Airworthiness Directive · Amendment 39-18204 · Flight controls
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.
(1) Model 747-8 and 747-8F series airplanes, as identified in Boeing Alert Service Bulletin 747-27A2506, dated February 3, 2014.
(2) Model 747-8 and 747-8F series airplanes, as identified in Boeing Service Bulletin 747-27A2513, Revision 1, dated July 18, 2014.
(3) Model 747-8 series airplanes that are operated less than 1,200 flight hours per calendar year.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-8 and 747-8F series airplanes. This AD was prompted by an analysis, which indicated that in a limited flight envelope with specific conditions, divergent flutter could occur during a high g-load maneuver in combination with certain system failures. This AD requires replacing the lateral control electronic (LCE) modules, replacing the inboard elevator power control packages (PCPs), installing new external compensators for the PCPs, and revising the maintenance or inspection program. We are issuing this AD to prevent certain system failures from resulting in divergent flutter, and subsequent loss of continued safe flight and landing.
For airplanes identified in paragraph (c)(1) of this AD: Within 12 months after the effective date of this AD, replace the LCE modules with new LCE modules having revised software, and do an operational test of the LCE modules, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-27A2506, dated February 3, 2014. If the operational test fails, before further flight, do corrective actions and repeat the operational test and applicable corrective actions until the operational test passes.
For airplanes identified in paragraph (c)(2) of this AD: Within 60 months after the effective date of this AD, replace both inboard elevator PCPs with new PCPs that have the internal compensators removed, install two larger external compensators for each PCP, and do an operational test of each inboard elevator PCP, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-27A2513, Revision 1, dated July 18, 2014. If the operational test fails, before further flight, do corrective actions and repeat the operational test and applicable corrective actions until the operational test passes.
For all airplanes: Within 90 days after the effective date of this AD, revise the maintenance or inspection program, as applicable, to incorporate Item Numbers 27-CMR-10, “Lubricate inboard elevator hinge bearings,” and 27-CMR-11, “Functional check of inboard elevator hinge bearing and power control unit rod end bearing free play,” of Section G., “CMR Tasks,” of the Boeing 747-8/8F Certification Maintenance Requirements (CMRs) Document D011U721-02-03, Revision December 2013. The initial compliance times and repetitive intervals for the lubrication and functional check are specified in paragraphs (i)(1) and (i)(2) of this AD.
(1) For airplanes identified in paragraphs (c)(1) and (c)(2) of this AD that are not identified in paragraph (c)(3) of this AD:
(i) The initial compliance time for the lubrication of the inboard elevator hinge bearings is within 18 months after the most recent lubrication. The repetitive lubrication intervals are specified in Item Number 27-CMR-10, “Lubricate inboard elevator hinge bearings,” of Section G., “CMR Tasks,” of the Boeing 747-8/8F Certification Maintenance Requirements (CMRs) Document D011U721-02-03, Revision December 2013.
(ii) The initial compliance time for the functional check of the inboard elevator hinge bearing and power control unit rod end bearing freeplay is within 12 months after the effective date of this AD. The repetitive functional check intervals are specified in Item Number 27-CMR-11, “Functional check of inboard elevator hinge bearing and power control unit rod end bearing free play,” of Section G., “CMR Tasks,” of the Boeing 747-8/8F Certification Maintenance Requirements, D011U721-02-03, Revision December 2013.
(2) For airplanes identified in paragraph (c)(3) of this AD:
(i) The initial compliance time for the lubrication of the inboard elevator hinge bearings is within 24 months after the most recent lubrication. Repeat the lubrication thereafter at intervals not to exceed 24 months.
(ii) The initial compliance time for the functional check of the inboard elevator hinge bearing and power control unit rod end bearing freeplay is within 36 months after the effective date of this AD. Repeat the functional check thereafter at intervals not to exceed 36 months.
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
