The US FAA proposes new airworthiness directives

Airline Industry Information, Nov 1, 1999

AIRLINE INDUSTRY INFORMATION-(C) 1997-9 M2 COMMUNICATIONS LTD

The US Federal Aviation Administration (FAA) is apparently going to release a new airworthiness directive aimed at toughening maintenance and operating rules for Boeing 777 jet aircraft due to persistent electrical problems. Repeated malfunctions in the dual backup generators on the 777 aircraft have apparently prompted the new directive and the FAA is also considering restricting Boeing 777 aircraft from being used on long over-water flights when both backup generators have recently shown problems or have undergone simultaneous maintenance. The faulty backup generators have already caused flight delays for 777 aircraft according to a report in the Wall Street Journal. The US Federal Aviation Administration (FAA) has proposed the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model Md-11 and MD-11F series aircraft. This AD would require the replacement of the existing terminal strips and supports above the main cabin area and the installation of spacers between terminal strips and mounting brackets in the avionics compartment as applicable. Comments must be received by 13 December. The FAA has also proposed the adoption of a new AD that is applicable to certain McDonnell Douglas Model Dc-8 series aircraft. This AD would require detailed visual and eddy current inspections of the lower wing skin at the three outboard fasteners of the stringer 64 end fitting to detect cracks, and corrective action if necessary. Comments for this AD are also due by 13 December. Again due on 13 December are comments relating to a proposed new AD applicable to certain Boeing Model 737, 757 and 767 series aircraft. This AD would require repetitive inspections of certain motor operated hydraulic shutoff valves to detect malfunctioning and replacement with new valves if necessary. This AD would also require the eventual replacement of certain existing valves with new ones, which would constitute terminating action for the repetitive inspections. A new AD applicable to certain Boeing Model 747 series aircraft equipped with General Electric Model CF6-45 or -50 series engines has been proposed by the FAA. This AD would require repetitive inspections and tests of the thrust reverser control and indication system, and corrective actions if necessary. This AD would also require the installation of a thrust reverser actuation system (TRAS) lock, repetitive functional tests of that installation, and repair if necessary. The installation of the TRAS lock would constitute terminating action for the repetitive inspections and certain tests. Comments must be received by 13 December. A document proposing the adoption of an AD applicable to certain Bombardier Model CL-60011 (CL-600), CL-600-2A12 (CL-601) and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) series aircraft has been released by the FAA. This AD would require for certain aircraft, the removal of the hydraulic tube assemblies from the main landing gear (MLG) bay, the installation of new re-routed hydraulic tube assemblies and the repositioning of a fuel line as applicable. For certain other aircraft this proposal would require a general visual inspection to determine the routing of certain hydraulic and fuel lines, and repair if necessary. Comments are due by 26 November. A new AD has been proposed that is applicable to certain Boeing Model 777 series aircraft. This AD would require replacement of the clevis ends on the tie rods for the centre stowage bin supports with improved clevis ends. Comments are due by 13 December. The FAA has proposed the adoption of a new AD that is applicable to certain McDonnell Douglas Model MD-90-30 series aircraft and requires repetitive flourescent penetrant and magnetic particle inspections to detect fatigue cracking of the main landing gear piston, and repair if necessary. Comments must be received by 13 December. Also due on the above date are comments relating to the adoption of a new AD applicable to certain McDonnell Douglas Model MD-90 series aircraft. This AD would require a one-time detailed visual inspection of certain longerons to detect fatigue cracking and the attachment of frames of the lower left nose, and repair if necessary. The AD would also require the installation of a preventative modification. Again due on 13 December are comments about a new AD proposed by the FAA that is applicable to certain McDonnell Douglas Model DC-8 series aircraft. This AD would require a one-time eddy current conductivity test to determine the material type of the lower cap of the wing front spar, as well as modification of the lower cap of the wing front spar if necessary. The FAA has also proposed the adoption of a new AD that is applicable to all Aerospatiale Model ATR42 and ATR72 series aircraft that would require modification of the alerting capability of the anti-icing advisory system to improve crew awareness of icing conditions. It would also require replacement of the median wing de-icing boots with extended de-icing boots and installation of de-icing boots on the metallic wing leading edge. Comments for this AD must be received by 26 November. Due 26 November are comments relating to a document proposing the supersedure of an existing AD applicable to certain Airbus Industrie Model A300, A310 and A300-600 series aircraft. The existing AD currently requires repetitive deployment tests of the ram air turbine (RAT) and checks of the adjustment of the locking rod, This proposed action would require modification of the RAT, which would terminate the repetitive tests and checks. The FAA has also proposed a document that would supersede an existing AD applicable to all Airbus Model A300 B4-600R and A300 F4-600R series aircraft. This Ad currently requires a one-time visual inspection of the centre tank fuel pumps and fuel pump canister for damage and replacement of damaged fuel pumps and fuel pump canisters with new or serviceable parts. This proposed action would also require repetitive visual inspections of the fuel pumps and repetitive eddy current inspections of the fuel pump canisters as well as replacement of damaged fuel pumps and fuel pump canisters with new or serviceable parts. This document would also reduce the applicability to include only those aircraft that have a trim tank system installed. Comments for this AD must be received by 26 November.