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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 al-
    ready 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 Modifi-
    cation 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.

    ______________________________________________________________________
                FIGURE 1 TO PARAGRAPH (G) – SERVICE INFORMATION           
    ______________________________________________________________________
    BOMBARDIER AIRPLANE MODEL–              BOMBARDIER SERVICE BULLETIN–
    ______________________________________________________________________
    CL-600-2B16 (604 Variant) Challenger    605-35-006, Revision 01, dated
    605                                     January 28, 2022

    CL-600-2B16 (604 Variant) Challenger    650-35-002, Revision 01, dated
    650                                     January 28, 2022
    ______________________________________________________________________


(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 effec-
    tive date of this AD,  and  thereafter  at intervals  not to exceed 36
    months,  in accordance with the Accomplishment Instructions of Bombar-
    dier 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 accord-
    ance with the Accomplishment Instructions of Bombardier Service Bulle-
    tin 650-35-002,  Revision 01,  dated January 28, 2022.  Doing this re-
    placement 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: 9-avs-nyaco-cos@faa.gov. If mailing  information,
    also submit information by email.

(i) Before using any approved AMOC,  notify your appropriate principal in-
    spector, or lacking a principal inspector,  the manager of the respon-
    sible Flight Standards Office.

(ii) AMOCs approved for AD 2023-12-20 are approved as AMOCs for the corre-
     sponding 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 re-
    lated 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 516-228-7300; email 9-avs-nyaco-cos@faa.gov.

(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 Bus-
    iness Aircraft  Customer  Response  Center,  400 Cote-Vertu Road West,
    Dorval, Quebec H4S 1Y9, Canada;  telephone 514-855-2999; email ac.yul@
    aero.bombardier.com; website bombardier.com.

(5) You may view this service information at the FAA,  Airworthiness Prod-
    ucts 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 refer-
    ence at the National Archives and Records Administration  (NARA).  For
    information on the availability  of this material  at NARA,  email fr.
    inspection@nara.gov,  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.

FOR FURTHER INFORMATION CONTACT:  Elizabeth Dowling, Aviation Safety Engi-
neer, FAA, 1600 Stewart Avenue, Suite 410,  Westbury, NY 11590;  telephone
516-228-7300; email 9-avsnyaco-cos@faa.gov.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1654; Project Identifier MCAI-2023-00920-T;
Amendment 39-22520; AD 2023-16-01]
RIN 2120-AA64

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: (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-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
Cote-Vertu Road West, Dorval, Quebec H4S 1Y9, Canada;
telephone 514-855-2999; email ac.yul@aero.bombardier.com; 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 516-228-7300; email 9-avsnyaco-cos@faa.gov.

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 516-228-7300; email
9-avsnyaco-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

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 x $85 per hour = $255
$100
$355
$14,910

Estimated Costs for Retained Optional Actions

Labor cost
Parts cost
Cost per product
1 work-hour x $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 x $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.

Sec. 39.13 [Amended]


2. The FAA amends Sec. 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: