2023-16648. Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is superseding Airworthiness Directive (AD) 2023–12–20, which applied to certain Bombardier, Inc., Model CL–600–2B16 (604 Variant) airplanes. AD 2023–12–20 required replacing certain oxygen system hoses and prohibited installing affected oxygen hoses. Since the FAA issued AD 2023–12–20, the FAA has learned of an error in a required compliance time. This AD retains the requirements of AD 2023–12–20, with a revised compliance time for the replacement. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective August 23, 2023.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of August 23, 2023 (88 FR 46063, July 19, 2023).

The FAA must receive comments on this AD by September 21, 2023.

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: [phone].

• 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–2023–1654; 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 street address for Docket Operations is listed above.

Material Incorporated by Reference:

• For service information identified in this final rule, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone [phone]; email [e-mail]; website bombardier.com.

• You may view this referenced 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. It is also available at regulations.gov under Docket No. FAA–2023–1654.

FOR FURTHER INFORMATION CONTACT:

Elizabeth Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA–2023–1654; Project Identifier MCAI–2023–00920–T” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 this final rule 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 final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Elizabeth Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail]. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The FAA issued AD 2023–12–20, Amendment 39–22479 (88 FR 46063, July 19, 2023) (AD 2023–12–20), for certain Bombardier, Inc., Model CL–600–2B16 (604 Variant) airplanes. AD 2023–12–20 was prompted by an MCAI originated by Transport Canada, which is the aviation authority for Canada. Transport Canada issued AD CF–2022–34, dated June 20, 2022 (Transport Canada AD CF–2022–34), to correct an unsafe condition.

AD 2023–12–20 required replacing oxygen system hoses having any part number in the O2C20T1 and O2C20T14 series and prohibited installing affected oxygen hoses. The FAA issued AD 2023–12–20 to address a leak in the oxygen system, which could result in failure to provide oxygen to passengers and crew and result in an oxygen- enriched atmosphere creating a fire risk on the airplane.

Actions Since AD 2023–12–20 Was Issued

Since AD 2023–12–20 was issued, the FAA has learned that paragraph (g)(1) of AD 2023–12–20 contains an error in the compliance time for the replacement of the oxygen system hoses. As written, paragraph (g)(1) of AD 2023–12–20 requires compliance for the affected airplanes within 31 months, or no later than “12 months after the completion of the interior modification specified in STC ST02355NY,” whichever occurs first. The correct compliance time is within 31 months, or no later than “12 months after the airplane reaches 6 years from the STC ST02355NY airplane's completion issuance (specific airplane's Modification Data Summary release date),” whichever occurs first. Paragraph (g)(1) of this AD specifies the correct compliance time. The compliance time as written in AD 2023–12–20 could unnecessarily ground some airplanes. Correcting this error in this AD provides relief by extending the compliance time. There are no other changes in this AD.

While the two ADs are effective August 23, 2023, this AD supersedes AD 2023–12–20.

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–2023–1654.

Related Service Information Under 1 CFR Part 51

This AD requires Bombardier Service Bulletins 605–35–006 and 650–35–002, both Revision 01, both dated January 28, 2022, which the Director of the Federal Register approved for incorporation by reference as of August 23, 2023 (88 FR 46063, July 19, 2023). This 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 ADDRESSES .

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 service information referenced above. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

AD Requirements

This AD retains all of the requirements of AD 2023–12–20, with a revised compliance time for replacing the oxygen system hoses for certain airplanes.

Justification for Immediate Adoption and Determination of the Effective Date

Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for “good cause,” finds that those procedures are “impracticable, unnecessary, or contrary to the public interest.” Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.

The FAA has learned of an error in a compliance time that could unnecessarily ground some airplanes. Correcting this error provides relief by extending that compliance time, and is the only change in this AD. To address this issue in a timely manner, the FAA has determined that it is appropriate to require the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. Accordingly, notice and opportunity for prior public comment are unnecessary pursuant to 5 U.S.C. 553(b)(3)(B).

In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment.

Regulatory Flexibility Act (RFA)

The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 42 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Retained Required Actions

Labor cost	Parts cost	Cost per product	Cost on U.S. operators
3 work-hours × $85 per hour = $255	$100	$355	$14,910

Estimated Costs for Retained Optional Actions

Labor cost	Parts cost	Cost per product
1 work-hour × $85 per hour = $85	$0	$85

The FAA estimates the following costs to do any necessary on-condition actions that would be required based on the results of any optional mitigating actions. The FAA has no way of determining the number of aircraft that might need this on-condition action:

Estimated Costs of Retained On-Condition Actions

Labor cost	Parts cost	Cost per product
3 work-hours × $85 per hour = $255	$100	$355

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this 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

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, and

(2) Will not affect intrastate aviation in Alaska.

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 2023–12–20, Amendment 39–22479 ( 88 FR 46063, July 19, 2023); and

b. Adding the following new airworthiness directive:

2023–16–01 Bombardier, Inc.: Amendment 39–22520; Docket No. FAA–2023–1654; Project Identifier MCAI–2023–00920–T.

(a) Effective Date

This airworthiness directive (AD) is effective August 23, 2023.

(b) Affected ADs

This AD replaces AD 2023–12–20, Amendment 39–22479 (88 FR 46063, July 19, 2023) (AD 2023–12–20).

(c) Applicability

This AD applies to Bombardier, Inc., Model C–600–2B16 (604 Variant) airplanes, certificated in any category, serial numbers 5701 through 5990 inclusive and 6050 through 6162 inclusive, with an interior modified in accordance with Supplemental Type Certificate (STC) ST02355NY.

(d) Subject

Air Transport Association (ATA) of America Code 35, Oxygen.

(e) Unsafe Condition

This AD was prompted by reports of oxygen leaks caused by cracked, brittle, or broken oxygen hoses that were found during scheduled maintenance tests of the airplane oxygen system. The FAA is issuing this AD to address a leak in the oxygen system. The unsafe condition, if not addressed, could result in failure to provide oxygen to passengers and crew and result in an oxygen-enriched atmosphere creating a fire risk on the airplane.

(f) Compliance

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

(g) Retained Replacement, With Revised Compliance Time in Paragraph (g)(1)

This paragraph restates the requirements of paragraph (g) of AD 2023–12–20, with a revised compliance time in paragraph (g)(1) of this AD. At the applicable compliance times specified in paragraphs (g)(1) and (2) of this AD: Replace oxygen system hoses having any part number in the O2C20T1 series, and, as applicable, the O2C20T14 series, in accordance with the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraph (g) of this AD.

(1) For airplanes having, as of the effective date of this AD, 6 years or less from the completion of the interior modification specified in STC ST02355NY: Within 31 months after the effective date of this AD, or no later than 12 months after the airplane reaches 6 years from the STC ST02355NY airplane's completion issuance (specific airplane's Modification Data Summary release date), whichever occurs first.

(2) For airplanes having, as of the effective date of this AD, more than 6 years from the completion of the interior modification specified in STC T02355NY: Within 7 months after the effective date of this AD.

(h) Retained Optional Mitigation for Certain Airplanes, With No Changes

This paragraph restates the provisions of paragraph (h) of AD 2023–12–20, with no changes. For airplanes identified in Bombardier Service Bulletin 650–35–002, Revision 01, dated January 28, 2022, having, as of the effective date of this AD, less than 6 years from the completion of the interior modification specified in STC ST02355NY: In lieu of accomplishing the oxygen system hose replacement required by paragraph (g) of this AD, comply with all conditions specified in paragraphs (h)(1) through (3) of this AD.

(1) The passenger oxygen system is tested within 6 months after the effective date of this AD, and thereafter at intervals not to exceed 36 months, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 650–35–002, Revision 01, dated January 28, 2022.

(2) If, during a test specified in paragraph (h)(1) of this AD, any leak is found on any hose, all oxygen system hoses having a part number in the O2C20T1 series must be replaced before further flight in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 650–35–002, Revision 01, dated January 28, 2022. Doing this replacement terminates the tests specified in paragraph (h)(1) of this AD.

(3) Except as specified by paragraph (h)(2) of this AD, all oxygen system hoses having a part number in the O2C20T1 series must be replaced within 6 years from the completion of the interior modification specified in STC ST02355NY. Doing this replacement terminates the tests specified in paragraph (h)(1) of this AD.

(i) Retained Parts Installation Prohibition, With No Changes

This paragraph restates the requirements of paragraph (i) of AD 2023–12–20, with no changes. As of the effective date of this AD, no person may install any oxygen system hose having a part number in the O2C20T1 and O2C20T14 series on any airplane.

(j) Retained Credit for Previous Actions, With No Changes

This paragraph restates the provisions of paragraph (j) of AD 2023–12–20, with no changes.

(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 Bombardier Service Bulletin 605–35–006, dated August 23, 2021; or Bombardier Service Bulletin 650–35–002, dated August 23, 2021; as applicable.

(2) This paragraph provides credit for actions specified in paragraph (h) of this AD, if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 650–35–002, dated August 23, 2021.

(k) 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, mail it to ATTN: Program Manager, Continuing Operational Safety, at the address identified in paragraph (l)(2) of this AD or email to: [e-mail]. If mailing information, also submit information by email.

(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 for AD 2023–12–20 are approved as AMOCs for the corresponding provisions 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, 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.

(l) Additional Information

(1) Refer to Transport Canada AD CF–2022–34, dated June 20, 2022, for related information. This Transport Canada AD may be found in the AD docket at regulations.gov under Docket No. FAA–2023–1654.

(2) For more information about this AD, contact Elizabeth Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (m)(4) and (5) of this AD.

(m) Material Incorporated by Reference

(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.

(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.

(3) The following service information was approved for IBR on August 23, 2023 (88 FR 46063, July 19, 2023).

(i) Bombardier Service Bulletin 605–35–006, Revision 01, dated January 28, 2022.

(ii) Bombardier Service Bulletin 650–35–002, Revision 01, dated January 28, 2022.

(4) For service information identified in this AD, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone [phone]; email [e-mail]; website bombardier.com.

(5) 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.

(6) 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 [e-mail], or go to: www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on July 31, 2023.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.