[Federal Register Volume 86, Number 53 (Monday, March 22, 2021)]
[Proposed Rules]
[Pages 15149-15151]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05352]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0183; Project Identifier MCAI-2020-01408-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-8-400 
series airplanes. This proposed AD was prompted by a report that a 
number of nacelle A-frames were not manufactured in accordance with 
engineering drawings. This proposed AD would require, depending on 
airplane configuration, removing the fasteners on the nacelle A-frame 
side brace sub-assemblies, doing an eddy current inspection for 
cracking, cold-working the holes, installing oversize fasteners, re-
identifying the reworked side brace fitting and A-frame, 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 May 6, 
2021.

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 https://www.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.
    For service information identified in this NPRM, contact De 
Havilland Aircraft of Canada Limited, Q-Series Technical Help Desk, 123 
Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-
4000; fax 416-375-4539; email thd@dehavilland.com; internet https://dehavilland.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.

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-
0183; 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, any comments received, and other information. The street 
address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Andrea Jimenez, Aerospace Engineer, 
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7330; fax 516-
794-5531; email 9-avs-nyaco-cos@faa.gov.

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-2021-0183; Project Identifier 
MCAI-2020-01408-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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposed AD.

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 
Andrea Jimenez, Aerospace Engineer, Airframe and Propulsion Section, 
FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; telephone 516-228-7330; fax 516-794-

[[Page 15150]]

5531; email 9-avs-nyaco-cos@faa.gov. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued TCCA AD CF-2020-39, dated October 14, 
2020 (referred to after this as the Mandatory Continuing Airworthiness 
Information, or the MCAI), to correct an unsafe condition for certain 
De Havilland Aircraft of Canada Limited Model DHC-8-400 series 
airplanes. You may examine the MCAI in the AD docket on the internet at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0183.
    This proposed AD was prompted by a report that a number of nacelle 
A-frames were not manufactured in accordance with engineering drawings. 
The holes in the side brace sub-assemblies were not cold-worked as 
required. As a result the side brace fitting might not meet its fatigue 
life, and cracking of the A-frame bottom flange may result. The FAA is 
proposing this AD to address possible cracking of the A-frame. This 
condition, if not addressed, may lead to collapse of the main landing 
gear (MLG). See the MCAI for additional background information.

Related Service Information Under 1 CFR Part 51

    De Havilland Aircraft of Canada Limited has issued Service Bulletin 
84-54-32, dated October 10, 2019. This service information describes 
procedures, depending on airplane configuration, for removing the 
fasteners on the nacelle A-frame side brace sub-assemblies, doing an 
eddy current inspection for cracking, cold-working the holes, 
installing oversize fasteners, and re-identifying the reworked side 
brace fitting and A-frame.
    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 the State of Design Authority, 
the FAA has been notified of the unsafe condition described in the MCAI 
and service information referenced above. The FAA is proposing this AD 
because the FAA evaluated all the relevant information and determined 
the unsafe condition described previously is likely to exist or develop 
on other products of the same type design.

Proposed Requirements of This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information described previously. This proposed AD would 
also require repairing any crack found during an eddy current 
inspection.

Costs of Compliance

    The FAA estimates that this proposed AD affects 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
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15 work-hours x $85 per hour = $1,275........................            $254           $1,529          $62,689
----------------------------------------------------------------------------------------------------------------

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-2021-0183; Project 
Identifier MCAI-2020-01408-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by May 6, 2021.

(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-8-400, -
401, and -402 airplanes,

[[Page 15151]]

certificated in any category, serial numbers 4081 through 4591 
inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 54, Nacelles/
pylons.

(e) Reason

    This AD was prompted by a report that a number of nacelle A-
frames were not manufactured in accordance with engineering 
drawings. The holes in the side brace sub-assemblies were not cold-
worked as required. As a result the side brace fitting might not 
meet its fatigue life, and cracking of the A-frame bottom flange may 
result. The FAA is issuing this AD to address possible cracking of 
the A-frame. This condition, if not addressed, may lead to collapse 
of the main landing gear (MLG).

(f) Compliance

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

(g) Required Actions

    (1) Within the compliance time specified in paragraph (g)(2) of 
this AD, do the applicable actions specified in paragraphs (g)(1)(i) 
and (ii) of this AD.
    (i) For airplanes having serial numbers 4081 through 4582 
inclusive: Remove the fasteners on the nacelle A-frame side brace 
sub-assemblies, do an eddy current inspection for cracking on 
airplanes having 30,000 total flight cycles or more, cold-work the 
holes, and install oversize fasteners, in accordance with Part A of 
paragraph 3.B. of the Accomplishment Instructions of De Havilland 
Aircraft of Canada Limited Service Bulletin 84-54-32, dated October 
10, 2019. If any cracking is found, before further flight, repair 
the cracking using a method approved by the Manager, New York ACO 
Branch, FAA; or Transport Canada Civil Aviation (TCCA); or De 
Havilland Aircraft of Canada Limited's TCCA Design Approval 
Organization (DAO). If approved by the DAO, the approval must 
include the DAO-authorized signature.
    (ii) For all airplanes: Re-identify the reworked side brace 
fitting and A-frame, in accordance with Part B of paragraph 3.B. of 
the Accomplishment Instructions of De Havilland Aircraft of Canada 
Limited Service Bulletin 84-54-32, dated October 10, 2019.
    (2) At the earlier of the times specified in paragraphs 
(g)(2)(i) and (ii) of this AD, do the applicable actions specified 
in paragraph (g)(1) of this AD.
    (i) Within 48 months or 8,000 flight hours after the effective 
date of this AD, whichever occurs first.
    (ii) At the later of the times specified in paragraphs 
(g)(2)(ii)(A) and (B) of this AD.
    (A) Before accumulating 40,000 total flight cycles.
    (B) Within 12 months or 1,290 flight cycles after the effective 
date of this AD, whichever occurs first.

(h) Other FAA 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 certification 
office, send it to ATTN: Program Manager, Continuing Operational 
Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531. 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 TCCA; or De Havilland Aircraft of Canada Limited's 
TCCA DAO. If approved by the DAO, the approval must include the DAO-
authorized signature.

(i) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) TCCA AD CF-2020-39, dated October 14, 2020, for related 
information. This MCAI may be found in the AD docket on the internet 
at https://www.regulations.gov by searching for and locating Docket 
No. FAA-2021-0183.
    (2) For more information about this AD, contact Andrea Jimenez, 
Aerospace Engineer, Airframe and Propulsion Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7330; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.
    (3) For service information identified in this AD, contact De 
Havilland Aircraft of Canada Limited, Q-Series Technical Help Desk, 
123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 
416-375-4000; fax 416-375-4539; email thd@dehavilland.com; internet 
https://dehavilland.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.

    Issued on March 10, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-05352 Filed 3-19-21; 8:45 am]
BILLING CODE 4910-13-P


