
[Federal Register Volume 88, Number 184 (Monday, September 25, 2023)]
[Proposed Rules]
[Pages 65635-65637]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-20514]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1885; Project Identifier MCAI-2022-01484-T]
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: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and 
-402 airplanes. This proposed AD was prompted by reports of moisture in 
the wing-to-fuselage joint, between the mating front spar and rear spar 
frame segments. This proposed AD would 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 proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by November 9, 
2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    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 NPRM, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For service information identified in this NPRM, 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: 
dehavilland.com">thd@dehavilland.com; website: dehavilland.com.
     You may view this service information 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.

FOR FURTHER INFORMATION CONTACT: Deep Gaurav, Aviation Safety Engineer, 
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2023-1885; Project Identifier 
MCAI-2022-01484-T'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
the proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Deep 
Gaurav, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; email: [email protected]. 
Any commentary that the FAA receives which is not specifically 
designated as CBI will be placed in the public docket for this 
rulemaking.

Background

    Transport Canada, which is the aviation authority for Canada, has 
issued Transport Canada AD CF-2022-63, dated November 17, 2022 
(Transport Canada AD CF-2022-63) (also referred to as the MCAI), to 
correct an unsafe condition on certain De Havilland Aircraft of Canada 
Limited Model DHC-8-401 and -402 airplanes. 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.
    The FAA is proposing 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.

Related Service Information 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 service 
information 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 service information is reasonably available because the 
interested parties have access to it through their normal

[[Page 65636]]

course of business or by the means identified in the ADDRESSES section.

FAA's Determination

    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 and 
the service information referenced above. The FAA is issuing this NPRM 
after determining that the unsafe condition previously described is 
likely to exist or develop on other products of the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described. This proposed AD would 
also require repairing any corrosion or structural degradation found 
during the ultrasonic test.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 41 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                      Estimated Costs for Required Actions
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                                                                                    Cost per       Cost on U.S.
                          Labor cost                              Parts cost        product         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 proposed 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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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 Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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:

De Havilland Aircraft of Canada Limited (Type Certificate Previously 
Held by Bombardier, Inc.): Docket No. FAA-2023-1885; Project 
Identifier MCAI-2022-01484-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 9, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to De Havilland Aircraft of Canada Limited (Type 
Certificate Previously Held by Bombardier, Inc.) Model DHC-8-401 and 
-402 airplanes, certificated in any category, having serial numbers 
4001 and 4003 through 4624 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code: 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of moisture in the wing-to-
fuselage joint, between the mating front spar and rear spar frame 
segments. The FAA is issuing this AD to address corrosion and 
structural degradation of the wing-to-fuselage joint. The unsafe 
condition, if not addressed, could result in wing separation from 
the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspection and Corrective Action

    At the applicable compliance times specified in paragraph (g)(1) 
or (2) of this AD, in accordance with Section 3.B., of the 
Accomplishment Instructions of De Havilland Aircraft of Canada 
Service Bulletin 84-53-81, Revision A, dated August 23, 2022, 
complete a general visual inspection of the fuselage spar frames and 
around the frame bolts for signs of moisture ingress (i.e., stains 
and streaks), accomplish other specified actions, and if necessary, 
perform an ultrasonic test. Do all applicable ultrasonic tests 
before further flight. If, during any ultrasonic test, any corrosion 
or structural degradation is found, before further flight, repair 
using a method approved by the Manager, International Validation 
Branch, FAA; or Transport Canada; or De Havilland Aircraft of Canada 
Limited's Transport Canada Design Approval Organization (DAO). If 
approved by the DAO, the approval must include the DAO-authorized 
signature.
    (1) For airplanes that, as of the effective date of this AD, 
have accumulated less than 32,000 total flight cycles: before 
accumulating 40,000 total flight cycles.
    (2) For airplanes that, as of the effective date of this AD, 
have accumulated 32,000 or more total flight cycles: within 8,000 
flight hours or 48 months, whichever occurs first after the 
effective date of this AD.

(h) Credit for Previous Actions

    This paragraph provides credit for actions required by paragraph 
(g) of this AD, if those actions were performed before the effective 
date of this AD using De Havilland Aircraft

[[Page 65637]]

of Canada Limited Service Bulletin 84-53-81, dated May 27, 2022.

(i) 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, 
International Validation Branch, mail it to the address identified 
in paragraph (j)(2) of this AD or email 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 by the Manager, International 
Validation Branch, FAA; or Transport Canada; or De Havilland 
Aircraft of Canada Limited's Transport Canada Design Approval 
Organization (DAO). If approved by the DAO, the approval must 
include the DAO-authorized signature.

(j) Additional Information

    (1) Refer to Transport Canada AD CF-2022-63, dated November 17, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2023-1885.
    (2) For more information about this AD, contact Deep Gaurav, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless this AD specifies otherwise.
    (i) De Havilland Aircraft of Canada Limited Service Bulletin 84-
53-81, Revision A, dated August 23, 2022.
    (ii) [Reserved]
    (3) For service information identified 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: 
dehavilland.com">thd@dehavilland.com; website: dehavilland.com.
    (4) You may view this service information 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on September 18, 2023.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-20514 Filed 9-22-23; 8:45 am]
BILLING CODE 4910-13-P


