Airworthiness Directive · Amendment 39-17059 · Stabilizers
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This AD was prompted by reports of corrosion damage on the outer diameter chrome surface of the horizontal stabilizer pivot pins. Micro-cracks in the chrome plating of the pivot pin, some of which extended into the base metal, were also reported. This condition, if not corrected, could result in a fractured horizontal stabilizer pivot pin. This AD requires replacing the existing horizontal stabilizer pivot pins with new or reworked pivot pins having improved corrosion resistance, doing repetitive inspections after installing the pivot pins, and doing corrective actions if necessary. We are issuing this AD to prevent a fractured horizontal stabilizer pivot pin, which may cause excessive horizontal stabilizer freeplay and structural damage significant enough to result in loss of control of the airplane.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012, except as required by paragraph (i) of this AD: Replace the pivot pins of the horizontal stabilizer with new or reworked pivot pins, including replacing the spacer with a new spacer or with one that has been determined to be without corrosion damage or other irregularities; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012: Do detailed inspections for cracks, corrosion damage, or other irregularity of the outer and inner pivot pins; and an ultrasonic inspection for cracking of the outer pivot pins; and do all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012. Corrective actions must be done before further flight. Repeat the inspections at the applicable interval specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012.
Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-55A0018, Revision 1, dated March 6, 2012, specifies a compliance time “after the Revision 1 date of this service bulletin,” this AD requires compliance within the specified compliance time “after the effective date 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.
Aircraft
