[Federal Register Volume 88, Number 39 (Tuesday, February 28, 2023)]
[Rules and Regulations]
[Pages 12557-12559]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-04026]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1480; Project Identifier MCAI-2022-00548-T; 
Amendment 39-22343; AD 2023-03-18]
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 reports of cracks found in the tailcone upper firewall 
where the auxiliary power unit (APU) muffler electrical bonding strap 
is attached. This AD requires a detailed visual inspection of the 
tailcone upper firewall for defects, rework by replacement of the APU 
electrical bonding strap, and repair if necessary. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective April 4, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of April 4, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2022-1480; 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 service information identified in this final rule, 
contact Bombardier Business Aircraft Customer Response Center, 400 
C[ocirc]te Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada; 
phone: (514) 855-2999; email: bombardier.com">[email protected]bombardier.com; website: 
bombardier.com.
     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. It is also available at 
regulations.gov under Docket No. FAA-2022-1480.

FOR FURTHER INFORMATION CONTACT: Yaser Osman, Aerospace Engineer, 
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; phone: (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 November 18, 2022 (87 FR 69225). The NPRM was prompted by 
AD CF-2022-19, dated April 19, 2022, issued by Transport Canada, which 
is the aviation authority for Canada (referred to after this as the 
MCAI). The MCAI states that cracks were found in the tailcone upper 
firewall where the APU muffler electrical bonding strap is attached. 
Crack initiation is related to the rigid electrical bonding strap. A 
crack in this area, if not addressed, could result in a breach of the 
firewall, which could allow a fire to propagate; reduced lightning 
strike protection, which could affect the airplane's grounding and 
potentially cause a fire; and increased radio interference during 
flight, which could reduce the ability of the flightcrew to maintain 
the safe flight and landing of the airplane.
    In the NPRM, the FAA proposed to require a detailed visual 
inspection of the tailcone upper firewall for defects, rework by 
replacement of the APU electrical bonding strap, and repair if 
necessary. The FAA is issuing this AD to address cracking in the 
tailcone upper firewall. The unsafe condition, if not addressed, could 
result in a breach of the firewall, which could allow a fire to 
propagate; reduced lightning strike protection, which could affect the 
airplane's grounding and potentially cause a fire; and increased radio 
interference during flight, which could reduce the ability of the 
flightcrew to maintain the safe flight and landing of the airplane.

[[Page 12558]]

    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2022-1480.

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 products 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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Bombardier Service Bulletin 100-53-35, dated 
December 6, 2021; and Service Bulletin 350-53-004, dated December 6, 
2021. This service information specifies procedures for doing a 
detailed visual inspection of the tailcone upper firewall for defects, 
including cracking, reworking the APU electrical bonding strap by 
replacing it with a new flexible APU muffler jumper cable assembly, and 
repairing the tailcone upper firewall. These documents are distinct 
since they apply to different airplane configurations.
    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.

Costs of Compliance

    The FAA estimates that this AD affects 691 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
                          Labor cost                              Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
1 work-hour x $85 per hour = $85.............................             $36             $121          $83,611
----------------------------------------------------------------------------------------------------------------

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

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
                                                             Cost per
              Labor cost                   Parts cost        product
------------------------------------------------------------------------
24 work-hours x $85 per hour = $2,040.          $0 \*\           $2,040
------------------------------------------------------------------------
* The FAA has received no definitive data on which to base the cost
  estimates for the parts specified in this AD.

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:

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:

2023-03-18 Bombardier, Inc.: Amendment 39-22343; Docket No. FAA-
2022-1480; Project Identifier MCAI-2022-00548-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 4, 2023.

(b) Affected ADs

    None.

[[Page 12559]]

(c) Applicability

    This AD applies to Bombardier, Inc., Model BD-100-1A10 
airplanes, certificated in any category, serial numbers 20003 
through 20500 inclusive and 20501 through 20916 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of cracks found in the tailcone 
upper firewall where the auxiliary power unit (APU) muffler 
electrical bonding strap is attached. The FAA is issuing this AD to 
address cracking in the tailcone upper firewall. The unsafe 
condition, if not addressed, could result in a breach of the 
firewall, which could allow a fire to propagate; reduced lightning 
strike protection, which could affect the airplane's grounding and 
potentially cause a fire; and increased radio interference during 
flight, which could reduce the ability of the flightcrew to maintain 
the safe flight and landing of the airplane.

(f) Compliance

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

(g) Inspection, Replacement, and Corrective Actions

    Within 48 months after the effective date of this AD: Do a 
detailed visual inspection of the tailcone upper firewall for 
defects, including cracking, rework the APU electrical bonding strap 
by replacing with a new flexible APU muffler jumper cable assembly, 
and repair the tailcone upper firewall, as applicable, in accordance 
with paragraphs 2.B., 2.C., and 2.D., of the Accomplishment 
Instructions of the applicable service information specified in 
figure 1 to paragraph (g) of this AD. Do all applicable repairs 
before further flight.

Figure 1 to paragraph (g)--Service Information
[GRAPHIC] [TIFF OMITTED] TR28FE23.013

(h) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York ACO 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 New York ACO 
Branch, mail it to ATTN: Program Manager, Continuing Operational 
Safety, at the address identified in paragraph (i)(2) of this AD or 
email to: [email protected]. If mailing information, also 
submit information by email. 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, New York ACO 
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

    (1) Refer to Transport Canada AD CF-2022-19, dated April 19, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2022-1480.
    (2) For more information about this AD, contact Yaser Osman, 
Aerospace Engineer, Airframe and Propulsion Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (516) 228-7300; email: [email protected].

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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 the AD specifies otherwise.
    (i) Bombardier Service Bulletin 100-53-35, dated December 6, 
2021.
    (ii) Bombardier Service Bulletin 350-53-004, dated December 6, 
2021.
    (3) For Bombardier service information 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; 
phone: (514) 855-2999; email: bombardier.com">[email protected]bombardier.com; website: 
bombardier.com.
    (4) You may view this service information at 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 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: [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on February 10, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-04026 Filed 2-27-23; 8:45 am]
BILLING CODE 4910-13-P


