Airworthiness Directives; Fokker Services B.V. Model F.28 Mark 0070 and 0100 Airplanes

Riepilogo

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Due to their position on the airplane, fuel fire shut-off valve actuators P/N [part number] 9409122 are susceptible to freezing, which has an adverse effect on the operation of the valve. Also, due to various causes, the failure rate of [fuel fire shut-off valve] actuator P/N 9409122 is higher than expected. Failure or freezing of the actuator may prevent the flight crew to close the fuel fire shut-off valve in case of an engine fire. Due to their position on the aeroplane, fuel crossfeed valve actuators P/N 9409122 are susceptible to freezing, which has an adverse effect on the operation of the valve. This condition, if not corrected, may generate fuel asymmetry alerts when a valve remains in the open position after being selected closed. It may also prevent the flight crew from correcting a fuel asymmetry when a valve remains in the closed position