DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1052; Project Identifier MCAI-2023-00260-T;
Amendment 39-22532; AD 2023-17-06]
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Bombardier, Inc., Model CL-600-1A11 (600), CL-600-2A12 (601),
and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. This AD
was prompted by an uncommanded flap extension accompanied by a flaps
fail caution message during climb. This AD requires initial and
repetitive operational tests of the flap control system. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective October 19, 2023.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of October 19,
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1052; 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;
telephone 514-855-2999; email email@example.com; website
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-2023-1052.
FOR FURTHER INFORMATION CONTACT: Chirayu Gupta, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
telephone 516-228-7300; email firstname.lastname@example.org.
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 CL-600-1A11 (600), CL-600-2A12
(601), and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes.
The NPRM published in the Federal Register on May 31, 2023 (88 FR
34794). The NPRM was prompted by AD CF-2023-07, dated February 10,
2023, issued by Transport Canada, which is the aviation authority for
Canada (referred to after this as the MCAI).
The MCAI states a Model CL-600-2B16 airplane experienced an
uncommanded flap extension from 0 to 45 degrees accompanied by a flaps
fail caution message during climb. The airplane returned to the
departure airport without further incident. The investigations of this
event by Transport Canada and the airplane manufacturer found that the
flap control system failed to arrest the uncommanded movement of the
flap, due to a failed retract relay. The failed retract relay also
caused the flap control system to operate at half speed, which had
occurred, but was undetected, during previous flights. The root cause
of the uncommanded flap extension remains under investigation.
Transport Canada considers the MCAI to be an interim action, and
further AD action may follow.
In the NPRM, the FAA proposed to require initial and repetitive
operational tests of the of the inboard and outboard flaps of the flap
control system to verify the functionality of the retract relays. The
FAA is issuing this AD to address the failure of the flap control
system to arrest the uncommanded flap extension. The unsafe condition,
if not addressed, could lead to the loss of control of the airplane.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-1052.
Discussion of Final Airworthiness Directive
The FAA received no comments on the NPRM or on the determination of
the cost to the public.
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
Related Service Information Under 1 CFR Part 51
The FAA reviewed the following service information, which specifies
procedures for performing initial and repetitive operational tests of
the inboard and outboard flaps to verify the functionality of the
retract relays. The service information also specifies contacting the
manufacturer for corrective action (repair) for any anomaly found
during an operational test. These documents are distinct since they
apply to different airplane models.
Bombardier Service Bulletin 600-0780, dated December 29, 2022.
Bombardier Service Bulletin 601-1112, Revision 01, dated February 23,
Bombardier Service Bulletin 604-27-040, dated December 29, 2022.
Bombardier Service Bulletin 605-27-011, dated December 29, 2022.
Bombardier Service Bulletin 650-27-004, dated December 29, 2022.
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.
The FAA considers this AD an interim action. If final action is
later identified, the FAA might consider further rulemaking then.
Costs of Compliance
The FAA estimates that this AD affects 1,124 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 =
|$95,540 per test cycle
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