Federal Aviation Administration April 26, 2006 – Federal Register Recent Federal Regulation Documents

The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney (PW) JT9D-7R4G2 turbofan engines. This proposed AD would require replacing the old configuration 2nd stage high pressure turbine (HPT) air seal assembly with a new design 2nd stage HPT air seal assembly that increases cooling air flow. This proposed AD results from a report of an uncontained failure of the 2nd stage air seal assembly, caused by the air seal assembly brace disengaging from the air seal, due to insufficient cooling air flow. We are proposing 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.

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 727, 727C, 727-100, and 727-100C series airplanes. This AD requires repetitive inspections for cracks in the body skin and bear strap at the upper and lower hinge cutouts of the mid-cabin galley doorway, along the upper fastener row of the stringer 14R lap splice, and in the doorstop fitting adjacent to the upper hinge cutout; and corrective action if necessary. This AD also provides for optional terminating action for certain inspections. This AD results from reports of skin and bear strap cracking at the upper and lower hinge cutout and along the upper fastener row of the stringer 14R lap splice, and cracking in the doorstop fitting adjacent to the upper hinge cutout. There are also reports of cracking on airplanes previously modified in production to resist such cracking. We are issuing this AD to find and fix fatigue cracking of the fuselage, which could result in reduced structural integrity and consequent rapid decompression of the airplane.