Federal Aviation Administration May 5, 2009 – Federal Register Recent Federal Regulation Documents

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. This proposed AD would require repetitive lubrications of the right and left main landing gear (MLG) forward trunnion pins. This proposed AD also would require an inspection for discrepancies of the transition radius of the MLG forward trunnion pins, and corrective actions if necessary. For certain airplanes, this proposed AD would also require repetitive detailed inspections for discrepancies (including finish damage, corrosion, pitting, and base metal scratches) of the transition radius of the left and right MLG trunnion pins, and corrective action if necessary. Replacing or overhauling the trunnion pins would terminate the actions required by this AD. This proposed AD results from a report that the protective finishes on the forward trunnion pins for the left and right MLG might have been damaged during final assembly. We are proposing this AD to prevent stress corrosion cracking of the forward trunnion pins, which could result in fracture of the pins and consequent collapse of the MLG.

The FAA is superseding an existing airworthiness directive (AD) for PW JT9D-7R4 series turbofan engines. That AD currently requires removing certain reduced cooling flow 2nd stage high-pressure turbine (HPT) vane assemblies installed in certain 2nd stage HPT vane cluster assemblies. It also requires a visual and a fluorescent penetrant inspection (FPI) of the 2nd stage HPT air seal assembly, part number (P/N) 815097. This AD requires a visual and FPI of all P/N 2nd stage HPT air seal assemblies that were used with reduced cooling flow 2nd stage HPT vane assemblies. This AD results from PW identifying additional P/N air seal assemblies that are affected by the unsafe condition. We are issuing this AD to prevent uncontained failure of the 2nd stage HPT air seal assembly, leading to engine in-flight shutdown and damage to the airplane.