, 1999, and prevents the future installation of these fuel selector valve cams or fuel selector valves. This AD allows the pilot to check the logbooks to determine whether one of these fuel selector valve cams or fuel selector valves is installed. This AD results from reports from Cessna that fuel selector valve cams and fuel selector valves were manufactured with control shafts that will not allow both tanks to supply fuel to the engine in certain situations. The actions specified by this AD are intended to prevent an inadequate supply of fuel from reaching the engine because of a fuel selector valve cam or fuel selector valve. This could result in an emergency landing or loss of control of the airplane.