[Federal Register Volume 89, Number 186 (Wednesday, September 25, 2024)]
[Rules and Regulations]
[Pages 78231-78233]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-21807]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1479; Project Identifier MCAI-2023-00657-T; 
Amendment 39-22824; AD 2024-16-18]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was 
prompted by a determination that a revised restrictive airworthiness 
limitation is necessary. This AD requires revising the existing 
maintenance or inspection program, as applicable, to incorporate a 
revised restrictive airworthiness limitation for the aft engine mount 
attachment bolts. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective October 30, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of October 30, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-1479; 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 Bombardier material identified in this AD, contact 
Bombardier Business Aircraft Customer Response Center, 400 C[ocirc]te-
Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada; telephone 514-
855-2999; email bombardier.com">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. It is also available at regulations.gov under 
Docket No. FAA-2024-1479.

[[Page 78232]]


FOR FURTHER INFORMATION CONTACT: Yaser Osman, Aviation Safety Engineer, 
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain Bombardier, 
Inc., Model BD-100-1A10 airplanes. The NPRM published in the Federal 
Register on June 5, 2024 (89 FR 48139). The NPRM was prompted by AD CF-
2023-29, dated May 5, 2023, issued by Transport Canada, which is the 
aviation authority for Canada (referred to after this as the MCAI). The 
MCAI states that the time limits/maintenance check (TLMC) airworthiness 
limitation (AWL) Task 54-51-00-111*, ``Discard of the Aft Engine Mount 
Bolts, Part No. MS21250-07, Non-Serialized,'' was not performed on some 
Challenger 300 in-service airplanes due to a misleading part number (P/
N) referenced in the TLMC manual. The task requires the discard and 
replacement of the aft engine mount attachment bolt, P/N MS21250-07, 
while the P/N shown in the TLMC manual is P/N MS21250-7 in lieu of P/N 
MS21250-07. Bombardier revised the TLMC AWL task and the relevant 
sections in the aircraft maintenance manual and the aircraft 
illustrated parts catalog with P/N MS21250-07 to ensure timely discard 
and replacement of the aft engine mount attachment bolts.
    In the NPRM, the FAA proposed to require revising the existing 
maintenance or inspection program, as applicable, to incorporate a 
revised restrictive airworthiness limitation for the aft engine mount 
attachment bolts. The FAA is issuing this AD to address potential 
failures of the aft engine mount attachment bolt, P/N MS21250-07. The 
unsafe condition, if not addressed, could lead to the detachment of the 
engine from the airplane, which could contribute to a catastrophic 
failure.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2024-1479.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the cost to the public.

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 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, 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

    The FAA reviewed the following documents. This material specifies a 
revised airworthiness limitation for the replacement of the aft engine 
mount attachment bolts, P/N MS21250-07. These documents are distinct 
since they apply to different airplane configurations. The asterisk (or 
``one star'') with the last three digits of the task numbers indicates 
that the task is an airworthiness limitation task.
     Task 54-51-00-111* ``Discard of the Aft Engine Mount 
Bolts, Part No. MS21250-07, Non-Serialized,'' Section 5-10-10 ``Life 
Limits (Structures),'' Part 2 ``Airworthiness Limitations,'' of the 
Bombardier Challenger 300 Time Limits/Maintenance Check, Publication 
No. CH 300 TLMC, Revision 24, dated August 9, 2023.
     Task 54-51-00-111* ``Discard of the Aft Engine Mount 
Bolts, Part No. MS21250-07, Non-Serialized,'' Section 5-10-10 ``Life 
Limits (Structures),'' Part 2 ``Airworthiness Limitations,'' of the 
Bombardier Challenger 350 Time Limits/Maintenance Check, Publication 
No. CH 350 TLMC, Revision 14, dated August 9, 2023.
    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 731 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:
    The FAA has determined that revising the maintenance or inspection 
program takes an average of 90 work-hours per operator, although the 
agency recognizes that this number may vary from operator to operator. 
Since operators incorporate maintenance or inspection program changes 
for their affected fleet(s), the FAA has determined that a per operator 
estimate is more accurate than a per-airplane estimate. Therefore, the 
agency estimates the average total cost per operator to be $7,650 (90 
work-hours x $85 per work-hour).

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,
    (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:

[[Page 78233]]

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2024-16-18 Bombardier, Inc.: Amendment 39-22824; Docket No. FAA-
2024-1479; Project Identifier MCAI-2023-00657-T.

(a) Effective Date

    This airworthiness directive (AD) is effective October 30, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bombardier, Inc., Model BD-100-1A10 
airplanes, certificated in any category, having serial numbers (S/
Ns) 20002 through 20912 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code America Code 54, 
Nacelles/Pylons.

(e) Unsafe Condition

    This AD was prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. The FAA is 
issuing this AD to address potential failures of the aft engine 
mount attachment bolt, part number MS21250-07. The unsafe condition, 
if not addressed, could lead to the detachment of the engine from 
the airplane, which could contribute to a catastrophic failure.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    Within 60 days after the effective date of this AD, revise the 
existing maintenance or inspection program, as applicable, to 
incorporate the information specified in paragraphs (g)(1) and (2) 
of this AD, as applicable. The initial compliance time for doing the 
tasks is at the time specified in the applicable time limit/
maintenance check (TLMC) document specified in paragraphs (g)(1) and 
(2) of this AD, or within 60 days after the effective date of this 
AD, whichever occurs later.
    (1) For airplane S/Ns 20002 through 20500 inclusive: Task 54-51-
00-111* ``Discard of the Aft Engine Mount Bolts, Part No. MS21250-
07, Non-Serialized,'' Section 5-10-10 ``Life Limits (Structures),'' 
Part 2, ``Airworthiness Limitations,'' of the Bombardier Challenger 
300 Time Limits/Maintenance Check, Publication No. CH 300 TLMC, 
Revision 24, dated August 9, 2023.
    (2) For airplane S/Ns 20501 through 20912 inclusive: Task 54-51-
00-111* ``Discard of the Aft Engine Mount Bolts, Part No. MS21250-
07, Non-Serialized,'' Section 5-10-10 ``Life Limits (Structures),'' 
Part 2 ``Airworthiness Limitations,'' of the Bombardier Challenger 
350 Time Limits/Maintenance Check, Publication No. CH 350 TLMC, 
Revision 14, dated August 9, 2023.
    Note 1 to paragraph (g): The asterisk (or ``one star'') with the 
last three digits of the task numbers listed in paragraphs (g)(1) 
and (2) of this AD indicates that the task is an airworthiness 
limitation task.

(h) No Alternative Actions or Intervals

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections) or intervals may be used unless the 
actions or intervals, are approved as an alternative method of 
compliance in accordance with the procedures specified in paragraph 
(i)(1) of this AD.

(i) Other FAA 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 the address identified 
in paragraph (j) of this AD. Information may be emailed to: 9-AVS-
[email protected]. 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.

(j) Additional Information

    For more information about this AD, contact Yaser Osman, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; email [email protected].

(k) 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) Task 54-51-00-111* ``Discard of the Aft Engine Mount Bolts, 
Part No. MS21250-07, Non-Serialized,'' Section 5-10-10 ``Life Limits 
(Structures),'' Part 2 ``Airworthiness Limitations,'' of the 
Bombardier Challenger 300 Time Limits/Maintenance Check, Publication 
No. CH 300 TLMC, Revision 24, dated August 9, 2023.
    Note 2 to paragraph (k)(2)(i): The asterisk (or ``one star'') 
with the last three digits of the task numbers listed in paragraphs 
(k)(2)(i) and (ii) of this AD indicates that the task is an 
airworthiness limitation task.
    (ii) Task 54-51-00-111* ``Discard of the Aft Engine Mount Bolts, 
Part No. MS21250-07, Non-Serialized,'' Section 5-10-10 ``Life Limits 
(Structures),'' of Part 2 ``Airworthiness Limitations,'' of the 
Bombardier Challenger 350 Time Limits/Maintenance Check, Publication 
No. CH 350 TLMC, Revision 14, dated August 9, 2023.
    (3) For Bombardier material identified in this AD, contact 
Bombardier Business Aircraft Customer Response Center, 400 
C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada; 
telephone 514-855-2999; email bombardier.com">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 [email protected].

    Issued on August 7, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-21807 Filed 9-24-24; 8:45 am]
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