DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1885; Project Identifier MCAI-2022-01484-T;
Amendment 39-22770; AD 2024-12-06]
RIN 2120-AA64
Airworthiness Directives; De Havilland Aircraft of Canada Limited
(Type Certificate Previously Held by 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 De Havilland Aircraft of Canada Limited Model DHC-8-401 and -
402 airplanes. This AD was prompted by reports of moisture in the wing-
to-fuselage joint, between the mating front spar and rear spar frame
segments. This AD requires a visual inspection of the fuselage front
and rear spar frames, an ultrasonic test if applicable, other specified
actions, and repair if necessary. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective August 21, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 21,
2024.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1885; 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 De Havilland Aircraft material incorporated by
reference in this AD, contact De Havilland Aircraft of Canada Limited,
Dash 8 Series Customer Response Centre, 5800 Explorer Drive,
Mississauga, Ontario, L4W 5K9, Canada; telephone 855-310-1013 or 647-
277-5820; email thd@dehavilland.com; website dehavilland.com.
You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th Street,
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-2023-1885.
FOR FURTHER INFORMATION CONTACT: Deep Gaurav, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email deep.gaurav@faa.gov.
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 De Havilland
Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. The NPRM
published in the Federal Register on September 25, 2023 (88 FR 65635).
The NPRM was prompted by AD CF-2022-63, dated November 17, 2022, issued
by Transport Canada, which is the aviation authority for Canada
(referred to after this as the MCAI). The MCAI states several reports
of moisture have been found in the wing-to-fuselage joint, between the
mating front spar and rear spar frame segments. This condition, if not
corrected, could lead to corrosion and structural degradation of the
wing-to-fuselage joint and possible wing separation from the airplane.
In the NPRM, the FAA proposed to require a visual inspection of the
fuselage front and rear spar frames, an ultrasonic test if applicable,
other specified actions, and repair if necessary. The FAA is issuing
this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-1885.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from De Havilland. The following
presents the comment received on the NPRM and the FAA's response.
Request To Update the Service Information
De Havilland stated that to allow some operators to accomplish the
AD, an update is necessary to the work instructions in De Havilland
Aircraft of Canada Limited Service Bulletin 84-53-81, Revision A, dated
August 23, 2022. The service bulletin is in the process of being
revised to allow operators an alternative means of accessing the front
spar joint via the forward fairing rib on certain airplanes.
To allow operators to use later revisions of the referenced
document (issued after publication of the AD), either the FAA must
revise the AD to reference specific later revisions, or operators may
request approval to use later revisions as an alternative method of
compliance with this AD under the provisions of paragraph (i)(1) of
this AD.
In light of the critical nature of the identified unsafe condition
(i.e., corrosion and structural degradation of the wing-to-fuselage
joint), the FAA does not consider it warranted to delay the issuance of
this final rule until the revised service information is published. The
FAA has not changed 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
comments 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, 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 De Havilland Aircraft of Canada Limited Service
Bulletin 84-53-81, Revision A, dated August 23, 2022. This material
specifies procedures for a general visual inspection of the fuselage
front and rear spar frames (including around the frame bolts) for signs
of moisture (i.e., stains and streaks). If signs of moisture ingress
are noted in the affected structure because of this inspection, then an
ultrasonic test and other specified actions will be required, which
includes installing a sealant plug, refinishing the frame edge sealing,
and removing the existing frame recess sealant between the frame and
struts in the cabin.
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 41 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
Labor cost
|
Parts cost
|
Cost per
product
|
Cost on
U.S. operators
|
16 work-hours x $85 per hour
= $1,360 |
$3,134
|
$4,494
|
$184,254
|
The FAA has received no definitive
data on which to base the cost
estimates for the on-condition actions 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
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
directive:
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