Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 727 airplanes. This proposed AD was prompted by an evaluation by the design approval holder (DAH) indicating that the frame-to-floor beam attachment is subject to widespread fatigue damage (WFD). This proposed AD would require repetitive high frequency eddy current inspections for any crack of the frames at body station (STA) 188 through STA 344, and repair if necessary. We are proposing this AD to detect and correct fatigue cracking at the frame-to-floor beam attachment, on both the left- and right-sides, which could result in reduced structural integrity of the airplane, and decompression of the cabin.