Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100,-200,-200C,-300,-400, and -500 series airplanes. This AD was prompted by reports of cracks in fuselage frames, and a report of a missing strap that was not installed on a fuselage frame during production. This AD requires an inspection to determine if the strap adjacent to a certain stringer is installed, and repair if it is missing; repetitive inspections of the frame for cracking or a severed frame web; and related investigative and corrective actions if necessary. This AD also provides optional actions to terminate certain repetitive inspections. We are issuing this AD to detect and correct missing fuselage frame straps and frame cracking that can result in severed frames which, with multiple adjacent severed frames, or the combination of a severed frame and fuselage skin chemical mill cracks, can result in uncontrolled decompression of the airplane.