90 FR 92 pgs. 20375-20380 - Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes
Type: RULEVolume: 90Number: 92Pages: 20375 - 20380
Pages: 20375, 20376, 20377, 20378, 20379, 20380Docket number: [Docket No. FAA-2024-2326; Project Identifier MCAI-2023-01048-T; Amendment 39-23023; AD 2025-09-02]
FR document: [FR Doc. 2025-08338 Filed 5-13-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
[top]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2326; Project Identifier MCAI-2023-01048-T; Amendment 39-23023; AD 2025-09-02]
RIN 2120-AA64
Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
SUMMARY:
[top] The FAA is superseding Airworthiness Directive (AD) 2022-19-09, which applied to all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2022-19-09 required repetitive inspections of the left and right main landing gear (MLG) lower spindle pins to detect corrosion and applicable repair or replacement. This AD was prompted by reports of in-service findings of
DATES:
This AD is effective June 18, 2025.
The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of June 18, 2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-2326; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Material Incorporated by Reference:
• For Transport Canada material identified in this AD, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-663-3639; email TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca ; website at tc.canada.ca/en/aviation .
• You may view this material 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. It is also available at regulations.gov under Docket No. FAA-2024-2326.
FOR FURTHER INFORMATION CONTACT:
Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: 9-avs-nyaco-cos@faa.gov .
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2022-19-09, Amendment 39-22178 (87 FR 57799, September 22, 2022) (AD 2022-19-09). AD 2022-19-09 applied to all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2022-19-09 required repetitive inspections of the left and right MLG lower spindle pins to detect corrosion and applicable repair or replacement if necessary. The FAA issued AD 2022-19-09 to address corrosion and subsequent cracking of the MLG lower spindle pin, which could result in failure of the pin, and consequent collapse of the MLG.
The NPRM published in the Federal Register on October 3, 2024 (89 FR 80427). The NPRM was prompted by AD CF-2023-66, dated October 3, 2023, issued by Transport Canada, which is the aviation authority for Canada (Transport Canada AD CF-2023-66) (also referred to as the MCAI). The MCAI states that the tracking of usage was changed from the MLG to the MLG lower spindle assembly for inspections. The MCAI also states that replacement of the MLG lower spindle assembly, part number (P/N) 4115A0500-01, 4115A0500-02, or 5965A0500-01 with P/N 4115A0500-03 on Model BD-500-1A10 airplanes, or P/N 5965A0500-02 on Model BD-500-1A11 airplanes, constitutes a terminating action to the initial and repetitive inspections. The MCAI also removed airplanes from the applicability because Model BD-500-1A10 airplanes, serial numbers (S/Ns) 50068 and subsequent, and Model BD-500-1A11 airplanes, S/Ns 55249 and subsequent, have a newly designed MLG lower spindle assembly installed.
In the NPRM, the FAA proposed to continue to require certain actions in AD 2022-19-09, as specified in Transport Canada AD CF-2021-22R1, dated May 13, 2022 (Transport Canada AD CF-2021-22R1). The NPRM also proposed to require changing the tracking of flight cycles for inspections from the usage of the MLG to the usage of MLG lower spindle assemblies, replacing affected MLG lower spindle assemblies, removing airplanes from the applicability, and prohibiting the installation of affected parts under certain conditions, as specified in Transport Canada AD CF-2023-66. The FAA is issuing this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2024-2326.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Delta Air Lines (Delta). The following presents the comments received on the NPRM and the FAA's response to each comment.
Request To Correct a Part Number
Delta requested the FAA add a new exception to paragraph (h) of the proposed AD to correct a typographical error in the third paragraph of Part III of Transport Canada AD CF-2023-66. Delta stated that MLG lower spindle assembly, part number (P/N) 415A0500-02 should be replaced with P/N 4115A0500-02.
The FAA agrees and has added a new exception in paragraph (h)(6) of this AD accordingly.
Request To Confirm Part Re-Identification Is Not Required and Previous Alternative Methods of Compliance (AMOCs) Are Approved
Delta requested the FAA agree with Delta's interpretation that re-identification of the MLG is not required for compliance (RC) with the proposed AD. Delta noted that part III of Transport Canada AD CF-2023-66 specifies replacing the MLG lower spindle assembly, P/Ns 4115A0500-01, 4115A0500-02, and 5965A0500-01 ( i.e., a pre-modification spindle), with a new MLG lower spindle assembly, P/N 4115A0500-03 or 5965A0500-02 ( i.e., a post-modification spindle), according to Airbus Canada Limited Partnership Service Bulletin BD500-321006, Issue 001, dated July 31, 2023. Delta also noted the service bulletin contains procedures for replacing pre-modification spindles with post-modification spindles and re-identifying the MLG. Since the Transport Canada only specifies the replacement, Delta interpreted this to mean re-identification of the MLG is not RC. Delta stated it believes that re-identification of the MLG may be required under 14 CFR 43.10, "Disposition of life-limited aircraft parts," but operators may deviate from the re-identification procedures in the service bulletin without needing approval of an AMOC. Delta also stated it previously received an AMOC to FAA AD 2022-19-09 that allowed Delta to accomplish Issue 001 of Airbus Canada Limited Partnership Service Bulletin BD500-321006 as a terminating action and re-identify the MLG using its own process standards in lieu of the procedures in the service bulletin. Delta stated it believes that same allowance should be offered in the proposed AD since the re-identification is not part of the unsafe condition addressed by the proposed AD.
[top] The FAA partially agrees. The FAA agrees that AMOCs approved previously
However, the FAA does not agree with Delta's interpretation that re-identification of the MLG is not RC. Except as specified in paragraph (h) of this AD, this AD adopts all the required actions specified in Transport Canada AD CF-2023-66, which must be done according to the Accomplishment Instructions of the service information referenced in the Transport Canada AD. The Accomplishment Instructions specify that the service information is classified as mandatory by an AD, and that the Procedure section of the Accomplishment Instructions is RC and must be done to comply with the AD. The Accomplishment Instructions also specify the job set-up and close-up sections, except for the return-to-service tests, are recommended. Therefore, all procedures and tests identified as RC in the service information must be done to comply with this AD, except as required by paragraph (j)(2) of this AD. Further, the FAA reviewed Issue 001 of Airbus Canada Limited Partnership Service Bulletin BD500-321006 and determined that re-identification of the MLG is RC. Therefore, any substitutions or changes to the re-identification procedures would require approval of an AMOC. The FAA has not changed this AD in this regard. However, for clarity, the FAA has added paragraph (j)(3) to this AD, which explains the requirements for RC service information.
Request To Confirm Vendor Service Information Is Not Required
Delta requested the FAA agree with Delta's interpretation that certain vendor service information is not required to be done concurrently ( i.e., concurrent service information) with the Airbus Canada Limited Partnership (ACLP) service information referenced in Transport Canada AD CF-2023-66, in order to show compliance with the proposed AD. Delta's interpretation is that, although the concurrent service information is necessary to complete the actions in the ACLP service information, the concurrent service information is not required by the proposed AD. Delta therefore concluded that operators may deviate from the actions specified in the concurrent service information without needing an AMOC for compliance with the proposed AD. Delta notes that the concurrent service information simply changes the serving placard on the MLG and does not address the unsafe condition.
The FAA does not agree with Delta's interpretation. As discussed in the previous comment, all procedures and tests identified as RC in the ACLP service information must be done to comply with this AD, except as required by paragraph (j)(2) of this AD. Further, the FAA reviewed the ACLP service information and determined that accomplishment of the concurrent service information is RC. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC. The FAA has not changed this AD in this regard.
Request To Expand Applicability To Prohibit Parts Installation on All Airplanes
Delta requested the FAA prohibit installation of the MLG lower spindle assembly, P/Ns 4115A0500-01, 4115A0500-02, or 5965A0500-01 ( i.e., a pre-modification spindle) on all Model BD-500-1A10 and BD-500-1A11 airplanes. To accomplish this, Delta requested the FAA expand the applicability in paragraph (c) of the proposed AD to all airplane serial numbers, and then revise paragraph (g) of the proposed AD to limit accomplishment of the provisions of Transport Canada AD CF-2023-66 to airplanes delivered with a pre-modification spindle and prohibit installation of a pre-modification spindle either on airplanes not identified in Transport Canada AD CF-2023-66, or airplanes not equipped with a pre-modification spindle as of the effective date of this AD. As justification, Delta stated the proposed AD would only be applicable to airplanes delivered with a pre-modification spindle; therefore, the proposed requirement prohibiting installation of a pre-modification spindle would be limited to only those airplanes. Delta further stated it believes that airplanes delivered with a post-modification spindle should be subject to the same regulatory restrictions as those modified in service.
The FAA acknowledges that there is a possibility that the pre-modification spindles are rotable parts that could later be installed on airplanes delivered with an acceptable MLG lower spindle assembly, P/N 4115A0500-03 or 5965A0500-02 ( i.e., a post-modification spindle). However, the FAA does not agree with adding airplanes delivered with post-modification spindles to the applicability of this AD. Revising this AD as requested would necessitate (under the provisions of the Administrative Procedure Act) reissuing the notice, reopening the period for public comment, and eventually issuing a final rule. That process would delay the issuance of the final rule for the airplanes identified in this AD. The FAA has determined that further delay by revising this AD would be inappropriate since the FAA has determined that an unsafe condition exists, and that inspections and replacements must be conducted to ensure continued safety for the airplanes identified in this AD. However, the FAA may consider additional rulemaking to address airplanes not identified in this AD on which a pre-modification spindle might be installed. The FAA has not changed this AD in this regard.
Request To Use Spindle Assembly Utilization or MLG Utilization for Compliance Times
Delta requested the FAA allow the compliance times to be tracked based on either MLG utilization, or lower spindle assembly utilization. Delta recognized that using spindle assembly utilization would more accurately track the unsafe condition of corrosion on the spindle. During the comment period for FAA AD 2022-19-09, Delta stated it requested that the compliance times be based on MLG lower spindle assembly utilization instead of MLG utilization. Delta noted the FAA denied that request. In the preamble to AD 2022-19-09, the FAA stated that, although the MLG lower spindle pin is the affected part, operators are not required to track the MLG and spindle pin times separately. The FAA also stated it concurred with the provision in Transport Canada AD CF-2021-22R1 to track time on the MLG as the only metric relating to the spindle pin and determined that using compliance times based on the MLG utilization provides an acceptable level of safety. Given that the FAA had previously determined tracking the unsafe condition by MLG utilization provides an acceptable level of safety, Delta stated it would like the superseding AD to continue to allow this.
[top] The FAA does not agree with allowing the compliance time to be tracked by MLG utilization because Transport Canada has determined that tracking compliance based on MLG utilization no longer provides an acceptable level of safety to address the unsafe condition, and the FAA concurs
Since the initial inspections are on the low spindle assemblies, the repetitive interval specified in Part II of Transport Canada AD CF-2023-66, is also intended to be time on the lower spindle assemblies. For clarity, the FAA has added paragraph (h)(4) to this AD to specify the repetitive inspections are on the lower spindle assembly, i.e., at intervals not to exceed 3,000 flight cycles or 24 months on the lower spindle assembly.
Conclusion
This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered the comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2023-66 specifies procedures for repetitive inspections (including general visual, detailed, and liquid penetrant inspections) of the left and right MLG lower spindle assembly, P/N 4115A0500-01, 4115A0500-02, or 5965A0500-01, for corrosion, and applicable repair or replacement of the MLG lower spindle assembly with the same part number.
Transport Canada AD CF-2023-66 also specifies procedures to replace MLG lower spindle assemblies, P/Ns 4115A0500-01, 4115A0500-02, and 5965A0500-01, with P/N 4115A0500-03 (for Model BD-500-1A10 airplanes) or P/N 5965A0500-02 (for Model BD-500-1A11 airplanes), which constitutes a terminating action to the initial and repetitive inspections. Transport Canada AD CF-2023-66 also prohibits the installation of MLG lower spindle assembly, P/N 4115A0500-01, 415A0500-02, or 5965A0500-01, on any airplane once an airplane has installed P/N 4115A0500-03 or 5965A0500-02, as applicable. This material 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.
Costs of Compliance
The FAA estimates that this AD affects 98 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Retained actions from AD 2022-19-09 | Up to 25 work-hours × $85 per hour = $2,125 | $0 | Up to $2,125 | Up to $208,250, per inspection cycle. |
| New replacement | Up to 26 work-hours × $85 per hour = $2,210 | Up to $37,077 | Up to $39,287 | Up to $3,850,126. |
The FAA estimates the following costs to do any necessary on-condition actions that would be required based on the results of any required actions. The FAA has no way of determining the number of aircraft that might need these on-condition actions:
| Labor cost | Parts cost | Cost per product |
|---|---|---|
| Up to 4 work-hours × $85 per hour = $340 | Up to $37,077 | Up to $37,417. |
According to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. The FAA does not control warranty coverage for affected individuals. As a result, the FAA has included all known costs in the cost estimate.
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.
[top] The 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
Regulatory Findings
This 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a "significant regulatory action" under Executive Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:
a. Removing Airworthiness Directive (AD) 2022-19-09, Amendment 39-22178 (87 FR 57799, September 22, 2022); and
b. Adding the following new AD:
2025-09-02 Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.): Amendment 39-23023; Docket No. FAA-2024-2326; Project Identifier MCAI-2023-01048-T.
(a) Effective Date
This airworthiness directive (AD) is effective June 18, 2025.
(b) Affected ADs
This AD replaces AD 2022-19-09, Amendment 39-22178 (87 FR 57799, September 22, 2022) (AD 2022-19-09).
(c) Applicability
This AD applies to Airbus Canada Limited Partnership (type certificate previously held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Model BD-500-1A10 and BD-500-1A11 airplanes, certificated in any category, as identified in Transport Canada AD CF-2023-66, dated October 3, 2023 (Transport Canada AD CF-2023-66).
(d) Subject
Air Transport Association (ATA) of America Code 32, Landing Gear.
(e) Unsafe Condition
This AD was prompted by reports of in-service findings of corrosion on the flange of the main landing gear (MLG) lower spindle pin. The FAA is issuing this AD to address corrosion and subsequent cracking of the MLG lower spindle pin. The unsafe condition, if not addressed, could result in failure of the pin, and consequent collapse of the MLG.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, Transport Canada AD CF-2023-66.
(h) Exceptions To Transport Canada AD CF-2023-66
(1) Where Transport Canada AD CF-2023-66 refers to May 20, 2021, the effective date of Transport Canada AD CF-2021-18, this AD requires using October 27, 2022 (the effective date of AD 2022-19-09).
(2) Where Transport Canada AD CF-2023-66 refers to its effective date, this AD requires using the effective date of this AD.
(3) Where Part I of Transport Canada AD CF-2023-66 specifies "Initial inspections carried out," this AD requires replacing that text with "Initial inspections and applicable repairs and replacements carried out."
(4) Where Part II of Transport Canada AD CF-2023-66 specifies "at intervals not to exceed 3000 FC or 24 months," this AD requires replacing that text with "at intervals not to exceed 3000 FC or 24 months on the lower spindle assembly."
(5) Where Part II of Transport Canada AD CF-2023-66 specifies "Repetitive inspections carried out," this AD requires replacing that text with "Repetitive inspections and applicable repairs and replacements carried out."
(6) Where Part III of Transport Canada AD CF-2023-66 specifies a compliance time for the terminating action, for this AD, the compliance time is within the time specified in Part III of Transport Canada AD CF-2023-66, or within 60 days after the effective date of this AD, whichever occurs later.
(7) Where Part III of Transport Canada AD CF-2023-66 specifies part number (P/N) "415A0500-02," this AD requires replacing that text with P/N "4115A0500-02."
(i) No Reporting or Return of Parts Requirement
Although the material referenced in Transport Canada AD CF-2023-66 specifies to submit certain information and send removed parts to the manufacturer, this AD does not include that requirement.
(j) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, AIR-520, Continued Operational Safety 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 responsible Flight Standards Office, as appropriate. If sending information directly to the manager of AIR-520, Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (k) of this AD and email to: AMOC@faa.gov.
(i) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.
(ii) AMOCs approved previously for AD 2022-19-09 are approved as AMOCs for the corresponding provisions of Transport Canada AD CF-2023-66 that are required by paragraph (g) of this AD.
(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, AIR-520, Continued Operational Safety Branch, FAA; or Transport Canada; or Airbus Canada Limited Partnership's Transport Canada Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.
(3) Required for Compliance (RC): Except as required by paragraph (j)(2) of this AD, if any material contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are not identified as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the procedures and tests identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC.
(k) Additional Information
[top] For more information about this AD, contact Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: 9-avs-nyaco-cos@faa.gov.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD, unless this AD specifies otherwise.
(i) Transport Canada AD CF-2023-66, dated October 3, 2023.
(ii) [Reserved]
(3) For Transport Canada material identified in this AD, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-663-3639; email TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca; website at tc.canada.ca/en/aviation.
(4) You may view this material 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.
(5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations, or email fr.inspection@nara.gov.
Issued on April 22, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service.
[FR Doc. 2025-08338 Filed 5-13-25; 8:45 am]
BILLING CODE 4910-13-P