Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 737-600, -700, - 700C, and -800 series airplanes. The existing AD currently requires replacing the point "D" splice fitting between windows number 1 and 2 with a new splice fitting; performing an eddy current inspection for cracking of the holes in the structure common to the new splice fitting, including doing any related investigative actions; and performing corrective actions if necessary. This proposed AD would add repetitive inspections for cracking of the skin just below each splice fitting, and related corrective actions if necessary. This proposed AD results from full-scale fuselage fatigue testing on the splice fitting that failed prior to the design objective on Boeing Model 737-800 series airplanes, and a report of a cracked splice fitting on an operational airplane. We are proposing this AD to prevent cracking of the existing fitting, which may result in cracking through the skin and consequent decompression of the flight cabin.