Airworthiness Directive · Amendment 39-16637 · Stabilizers
The Boeing Company Model MD-90-30 Airplanes
This AD applies to all The Boeing Company Model MD-90-30 airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires repetitive inspections for cracking of the left and right upper center skin panels of the horizontal stabilizer, and corrective action if necessary. This AD was prompted by a report of a crack found in the upper skin panel at the aft inboard corner of a right horizontal stabilizer. We are issuing this AD to detect and correct cracks in the upper center skin panels of the horizontal stabilizer. Uncorrected cracks might ultimately lead to the loss of overall structural integrity of the horizontal stabilizer.
Comply with this AD within the compliance times specified, unless already done.
Before the accumulation of 20,000 total flight cycles, or within 3,778 flight cycles after the effective date of this AD, whichever occurs later, do eddy current inspections to detect cracking of the left and right upper center skin panels of the horizontal stabilizer, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010.
(1) If no crack is found during any inspection required by paragraph (g) of this AD, repeat the applicable inspections thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010.
(2) If any crack is found during any inspection required by paragraph (g) of this AD, before further flight, replace the skin panel with a serviceable skin panel, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010. Within 20,000 flight cycles after the replacement, do eddy current inspections as required by paragraph (g) of this AD.
