Federal Aviation Administration March 9, 2010 – Federal Register Recent Federal Regulation Documents

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 after being selected open. One event was reported where, due to such problems, the flight crew shut down an engine in-flight and diverted the aircraft. [D]ue to their position on the aircraft, ice may form on actuators P/N 9409122 installed on fuel crossfeed valves and fuel fire shut-off valves. Tests revealed that the ice can prevent the actuator and thus the valve from operating in flight (frozen stuck).

We are adopting a new airworthiness directive (AD) for the products listed above. This 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:

We are adopting a new airworthiness directive (AD) for certain Model 747-100, 747-200B, 747-300, and 747SR series airplanes. This AD requires installation of a closeout panel and moisture curtains for the main equipment center. This AD results from a report of water contamination in the electrical and electronic units in the main equipment center. We are issuing this AD to prevent the malfunction of one or more electrical and electronic units in the main equipment center, which could adversely affect the airplane's continued safe flight.