Airworthiness Directive · Amendment 39-14711 · Boeing Model 737-700 and 737-800 Series Airplanes
Boeing Model 737-700 and 737-800 Series Airplanes
This AD applies to Boeing Model 737-700 and 737-800 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-700 and 737-800 series airplanes. This AD requires performing a one-time high frequency eddy current inspection for cracking of the backup intercostals located above the cutout for the forward airstair door; doing related investigative and corrective actions if any crack is found; and doing other specified corrective actions if no crack is found. This AD results from a report of fatigue cracks discovered during a full-scale fatigue test conducted by the manufacturer. We are issuing this AD to detect and correct such cracking, which could result in more extensive fatigue cracking and lead to possible loss of cabin pressure.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Before the accumulation of 24,000 total flight cycles, or within 4,500 flight cycles after the effective date of this AD, whichever comes later: Perform a high frequency eddy current (HFEC) inspection for cracking of the backup intercostals located above the cutout for the forward airstair door, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005; and, before further flight, do related investigative actions and applicable corrective actions if any crack is found, and other specified corrective actions if no crack is found. Related investigative actions, applicable corrective actions, and other specified corrective actions must be done in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005; except where the service bulletin specifies to contact Boeing for repair instructions, repair all cracks using a method approved in accordance with the procedures specified in paragraph (h) of this AD.
Actions accomplished before the effective date of this AD in accordance with Boeing Service Bulletin 737-53-1236, dated July 11, 2002, are considered acceptable for compliance with the corresponding requirements of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
