DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0462; Project Identifier MCAI-2020-01714-T;
Amendment 39-21751; AD 2021-20-13]
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)
certain Bombardier, Inc., Model CL-600-2B16 (604 Variant) airplanes.
This AD was prompted by multiple reports of cracking of the main
landing gear (MLG) shock strut lower pin. This AD requires repetitive
lubrication and repetitive detailed visual inspections (DVI) and non-
destructive test (NDT) inspections of the MLG shock strut lower pins,
and replacement if necessary. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective November 18, 2021.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 18,
ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 200 Cote-Vertu Road West, Dorval,
Quebec H4S 2A3, Canada; North America toll-free telephone 1-866-
538-1247 or direct-dial telephone 1-514-855-2999; email
email@example.com; internet https://www.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 on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2021-0462.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-
0462; 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, 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.
FOR FURTHER INFORMATION CONTACT: Chirayu Gupta, Aerospace Engineer,
Mechanical Systems and Administrative Services Section, FAA, New York
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
telephone 516-228-7300; fax 516-794-5531; email firstname.lastname@example.org.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued TCCA AD CF-2020-54R1, dated December
23, 2020 (TCCA AD CF-2020-54R1) (also referred to after this as the
Mandatory Continuing Airworthiness Information, or the MCAI), to
correct an unsafe condition for certain Bombardier, Inc., Model CL-600-
2B16 (604 Variant) airplanes. You may examine the MCAI in the AD docket
at https://www.regulations.gov by searching for and locating Docket No.
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-600-2B16 (604 Variant) airplanes. The NPRM published in
the Federal Register on June 14, 2021 (86 FR 31453). The NPRM was
prompted by multiple reports of cracking of the MLG shock strut lower
pin part number (P/N) 19146-3. The subsequent investigation concluded
that the friction torque when the shock strut is under compression
loading, causes the pin anti-rotation tangs to become loaded beyond
their load carrying capability. This overload condition can result in
pin fracture originating at the base of the pin anti-rotation tang.
Inadequate lubrication aggravates the condition. The NPRM proposed to
require repetitive lubrication and repetitive DVI and NDT inspections
of the MLG shock strut lower pins, and replacement if necessary. The
FAA is issuing this AD to address cracking of the MLG shock strut lower
pin. If not addressed, this condition could result in structural
failure of one or both MLG. See the MCAI for additional background
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed,
except for minor editorial changes. The FAA has determined that these
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
Bombardier, Inc., has issued the following service information:
Service Bulletin 604-32-030, dated June 30, 2020.
Service Bulletin 605-32-007, dated June 30, 2020.
Service Bulletin 650-32-004, dated June 30, 2020.
This service information describes procedures for lubricating,
inspecting (DVI and NDT inspections for cracking and damage, including
fracture of the MLG shock strut lower pin at the pin rotation tang
location), and replacing the MLG shock strut lower pin. 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 the ADDRESSES section.
Costs of Compliance
The FAA estimates that this AD affects 433 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
|7 work-hours 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
|6 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
Adoption of 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
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