Source: https://www.federalregister.gov/documents/2017/05/30/2017-10288/airworthiness-directives-the-boeing-company-airplanes
Timestamp: 2017-08-17 18:20:24
Document Index: 230604938

Matched Legal Cases: ['art 39', 'art 1', 'art 39', '§\u200939', 'art 4', 'art 6', 'art 6', 'art 6', 'art 3', 'art 3', 'art 3']

24468-24472 (5 pages)
Docket No. FAA-2016-6667
Directorate Identifier 2015-NM-125-AD
Amendment 39-18882
AD 2017-10-08
FAA-2016-6667
2015-NM-125-AD Boeing Model 737-300 and 737-400 series airplanes
Request To Revise the Precipitating Event Statement
Request To Require Reinstalling Lap Joint Modification
Request To Address Certain Repairs
Request To Specify the Service Information Accomplishment Instructions Part Numbers
Request To Revise Flight Cycle Limit for Replacement Kit Skin Panels
Request To Remove Flight-Cycle Restriction for Certain Actions
(h) Exceptions to SASB 737-53-1168, Revision 4
https://www.federalregister.gov/d/2017-10288 https://www.federalregister.gov/d/2017-10288
For service information identified in this final rule, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; Internet https://www.myboeingfleet.com. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-6667.
You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-6667; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: 800-647-5527) is Docket Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2009-21-01, Amendment 39-16038 (74 FR 52395, October 13, 2009) (“AD 2009-21-01”). AD 2009-21-01 applied to certain the Boeing Company Model 737-300 and 737-400 series airplanes. The NPRM published in the Federal Register on May 13, 2016 (81 FR 29802). The NPRM was prompted by an evaluation by the DAH indicating that the aft fuselage skin is subject to WFD, and by reports of aft fuselage cracking. The NPRM proposed to continue to require repetitive inspections to detect cracking of the aft fuselage skin, and related investigative and corrective actions if necessary. The NPRM also proposed to add new aft fuselage skin inspections for cracking, inspections to detect missing or loose fasteners and any disbonding or cracking of bonded doublers, permanent repairs of time-limited repairs, related investigative and corrective actions if necessary, and skin panel replacement. The NPRM also proposed to remove Model 737-400 series airplanes from the applicability. We are issuing this AD to detect and correct cracking in the aft fuselage skin along the longitudinal edges of the chem-milled pockets in the bonded skin doubler, which could result in possible rapid decompression and reduced structural integrity of the airplane.
Boeing requested that we revise the precipitating event statement by including that there have been reports of aft fuselage cracking. Boeing stated that this revision would be consistent with wording of other related rulemaking.
We agree with Boeing's request because it provides additional clarity to the precipitating event statement. We have revised the SUMMARY and Discussion sections, and paragraph (e) of this AD accordingly.Start Printed Page 24469
Jet2.com Limited (Jet2) requested that we revise the NPRM to require reinstalling the lap joint modification previously installed in accordance with AD 2015-21-06, Amendment 39-18298 (80 FR 69839, November 12, 2015) (“AD 2015-21-06”), which requires the S-14 lap joint to be trimmed out prior to 50,000 total flight cycles. Jet2 stated that Boeing Special Attention Service Bulletin 737-53-1168, Revision 4, dated June 3, 2015 (“SASB 737-53-1168, Revision 4”) specifies reinstalling the lap joint modification.
We do not agree with the commenter's request. The modification required in AD 2015-21-06 consists of trimming out the lap splice, such that if this modification were installed, it would be impossible to install a new skin without reinstalling the lap modification. If the instructions in SASB 737-53-1168, Revision 4, to reinstall the lap splice modification were accidently overlooked, it would become clear to the installer that the reinstallation would be required. We have not changed this AD in this regard.
Boeing requested that we add a paragraph to the proposed AD to address repairs that are installed on the airplane for reasons other than chem-mill cracking. Boeing submitted suggested language and pointed out that the additional language is similar to that in other rulemaking.
We disagree with Boeing's request. Part 1 of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, does not make a distinction regarding why an existing repair was installed. Therefore, repairs installed for damage other than a chem-mill crack are already addressed. We have not changed this AD in this regard.
Boeing requested that we revise paragraph (h)(4) of the proposed AD to do the actions at an initial compliance time obtained through the alternative method of compliance (AMOC) process specified in paragraph (n)(1) of the proposed AD. Boeing stated that the repetitive inspections would still be done at the times specified in the service information. Boeing also requested that we include in the paragraph revision the terminating action of skin panel replacement at the time approved through an AMOC. Boeing stated that its request would provide a reset on the compliance times if the skin panel was replaced prior to 53,000 total airplane cycles. Boeing explained that its authorized representative under the Boeing Commercial Airplanes Organization Designation Authorization (ODA) cannot approve extensions to the compliance times.
We partially agree with Boeing's request. We agree that, for airplanes with skin panels replaced prior to 53,000 total flight cycles, in order to reset the inspection threshold on the replaced skin panels, approval must come from the FAA. Under the provisions of paragraph (n) of this AD, we may consider requests for a reset of the compliance times if the skin panel was replaced prior to 53,000 total airplane cycles if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed this AD in this regard.
Boeing requested that we add the specific part of the accomplishment instructions in paragraphs (i)(1)(ii), (i)(2)(ii), and (j) of the proposed AD. Boeing stated that paragraph (g) of the proposed AD specifies the specific part number, and that this change would make these paragraphs consistent with the wording in paragraph (g) of the proposed AD.
We agree with Boeing's request. We agree that specifying the specific part of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, will add clarity to the AD. We have revised paragraphs (i)(1)(ii), (i)(2)(ii), and (j) of this AD accordingly.
Boeing requested that we revise paragraph (l) of the proposed AD to specify that skin panel replacements using the kit identified in SASB 737-53-1168, Revision 4, do not have the lower flight cycle limit restriction that the production skin panel replacements have.
We agree with Boeing's request because the skin panel replacements using the kit identified in SASB 737-53-1168, Revision 4, is an improved design compared to the production skin panels, and therefore, do not need the lower flight cycle limit restriction. We have added paragraph (l)(3) to this AD, which states, in part, that if the skin panel is replaced with a kit skin panel as specified in SASB 737-53-1168, Revision 4, the 53,000 total flight cycle limit does not apply.
Boeing requested that we revise paragraphs (m)(2), (m)(3), and (n)(5) of the proposed AD to remove the flight cycle restriction for certain previously accomplished actions using certain service information. Boeing stated that the only skin panel replacements specified in previous revisions of SASB 737-53-1168 are those using the kit panels, and that those panels do not have the flight-cycle limit specified in paragraphs (m)(2), (m)(3), and (n)(5) of the proposed AD.
We agree with the commenter's request because the skin panel replacements using the kit identified in SASB 737-53-1168, Revision 4, are an improved design compared to the production skin panels, and therefore, do not need the lower flight cycle limit restriction. We have revised paragraphs (m)(2), (m)(3), and (n)(5) of this AD accordingly.
Qantas Airways Limited (Qantas) requested that we revise paragraphs (g) and (l) of the proposed AD to specify terminating action. Qantas pointed out that replacing the skin panels with kit panels instead of production panels, as specified in SASB 737-53-1168, terminates the repetitive inspections identified in paragraphs (g), (i), and (j) of the proposed AD. Additionally, Qantas pointed out that replacement with kit skin panels using any revision of SASB 737-53-1168 before the effective date of the AD should also terminate the repetitive inspections identified in paragraphs (g), (i), and (j) of the proposed AD.
We agree with the commenter's request because the skin panel replacements using the kit identified in SASB 737-53-1168, Revision 4, are an improved design compared to the production skin panels and therefore, should terminate the repetitive inspections. We have revised paragraphs (m)(2), (m)(3), and (n)(5) of this AD accordingly.
We concur with the commenter. We have redesignated paragraph (c) of the proposed AD as paragraph (c)(1) of this AD and added paragraph (c)(2) to this AD to state that installation of STC ST01219SE does not affect the ability to Start Printed Page 24470accomplish the actions required by this final rule. Therefore, for airplanes on which STC ST01219SE is installed, a “change in product” AMOC approval request is not necessary to comply with the requirements of 14 CFR 39.17.
We reviewed SASB 737-53-1168, Revision 4. The service information describes procedures for doing inspections of the fuselage skin, repairs, and skin panel replacement. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.
Inspections Up to 1,791 work-hours × $85 per hour = $152,235 $0 Up to $152,235 Up to $25,575,480.
Skin replacement 624 work-hours × $85 per hour = $53,040 98,275 $151,315 $25,420,920.
Permanent repair Up to 43 work-hours × $85 per hour = $3,655 per repair (1) Up to $3,655 per repair.
Accordingly, under the authority delegated to me by the Administrator, Start Printed Page 24471the FAA amends 14 CFR part 39 as follows:
2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2009-21-01, Amendment 39-16038 ( 74 FR 52395, October 13, 2009), and adding the following new AD:
2017-10-08 The Boeing Company: Amendment 39-18882; Docket No. FAA-2016-6667; Directorate Identifier 2015-NM-125-AD.
This AD replaces AD 2009-21-01, Amendment 39-16038 (74 FR 52395, October 13, 2009) (“AD 2009-21-01”).
(1) This AD applies to The Boeing Company Model 737-300 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 737-53-1168, Revision 4, dated June 3, 2015 (“SASB 737-53-1168, Revision 4”).
This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the aft fuselage skin is subject to widespread fatigue damage (WFD), and reports of aft fuselage cracking. We are issuing this AD to detect and correct cracking in the aft fuselage skin along the longitudinal edges of the chem-milled pockets in the bonded skin doubler, which could result in possible rapid decompression and reduced structural integrity of the airplane.
At the applicable times specified in tables 1 and 2 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, except as required by paragraphs (h)(1) and (h)(2) of this AD: Do the applicable inspections to detect cracks in the aft fuselage skin panels, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraphs (h)(3) and (h)(4) of this AD. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspections thereafter at the applicable intervals specified in tables 1 and 2 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4. Accomplishment of a repair in accordance with “Part 4: Repair” of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraph (h)(3) of this AD, is terminating action for the repetitive inspections required by this paragraph at the repaired locations only.
(1) Where SASB 737-53-1168, Revision 4, specifies compliance times “after the Revision 4 date of this service bulletin,” this AD requires compliance within the specified compliance times after the effective date of this AD.
(2) The Condition column of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, refers to airplanes in certain configurations as of the “issue date of Revision 4 of this service bulletin.” However, this AD applies to airplanes in the specified configurations “as of the effective date of this AD.”
(3) Where SASB 737-53-1168, Revision 4, specifies contacting Boeing for repair instructions or work instructions, before further flight, repair or perform the work instructions using a method approved in accordance with the procedures specified in paragraph (n) of this AD, except as required by paragraph (h)(4) of this AD.
(4) For airplanes on which an operator has a record that a skin panel was replaced with a production skin panel before 53,000 total flight cycles: At the applicable time for the next inspection as specified in tables 1 and 2 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, except as provided by paragraph (h)(1) and (h)(2) of this AD, perform inspections and applicable corrective actions using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(1) For airplanes with a time-limited repair installed, as specified in Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006: At the applicable times specified in table 3 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, except as provided by paragraphs (h)(1) and (h)(2) of this AD, do the actions specified in paragraphs (i)(1)(i) and (i)(1)(ii) of this AD.
(i) Do the applicable inspections to detect missing or loose fasteners and any disbonding or cracking of bonded doublers, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspections thereafter at the applicable intervals specified in SASB 737-53-1168, Revision 4.
(ii) Make the time-limited repair permanent, and do all applicable related investigative and corrective actions, in accordance with Part 6 of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Accomplishing the permanent repair required by this paragraph terminates the inspections required by paragraph (i)(1)(i) of this AD for the permanently repaired area only.
(2) For airplanes with a time-limited repair installed, as specified in SASB 737-53-1168, Revision 4: At the applicable times specified in table 4 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, do the actions specified in paragraphs (i)(2)(i) and (i)(2)(ii) of this AD.
(i) Do the applicable inspections to detect missing or loose fasteners and any disbonding or cracking of bonded doublers, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspections thereafter at the applicable intervals specified in table 4 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4.
(ii) Make the time-limited repair permanent, and do all applicable related investigative and corrective actions, in accordance with Part 6 of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Accomplishing the permanent repair required by this paragraph terminates the inspections required by paragraph (i)(2)(i) of this AD for the permanently repaired area only.
For airplanes with an existing time-limited repair that was made permanent, as specified in Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006: At the applicable times specified in table 5 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, except as provided by paragraphs (h)(1) of this AD, modify the existing permanent repair, and do all applicable related investigative and corrective actions, in accordance with Part 6 of the Accomplishment Instructions of SASB 737-53-1168, Revision 4, except as required Start Printed Page 24472by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight.
Table 6 of paragraph 1.E., “Compliance,” of SASB 737-53-1168, Revision 4, specifies post-repair airworthiness limitation inspections in compliance with 14 CFR 25.571(a)(3) at the repaired locations, which support compliance with 14 CFR 121.1109(c)(2) or 129.109(b)(2). As airworthiness limitations, these inspections are required by maintenance and operational rules. It is therefore unnecessary to mandate them in this AD. Deviations from these inspections require FAA approval, but do not require an AMOC.
At the later of the times specified in paragraphs (l)(1), (1)(2), and (l)(3) of this AD: Replace the applicable skin panels, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of SASB 737-53-1168, Revision 4. Do all applicable related investigative and corrective actions before further flight. Doing the skin panel replacement required by this paragraph terminates the inspection requirements of paragraphs (g), (i), and (j) of this AD for that skin panel only, provided the skin panel replacement was done with a production skin panel after 53,000 total flight cycles.
(3) If the skin panel is replaced with a production skin panel, not before 53,000 total flight cycles. If the skin panel is replaced with a kit skin panel as specified in SASB 737-53-1168, Revision 4, the 53,000 total flight cycle limit does not apply.
(1) This paragraph provides credit for the actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006, except as required by paragraph (h)(4) of this AD. Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006, was incorporated by reference in AD 2009-21-01.
(2) This paragraph provides credit for the actions required by paragraph (l) of this AD, if those actions were performed before the effective date of this AD using Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006, except as required by paragraph (h)(4) of this AD. Boeing Service Bulletin 737-53-1168, Revision 3, dated November 28, 2006, was incorporated by reference in AD 2009-21-01.
(3) This paragraph provides credit for the actions required by paragraph (l) of this AD, if those actions were performed before November 17, 2009 (the effective date of AD 2009-21-01), using any service information specified in paragraphs (m)(3)(i), (m)(3)(ii), and (m)(3)(iii) of this AD, provided the replacement is made with a kit skin panel, except as required by paragraph (h)(4) of this AD. The service information specified in paragraphs (m)(3)(i), (m)(3)(ii), and (m)(3)(iii) of this AD was incorporated by reference in AD 2009-21-01.
(i) Part 3 of the Accomplishment Instructions of Boeing Service Bulletin 737-53-1168, dated March 16, 1995.
(ii) Part 3 of the Accomplishment Instructions of Boeing Service Bulletin 737-53-1168, Revision 1, dated August 17, 1995.
(iii) Part 3 of the Accomplishment Instructions of Boeing Service Bulletin 737-53-1168, Revision 2, dated November 27, 1996.
(4) AMOCs approved previously for repairs required by AD 2009-21-01 are approved as AMOCs for the corresponding provisions of paragraph (g) of this AD.
(5) AMOCs approved previously for modifications done as optional terminating action for AD 2009-21-01 are approved as AMOCs for the skin panel replacement required by paragraph (l) of this AD.
(i) Boeing Special Attention Service Bulletin 737-53-1168, Revision 4, dated June 3, 2015.
[FR Doc. 2017-10288 Filed 5-26-17; 8:45 am]