Airworthiness Directive · Amendment 39-18411 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the skin lap splices at certain stringers in certain fuselage sections are subject to widespread fatigue damage (WFD) on aging Model 777 airplanes that have accumulated at least 45,000 total flight cycles. This AD requires inspections to detect cracking of fuselage skin lap splices in certain fuselage sections, and corrective actions if necessary; modification of left-side and right-side lap splices; and post-modification repetitive inspections for cracks in the modified lap splices, and corrective actions if necessary. We are issuing this AD to detect and correct fatigue cracking of the skin lap splices, and consequent risk of sudden decompression and the inability to sustain limit flight and pressure loads.
Except as provided by paragraph (h)(1) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014: Do Part 1, inspection “A,” of the modification area for cracks; Part 2, inspection “B,” of the modification area for cracks; and Part 3, inspection “C,” of the modification area for scribe lines and cracks; as applicable; and do all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, except as provided by paragraph (h)(2) of this AD. Do all applicable corrective actions before further flight.
(1) Inspection “A” includes an external phased array ultrasonic inspection for cracks in the lower/overlapped skin of the stringer S-14 left and right (L/R) lap splices between fuselage station 655 and station 1434, and an open hole high frequency eddy current (HFEC) inspection for skin cracks at the upper and lower fastener rows of the stringer S-14 L/R lap splices.
(2) Inspection “B” includes the inspections specified in paragraphs (g)(2)(i) through (g)(2)(iv) of this AD.
(i) A detailed inspection for cracks of any skin panel common to a stringer S-14 L/R lap splice between fuselage station 655 and station 1434 that has a scribe line 0.001 inch or deeper.
(ii) Either an ultrasonic inspection or a surface HFEC inspection for cracks (depending on the location of the scribe line(s)) of any skin panel common to a stringer S-14 L/R lap splice between fuselage station 655 and station 1434 that has a scribe line 0.001 inch or deeper.
(iii) An external phased array ultrasonic inspection for cracks in the lower/overlapped skin of the stringer S-14 L/R lap splices between fuselage station 655 and station 1434.
(iv) An open hole HFEC inspection for skin cracks at the upper and lower fastener rows of the stringer S-14 L/R lap splices.
(3) Inspection “C” includes the inspections for scribe lines and cracks specified in paragraphs (g)(3)(i), (g)(3)(ii), and (g)(3)(iii) of this AD on stringer S-14 L/R lap splice between fuselage station 655 and station 1434 on both sides of the airplane.
(i) A detailed inspection for scribe lines. If any scribe line is found during the inspection required by this paragraph, the actions include the inspections specified in paragraphs (g)(3)(i)(A) and (g)(3)(i)(B) of this AD.
(A) A detailed inspection for cracks of the scribe line area(s).
(B) Either an ultrasonic inspection or a surface HFEC inspection for cracks (depending on the location of the scribe line(s)).
(ii) An external phased array ultrasonic inspection for cracks in the lower/overlapped skin of the stringer S-14 L/R lap splices between fuselage station 655 and station 1434.
(iii) An open hole HFEC inspection for skin cracks at the upper and lower fastener rows of the stringer S-14 L/R lap splices.
(1) Where Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, 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, during accomplishment of any inspection required by this AD, any condition is found for which Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, specifies to contact Boeing for special repair instructions or supplemental instructions for the modification, and specifies that action as “RC” (Required for Compliance): Before further flight, do the repair or modification using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014: Do the left-side and right-side lap splice modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, except as provided by paragraph (h)(2) of this AD.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014: Do a post-modification internal surface HFEC inspection for skin cracks in the modified lap splices on both sides of the airplane; and do all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, except as provided by paragraph (h)(2) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection of the modified lap splices thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014.
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
