Airworthiness Directive · Amendment 39-18732 · 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), and DC-9-87 (MD-87) airplanes; and Model 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), and DC-9-87 (MD-87) airplanes; and Model MD-88 airplanes. This AD was prompted by a report of fatigue cracking in a rear spar lower cap of the horizontal stabilizer. This AD requires repetitive inspections for cracking of the rear spar lower caps of the horizontal stabilizer, post-modification and post-repair inspections, and corrective actions if necessary. This AD also provides an optional terminating fatigue life enhancement modification. We are issuing this AD to address the unsafe condition on these products.
Except as specified in paragraph (i)(1) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016: Do an open hole high frequency eddy current inspection (HFEC) or surface HFEC inspection for cracking of the rear spar lower caps of the horizontal stabilizer, and do all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, except as specified in paragraph (i)(2) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection thereafter at the applicable interval specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, until accomplishment of the actions provided by paragraph (h) of this AD.
Accomplishment of the fatigue life enhancement modification in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, terminates the repetitive inspections required by paragraph (g) of this AD.
(1) Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, 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.
(2) If any cracking is found during any inspection required by this AD, and Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, specifies to contact Boeing for appropriate action: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
For airplanes on which any modification or repair specified in (g) or (h) of this AD has been done: At the applicable time and intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016, do all applicable post-modification and post-repair inspections and all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-55A072, dated April 8, 2016; except as specified in paragraph (i)(2) of this AD. All applicable corrective actions must be done before further flight.
