Federal Aviation Administration March 16, 2005 – Federal Register Recent Federal Regulation Documents

The FAA proposes to supersede Airworthiness Directive (AD) 2003-14-20, which applies to all AeroSpace Technologies of Australia Pty Ltd. (ASTA) Models N22B and N24A airplanes. AD 2003-14-20 requires you to repetitively inspect, using either dye penetrant or magnetic particle methods, the rudder control lever shafts for cracks; inspect (one-time) all lever shaft side plates by measuring the thickness; and if cracks or discrepancies in thickness are found, replace unserviceable parts with new or serviceable parts. Since AD 2003-14-20 was issued, we determined that the AD should also affect Model N22S airplanes. The manufacturer has also revised the service information to include a rudder control lever shaft part number (P/N) that was not part of AD 2003-14-20. Consequently, this proposed AD would require the actions of AD 2003-14-20, add Model N22S airplanes to the applicability, and add rudder control lever shaft P/N 1/N-45-1102 to the inspection requirements. We are issuing this proposed AD to detect and correct cracks in the rudder control lever torque shafts and discrepancies in the thickness of the lever shaft side plates, which could result in failure of the rudder control lever torque shaft. Such failure could lead to reduced controllability of the airplane.

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This proposed AD would require replacing the fuel shutoff valve wires and conduit assemblies in the left and right engine strut aft fairing areas. This proposed AD is prompted by a report that an operator discovered many small chafe marks and exposed shield braid on fuel shutoff wires routed through a conduit in the wing. We are proposing this AD to prevent exposed wires that could provide an ignition source in a flammable leakage zone and possibly lead to an uncontrolled fire or explosion.

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 757-200 series airplanes. This AD requires modifying the wiring of the test ground signal for the master dim and test system circuit in the flight compartment. This AD is prompted by a report that the master dim and test system circuit does not have wiring separation of the test ground signal for redundant equipment in the flight compartment. We are issuing this AD to prevent a single fault failure during flight, which could result in test patterns instead of the selected radio frequencies showing on the communications panel. These conditions could adversely affect voice and transponder communication capability between the flightcrew and air traffic control, which could result in increased pilot workload.