Airworthiness Directive · Amendment 39-17996 · Stabilizers
the Boeing Company Airplanes
This AD applies to all the Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes; certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. This AD was prompted by reports of cracks emanating from the aft-most barrel nut holes of the left and right upper rear spar caps of the horizontal stabilizer. This AD requires repetitive high frequency eddy current (ETHF) inspections for cracks in the areas around the two aft-most barrel nut holes of the upper rear spar caps, and corrective actions if necessary; and repetitive ETHF inspections for cracks in the areas around the two aft- most barrel nut holes of any repaired or replaced upper rear spar cap, and corrective actions if necessary. We are issuing this AD to detect and correct cracks in the horizontal stabilizer, which could propagate until an upper rear spar cap severs, and result in failure of the horizontal stabilizer upper center or aft skin panel and adversely affect the structural integrity of the airplane.
At the applicable compliance time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013; except as provided by paragraph (i) of this AD: Do a high frequency eddy current inspection (ETHF) for cracks in the areas around the two aft-most barrel nut holes of the left and right upper rear spar caps, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013. Thereafter, repeat the ETHF inspection at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013; except as provided by paragraph (i) of this AD. If any cracking is found during any inspection, before further flight, do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013.
For airplanes on which a splice repair or replacement was done, as specified in Boeing Alert Service Bulletin MD80-55A070: At the applicable compliance time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013, do a ETHF inspection for cracks at the two aft-most barrel nut holes of any repaired or replaced upper rear spar cap, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013. Thereafter, repeat the ETHF inspection at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013. If any cracking is found during any inspection, before further flight, do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013.
Where Boeing Alert Service Bulletin MD80-55A070, Revision 1, dated December 17, 2013, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
