Summary
We propose to supersede airworthiness directive (AD) 2005-07- 12 that applies to certain The Boeing Company Model 737-100, -200, - 200C, -300, -400, and -500 series airplanes. AD 2005-07-12 requires detailed and eddy current inspections to detect cracking of the frame web around the cutout for the doorstop intercostal strap at the aft side of the station (STA) 291.5 frame at stringer 16R, and corrective action if necessary. Since we issued AD 2005-07-12, we received reports of new findings of cracking at various locations of the STA 277 to STA 291.5 frames and intercostals, including webs, chords, clips, and shear ties, between stringers 7R and 17R. This proposed AD would add new inspections for cracking at the forward galley door cutout, and corrective actions if necessary. This proposed AD would also reduce a certain inspection threshold required by AD 2005-07-12. We are proposing this AD to detect and correct fatigue cracking of the aft frame and frame support structure ofthe forward galley door, which could result in a severed fuselage frame web, rapid decompression of the airplane, and possible loss of the forward galley door.