DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-1251; Project Identifier MCAI-2022-00588-T;
Amendment 39-22308; AD 2023-02-01]
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was prompted by
an investigation that indicated that one of the springs in the pitch
trim switch of the horizontal stabilizer had failed. The failure of the
spring could result in the airplane pitching nose down when actually
commanded nose up. This AD requires a verification of the serial
numbers of certain pitch trim switches, and replacement of the affected
pitch trim switches with new ones in the pilot and co-pilot control
wheels. This AD would also prohibit the installation of affected parts.
The FAA is issuing this AD to address the unsafe condition on these
DATES: This AD is effective March 14, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 14,
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-1251; 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
Cote Vertu Road West, Dorval, Quebec H4S 1Y9, Canada;
telephone 1-514-855-2999; email email@example.com; internet
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-2022-1251.
FOR FURTHER INFORMATION CONTACT: Thomas Niczky, Aerospace Engineer,
Avionics and Electrical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7347;
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Bombardier, Inc.,
Model BD-100-1A10 airplanes. The NPRM published in the Federal Register
on October 5, 2022 (87 FR 60352). The NPRM was prompted by AD CF-2022-
24, dated May 2, 2022, (referred to after this as the MCAI) issued by
Transport Canada, which is the aviation authority for Canada. The MCAI
states that during several in-service events, following a stab trim
fault advisory message and an auto-pilot 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 two 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. As a result, this led to
increased crew workload and reduced safety margins.
Subsequent investigation by Bombardier and the supplier of the
horizontal stabilizer pitch trim switch determined that one of the
springs within the pitch trim switch had failed. The supplier of the
springs was changed in 2019. The majority of observed pitch trim switch
failures occurred in pitch trim switches that were manufactured after
In the NPRM, the FAA proposed to require the replacement of the
affected pitch trim switches with re-designed pitch trim switches that
have reliable springs. The FAA is issuing this AD to address the
failure of the springs in the pitch trim switch, which, if not
corrected, could result in the airplane pitching nose down when
actually commanded nose up, resulting in reduced controllability of the
airplane and high control forces. The FAA is issuing this AD to address
the failure of the springs in the pitch trim switch. The unsafe
condition, if not corrected, could result in the airplane pitching nose
down when actually commanded nose up, resulting in reduced
controllability of the airplane and high control forces.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2022-1251.
Discussion of Final Airworthiness Directive
The FAA received a comment from NetJets. The following presents the
comment received on the NPRM and the FAA's response.
Request To Correct the Date for Bombardier Service Bulletin 350-27-011
NetJets requested that the proposed AD be revised to correct the
date for Bombardier Service Bulletin 350-27-011. The date was entered
incorrectly in figure 1 to paragraph (h) of the proposed AD and two
times in paragraph (i) of the proposed AD as ``March 21, 2002.''
The FAA agrees with the requested change by the commenter. The FAA
has corrected the date for Bombardier Service Bulletin 350-27-011 in
figure 1 to paragraph (h) of this AD and two times in paragraph (i) of
this AD to ``March 21, 2022.''
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 as proposed. Accordingly, the FAA is issuing this AD to address the
unsafe condition on this product. Except for
minor editorial changes, and any other changes described previously,
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 100-27-21, dated March
21, 2022, for Model BD-100-1A10 (CH-300) airplanes, S/Ns 20003 to
20500. This service information specifies procedures for verifying
serial numbers (S/Ns) of certain pitch trim switch part numbers in the
pilot and co-pilot control wheels, and replacing affected pitch trim
The FAA has also requires Bombardier Service Bulletin 350-27-011,
dated March 21, 2022, for Model BD-100-1A10 (CH-350) airplanes, S/Ns
20501 to 20936. This service information describes procedures for
verifying S/Ns of certain pitch trim switch part numbers in leather and
non-leather covered pilot and co-pilot control wheels, and replacing
affected pitch trim switches.
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 the ADDRESSES section.
Costs of Compliance
The FAA estimates that this AD affects 697 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
||1 work-hour x $85 per hour =
The FAA estimates the following costs
to do any necessary on-
condition actions that would be required based on the results of any
required actions. The FAA has no way of determining the number of
aircraft that might need these on-condition actions:
Estimated Costs of On-Condition Actions
|Switch replacement (Airplane
||4 work-hours x $85 per hour =
|Switch replacement (Airplane
||4 work-hours x $85 per hour =
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.
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
(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
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 adding the following new airworthiness