[Federal Register Volume 90, Number 26 (Monday, February 10, 2025)]
[Rules and Regulations]
[Pages 9207-9209]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-02397]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2023; Project Identifier MCAI-2023-01246-T;
Amendment 39-22934; AD 2025-02-01]
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 uncommanded horizontal stabilizer motion during several in-
service events caused by a problem with the trim switch wiring. This AD
requires installing the pitch/roll trim switch relays. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective March 17, 2025.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of March 17,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-2023; 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; phone 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-2024-2023.
FOR FURTHER INFORMATION CONTACT: Steven Dzierzynski, 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 August 21, 2024 (89 FR 67577). The NPRM was prompted by AD
CF-2023-77, dated December 7, 2023, issued by Transport Canada, which
is the aviation authority for Canada (Transport Canada AD CF-2023-77)
(referred to after this as the MCAI). The MCAI states that during
several in-service events, following a STAB TRIM FAULT advisory message
and an autopilot disconnect, both pilot and co-pilot commands to trim
the horizontal stabilizer nose-up resulted in a nose-down movement of
the horizontal stabilizer. In some events, the horizontal stabilizer
reached the full travel nose-down position before the crew recognized
the nature of the problem, and quickly recovered control of the
airplane for safe landing. An issue with the trim switch wiring
installation was identified as the main cause of the in-service
unintended horizontal stabilizer motion events. The current wiring of
the system is such that, if trim is enabled via the copilot-side trim
switch, and the pilot-side trim switch malfunctions, it is possible for
trim to move uncommanded or opposite to the intended direction.
In the NPRM, the FAA proposed to require installing the pitch/roll
trim switch relays. The FAA is issuing this AD to address the problem
with the trim switch wiring, which is the main cause of the uncommanded
horizontal stabilizer motion. The unsafe condition, if not addressed,
could result in increased crew workload and reduced safety margins, and
if the flightcrew is unable to regain control of the horizontal
stabilizer, would result in loss of control of the airplane and high
control forces.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-2023.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from an individual. The following
presents the comment received on the NPRM and the FAA's response to
that comment.
Request To Develop a Preventive Maintenance Program To Assess Affected
Airplanes
The commenter suggested that Bombardier should develop a preventive
maintenance program to assess if the proposed AD would apply to the
same airplanes of different serial numbers. The commenter referenced
another AD (PA-28 wing spar), pointing out that operators were only
required to repair the affected part if damage or failure was detected.
The commenter noted that a preventive replacement of the affected part
was not required, and that is something that Bombardier should consider
researching. The commenter further asserted that this would only be
considered if engineers and researchers can show with evidence that
periodic inspections outweigh the cost of a preventive repair.
The FAA does not agree. The NPRM specifically stated that ``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.'' Bombardier has confirmed that airplanes having
serial number 20937 and subsequent, also subject to the unsafe
condition addressed in this AD, were modified in production. Further,
this AD bypasses any type of preventive maintenance inspection prior to
modifying the trim switches because Bombardier has determined that the
trim switches have a problem with the wiring installation, which is why
all affected trim switches must be rewired (not simply inspected and
repaired only if damage or failure is found). No change has been made
to this AD in this regard.
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, considered the
comment received, and determined that air safety requires adopting this
AD
[[Page 9208]]
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 Bombardier Service Bulletin 100-27-22 and
Bombardier Service Bulletin 350-27-012, both dated December 29, 2022.
This material specifies procedures to install the pitch/roll trim
switch relays. The installation includes reworking the plate assembly;
installing relay bracket assemblies, relays, ground return stacks on
the relay bracket assemblies, wires for the relays, and line
replaceable units and trays on the left-side and right-side avionic
racks; and performing operational testing. These documents are distinct
since they apply to different airplane serial numbers. 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 359 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
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Labor cost Parts cost Cost per product Cost on U.S. operators
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Up to 45 work-hours x $85 per hour = Up $3,582 Up to $7,407............... Up to $2,659,113.
to $3,825.
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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:
2025-02-01 Bombardier, Inc.: Amendment 39-22934; Docket No. FAA-
2024-2023; Project Identifier MCAI-2023-01246-T.
(a) Effective Date
This airworthiness directive (AD) is effective March 17, 2025.
(b) Affected ADs
None.
(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 20936 inclusive.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
controls.
(e) Unsafe Condition
This AD was prompted by uncommanded horizontal stabilizer motion
during several in-service events caused by a problem with the trim
switch wiring. The FAA is issuing this AD to address the problem
with the trim switch wiring. The unsafe condition, if not addressed,
could result in increased crew workload and reduced safety margins,
and if the flightcrew is unable to regain control of the horizontal
stabilizer, would result in loss of control of the airplane and high
control forces.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Installation of Pitch/Roll Trim Switch Relays and Tests
Within 3,000 flight hours or 5 years, whichever occurs first,
from the effective date of this AD, install the pitch/roll trim
switch relays, in accordance with sections 2.B. and 2.C. of the
Accomplishment Instructions of the applicable material specified in
paragraph (g)(1) or (2) of this AD.
(1) Bombardier Service Bulletin 100-27-22, dated December 29,
2022 (for airplane serial numbers 20003 through 20500 inclusive).
(2) Bombardier Service Bulletin 350-27-012, dated December 29,
2022 (for airplane serial numbers 20501 through 20936 inclusive).
(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, mail it to the address identified
in paragraph (i) of this AD. Information may be emailed to:
[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
[[Page 9209]]
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 Steven Dzierzynski,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; telephone 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 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 100-27-22, dated December 29,
2022.
(ii) Bombardier Service Bulletin 350-27-012, dated December 29,
2022.
(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;
phone 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 January 16, 2025.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-02397 Filed 2-7-25; 8:45 am]
BILLING CODE 4910-13-P