Source: https://www.federalregister.gov/articles/2011/01/11/2011-367/airworthiness-directives-the-boeing-company-model-737-600--700--700c--800--900-and--900er-series
Timestamp: 2016-05-28 13:47:04
Document Index: 316851480

Matched Legal Cases: ['art 39', 'art 39', 'art 2', 'art 2', 'art 2', '§ 39', 'art 2', 'art 2']

Federal Register | Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER Series Airplanes
Publication Date: Tuesday, January 11, 2011
Dates: You may send comments by any of the following methods:
Action: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.
76 FR 1552
-1556 (5 pages)
Docket No. FAA-2008-1118
Directorate Identifier 2007-NM-318-AD
Document Number: 2011-367
Shorter URL: https://federalregister.gov/a/2011-367 Related Topics
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. The original NPRM would have superseded an existing AD that currently requires reviewing the airplane maintenance records to determine whether an engine has been removed from the airplane since the airplane was manufactured. For airplanes on which an engine has been removed, the existing AD also requires an inspection of the aft engine mount to determine if the center link assembly is correctly installed, and follow-on actions if necessary. The original NPRM proposed to require the same actions for airplanes on which the engine has not been previously removed. The original NPRM resulted from reports indicating that operators found that the center link assembly for the aft engine mount was reversed on several airplanes that had not had an engine removed since delivery. This new action revises the original NPRM by expanding the applicability to include Model 737-900ER airplanes. We are proposing this supplemental NPRM to prevent increased structural loads on the aft engine mount, which could result in failure of the aft engine mount and consequent separation of the engine from the airplane.
Actions Since Original NPRM Was Issued
Request for Exemption From AD Requirements
Request To Change Paragraph (d)
Request To Change Paragraph (n)
Request To Clarify Requirements in Paragraph (n)
Request To Change Paragraphs (i) and (o)
Explanation of Change to Costs of Compliance
Restatement of the Requirements of AD 2003-03-01
Review of Maintenance Records
Inspection of Engines That Have Been Removed to Determine if Center Link Assembly is Installed Correctly
Follow-on and Corrective Actions
Inspection of Engines That Have Not Been Removed To Determine if Center Link Assembly Is Installed Correctly
Table 1—Previous Service Bulletins
We must receive comments on this supplemental NPRM by February 25, 2011.
Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6450; fax (425) 917-6590.
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-2008-1118; Directorate Identifier 2007-NM-318-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 proposed to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) with a notice of proposed rulemaking (NPRM) for an AD (the “original NPRM”) to supersede AD 2003-03-01, Amendment 39-13025 (68 FR 4367, January 29, 2003). The original NPRM applied to all Model 737-600, -700, -700C, -800, and -900 series airplanes. The original NPRM was published in the Federal Register on October 30, 2008 (73 FR 64568). The original NPRM would have superseded an existing AD that currently requires reviewing the airplane maintenance records to determine whether an engine has been removed from the airplane since the airplane was manufactured. For airplanes on which an engine has been removed, the existing AD also requires an inspection of the aft engine mount to determine if the center link assembly is correctly installed, and follow-on actions if necessary. The original NPRM proposed to require the same actions for airplanes on which the engine has not been previously removed.
Actions Since Original NPRM Was Issued Back to Top
Since we issued the original NPRM, the manufacturer has informed us that Model 737-900ER airplanes should be included in the applicability of the supplemental NPRM. Model 737-900ER airplanes were not being produced in May 2004 when Revision 3, dated May 20, 2004, of Boeing Alert Service Bulletin 737-71A1462, was issued. (Revision 3 was referred to as an appropriate source of service information for accomplishing the proposed actions in the original NPRM.) Following production it was determined that the affected aft engine mount is interchangeable with Model 737-900ER airplanes; however, those airplanes were inspected in production to ensure that the center link was properly installed. Therefore, the requirements in the existing AD do not apply to those airplanes. However, since we are including airplanes on which the engines have been removed since production, we have added Model 737-900ER airplanes to the applicability section of this supplemental NPRM.
Request for Exemption From AD Requirements Back to Top
American Airlines (AA) asks that all operators that have performed the actions specified in Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004, be exempt from repeating maintenance actions in accordance with the original NPRM for a maintenance program that is already in place and proven effective. AA states that it has exceeded the requirements of AD 2003-03-01 by inspecting both engine aft mount center link assemblies, regardless of the stipulation in the existing AD, which limited the inspection requirement to engines removed since the airplane date of manufacture. AA adds that the inspections revealed that none of its installed or spare engines had incorrectly installed aft mount center link assemblies. AA notes that it is doing Part 2 of the Accomplishment Instructions of the service bulletin at every engine shop visit, and has implemented maintenance task documentation to verify the proper aft mount center link configuration at every engine change. AA concludes that it has not accepted delivery of any additional Model 737 airplanes since the release of the existing AD and Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004.
We acknowledge the commenter's request. Actions done in accordance with Boeing Alert Service Bulletin 737-71A1462, Revision 3, before the effective date of this AD are acceptable for compliance with the AD, as indicated by the phrase “unless the actions have already been done” in paragraph (f) of this AD. We have made no change to the supplemental NPRM in this regard.
Request To Change Paragraph (d) Back to Top
Boeing asks that paragraph (d) of the original NPRM be changed to indicate that the center link assembly for the aft engine mount was reversed on one airplane that had not had an engine removed since delivery. Boeing is aware of only one such report.
We do not agree with the commenter. We have received another report indicating that some airplanes were found with the engine mounts installed incorrectly on engines that had not been removed since airplane delivery. Therefore, we have not changed paragraph (d) of the NPRM (paragraph (e) of the supplemental NPRM).
Request To Change Paragraph (n) Back to Top
Boeing asks that paragraph (n) of the original NPRM be changed to clarify parts not affected by the “Parts Installation” paragraph by including the permanent part marking on the center link assembly, as specified in Part 2 of the Work Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004. Boeing states that this change would be equivalent to an existing alternative method of compliance (AMOC) for AD 2003-03-01, requiring the installation of marked engine mounts, as specified in the approved section of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004.
We agree with the commenter for the reasons provided. We have changed paragraph (n) of the supplemental NPRM to include permanent part marking on the center link assembly, as specified in Part 2 of the Work Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004.
Request To Clarify Requirements in Paragraph (n) Back to Top
Japan Airlines (JAL) asks for clarification whether the requirement in paragraph (n) of the original NPRM applies only to airplanes affected by Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004; or to all Model 737-600, -700, -700C, -800, and -900 series airplanes. JAL states that if the requirement in paragraph (n) applies to all Model 737NG (next generation) airplanes then a change should be made to paragraph (n) of the supplemental NPRM for clarification.
We acknowledge the commenter's concern and provide the following clarification. As noted under “Actions Since Original NPRM Was Issued,” we have added Model 737-900ER airplanes to the applicability section of this supplemental NPRM; therefore, the requirement in paragraph (n) of the supplemental NPRM applies to all Model 737NG airplanes. No change to paragraph (n) of the supplemental NPRM is necessary.
Request To Change Paragraphs (i) and (o) Back to Top
CFM International states that the acronym CFMI is not accurate and recommends using CFM International (CFM) throughout the NPRM.
We agree that the correct acronym should be used in the supplemental NPRM and in future rulemaking. However, CFMI is not referred to anywhere in this supplemental NPRM; therefore, no change is necessary.
CFM also asks that paragraphs (i) and (o) of the original NPRM be changed to include the Engine and Propeller Directorate, Engine Certification Office (ECO), as an approved source for obtaining repair procedures. CFM states that the engine mounting lugs and adjacent engine turbine rear frame are under the responsibility of CFM as part of the engine type certificate. CFM notes that it is in charge of approval of repairs by delegation of both engine authorities, which are the FAA and European Aviation Safety Agency (EASA); CFM is a joint certification. CFM adds that for any part problems it contacts the ECO, in Burlington, Massachusetts, and the EASA Engine Certification Office, in Cologne, Germany. In light of this, CFM does not recommend the parts be repaired under approval of a Boeing Representative.
We partially agree with the commenter for the reasons provided. We agree that the appropriate office for approval of certain repairs specified in the original NPRM is the ECO. Paragraph (i) of the original NPRM is a restatement of the requirements in AD 2003-03-01. However, paragraph (i) of the supplemental NPRM does refer to paragraph (o) of the supplemental NPRM for AMOC approval. We have changed paragraph (o) of this supplemental NPRM to allow for certain AMOC approvals by the ECO.
Explanation of Additional Changes Made to This Supplemental NPRM Back to Top
We have changed this supplemental NPRM to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models.
We have added a new paragraph (d) to this supplemental NPRM to provide the Air Transport Association (ATA) of America subject code 71: Powerplant. This code is added to make this supplemental NPRM parallel with other new AD actions. We have reidentified subsequent paragraphs accordingly. FAA's Determination and Proposed Requirements of the Supplemental NPRM Back to Top
Explanation of Change to Costs of Compliance Back to Top
Since issuance of the original NPRM, we have increased the labor rate in the Costs of Compliance from $80 per work hour to $85 per work hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate.
There are about 1,846 airplanes of the affected design in the worldwide fleet. We estimate that 854 airplanes of U.S. registry would be affected by this proposed AD. There are no new requirements in this proposed AD; however, we have expanded the applicability as noted under “Actions Since Original NPRM Was Issued.” The current costs for this proposed AD are recalculated for the convenience of affected operators, as follows:
Maintenance records review (required by AD 2003-03-01)
Inspection for correct installation of center link assembly (new proposed action)
2. The FAA amends § 39.13 by removing amendment 39-13025 (68 FR 4367, January 29, 2003) and adding the following new AD:
The Boeing Company: Docket No. FAA-2008-1118; Directorate Identifier 2007-NM-318-AD.
(a) The FAA must receive comments on this AD action by February 25, 2011.
(b) This AD supersedes AD 2003-03-01, Amendment 39-13025.
(c) This AD applies to all The Boeing Company Model 737 -600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category.
(d) Air Transport Association (ATA) of America Code 71: Powerplant.
(e) This AD results from reports indicating that operators found that the center link assembly for the aft engine mount was reversed on several airplanes that had not had an engine removed since delivery. We are issuing this AD to prevent increased structural loads on the aft engine mount, which could result in failure of the aft engine mount and consequent separation of the engine from the airplane.
Restatement of the Requirements of AD 2003-03-01 Back to Top
Review of Maintenance Records Back to Top
(g) For Model 737-600, -700, -700C, -800, and -900 series airplanes: Within 90 days after February 13, 2003 (the effective date of AD 2003-03-01), review the airplane maintenance records to determine whether either engine has been removed since the airplane's date of manufacture. If neither engine has been removed since the airplane's date of manufacture, no further action is required by this paragraph.
Inspection of Engines That Have Been Removed to Determine if Center Link Assembly is Installed Correctly Back to Top
(h) For Model 737-600, -700, -700C, -800, and -900 series airplanes on which any installed engine has been removed from the airplane since the airplane's date of manufacture: Within 90 days after February 13, 2003, do a one-time general visual inspection to determine if the center link assembly of the aft engine mount is installed correctly, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 1, dated November 7, 2002; or Revision 3, dated May 20, 2004. If the center link assembly is installed correctly, no further action is required by paragraph (h) or (i) of this AD for that engine. As of the effective date of this AD, use only Boeing Alert Service Bulletin 737-71A1462, Revision 3.
For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hanger lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
Follow-on and Corrective Actions Back to Top
(i) For airplanes on which any center link assembly is found installed incorrectly during any inspection required by paragraph (h), (k), or (l) of this AD: Before further flight, do the actions specified in paragraphs (i)(1), (i)(2), and (i)(3) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 1, dated November 7, 2002; or Revision 3, dated May 20, 2004; except that it is not necessary to submit a report of findings to the airplane manufacturer. As of the effective date of this AD, use only Boeing Alert Service Bulletin 737-71A1462, Revision 3.
(1) Remove the center link assembly and install it correctly.
(2) Perform a detailed inspection of the engine mounting lugs and engine turbine rear frame for cracking, yielding, buckling, or wear damage.
(3) Perform a detailed inspection of the hardware for the aft engine mount; including the center link assembly, right link assembly, aft mount hanger assembly, and link pins; for cracking, yielding, buckling, or wear damage.
Repair Back to Top
(j) If any cracking, yielding, buckling, or wear damage is found during the inspections required by paragraphs (i)(2) and (i)(3) of this AD: Before further flight, replace the discrepant part with a new or serviceable part, or repair in accordance with a method approved in accordance with the procedures specified in paragraph (o) of this AD.
New Requirements of This AD Back to Top
Inspection of Engines That Have Not Been Removed To Determine if Center Link Assembly Is Installed Correctly Back to Top
(k) For airplanes identified in Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004, on which any installed engine has not been removed from the airplane since the airplane's date of manufacture: Within 90 days after the effective date of this AD, do a detailed inspection to determine if the center link assembly of the aft engine mount is installed correctly, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004. If the center link is installed correctly, no further action is required by this paragraph for that engine.
(l) For airplanes on which any center link assembly is found installed incorrectly during the inspection required by paragraph (k) of this AD: Before further flight, do the follow-on and corrective actions required by paragraph (i) of this AD.
Credit for Actions Done Using Previous Service Information Back to Top
(m) Inspections and corrective actions done before the effective date of this AD in accordance with a Boeing service bulletin listed in Table 1 of this AD are acceptable for compliance with the corresponding requirements of this AD.
Table 1—Previous Service Bulletins Back to Top
737-71A1462
November 7, 2002.
(n) As of the effective date of this AD, no person may install an engine on any airplane identified in paragraph (c) of this AD unless the actions required by paragraph (n)(1) or (n)(2) of this AD are accomplished.
(1) The inspection is accomplished in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004, and the center link assembly of the aft engine mount is found to be installed correctly.
(2) The hanger fitting and center link assembly are marked and part marked in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004.
For hanger fittings and center link assemblies marked and part marked in production, as specified in Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 3, dated May 20, 2004, the actions specified in paragraph (n)(2) of this AD do not apply.
(o) The certification office specified in paragraph (o)(1) or (o)(2) of this AD, as applicable, has the authority to approve AMOCs for paragraphs (i) and (j) of this AD, if requested using the procedures found in 14 CFR 39.19.
(1) For the structure identified in paragraph (i)(2) of this AD: The Manager, Engine Certification Office (ECO), FAA. Send information to ATTN: Antonio Cancelliere, Aerospace Engineer, ANE-141, FAA, ECO, 12 New England Executive Park, Burlington, MA 01803-5299; telephone 781-238-7751; fax 781-238-7199.
(2) For the structure identified in paragraph (i)(3) of this AD: The Manager, Seattle Aircraft Certification Office (ACO), FAA. Send information to ATTN: Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6450; fax (425) 917-6590. Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
(3) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.
(4) An AMOC that provides an acceptable level of safety may be used for any repair required by paragraph (i)(3) of this AD if it is approved by Boeing Commercial Airplanes Organization Designation Authorization (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, and the approval must specifically refer to this AD.
Assistant Directorate Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. 2011-367 Filed 1-10-11; 8:45 am]