AD 2021-19-12

The FAA is adopting a new airworthiness directive (AD) for MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet Series 700, 701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by reports and a design review indicating that there could be possible corrosion on the main landing gear (MLG) outer cylinder at the interface with the gland nut on the shock strut installation and on the forward and aft trunnion pins in the MLG dressed shock strut assembly. This AD requires detailed inspections for corrosion on the MLG outer cylinder assemblies, certain MLG dressed shock strut assemblies, and the MLG outer cylinder at the gland nut threads, thread relief groove, and chamfer; a detailed inspection for the presence of corrosion-inhibiting compound (CIC) on the MLG forward and aft trunnion pins and grease adapter assemblies; applicable corrective actions; application of primer, paint, and CIC as applicable; re-identification of certain part numbers; and marking of the MOD STATUS field of the nameplate of certain parts. The FAA is issuing this AD to address the unsafe condition on these products.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive: \n\n((Page 55482)) \n\n2021-19-12 MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.): Amendment 39-21730; Docket No. FAA-2021-0309; Project Identifier MCAI-2020-00918-T. \n\n(a) Effective Date \n\n\n\tThis airworthiness directive (AD) is effective November 10, 2021. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to the MHI RJ Aviation ULC (type certificate previously held by Bombardier, Inc.) airplanes, certificated in any category, specified in paragraphs (c)(1) through (3) of this AD. \n\t(1) Model CL-600-2C10(Regional Jet Series 700, 701 & 702) and Model CL-600-2C11 (Regional Jet Series 550) airplanes, serial numbers 10002 and subsequent. \n\t(2) Model CL-600-2D15 (Regional Jet Series 705) airplanes and CL-600-2D24 (Regional Jet Series 900) airplanes, serial numbers 15001 and subsequent. \n\t(3) Model CL-600-2E25 (Regional Jet Series 1000) airplanes, serial numbers 19001 and subsequent. \n\n(d) Subject \n\n\n\tAir Transport Association (ATA) of America Code 32, Landing Gear. \n\n(e) Reason \n\n\n\tThis AD was prompted by reports and a design review indicating that there could be corrosion on the main landing gear (MLG) outer cylinder assemblies at the interface with the gland nut on the shock strut installation and on the forward and aft trunnion pins in the MLG dressed shock strut assemblies; primer was not correctly applied at the gland nut thread relief groove and chamfer areas on certain MLG outer cylinders during production; and corrosion-inhibiting compound (CIC) could have inadvertently been removed from certain MLG forward and aft trunnion pins and grease adapter assemblies during maintenance. The FAA is issuing this AD to address undetected corrosion on the MLG forward and aft trunnion pins, and the gland nut interface on certain MLG outer cylinders, which could result in an MLG collapse. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Inspection and Application of Corrosion Protection for MLG Outer Cylinder Assemblies and Certain MLG Dressed Shock Strut Assemblies \n\n\n\tFor airplanes identified in paragraphs (c)(1) and (2) of this AD with MLG outer cylinder assemblies and MLG dressed shock strut assemblies having part numbers and serial numbers specified in the effectivity tables in Section 1.A.(1) of Bombardier Service Bulletin 670BA-32-024, Revision C, dated February 11, 2015 (Bombardier Service Bulletin 670BA-32-024, Revision C): At the applicable time specified in paragraph (g)(1) or (2) of this AD, do a detailed visual inspection for corrosion, and all other required actions specified in, and in accordance with, Section 2., Part A, of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32- 024, Revision C. \n\t(1) For MLG assemblies that have accumulated 12,500 total flight hours or less, and have been in service for 72 months or less from entry into service or the last overhaul date: Within 6,500 flight hours or 36 months, whichever comes first, after the effective date of this AD. \n\t(2) For MLG assemblies that have accumulated more than 12,500 total flight hours, or have been in service for more than 72 months from entry into service or the last overhaul date: Within 3,500 flight hours or 24 months, whichever occurs first, after the effective date of this AD. \n\n(h) Inspection of Certain Other MLG Dressed Shock Strut Assemblies and Corrective Action \n\n\n\tFor airplanes identified in paragraphs (c)(1) and (2) of this AD, equipped with MLG dressed shockstrut assemblies having part numbers (P/Ns) 49000-25 through 49000-46 and P/Ns 49050-15 through 49050-22, on which the MLG active dynamic seal has been replaced with the spare dynamic seal as specified in Bombardier CRJ700/705/ 900/1000 Aircraft Maintenance Manual (AMM), CSP B-001, Task 32-11- 10-960-802, Revision 37, dated November 25, 2011, or earlier: At the applicable time specified in paragraph (h)(1) or (2) of this AD, do a detailed visual inspection of the MLG dressed shock strut assemblies for corrosion, and all applicable corrective actions, in accordance with Section 2., Part B, of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-024, Revision C. \n\t(1) For MLG assemblies that have accumulated 12,500 total flight hours or less, and have been in service for 72 months or less from entry into service or the last overhaul date: Within 6,500 flight hours or 36 months, whichever comes first, after the effective date of this AD. \n\t(2) For MLG assemblies thathave accumulated more than 12,500 total flight hours, or have been in service for more than 72 months from entry into service or the last overhaul date: Within 3,500 flight hours or 24 months, whichever occurs first, after the effective date of this AD. \n\n(i) Inspection of MLG Outer Cylinder at the Gland Nut Threads, Thread Relief Groove, and Chamfer and Corrective Action \n\n\n\tFor airplanes identified in paragraphs (c)(1) through (3) of this AD equipped with MLG outer cylinder assemblies having part numbers and serial numbers specified in Section 1.A., Effectivity, of Bombardier Service Bulletin 670BA-32-052, dated February 9, 2015: Within 6,500 flight hours or 36 months, whichever occurs first after the effective date of this AD, do a detailed visual inspection of the MLG shock strut outer cylinder assemblies, and do all other required actions specified in, and in accordance with, Section 2. of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-052, dated February 9, 2015. \n\n(j) Inspection of Certain MLG Forward and Aft Trunnion Pins, and Corrective Action \n\n\n\tFor airplanes identified in paragraphs (c)(1) through (3) of this AD equipped with MLG forward and aft trunnion pins and grease adapter assemblies having part numbers and serial numbers specified in Section 1.A., Effectivity, of Bombardier Service Bulletin 670BA- 32-034, Revision B, dated December 21, 2018 (Bombardier Service Bulletin 670BA-32-034, Revision B): At the applicable time specified in paragraph (j)(1) or (2) of this AD, do a detailed visual inspection of the MLG forward and aft trunnion pins and do all applicable corrective actions, in accordance with Section 2.B. and paragraphs 2.C.(6) and (8) of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-034, Revision B. \n\tNote 1 to the introductory text of paragraph (j): The corrective action is applicable only to MLG forward and aft trunnion pins having P/Ns 49101-9, -11, and -13 reworked from P/Ns 49101-1, -5, and -7, as specified in the procedures in Goodrich Service Bulletin 49101-32-47, any revision. The corrective action is not applicable to MLG forward and aft trunnion pins having P/Ns 49101-9, -11, and - 13 that were installed as original equipment or purchased from Goodrich Landing Gear. \n\t(1) For MLG forward and aft trunnion pins and grease adapter assemblies that have not had the procedures specified in Goodrich Service Bulletin 49101-32-47, any revision, incorporated, at the applicable time specified in paragraph (j)(1)(i) or (ii) of this AD. \n\t(i) For MLG forward and aft trunnion pins that have accumulated 10,000 total flight hours or less, and have been in service 60 months or less from the entry into service or last overhaul date: Within 6,500 flight hours or 36 months, whichever occurs first, after the effective date of this AD. \n\t(ii) For MLG forward and aft trunnion pins that have accumulated more than 10,000 total flight hours, or have been in service for morethan 60 months from entry into service or last overhaul date: Within 3,000 flight hours or 24 months, whichever occurs first, after the effective date of this AD. \n\t(2) For MLG forward and aft trunnion pins that have had the procedures specified in Goodrich Service Bulletin 49101-32-47, any revision, incorporated: Within 6,500 flight hours or 36 months, whichever occurs first, after the effective date of this AD. \n\n(k) Inspection of Certain Other MLG Trunnion Pins Having P/Ns 49101-9, 49101-11, and 49101-13, Maintained Using Certain Maintenance Instructions \n\n\n\tFor airplanes identified in paragraphs (c)(1) through (3) of this AD equipped with MLG forward and aft trunnion pins having P/Ns 49101-9, 49101-11, and 49101-13 that were maintained in accordance with the tasks identified in paragraphs (k)(1) through (4) of this AD: Within 6,500 flight hours or 36 months after the effective date of this AD, whichever occurs first, do a detailed visual inspection of the MLG forward and afttrunnion pins, and do all applicable corrective actions, in accordance with Section 2. of the Accomplishment \n\n((Page 55483)) \n\nInstructions of Bombardier Service Bulletin 670BA-32-039, dated February 29, 2012. \n\tNote 2 to the introductory text of paragraph (k): The corrective action described in this paragraph is not applicable to MLG forward and aft trunnion pins having P/Ns 49101-9, -11, and -13 reworked from P/Ns 49101-1, -5, and -7 as specified in the procedures in Goodrich SB 49101-32-47, any revision. The corrective action described in this paragraph is applicable to MLG forward and aft trunnion pins having P/Ns 49101-9, -11, and -13 installed as original equipment or purchased from Goodrich Landing Gear. \n\t(1) Bombardier CRJ700/705/900/1000 AMM, CSP B-001, Task 32-11- 05-400-801 A01, Revision 31, dated March 20, 2010, or earlier. \n\t(2) Bombardier CRJ700/705/900/1000 AMM, CSP B-001, Task 32-11- 05-400-801 A02, Revision 34, dated November 20, 2010, or earlier. \n\t(3) Bombardier CRJ700/705/900/1000 AMM, CSP B-001, Task 32-11- 05-400-804 A01, Revision 35, dated March 20, 2011, or earlier. \n\t(4) Bombardier CRJ700/705/900/1000 AMM, CSP B-001, Task 32-11- 05-400-805 A01, Revision 35, dated March 20, 2011, or earlier. \n\n(l) Credit for Previous Actions \n\n\n\t(1) This paragraph provides credit for actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Section 2., Part A, of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32- 024, Revision B, dated December 19, 2012. \n\t(2) This paragraph provides credit for actions required by paragraph (h) of this AD if those actions were performed before the effective date of this AD using Section 2., Part B, of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32- 024, Revision B, dated December 19, 2012; or Bombardier CRJ700/705/ 900/1000 AMM, CSP B-001, Task 32-11-10-960-802, Revision 38, dated March 25, 2012. \n\t(3) This paragraph provides credit for actions required by paragraph (j) of this AD if those actions were performed before the effective date of this AD using Section 2.B. and paragraphs 2.C.(6) and (8) of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-034, dated February 29, 2012; or Revision A, dated August 17, 2012. \n\t(4) This paragraph provides credit for actions required by paragraph (k) of this AD, if those actions were performed before the effective date of this AD using the service information specified in paragraphs (l)(4)(i) through (iv) of this AD. \n\t(i) Bombardier CRJ700/900/1000 AMM, CSP B-001, Task 32-11-05- 400-801 A01, Revision 38, dated March 25, 2012. \n\t(ii) Bombardier CRJ700/900/1000 AMM, CSP B-001, Task 32-11-05- 400-801 A02, Revision 38, dated March 25, 2012. \n\t(iii) Bombardier CRJ700/900/1000 AMM, CSP B-001, Task 32-11-05- 400-804 A01, Revision 37, dated November 25, 2011, for actions specified in Section 2.B.(1) of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-039, dated February 29, 2012. \n\t(iv) Bombardier CRJ700/900/1000 AMM, CSP B-001, Task 32-11-05- 400-805 A01, Revision 37, dated November 25, 2011, for actions specified in Section 2.B.(2) of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-039, dated February 29, 2012. \n\n(m) No Requirement for Return of Parts \n\n\n\tAlthough certain service information referenced in this AD specifies to return damaged MLG trunnion pins to Goodrich Landing Gear, this AD does not include that requirement. \n\n(n) Other FAA AD Provisions \n\n\n\tThe following provisions also apply to this AD: \n\t(1) Alternative Methods of Compliance (AMOCs): The Manager, New York ACO Branch, 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 certification office, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531. 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. \n\t(2) Contacting the Manufacturer: For any requirement in this AD to obtain instructions from a manufacturer, the instructions must be accomplished using a method approved by the Manager, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or MHI RJ Aviation ULC's TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature. \n\n(o) Related Information \n\n\n\t(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) TCCA AD CF-2019-17R1, dated June 18, 2020, for related information. This MCAI may be found in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0309. \n\t(2) For more information about this AD, contact: Darren Gassetto, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7323; fax 516-794- 5531; email 9-avs-nyaco-cos@faa.gov. \n\n(p) Material Incorporated by Reference \n\n\n\t(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise. \n\t(i) Bombardier Service Bulletin 670BA-32-024, Revision C, dated February 11, 2015. \n\t(ii) Bombardier Service Bulletin 670BA-32-034, Revision B, dated December 21,2018. \n\t(iii) Bombardier Service Bulletin 670BA-32-039, dated February 29, 2012. \n\t(iv) Bombardier Service Bulletin 670BA-32-052, dated February 9, 2015. \n\t(3) For service information identified in this AD, contact MHI RJ Aviation ULC, 12655 Henri-Fabre Blvd., Mirabel, Qu(eacute)bec J7N 1E1 Canada; Widebody Customer Response Center North America toll- free telephone +1-844-272-2720 or direct-dial telephone +1-514-855- 8500; fax +1-514-855-8501; email thd.crj@mhirj.com; internet https://eservices.aero.bombardier.com. \n\t(4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. \n\t(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email fr.inspection@nara.gov, or goto: https://www.archives.gov/federal-register/cfr/ibr-locations.html. \n\n\n\tIssued on September 30, 2021. Ross Landes, Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service. (FR Doc. 2021-21830 Filed 10-5-21; 8:45 am) BILLING CODE 4910-13-P

Background \n\n\n\tTransport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued TCCA AD CF-2019-17R1, dated June 18, 2020 (TCCA AD CF-2019-17R1, dated June 18, 2020) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for MHI RJ Aviation ULC (type certificate previously held by Bombardier, Inc.) Model CL-600-2C10 (Regional Jet Series 700, 701 & 702) airplanes, Model CL-600-2C11 (Regional Jet Series 550) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, CL-600-2D24 (Regional Jet Series 900) airplanes, and Model CL-600-2E25 (Regional Jet Series 1000) airplanes. You may examine the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0309. \n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to MHI RJ Aviation ULC ModelCL-600-2C10 (Regional Jet Series 700, 701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), CL- 600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. The NPRM published in the Federal Register on April 20, 2021 (86 FR 20461). The NPRM was prompted by reports and a design review indicating that there could be corrosion on the MLG outer cylinder assemblies and certain MLG dressed shock strut assemblies; primer was not correctly applied at the gland nut thread relief groove and chamfer areas on certain MLG outer cylinders during production; and CIC was inadvertently removed from certain MLG forward and aft trunnion pins and grease adapter assemblies during maintenance. The NPRM proposed to require detailed inspections for corrosion on the MLG outer cylinder assemblies, certain MLG dressed shock strut assemblies, and the MLG outer cylinder at the gland nut threads, thread relief groove, and chamfer; a detailed inspection for the presence of CIC on the MLG forward and aft trunnion pins and grease adapter assemblies; applicable corrective actions; application of primer, paint, and CIC as applicable; re-identification of certain part numbers; and marking of the MOD STATUS field of the nameplate of certain parts. The FAA is issuing this AD to address undetected corrosion on the MLG forward and aft trunnion pins, and the gland nut interface on certain MLG outer cylinders, which could result in an MLG collapse. See the MCAI for additional background information. \n\nComments \n\n\n\tThe FAA gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment. \n\nSupport for the NPRM \n\n\n\tAir Line Pilots Association, International (ALPA) stated that it supports the NPRM. \n\nRequest to Separate the Proposed AD Into Two Separate AD Actions \n\n\n\tSkyWest Airlines (SkyWest) requested that the proposed AD be separated into two AD actions. The commenter recommended that one AD address the MLG outer cylinder assemblies and dressed shock strut assemblies and the other AD address the MLG forward and aft trunnion pins. The commenter stated that there are multiple service bulletins and requirements specified in the proposed AD that are related to different MLG components. \n\tThe FAA disagrees with the commenter's request. The FAA acknowledges that this AD includes requirements for different MLG components and specifies multiple service bulletins; however, these MLG components are interrelated. In order to address the identified unsafe condition the requirements must be completed at the same time. In addition, the AD body is organized to facilitate an owner/operator's compliance with the requirements of this AD. Each header for paragraphs (g) through (k) of this AD identifies the affected MLG component and the applicable actions. The FAA has not changed this AD in regard to this issue. \n\nRequest To Allow Credit for Vendor Service Bulletins \n\n\n\tSkyWest requested that paragraph (l) of the proposed AD, Credit for Previous Actions, be revised to include the applicable vendor service bulletins published by Goodrich. The commenter stated that this would alleviate the need to request multiple alternative methods of compliance (AMOCs) for airplanes on which the MLG gear is returned from overhaul with only the actions described in the Goodrich service bulletins accomplished rather that the actions described in the corresponding Bombardier service bulletins. The commenter noted that each Bombardier service bulletin specified in paragraph (l) of the proposed AD refers to a corresponding Goodrich service bulletin. \n\tThe FAA agrees to clarify what must be done if certain actions required by this AD have already been accomplished. Paragraph (f) of this AD states ''Comply with this AD within the compliance times specified, unless already done.'' If an operator has already accomplished some of the actions required by this AD then only the remaining actions need to be completed. Therefore, for airplanes that have already incorporated the actions described in UTC Aerospace Systems (Goodrich Aerospace Canada Ltd) Service Bulletin 49101-32-72, Goodrich Service Bulletin 49200-32-44, or Goodrich Service Bulletin 49200-32-80 prior to the effective date of this AD, only the remaining requirements described in the corresponding Bombardier service bulletins need to be completed on those airplanes. \n\tThe FAA does not agree with granting complete credit for the actions required by paragraphs (g), (i), and (j) of this AD using only the procedures described in the applicable Goodrich service \n\n((Page 55481)) \n\nbulletins. There are additional actions required for these inspections, including corrective actions and operational tests, that are included in the Bombardier service bulletins but not in the corresponding Goodrich service bulletins. \n\tIn regards to paragraph (l)in this AD, Credit for Previous Actions, the intent of that paragraph is to provide credit for actions required by paragraphs (g), (h), and (j) of this AD if those actions were performed before the effective date of this AD using the certain earlier revisions of the applicable Bombardier service bulletins specified in paragraph (l) of this AD or equivalent service information. The FAA has not changed this AD in regard to this issue. \n\nConclusion \n\n\n\tThe FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tBombardier has issued the following service information. \n\tService Bulletin 670BA-32-024, Revision C, dated February 11, 2015, which describes procedures for a detailed visual inspection of the MLG outer cylinder assemblies and dressed shock strut assemblies for corrosion of the outer cylinder gland nut thread interface and relief area, and corrective actions including repair and corrosion removal. \n\tService Bulletin 670BA-32-034, Revision B, dated December 21, 2018, which describes procedures for a detailed visual inspection of the inside diameter of the MLG trunnion pins for discrepancies including the condition of paint and CIC and evidence of corrosion, and corrective actions including replacement and rework of the trunnion pins as applicable. \n\tService Bulletin 670BA-32-039, dated February 29, 2012, which describes procedures for inspections of the inner diameter of the MLG forward and aft trunnion pins for discrepancies including corrosion and inadequate CIC, and corrective actions including application of CIC and replacement of corroded forward and aft trunnion pins with serviceable parts. \n\tService Bulletin 670BA-32-052, dated February 9, 2015, which describes procedures for a detailed visual inspection of the gland nut thread relief groove and chamfer surface for the condition of the protective coating and for discrepancies including evidence of corrosion or rework at the gland nut thread relief groove and chamfer surface of the MLG shock strut outer cylinder assemblies, and corrective actions including corrosion removal. \n\tThis 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. \n\nDifferences Between This AD and the MCAI or Service Information \n\n\n\tAlthough certain service information specifies to return damaged MLG trunnion pins to Goodrich Landing Gear, that action would not be required by this AD. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 562 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tLabor cost Parts cost Cost per product Cost on U.S. operators ---------------------------------------------------------------------------------------------------------------- Up to 100 work-hours x $85 per hour = Up to $36,604.......... Up to $45,104.......... Up to $25,348,448. \n\tUp to $8,500. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tAccording to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. The FAA does not control warranty coverage for affected operators. As a result, the FAA has included all known costs in the cost estimate. \n\nAuthority for This Rulemaking \n\n\n\tTitle 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. \n\tThe FAA is 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. \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Will not affect intrastate aviation in Alaska, and \n\t(3) 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.