Airworthiness Directives; The Boeing Company Model 737-200, -200C, -300, -400, and -500 Series Airplanes, 54399-54403 [2011-22370]

Download as PDF Federal Register / Vol. 76, No. 170 / Thursday, September 1, 2011 / Proposed Rules Regulatory Findings We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify this proposed regulation: (1) Is not a ‘‘significant regulatory action’’ under Executive Order 12866, (2) Is not a ‘‘significant rule’’ under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska, and (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: 54399 Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): Lycoming Engines (Type Certificate previously held by Textron Lycoming) Reciprocating Engines: Docket No. FAA– 2011–0533; Directorate Identifier 2011– NE–16–AD. Comments Due Date (a) We must receive comments by October 17, 2011. Affected ADs (b) None. Applicability (c) This AD applies to the Lycoming Engines reciprocating engines listed in Table 1 of this AD, with carburetor part numbers listed in Table 2 of this AD. TABLE 1—AFFECTED LYCOMING ENGINE MODELS O–320–D1D O–360–A2G O–360–A4K O–360–F1A6 LO–360–A1H6 O–540–J3C5D O–360–A1G6D O–360–A4G O–360–C4F HO–360–C1A LO–360–E1A6D O–540–L3C5D O–360–A1H6 O–360–A4J O–360–E1A6D LO–360–A1G6D TO–360–C1A6D N/A TABLE 2—PART NUMBERS (INCLUDING ALL DASH NUMBERS) OF KNOWN AFFECTED HA–6 MODEL CARBURETORS 10–5219–XX 10–5255–XX 10–5224–XX 10–5283–XX Unsafe Condition (d) This AD was prompted by a report of a ‘‘machined-from-billet’’ HA–6 carburetor having a loose mixture control sleeve that rotated in the carburetor body causing restriction of fuel and power loss. We are issuing this AD to prevent engine in-flight shutdown, power loss, and reduced control of the airplane. emcdonald on DSK2BSOYB1PROD with PROPOSALS Compliance (e) Comply with this AD within 50 flight hours after the effective date of this AD, unless already done. Inspection (f) Inspect the carburetor to determine the type of body the carburetor has. Use MarvelSchebler Emergency Service Bulletin (SB) No. SB–18, dated October 14, 2010, Figure (3) to determine which type of body is used. (g) If the carburetor has a die-cast body, no further action is required. (h) If the carburetor has an affected ‘‘machined-from-billet’’ body, remove the carburetor; and replace the carburetor with: (i) An HA–6 carburetor not listed in Table 2 of this AD; or (ii) An HA–6 carburetor that is listed in Table 2 but is exempted as described in paragraphs 1.A. and 1.B of Marvel-Schebler Emergency SB No. SB–18, dated October 14, 2010; or that has already been repaired using that Emergency SB. VerDate Mar<15>2010 16:04 Aug 31, 2011 Jkt 223001 10–5230–XX 10–6001–XX 10–5235–XX 10–6019–XX Alternative Methods of Compliance (AMOCs) (i) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Issued in Burlington, Massachusetts, on August 24, 2011. Thomas A. Boudreau, Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service. [FR Doc. 2011–22351 Filed 8–31–11; 8:45 am] BILLING CODE 4910–13–P Related Information (j) For more information about this AD, contact Neil Duggan, Aerospace Engineer, Propulsion, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate; 1701 Columbia Avenue, College Park, Georgia 30337; phone: (404) 474–5576; fax: (404) 474–5606; e-mail: neil.duggan@faa.gov. (k) For service information identified in this AD, contact Marvel-Schebler Aircraft Carburetors LLC, 125 Piedmont Avenue, Gibsonville, NC 27249; phone: 336–446– 0002; fax: 336–446–0007; e-mail: customerservice@msacarbs.com; Web site: https://www.msacarbs.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125. PO 00000 10–5253–XX 10–6030–XX DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2011–0914; Directorate Identifier 2010–NM–166–AD] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Model 737–200, –200C, –300, –400, and –500 Series Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to supersede an existing airworthiness directive (AD) that applies to certain Model 737–300, SUMMARY: Frm 00008 Fmt 4702 Sfmt 4702 E:\FR\FM\01SEP1.SGM 01SEP1 emcdonald on DSK2BSOYB1PROD with PROPOSALS 54400 Federal Register / Vol. 76, No. 170 / Thursday, September 1, 2011 / Proposed Rules –400, and –500 series airplanes. The existing AD currently requires repetitive external non-destructive inspections to detect cracks in the fuselage skin along the chem-mill step at stringers S–1 and S–2 right, between station (STA) 827 and STA 847, and repair if necessary. Since we issued that AD, we have received reports of additional crack findings of the fuselage crown skin at the chem-milled steps. This proposed AD would add inspections for cracking in additional fuselage crown skin locations, and repair if necessary. This proposed AD would also reduce the inspection thresholds for certain airplanes, extend certain repetitive inspection intervals, and add airplanes to the applicability of the existing AD. We are proposing this AD to detect and correct fatigue cracking of the fuselage skin panels at the chem-milled steps, which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of the airplane. DATES: We must receive comments on this proposed AD by October 17, 2011. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: 202–493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590. • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766–5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425–227– 1221. Examining the AD Docket You may examine the AD docket on the Internet at https:// www.regulations.gov; 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 proposed AD, the VerDate Mar<15>2010 16:04 Aug 31, 2011 Jkt 223001 regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800–647–5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; phone: 425– 917–6447; fax: 425–917–6590; e-mail: wayne.lockett@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA–2011–0914; Directorate Identifier 2010–NM–166–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments. We will post all comments we receive, without change, to https:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD. Discussion On December 21, 2009, we issued AD 2010–01–09, Amendment 39–16167 (75 FR 1527, January 12, 2010), for certain Model 737–300, ¥400, and ¥500 series airplanes. That AD requires repetitive external non-destructive inspections to detect cracks in the fuselage skin along the chem-mill step at stringers S–1 and S–2 right, between STA 827 and STA 847, and repair if necessary. That AD resulted from a report of a hole in the fuselage skin common to stringers S–1 and S–2 left, between STA 827 and STA 847, on an airplane that diverted to an alternate airport due to cabin depressurization and subsequent deployment of the oxygen masks. We issued that AD to detect and correct fatigue cracking of the fuselage skin panels at the chem-milled steps, which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of the airplane. PO 00000 Frm 00009 Fmt 4702 Sfmt 4702 Actions Since Existing AD Was Issued Since we issued AD 2010–01–09, we have received reports of new findings of cracking in the fuselage crown skin at the horizontal chem-milled steps at locations between body stations 259.5 and 1016 and between stringers S–10L and S–10R. The cause of the cracking is under investigation. Relevant Service Information We reviewed Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011. Boeing Alert Service Bulletin 737–53A1301, dated September 3, 2009, was referred to for accomplishing the actions in the existing AD. We also reviewed Boeing Alert Service Bulletin 737–53A1301, Revision 1, dated June 7, 2010. Revision 1 of this service bulletin adds inspections for cracking in additional fuselage crown skin locations, and repair if necessary; it reduces the inspection threshold for certain airplanes; extends certain repetitive inspection intervals; and adds airplanes to the effectivity (Model 737–200 and ¥200C series airplanes, and Model 737–300, ¥400, and ¥500 series without ELT antenna provisions). The new inspection types specified in Revision 1 of this service bulletin are detailed inspections, and optional external nondestructive: ultrasonic phased array inspections. Revision 1 of this service bulletin also recommends contacting Boeing for inspection instructions for Group 26 airplanes. Revision 2 of this service bulletin specifies that no more work is necessary on airplanes changed as specified in Revision 1 of this service bulletin. Revision 2 of this service bulletin only includes minor editorial changes. Boeing Alert Service Bulletin 737– 53A1301, Revision 2, dated April 25, 2011; and Boeing Alert Service Bulletin 737–53A1301, Revision 1, dated June 7, 2010; specify that the compliance times for the initial inspections for Groups 2, 8, and 10 airplanes at the ELT antenna provision at stringers S–1 and S–2R between BS 827 and BS 847, are at the latest of the following: Prior to the accumulation of 35,000 total flight cycles, or, depending on inspection locations, within 1,800 flight cycles after the issue date of the original issue or Revision 1 of this service bulletin, or within 1,800 flight cycles after the most recent inspection done in accordance with Boeing Alert Service Bulletin 737– 53A1301, dated September 3, 2009. For Groups 1 through 12 airplanes, at the new inspection locations, the compliance times are prior to the accumulation of 35,000 total flight E:\FR\FM\01SEP1.SGM 01SEP1 54401 Federal Register / Vol. 76, No. 170 / Thursday, September 1, 2011 / Proposed Rules cycles, or within 1,800 flight cycles after the issue date of Revision 1 of this service bulletin. For groups 1 through 12, the repetitive inspection interval is 1,800 flight cycles (for Option 1 inspections) and 2,400 flight cycles (for Option 2 inspections). For airplanes on which the inspection procedure is changed from Option 2 to Option 1, the first Option 1 inspection must be done within 2,400 flight cycles after doing the Option 2 inspection. For airplanes on which the inspection procedure is changed from Option 1 to Option 2, the first two Option 2 inspections must be done within 1,800 flight cycles. Boeing Alert Service Bulletin 737– 53A1301, Revision 2, dated April 25, 2011; specifies that the compliance times for the initial inspections for Groups 13 through 18 and 21 through 25 airplanes at the ELT antenna provision at stringers S–1 and S–2R, between BS 827 and BS 847, are as follows: • For airplanes on which the inspections specified in Boeing Alert Service Bulletin 737–53A1301, dated September 3, 2009; or Revision 1, dated June 7, 2010; have been done: At the latest of the following, prior to the accumulation of 33,000 total flight cycles, or within 500 flight cycles after the most recent inspection done in accordance with Boeing Alert Service Bulletin 737–53A1301, dated September 3, 2009; or Revision 1, dated June 7, 2010. • For airplanes on which the inspections specified in Boeing Alert Service Bulletin 737–53A1301, dated September 3, 2009; or Revision 1, dated June 7, 2010; have not been done: Prior to the accumulation of 33,000 total flight cycles, or within 500 flight cycles after the issue date of Revision 2 of this service bulletin, whichever occurs later. For Groups 13 through 25, Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011; specifies that the compliance times for the initial inspections for Groups 13 through 25 airplanes at the new inspection locations are as follows: Prior to the accumulation of 33,000 total flight cycles, or within 500 flight cycles after the issue date of Revision 1 of Boeing Alert Service Bulletin 737– 53A1301, whichever occurs later. For Groups 13 through 25, Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011; specifies that the repetitive inspection interval is 500 flight cycles (for Option 1) and 1,000 flight cycles (for Option 2). For airplanes on which the inspection procedure is changed from Option 2 to Option 1, the first Option 1 inspection must be done within 1,000 flight cycles after doing the Option 2 inspection. For airplanes on which the inspection procedure is changed from Option 1 to Option 2, the first two Option 2 inspections must be done within 500 flight cycles. For Group 26 airplanes, Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011, specifies contacting Boeing to obtain engineering and accomplishment instructions for certain inspections. FAA’s Determination We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. Proposed AD Requirements This proposed AD would retain the requirements of AD 2010–01–09, and would add inspections for cracking in additional fuselage crown skin locations, and repair if necessary. This proposed AD would also reduce the inspection thresholds for certain airplanes, extend certain repetitive inspection intervals, and add airplanes to the applicability of AD 2010–01–09. This proposed AD would require accomplishing the actions specified in the service information described previously. Interim Action We consider this proposed AD interim action. If final action is later identified, we might consider further rulemaking then. Costs of Compliance We estimate that this proposed AD affects 654 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD: ESTIMATED COSTS Action Inspection in AD 2010– 01–09. New inspection in this proposed AD. 2 ...................................... $85 Between 2 and 30 .......... 85 emcdonald on DSK2BSOYB1PROD with PROPOSALS We have received no definitive data that would enable us to provide a cost estimate for the on-condition actions specified in this proposed AD. Authority for This Rulemaking Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency’s authority. We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, VerDate Mar<15>2010 Average labor rate per hour Work hours 16:04 Aug 31, 2011 Jkt 223001 $170 per inspection cycle 135 Between $170 and $2,550 per inspection cycle. 654 ‘‘General requirements.’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings We have determined that this proposed AD would not have federalism implications under Executive Order PO 00000 Frm 00010 Fmt 4702 Number of U.S.-registered airplanes Cost per product Sfmt 4702 Fleet cost $22,950 per inspection cycle. Between $111,180 and $1,667,700 per inspection cycle. 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify that the proposed regulation: (1) Is not a ‘‘significant regulatory action’’ under Executive Order 12866, (2) Is not a ‘‘significant rule’’ under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska, and E:\FR\FM\01SEP1.SGM 01SEP1 54402 Federal Register / Vol. 76, No. 170 / Thursday, September 1, 2011 / Proposed Rules (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2010–01–09, Amendment 39–16167 (75 FR 1527, January 12, 2010), and adding the following new AD: The Boeing Company: Docket No. FAA– 2011–0914; Directorate Identifier 2010– NM–166–AD. Comments Due Date (a) The FAA must receive comments on this AD action by October 17, 2011. Affected ADs (b) This AD supersedes AD 2010–01–09, Amendment 39–16167. Applicability (c) This AD applies to all The Boeing Company Model 737–200, ¥200C, ¥300, ¥400, and ¥500 series airplanes, certificated in any category. Subject (d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 53, Fuselage. emcdonald on DSK2BSOYB1PROD with PROPOSALS Unsafe Condition (e) This AD was prompted by reports of additional crack findings of the fuselage crown skin at the chem-milled steps. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin panels at the chem-milled steps, which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of the airplane. Compliance (f) Comply with this AD within the compliance times specified, unless already done. Restatement of Requirements of AD 2010– 01–09, Amendment 39–16167 Initial and Repetitive Inspections (g) For airplanes identified in Boeing Alert Service Bulletin 737–53A1301, dated VerDate Mar<15>2010 16:04 Aug 31, 2011 Jkt 223001 September 3, 2009: Before the accumulation of 35,000 total flight cycles, or within 500 flight cycles after February 16, 2010 (the effective date of AD 2010–01–09), whichever occurs later, except as provided by paragraph (i) of this AD, do an external non-destructive inspection (NDI) to detect cracks in the fuselage skin along the chem-mill steps at stringers S–1 and S–2 right, between station (STA) 827 and STA 847, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1301, dated September 3, 2009; or Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011. If no cracking is found, repeat the inspection thereafter at intervals not to exceed 500 flight cycles; except as provided by paragraphs (i) and (n) of this AD. Accomplishing the inspections required by paragraph (j) of this AD terminates the inspections required by this paragraph. Repair (h) If any crack is found during any inspection required by paragraph (g) of this AD, and Boeing Alert Service Bulletin 737– 53A1301, dated September 3, 2009; or Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011; specifies to contact Boeing for repair instructions: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (q) of this AD. Optional Terminating Action for Repetitive Inspections in Paragraph (g) of This AD (i) Installing an external repair doubler along the chem-milled steps at stringers S– 1 and S–2 right, between STA 827 and STA 847, constitutes terminating action for the repetitive inspections required by paragraph (g) of this AD for the repaired area only, provided all of the conditions specified in paragraphs (i)(1), (i)(2), and (i)(3) of this AD are met. (1) The repair is installed after September 3, 2009; (2) The repair was approved by the FAA or by a Boeing Company Authorized Representative or the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle Aircraft Certification Office (ACO) to make such findings; and (3) The repair extends a minimum of three rows of fasteners on each side of the chemmill line in the circumferential direction. New Inspections Including Additional Locations and Reduced Inspection Intervals Groups 1 Through 25: Initial and Repetitive Inspections (j) For Groups 1 through 25 airplanes identified in Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011: Except as provided by paragraph (k) of this AD, at the applicable time specified in paragraph 1.E., ‘‘Compliance,’’ of Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011, do the applicable inspections required by paragraphs (j)(1) and (j)(2) of this AD, in accordance with paragraphs 3.B.1 through 3.B.25 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1301, PO 00000 Frm 00011 Fmt 4702 Sfmt 4702 Revision 2, dated April 25, 2011. If no cracking is found, repeat the applicable inspections thereafter at the applicable intervals specified in paragraph 1.E., ‘‘Compliance,’’ of Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011; except as provided by paragraphs (m) and (n) of this AD. Doing the inspections required by this paragraph terminates the inspections required by paragraph (g) of this AD. (1) For Groups 2, 8, 10, 13 through 18, and 21 through 25 airplanes: Do a detailed inspection and an external non-destructive inspection (NDI) (medium frequency eddy current inspection, magneto optical imaging inspection, c-scan inspection, or ultrasonic phased array inspection) for cracking in the fuselage skin at the chem-mill steps at S–1 and S–2R between STA 827 and STA 847, as identified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011. (2) For Groups 1 through 25 airplanes: Do a detailed inspection and an external NDI (medium frequency eddy current inspection; magneto optical imaging inspection, c-scan inspection, or ultrasonic phased array inspection) for cracking in the fuselage skin at the chem-mill steps at the specified locations other than at S–1 and S–2R between STA 827 and STA 847, as identified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011. Note 1: Option 1 of Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011, specifies a detailed inspection, and one additional inspection (external NDI, medium frequency eddy current inspection, magneto optical imaging inspection, or c-scan inspection). Option 2 specifies a detailed inspection and an external ultrasonic phased array inspection. These options have different compliance times after the initial inspection. (k) Where Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011, specifies a compliance time after ‘‘the date of Revision 1,’’ or ‘‘the date of Revision 2’’ of that service bulletin, this AD requires compliance within the specified time after the effective date of this AD. Repair (l) If any crack is found during any inspection required by paragraph (j) of this AD: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (q) of this AD. Doing the repair ends the repetitive inspections required by paragraph (j) for the repaired area only. Optional Terminating Action for Repetitive Inspections (m) Installing an external repair doubler along the chem-milled steps at any location identified in Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011, constitutes terminating action for the repetitive inspections required by paragraph (j) of this AD for the repaired area only, provided all of the conditions specified in E:\FR\FM\01SEP1.SGM 01SEP1 Federal Register / Vol. 76, No. 170 / Thursday, September 1, 2011 / Proposed Rules paragraphs (m)(1), (m)(2), and (m)(3) of this AD are met. (1) The repair is installed after the applicable date specified in paragraph (m)(1)(i) and (m)(1)(ii) of this AD. (i) For repairs at S–1 and S–2R between STA 827 and STA 847: Installed after September 3, 2009. (ii) For repairs at locations other than at S– 1 and S–2R between STA 827 and STA 847: Installed after June 7, 2010. (2) The repair was approved by the FAA or by a Boeing Company Authorized Representative or the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle Aircraft Certification Office (ACO) to make such findings; and (3) The repair extends a minimum of three rows of fasteners on each side of the chemmill line in the circumferential direction. (n) Accomplishing a modification of the chem-milled steps at any location identified in Boeing Alert Service Bulletin 737– 53A1301, Revision 2, dated April 25, 2011, using a method approved in accordance with the procedures specified in paragraph (q)(1) of this AD, terminates the repetitive inspections required by paragraphs (g) and (j) of this AD for the modified area only. Group 26 Airplanes (o) For Group 26 airplanes identified in Boeing Alert Service Bulletin 737–53A1301, Revision 2, dated April 25, 2011: Within 1,800 flight cycles after the effective date of this AD, accomplish applicable inspections and corrective action, as identified in the service bulletin, using a method approved in accordance with the procedures specified in paragraph (q)(1) of this AD. emcdonald on DSK2BSOYB1PROD with PROPOSALS Credit for Actions Accomplished in Accordance With Previous Service Information (p) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737–53A1301, Revision 1, dated June 7, 2010, are acceptable for compliance with the corresponding requirements of this AD. Alternative Methods of Compliance (AMOCs) (q)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be e-mailed to: 9-ANMSeattle-ACO-AMOC-Requests@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/ certificate holding district office. (3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO VerDate Mar<15>2010 16:04 Aug 31, 2011 Jkt 223001 to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane. Related Information (r) For more information about this AD, contact Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057– 3356; phone: 425–917–6447; fax: 425–917– 6590; e-mail: wayne.lockett@faa.gov. (s) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766– 5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425–227–1221. Issued in Renton, Washington, on August 25, 2011. Ali Bahrami, Manager Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011–22370 Filed 8–31–11; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2011–0954; Directorate Identifier 2011–CE–028–AD] 54403 subsequent possible damage to the aeroplane and injuries to occupants during landing. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. DATES: We must receive comments on this proposed AD by October 17, 2011. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: (202) 493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590. • Hand Delivery: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact Piaggio Aero Industries S.p.A Airworthiness Office; Via Luigi Cibrario, 4–16154 Genova– Italy; telephone: +39 010 6481353; fax: +39 010 6481881; E-mail: airworthiness@piaggioaero.it. You may review copies of the referenced service information at the FAA, Small Airplane Directorate, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the FAA, call (816) 329–4148. We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Examining the AD Docket You may examine the AD docket on the Internet at https:// www.regulations.gov; 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647–5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329–4144; fax: (816) 329–4090; e-mail: mike.kiesov@faa.gov. SUPPLEMENTARY INFORMATION: Some lock sleeves (part number (P/N) 114146681), which were installed in some Main Landing Gear (MLG) actuators, had been incorrectly manufactured. If left uncorrected, this condition could lead to failure to lock the MLG actuator or to its unlock from the correct position, with Comments Invited We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. RIN 2120–AA64 Airworthiness Directives; PIAGGIO AERO INDUSTRIES S.p.A Model PIAGGIO P–180 Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). AGENCY: SUMMARY: PO 00000 Frm 00012 Fmt 4702 Sfmt 4702 E:\FR\FM\01SEP1.SGM 01SEP1

Agencies

[Federal Register Volume 76, Number 170 (Thursday, September 1, 2011)]
[Proposed Rules]
[Pages 54399-54403]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-22370]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0914; Directorate Identifier 2010-NM-166-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Model 737-200, -
200C, -300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede an existing airworthiness directive
(AD) that applies to certain Model 737-300,

[[Page 54400]]

-400, and -500 series airplanes. The existing AD currently requires
repetitive external non-destructive inspections to detect cracks in the
fuselage skin along the chem-mill step at stringers S-1 and S-2 right,
between station (STA) 827 and STA 847, and repair if necessary. Since
we issued that AD, we have received reports of additional crack
findings of the fuselage crown skin at the chem-milled steps. This
proposed AD would add inspections for cracking in additional fuselage
crown skin locations, and repair if necessary. This proposed AD would
also reduce the inspection thresholds for certain airplanes, extend
certain repetitive inspection intervals, and add airplanes to the
applicability of the existing AD. We are proposing this AD to detect
and correct fatigue cracking of the fuselage skin panels at the chem-
milled steps, which could result in sudden fracture and failure of the
fuselage skin panels, and consequent rapid decompression of the
airplane.

DATES: We must receive comments on this proposed AD by October 17,
2011.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this AD, contact Boeing
Commercial Airplanes, Attention: Data & Services Management, P.O. Box
3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000,
extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet
https://www.myboeingfleet.com. You may review copies of the referenced
service information at the FAA, Transport Airplane Directorate, 1601
Lind Avenue, SW., Renton, Washington. For information on the
availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at https://www.regulations.gov; 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 proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES
section. Comments will be available in the AD docket shortly after
receipt.

FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: 425-917-
6447; fax: 425-917-6590; e-mail: wayne.lockett@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2011-0914;
Directorate Identifier 2010-NM-166-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to https://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion

On December 21, 2009, we issued AD 2010-01-09, Amendment 39-16167
(75 FR 1527, January 12, 2010), for certain Model 737-300, -400, and -
500 series airplanes. That AD requires repetitive external non-
destructive inspections to detect cracks in the fuselage skin along the
chem-mill step at stringers S-1 and S-2 right, between STA 827 and STA
847, and repair if necessary. That AD resulted from a report of a hole
in the fuselage skin common to stringers S-1 and S-2 left, between STA
827 and STA 847, on an airplane that diverted to an alternate airport
due to cabin depressurization and subsequent deployment of the oxygen
masks. We issued that AD to detect and correct fatigue cracking of the
fuselage skin panels at the chem-milled steps, which could result in
sudden fracture and failure of the fuselage skin panels, and consequent
rapid decompression of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2010-01-09, we have received reports of new
findings of cracking in the fuselage crown skin at the horizontal chem-
milled steps at locations between body stations 259.5 and 1016 and
between stringers S-10L and S-10R. The cause of the cracking is under
investigation.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 737-53A1301, Revision 2,
dated April 25, 2011. Boeing Alert Service Bulletin 737-53A1301, dated
September 3, 2009, was referred to for accomplishing the actions in the
existing AD. We also reviewed Boeing Alert Service Bulletin 737-
53A1301, Revision 1, dated June 7, 2010. Revision 1 of this service
bulletin adds inspections for cracking in additional fuselage crown
skin locations, and repair if necessary; it reduces the inspection
threshold for certain airplanes; extends certain repetitive inspection
intervals; and adds airplanes to the effectivity (Model 737-200 and -
200C series airplanes, and Model 737-300, -400, and -500 series without
ELT antenna provisions). The new inspection types specified in Revision
1 of this service bulletin are detailed inspections, and optional
external nondestructive: ultrasonic phased array inspections. Revision
1 of this service bulletin also recommends contacting Boeing for
inspection instructions for Group 26 airplanes. Revision 2 of this
service bulletin specifies that no more work is necessary on airplanes
changed as specified in Revision 1 of this service bulletin. Revision 2
of this service bulletin only includes minor editorial changes.
Boeing Alert Service Bulletin 737-53A1301, Revision 2, dated April
25, 2011; and Boeing Alert Service Bulletin 737-53A1301, Revision 1,
dated June 7, 2010; specify that the compliance times for the initial
inspections for Groups 2, 8, and 10 airplanes at the ELT antenna
provision at stringers S-1 and S-2R between BS 827 and BS 847, are at
the latest of the following: Prior to the accumulation of 35,000 total
flight cycles, or, depending on inspection locations, within 1,800
flight cycles after the issue date of the original issue or Revision 1
of this service bulletin, or within 1,800 flight cycles after the most
recent inspection done in accordance with Boeing Alert Service Bulletin
737-53A1301, dated September 3, 2009. For Groups 1 through 12
airplanes, at the new inspection locations, the compliance times are
prior to the accumulation of 35,000 total flight

[[Page 54401]]

cycles, or within 1,800 flight cycles after the issue date of Revision
1 of this service bulletin. For groups 1 through 12, the repetitive
inspection interval is 1,800 flight cycles (for Option 1 inspections)
and 2,400 flight cycles (for Option 2 inspections). For airplanes on
which the inspection procedure is changed from Option 2 to Option 1,
the first Option 1 inspection must be done within 2,400 flight cycles
after doing the Option 2 inspection. For airplanes on which the
inspection procedure is changed from Option 1 to Option 2, the first
two Option 2 inspections must be done within 1,800 flight cycles.
Boeing Alert Service Bulletin 737-53A1301, Revision 2, dated April
25, 2011; specifies that the compliance times for the initial
inspections for Groups 13 through 18 and 21 through 25 airplanes at the
ELT antenna provision at stringers S-1 and S-2R, between BS 827 and BS
847, are as follows:
For airplanes on which the inspections specified in Boeing
Alert Service Bulletin 737-53A1301, dated September 3, 2009; or
Revision 1, dated June 7, 2010; have been done: At the latest of the
following, prior to the accumulation of 33,000 total flight cycles, or
within 500 flight cycles after the most recent inspection done in
accordance with Boeing Alert Service Bulletin 737-53A1301, dated
September 3, 2009; or Revision 1, dated June 7, 2010.
For airplanes on which the inspections specified in Boeing
Alert Service Bulletin 737-53A1301, dated September 3, 2009; or
Revision 1, dated June 7, 2010; have not been done: Prior to the
accumulation of 33,000 total flight cycles, or within 500 flight cycles
after the issue date of Revision 2 of this service bulletin, whichever
occurs later.
For Groups 13 through 25, Boeing Alert Service Bulletin 737-
53A1301, Revision 2, dated April 25, 2011; specifies that the
compliance times for the initial inspections for Groups 13 through 25
airplanes at the new inspection locations are as follows: Prior to the
accumulation of 33,000 total flight cycles, or within 500 flight cycles
after the issue date of Revision 1 of Boeing Alert Service Bulletin
737-53A1301, whichever occurs later.
For Groups 13 through 25, Boeing Alert Service Bulletin 737-
53A1301, Revision 2, dated April 25, 2011; specifies that the
repetitive inspection interval is 500 flight cycles (for Option 1) and
1,000 flight cycles (for Option 2). For airplanes on which the
inspection procedure is changed from Option 2 to Option 1, the first
Option 1 inspection must be done within 1,000 flight cycles after doing
the Option 2 inspection. For airplanes on which the inspection
procedure is changed from Option 1 to Option 2, the first two Option 2
inspections must be done within 500 flight cycles.
For Group 26 airplanes, Boeing Alert Service Bulletin 737-53A1301,
Revision 2, dated April 25, 2011, specifies contacting Boeing to obtain
engineering and accomplishment instructions for certain inspections.

FAA's Determination

We are proposing this AD because we evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would retain the requirements of AD 2010-01-09,
and would add inspections for cracking in additional fuselage crown
skin locations, and repair if necessary. This proposed AD would also
reduce the inspection thresholds for certain airplanes, extend certain
repetitive inspection intervals, and add airplanes to the applicability
of AD 2010-01-09. This proposed AD would require accomplishing the
actions specified in the service information described previously.

Interim Action

We consider this proposed AD interim action. If final action is
later identified, we might consider further rulemaking then.

Costs of Compliance

We estimate that this proposed AD affects 654 airplanes of U.S.
registry.
We estimate the following costs to comply with this proposed AD:

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Number of U.S.-
Action Work hours Average labor Cost per registered Fleet cost
rate per hour product airplanes
----------------------------------------------------------------------------------------------------------------
Inspection in AD 2010-01-09.. 2.............. $85 $170 per 135 $22,950 per
inspection inspection
cycle. cycle.
New inspection in this Between 2 and 85 Between $170 654 Between
proposed AD. 30. and $2,550 per $111,180 and
inspection $1,667,700 per
cycle. inspection
cycle.
----------------------------------------------------------------------------------------------------------------

We have received no definitive data that would enable us to provide
a cost estimate for the on-condition actions specified in this proposed
AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify that the proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and

[[Page 54402]]

(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by removing airworthiness directive
(AD) 2010-01-09, Amendment 39-16167 (75 FR 1527, January 12, 2010), and
adding the following new AD:

The Boeing Company: Docket No. FAA-2011-0914; Directorate Identifier
2010-NM-166-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by October
17, 2011.

Affected ADs

(b) This AD supersedes AD 2010-01-09, Amendment 39-16167.

Applicability

(c) This AD applies to all The Boeing Company Model 737-200, -
200C, -300, -400, and -500 series airplanes, certificated in any
category.

Subject

(d) Joint Aircraft System Component (JASC)/Air Transport
Association (ATA) of America Code 53, Fuselage.

Unsafe Condition

(e) This AD was prompted by reports of additional crack findings
of the fuselage crown skin at the chem-milled steps. We are issuing
this AD to detect and correct fatigue cracking of the fuselage skin
panels at the chem-milled steps, which could result in sudden
fracture and failure of the fuselage skin panels, and consequent
rapid decompression of the airplane.

Compliance

(f) Comply with this AD within the compliance times specified,
unless already done.

Restatement of Requirements of AD 2010-01-09, Amendment 39-16167

Initial and Repetitive Inspections

(g) For airplanes identified in Boeing Alert Service Bulletin
737-53A1301, dated September 3, 2009: Before the accumulation of
35,000 total flight cycles, or within 500 flight cycles after
February 16, 2010 (the effective date of AD 2010-01-09), whichever
occurs later, except as provided by paragraph (i) of this AD, do an
external non-destructive inspection (NDI) to detect cracks in the
fuselage skin along the chem-mill steps at stringers S-1 and S-2
right, between station (STA) 827 and STA 847, in accordance with the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1301, dated September 3, 2009; or Boeing Alert Service Bulletin
737-53A1301, Revision 2, dated April 25, 2011. If no cracking is
found, repeat the inspection thereafter at intervals not to exceed
500 flight cycles; except as provided by paragraphs (i) and (n) of
this AD. Accomplishing the inspections required by paragraph (j) of
this AD terminates the inspections required by this paragraph.

Repair

(h) If any crack is found during any inspection required by
paragraph (g) of this AD, and Boeing Alert Service Bulletin 737-
53A1301, dated September 3, 2009; or Boeing Alert Service Bulletin
737-53A1301, Revision 2, dated April 25, 2011; specifies to contact
Boeing for repair instructions: Before further flight, repair the
crack using a method approved in accordance with the procedures
specified in paragraph (q) of this AD.

Optional Terminating Action for Repetitive Inspections in Paragraph (g)
of This AD

(i) Installing an external repair doubler along the chem-milled
steps at stringers S-1 and S-2 right, between STA 827 and STA 847,
constitutes terminating action for the repetitive inspections
required by paragraph (g) of this AD for the repaired area only,
provided all of the conditions specified in paragraphs (i)(1),
(i)(2), and (i)(3) of this AD are met.
(1) The repair is installed after September 3, 2009;
(2) The repair was approved by the FAA or by a Boeing Company
Authorized Representative or the Boeing Commercial Airplanes
Organization Designation Authorization (ODA) that has been
authorized by the Manager, Seattle Aircraft Certification Office
(ACO) to make such findings; and
(3) The repair extends a minimum of three rows of fasteners on
each side of the chem-mill line in the circumferential direction.

New Inspections Including Additional Locations and Reduced Inspection
Intervals

Groups 1 Through 25: Initial and Repetitive Inspections

(j) For Groups 1 through 25 airplanes identified in Boeing Alert
Service Bulletin 737-53A1301, Revision 2, dated April 25, 2011:
Except as provided by paragraph (k) of this AD, at the applicable
time specified in paragraph 1.E., ``Compliance,'' of Boeing Alert
Service Bulletin 737-53A1301, Revision 2, dated April 25, 2011, do
the applicable inspections required by paragraphs (j)(1) and (j)(2)
of this AD, in accordance with paragraphs 3.B.1 through 3.B.25 of
the Accomplishment Instructions of Boeing Alert Service Bulletin
737-53A1301, Revision 2, dated April 25, 2011. If no cracking is
found, repeat the applicable inspections thereafter at the
applicable intervals specified in paragraph 1.E., ``Compliance,'' of
Boeing Alert Service Bulletin 737-53A1301, Revision 2, dated April
25, 2011; except as provided by paragraphs (m) and (n) of this AD.
Doing the inspections required by this paragraph terminates the
inspections required by paragraph (g) of this AD.
(1) For Groups 2, 8, 10, 13 through 18, and 21 through 25
airplanes: Do a detailed inspection and an external non-destructive
inspection (NDI) (medium frequency eddy current inspection, magneto
optical imaging inspection, c-scan inspection, or ultrasonic phased
array inspection) for cracking in the fuselage skin at the chem-mill
steps at S-1 and S-2R between STA 827 and STA 847, as identified in
the Accomplishment Instructions of Boeing Alert Service Bulletin
737-53A1301, Revision 2, dated April 25, 2011.
(2) For Groups 1 through 25 airplanes: Do a detailed inspection
and an external NDI (medium frequency eddy current inspection;
magneto optical imaging inspection, c-scan inspection, or ultrasonic
phased array inspection) for cracking in the fuselage skin at the
chem-mill steps at the specified locations other than at S-1 and S-
2R between STA 827 and STA 847, as identified in the Accomplishment
Instructions of Boeing Alert Service Bulletin 737-53A1301, Revision
2, dated April 25, 2011.

Note 1: Option 1 of Boeing Alert Service Bulletin 737-53A1301,
Revision 2, dated April 25, 2011, specifies a detailed inspection,
and one additional inspection (external NDI, medium frequency eddy
current inspection, magneto optical imaging inspection, or c-scan
inspection). Option 2 specifies a detailed inspection and an
external ultrasonic phased array inspection. These options have
different compliance times after the initial inspection.

(k) Where Boeing Alert Service Bulletin 737-53A1301, Revision 2,
dated April 25, 2011, specifies a compliance time after ``the date
of Revision 1,'' or ``the date of Revision 2'' of that service
bulletin, this AD requires compliance within the specified time
after the effective date of this AD.

Repair

(l) If any crack is found during any inspection required by
paragraph (j) of this AD: Before further flight, repair the crack
using a method approved in accordance with the procedures specified
in paragraph (q) of this AD. Doing the repair ends the repetitive
inspections required by paragraph (j) for the repaired area only.

Optional Terminating Action for Repetitive Inspections

(m) Installing an external repair doubler along the chem-milled
steps at any location identified in Boeing Alert Service Bulletin
737-53A1301, Revision 2, dated April 25, 2011, constitutes
terminating action for the repetitive inspections required by
paragraph (j) of this AD for the repaired area only, provided all of
the conditions specified in

[[Page 54403]]

paragraphs (m)(1), (m)(2), and (m)(3) of this AD are met.
(1) The repair is installed after the applicable date specified
in paragraph (m)(1)(i) and (m)(1)(ii) of this AD.
(i) For repairs at S-1 and S-2R between STA 827 and STA 847:
Installed after September 3, 2009.
(ii) For repairs at locations other than at S-1 and S-2R between
STA 827 and STA 847: Installed after June 7, 2010.
(2) The repair was approved by the FAA or by a Boeing Company
Authorized Representative or the Boeing Commercial Airplanes
Organization Designation Authorization (ODA) that has been
authorized by the Manager, Seattle Aircraft Certification Office
(ACO) to make such findings; and
(3) The repair extends a minimum of three rows of fasteners on
each side of the chem-mill line in the circumferential direction.
(n) Accomplishing a modification of the chem-milled steps at any
location identified in Boeing Alert Service Bulletin 737-53A1301,
Revision 2, dated April 25, 2011, using a method approved in
accordance with the procedures specified in paragraph (q)(1) of this
AD, terminates the repetitive inspections required by paragraphs (g)
and (j) of this AD for the modified area only.

Group 26 Airplanes

(o) For Group 26 airplanes identified in Boeing Alert Service
Bulletin 737-53A1301, Revision 2, dated April 25, 2011: Within 1,800
flight cycles after the effective date of this AD, accomplish
applicable inspections and corrective action, as identified in the
service bulletin, using a method approved in accordance with the
procedures specified in paragraph (q)(1) of this AD.

Credit for Actions Accomplished in Accordance With Previous Service
Information

(p) Actions done before the effective date of this AD in
accordance with Boeing Alert Service Bulletin 737-53A1301, Revision
1, dated June 7, 2010, are acceptable for compliance with the
corresponding requirements of this AD.

Alternative Methods of Compliance (AMOCs)

(q)(1) The Manager, Seattle ACO, FAA, has the authority to
approve AMOCs for this AD, if requested using the procedures found
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request
to your principal inspector or local Flight Standards District
Office, as appropriate. If sending information directly to the
manager of the ACO, send it to the attention of the person
identified in the Related Information section of this AD.
Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair required by this AD if it is approved by the
Boeing Commercial Airplanes ODA that has been authorized by the
Manager, Seattle ACO to make those findings. For a repair method to
be approved, the repair must meet the certification basis of the
airplane.

Related Information

(r) For more information about this AD, contact Wayne Lockett,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington
98057-3356; phone: 425-917-6447; fax: 425-917-6590; e-mail:
wayne.lockett@faa.gov.
(s) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone
206-544-5000, extension 1; fax 206-766-5680; e-mail
me.boecom@boeing.com; Internet https://www.myboeingfleet.com. You
may review copies of the referenced service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington. For information on the availability of this material at
the FAA, call 425-227-1221.

Issued in Renton, Washington, on August 25, 2011.
Ali Bahrami,
Manager Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2011-22370 Filed 8-31-11; 8:45 am]
BILLING CODE 4910-13-P

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