[Federal Register Volume 88, Number 75 (Wednesday, April 19, 2023)]
[Proposed Rules]
[Pages 24144-24146]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08202]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0933; Project Identifier MCAI-2022-00554-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).

-----------------------------------------------------------------------

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 that the 
saddle washer (radius filler) for the front and rear spar joints may 
have been incorrectly manufactured for several years. This proposed AD 
would require inspecting the horizontal stabilizer to vertical joint 
for gaps and bending of the saddle washer and adjacent washers, and 
replacing parts 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 June 5, 
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-2023-0933; 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: Yaser Osman, Aerospace Engineer, 
Airframe and Propulsion Section, FAA, New York ACO Branch, 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-2023-0933; Project Identifier 
MCAI-2022-00554-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

[[Page 24145]]

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 Yaser 
Osman, Aerospace Engineer, Airframe and Propulsion Section, FAA, New 
York ACO Branch, 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-2022-21, dated April 21, 2022 (Transport 
Canada AD CF-2022-21) (also referred to after this 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 that 
certain saddle washers for the front and rear spar joint, may have been 
incorrectly manufactured for several years. Non-conforming saddle 
washers could potentially become deformed when installed, and lead to 
gaps at the horizontal stabilizer to vertical stabilizer joint, that 
would result in reduction of the pre-load at the joint.
    The FAA is proposing this AD to address gapping and bending of the 
saddle washer that could have the potential to reduce the life of the 
bolt, which in turn could affect the structural integrity of the 
horizontal stabilizer to vertical stabilizer joint.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-0933.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed De Havilland Aircraft of Canada Limited Service 
Bulletin 84-55-12, Revision A, dated February 16, 2022. This service 
information specifies procedures for a detailed visual inspection of 
the front and rear spar joints for signs of gapping or bending of the 
radius filler and/or adjacent washers, and depending on the inspection 
results, replacement of the saddle washer, adjacent washers, bolt, and 
barrel nut.
    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.

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 service information referenced above. The FAA is issuing this NPRM 
after determining that the unsafe condition described previously 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.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 400 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
                          Labor cost                              Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
5 work-hours x $85 per hour = $425...........................              $0             $425         $170,000
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition action 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 this on-condition action:

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
                                                             Cost per
              Labor cost                   Parts cost        product
------------------------------------------------------------------------
2 work-hours x $85 per hour = $170....          $5,333           $5,503
------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this proposed 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

[[Page 24146]]

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-2023-0933; Project 
Identifier MCAI-2022-00554-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by June 5, 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 4633 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code: 55, 
Stabilizers.

(e) Unsafe Condition

    This AD was prompted by reports that the saddle washer (radius 
filler) for the front and rear spar joints may have been incorrectly 
manufactured for several years. The FAA is issuing this AD to 
address gaps and bending of the saddle washer that could have the 
potential to reduce the life of the bolt, which in turn could affect 
the structural integrity of the horizontal stabilizer to vertical 
stabilizer joint.

(f) Compliance

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

(g) Inspection

    Within 8,000 flight hours after the effective date of this AD, 
perform a detailed visual inspection for signs of gapping or bending 
of the saddle washers and adjacent washers in the front spar and 
rear spar horizontal/vertical stabilizer joint fitting in accordance 
with Section 3.B., Part A, of the Accomplishment Instructions of De 
Havilland Aircraft of Canada Service Bulletin 84-55-12, Revision A, 
dated February 16, 2022.

(h) Corrective Actions

    If any gaps or bending of the washers is found during the 
inspection required in paragraph (g) of this AD, before further 
flight, replace the saddle washer, washers, PLI washer, bolt, and 
barrel nut, as applicable, in accordance with Section 3.B., Part B, 
of the Accomplishment Instructions of De Havilland Aircraft of 
Canada Service Bulletin 84-55-12, Revision A, dated February 16, 
2022.

(i) Credit for Previous Actions

    This paragraph provides credit for actions required by 
paragraphs (g) and (h) of this AD, if those actions were performed 
before the effective date of this AD using De Havilland Aircraft of 
Canada Limited Service Bulletin 84-55-12, dated September 7, 2021.

(j) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York ACO 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 of the New York ACO 
Branch, mail it to ATTN: Program Manager, Continuing Operational 
Safety, at the address identified in paragraph (k)(2) of this AD or 
email to: [email protected]. If mailing information, also 
submit information by email. 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, New York ACO 
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.

(k) Additional Information

    (1) Refer to Transport Canada AD CF-2022-21, dated April 21, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2023-0933.
    (2) For more information about this AD, contact Yaser Osman, 
Aerospace Engineer, Airframe and Propulsion Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7300; email [email protected].

(l) 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-
55-12, Revision A, dated February 16, 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 April 13, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-08202 Filed 4-18-23; 8:45 am]
BILLING CODE 4910-13-P