90 FR 96 pgs. 21437-21439 - Airworthiness Directives; Bombardier, Inc., Airplanes
Type: PRORULEVolume: 90Number: 96Pages: 21437 - 21439
Pages: 21437, 21438, 21439Docket number: [Docket No. FAA-2025-0908; Project Identifier MCAI-2025-00035-T]
FR document: [FR Doc. 2025-08934 Filed 5-19-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0908; Project Identifier MCAI-2025-00035-T]
RIN 2120-AA64
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Notice of proposed rulemaking (NPRM).
SUMMARY:
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-1A10 airplanes. This proposed AD was prompted by a report indicating that the clearance between therapeutic flexible oxygen hoses and electrical harnesses may be non-compliant to design requirements, and that positive separation mechanisms and appropriate protective barriers may not have been installed in accordance with the applicable installation standards. This proposed AD would require a detailed inspection of the therapeutic flexible oxygen hose for damage and protection, and the electrical harnesses for damage; a detailed inspection for the clearance between the therapeutic oxygen rigid tube to oxygen hose elbow fitting (also referred to as elbow fitting), if applicable, and the nearest electrical harness, and between the therapeutic flexible oxygen hose and electrical harness; and applicable related investigative and corrective actions. The FAA is proposing this AD to address the unsafe condition on these products.
DATES:
The FAA must receive comments on this proposed AD by July 7, 2025.
ADDRESSES:
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
• Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• 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.
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-0908; 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 NPRM, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
• For Bombardier material identified in this proposed AD, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-2999; email ac.yul@aero.bombardier.com; website bombardier.com.
• 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.
FOR FURTHER INFORMATION CONTACT:
Brenda L. Buitrago, 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:
Comments Invited
The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2025-0908; Project Identifier MCAI-2025-00035-T" at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend the proposal because of those comments.
Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as "PROPIN." The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to contact Brenda L. Buitrago, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: 9-avs-nyaco-cos@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.
Background
[top] Transport Canada, which is the aviation authority for Canada, has issued Transport Canada AD CF-2025-02, dated January 14, 2025 (Transport Canada AD CF-2025-02) (also referred to as the MCAI), to correct an unsafe condition on certain Bombardier, Inc., Model BD-700-1A10 airplanes. The MCAI states that Bombardier, Inc., has discovered that the clearance between therapeutic flexible oxygen hoses and electrical harnesses may be non-compliant to design requirements, and that the positive separation mechanisms and appropriate protective barriers may not have been installed in accordance with the applicable installation standards. The MCAI also states that instances of hard fouling have been observed on the production line, which
The FAA is proposing 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-2025-0908.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Bombardier Service Bulletin 700-35-016, Bombardier Service Bulletin 700-35-6006, and Bombardier Service Bulletin 700-35-6503, all dated June 12, 2024. This material specifies procedures for accomplishing the following actions near fuselage station (FS) 530 right-hand side (RHS) and FS 650.00 RHS and applicable related investigative and corrective actions, including:
• A detailed inspection to determine the gap between the clocking angle of the therapeutic oxygen rigid tube to oxygen hose elbow fitting, if equipped, and the nearest electrical harness.
• A detailed inspection for damage ( i.e., crushing, fraying, or permanent deformation) to the therapeutic flexible oxygen hose, part number (P/N) 38911-5-0250, and to determine if protection ( i.e., split convolex shroud, P/N HCTE0437-0-SP or similar, or spiral wrap, P/N TSW 1⁄4 or similar) is installed on the therapeutic flexible oxygen hose.
• A detailed inspection of the electrical harnesses surrounding the therapeutic flexible oxygen hose for damage ( i.e., damaged wire sheathing or cut or nicked wires).
The applicable corrective actions include the following:
• If the gap between the clocking angle of the therapeutic oxygen rigid tube to oxygen hose elbow fitting and nearest harness is less than 0.5 inches, adjusting the elbow fitting to ensure the maximum possible clearance between the fitting and nearest harness.
• If the clearance between the wiring harness and oxygen hose is less than 0.5 inches, installing a Teflon cable wrap or Nomex sleeving on the wiring harness.
• Replacing any damaged therapeutic flexible oxygen hose with a new hose.
• Installing a split convolex shroud (P/N HCTE0437-0-SP) on the therapeutic flexible oxygen hose, if the protection is missing.
• Repairing any damaged electrical harnesses surrounding the therapeutic flexible oxygen hose.
The related investigative actions are leak and operational tests of the therapeutic oxygen system if any parts are repaired or replaced.
These documents are distinct since they apply to different airplane configurations.
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.
FAA's Determination
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 and material referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified in the material already described. See "Differences Between This Proposed AD and the Referenced Material" for a discussion of the general differences included in this AD.
Differences Between This Proposed AD and the Referenced Material
Steps 2.B.(7) and (14) of Bombardier Service Bulletin 700-35-016, Bombardier Service Bulletin 700-35-6006, and Bombardier Service Bulletin 700-35-6503, all dated June 12, 2024, specify a corrective action to install a Teflon cable wrap or Nomex sleeving on the electrical wiring harness if the clearance between the electrical wiring harness and therapeutic flexible oxygen hose is less than 0.5 inches. This proposed AD clarifies that prior to that corrective action, a detailed inspection to determine the clearance between the electrical wiring harnesses and therapeutic flexible oxygen hose must be performed.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 317 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:
| Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|
| 10 work-hours × $85 per hour = $850 | $0 | $850 | $269,450 |
The FAA has received no definitive data on which to base the cost estimates for the on-condition actions specified in this proposed AD.
The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators.
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.
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 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
The FAA 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.
[top] For the reasons discussed above, I certify this proposed regulation:
(1) Is not a "significant regulatory action" under Executive Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 adding the following new airworthiness directive:
Bombardier, Inc.: Docket No. FAA-2025-0908; Project Identifier MCAI-2025-00035-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by July 7, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Bombardier, Inc., Model BD-700-1A10 airplanes, certificated in any category, as identified in Bombardier Service Bulletin 700-35-016, dated June 12, 2024; Bombardier Service Bulletin 700-35-6006, dated June 12, 2024; and Bombardier Service Bulletin 700-35-6503, dated June 12, 2024.
(d) Subject
Air Transport Association (ATA) of America Code 35, Oxygen.
(e) Unsafe Condition
This proposed AD was prompted by a report indicating that the clearance between therapeutic flexible oxygen hoses and electrical harnesses may be non-compliant to design requirements, and that positive separation mechanisms and appropriate protective barriers may not have been installed in accordance with the applicable installation standards. The FAA is proposing this AD to prevent damage to the electrical harness for the therapeutic flexible oxygen hose and subsequent latent failure of the firewall hydraulic shutoff valve. The unsafe condition, if not addressed, could result in the inability to control a powerplant fire in the presence of a hydraulic fluid leak.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Detailed Inspections and Related Investigative and Corrective Actions
Within 10 years after the effective date of this AD, do all the actions specified in paragraphs (g)(1) through (4) of this AD, and do all the applicable related investigative and corrective actions before further flight, in accordance with sections 2.B and 2.C of the Accomplishment Instructions of Bombardier Service Bulletin 700-35-016, Bombardier Service Bulletin 700-35-6006, and Bombardier Service Bulletin 700-35-6503, all dated June 12, 2024, as applicable.
(1) Do a detailed inspection to determine the gap between the clocking angle of the therapeutic oxygen rigid tube to oxygen hose elbow fitting, if equipped, and the nearest electrical harness.
(2) Do a detailed inspection of the therapeutic flexible oxygen hose, P/N 38911-5-0250, for damage and to determine if protection is installed on the hose.
(3) Do a detailed inspection of the electrical harnesses surrounding the therapeutic flexible oxygen hose for damage.
(4) Do a detailed inspection to determine the clearance between the electrical harnesses and therapeutic flexible oxygen hose.
(h) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, International Validation 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 the International Validation Branch, send it to the attention of the person identified in paragraph (i) of this AD and email to: AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.
(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, International Validation Branch, FAA; or Transport Canada; or Bombardier, Inc.'s Transport Canada Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.
(i) Additional Information
For more information about this AD, contact Brenda L. Buitrago, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: 9-avs-nyaco-cos@faa.gov.
(j) 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) Bombardier Service Bulletin 700-35-016, dated June 12, 2024.
(ii) Bombardier Service Bulletin 700-35-6006, dated June 12, 2024.
(iii) Bombardier Service Bulletin 700-35-6503, dated June 12, 2024.
(3) For Bombardier material identified in this AD, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-2999; email ac.yul@aero.bombardier.com; website bombardier.com.
(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 May 13, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-08934 Filed 5-19-25; 8:45 am]
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