Department of Transportation May 25, 2007 – Federal Register Recent Federal Regulation Documents

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 a one-time general visual inspection of frames between body station (BS) 360 and BS 907 to determine if certain support brackets of the air conditioning (A/C) outlet extrusions are installed; medium- and high-frequency eddy current inspections for cracking of the frames around the attachment holes of the subject brackets; and repair if necessary. This proposed AD would also require installing new, improved fittings for all support brackets of the A/C outlet extrusions between BS 360 and BS 907. This proposed AD results from numerous reports of multiple cracks in the frames around the attachment holes of certain support brackets of the A/C outlet extrusions. We are proposing this AD to detect and correct frame cracking, which, if not corrected, could lead to a severed frame that, combined with cracking of the skin lap splice above stringer 10, could result in rapid decompression of the airplane.

The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 767 airplanes. This proposed AD would require repetitive replacement of the internal electrical feed-through connectors of the main fuel tank boost pumps. This proposed AD results from a report of cracking in the epoxy potting compound on the internal feed-through connector of the fuel boost pump in the area of the soldered wire connector lugs. We are proposing this AD to prevent a hazardous electrical path from the dry side to the wet side of the fuel boost pump through a cracked feed-through connector, which could create an ignition source on the wet side of the fuel boost pump and lead to subsequent explosion of the fuel tank.

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Bombardier Model DHC-8-400 series airplanes. That AD currently requires inspecting the electrical connectors of the fire bottles for the forward and aft baggage compartments and for the auxiliary power unit (APU) and engine nacelles to determine if they are connected correctly, and doing related investigative and corrective actions if necessary. This new AD adds a requirement to install/modify lanyards, mounts, and clamps to the forward and aft baggage compartment, APU, and engine nacelle fire extinguishing systems. This new AD also requires revising the aircraft maintenance manual to incorporate installation and removal procedures for certain fire bottles and fire extinguisher cartridges. This new AD also adds two airplanes to the applicability. This AD results from reports of the electrical connectors for the fire bottles in the forward and aft baggage compartments, APU, and engine nacelle being cross-connected. We are issuing this AD to detect and correct cross- connection of the fire bottles and to prevent cross-connection, which could result in failure of the fire bottles to discharge and consequent inability to extinguish a fire in the affected areas.

The FAA is superseding an existing airworthiness directive (AD), which applies to all McDonnell Douglas Model 717-200 airplanes. That AD currently requires revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate new removal limits for certain components of the flap system and to reduce the interval of inspections for fatigue cracking of certain principal structural elements (PSEs). This new AD requires revising the ALS of the Instructions for Continued Airworthiness to incorporate reduced initial inspection and repeat inspection intervals for certain PSEs. This AD results from a revised damage tolerance analysis. We are issuing this AD to detect and correct fatigue cracking of certain PSEs, which could adversely affect the structural integrity of the airplane.