[Federal Register Volume 88, Number 105 (Thursday, June 1, 2023)]
[Proposed Rules]
[Pages 35788-35791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-11590]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1047; Project Identifier MCAI-2022-01601-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 the main 
landing gear (MLG) aft door not opening when using the alternate 
extension system. This proposed AD would require a one-time inspection 
of the spring box assembly, repetitive inspections of the cam assembly 
and alternate release cable assembly, corrective actions if necessary, 
and a replacement of certain alternate release cable assemblies. In 
addition, this proposed AD would also require certain aircraft 
maintenance manuals tasks when installing the cam assembly or alternate 
release cable assembly. This proposed AD would also prohibit the 
installation of affected parts. 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 July 17, 
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-2023-1047; 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 North America (toll-free): 855-310-1013, Direct: 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: Gabriel Kim, 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-2023-1047; Project Identifier 
MCAI-2022-01601-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 
this 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.

[[Page 35789]]

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 
Gabriel Kim, 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-2022-69, dated December 16, 2022 
(Transport Canada AD CF-2022-69) (also referred to as the MCAI), to 
correct an unsafe condition for certain De Havilland Aircraft of Canada 
Limited (Type Certificate Previously Held by Bombardier, Inc.) Model 
DHC-8-401 and -402 airplanes. The MCAI states that several instances 
occurred where the maintenance crew using the MLG alternate extension 
system did not open the MLG aft doors. An investigation found that the 
associated cam assembly failed due to a fractured cam assembly lever, a 
damaged spring box assembly, or a broken alternate release cable 
assembly.
    The FAA is proposing this AD to address possible cam assembly, 
spring box assembly, and alternate release cable assembly failures. The 
unsafe condition, if not addressed, could result in asymmetric main 
landing gear configuration at landing, and a runway excursion.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-1047.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed De Havilland Aircraft of Canada Limited Service 
Bulletin 84-32-159, dated June 28, 2019. This service information 
specifies procedures for performing a general visual inspection of the 
cam assembly (part number (P/N) 48510-5) for discrepancies (such as the 
cam assembly does not return to its original rested position, or signs 
of an increased gap between the roller and the cam guide); a general 
visual inspection of the alternate release cable assembly (or uplock 
cable assembly) (P/N 48503-3) for discrepancies (such as a broken 
cable); a one-time general visual inspection for discrepancies (such as 
any bend on the plunger) of the left and right MLG spring box assembly 
(P/N 48504-1); and corrective actions. Corrective actions include 
replacing the cam assembly with a new cam assembly, replacing the 
alternate release cable assembly with a new alternate release cable 
assembly, and replacing the spring box assembly with a new spring box 
assembly.
    The FAA also reviewed De Havilland Aircraft of Canada Limited 
Service Bulletin 84-32-172, dated August 16, 2022, including Collins 
Aerospace Service Bulletin 48500-32-152, dated July 18, 2022. This 
service information specifies procedures for replacing the left and 
right MLG alternate release cable assemblies, P/N 48503-3, with the 
redesigned alternate release cable assembly, P/N 48503-5.
    The FAA also reviewed De Havilland Aircraft of Canada Limited 
Temporary Revision 32-603, dated December 1, 2022, which describes 
aircraft maintenance manual (AMM) TASK 32-34-16-400-804, ``Installation 
of the Alternate Extension Cables--Center Fuselage to Nacelle.''
    The FAA also reviewed AMM TASK 32-34-26-400-801, ``Installation of 
the MLG Alternate-Extension Cam-Mechanism Assembly'' of Subject 32-34-
26, ``Cam Mechanism Assembly--MLG Alternative Extension'' in Chapter 
32, ``Landing Gear,'' of the De Havilland Aircraft of Canada Limited 
Aircraft Maintenance Manual, Revision 76, dated March 5, 2022.
    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 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, 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 in other products of the same type designs.

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 prohibit the installation of affected parts.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 55 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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               Labor cost                   Parts cost         Cost per product         Cost on U.S. operators
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Up to 5 work-hour x $85 per hour = $425          $4,780   Up to $5,205..............  Up to $286,275.
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    The FAA estimates the following costs to do any necessary on-
condition action that would be required based on the results of any 
required action. The FAA has no way of determining the number of 
aircraft that might need this on-condition action:

[[Page 35790]]



                 Estimated Costs of On-Condition Actions
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                                                             Cost per
              Labor cost                   Parts cost        product
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4.5 work-hours x $85 per hour = $383..         $41,328          $41,711
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    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 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-2023-1047; Project 
Identifier MCAI-2022-01601-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by July 17, 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: 32, Landing 
Gear.

(e) Unsafe Condition

    This AD was prompted by reports of the main landing gear (MLG) 
aft door not opening when using the alternate extension system. The 
FAA is issuing this AD to address possible cam assembly, spring box 
assembly, and alternate release cable assembly failures. The unsafe 
condition, if not addressed, could result in asymmetric MLG 
configuration at landing, and a runway excursion.

(f) Compliance

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

(g) One-Time Inspection

    Within 2,400 flight hours or 12 months, whichever occurs first, 
after the effective date of this AD, do a one-time general visual 
inspection for discrepancies on the left and right MLG spring box 
assemblies (part number (P/N) 48504-1), in accordance with Section 
3.B., Part A, of the Accomplishment Instructions of De Havilland 
Aircraft of Canada Service Bulletin 84-32-159, dated June 28, 2019. 
If any discrepancy is discovered in the spring box assembly, before 
further flight, replace with a new spring box assembly, in 
accordance with Section 3.B. Part B, of the Accomplishment 
Instructions of De Havilland Aircraft of Canada Service Bulletin 84-
32-159, dated June 28, 2019.

(h) Repetitive Inspections

    (1) Within 2,400 flight hours or 12 months, whichever occurs 
first, after the effective date of this AD, do a general visual 
inspection for discrepancies of the cam assemblies (P/N 48510-5) on 
the left and right MLG, in accordance with Section 3.B. Part A, of 
the Accomplishment Instructions of De Havilland Aircraft of Canada 
Service Bulletin 84-32-159, dated June 28, 2019. Thereafter, repeat 
the inspection at intervals not to exceed 2,400 flight hours or 12 
months, whichever occurs first. If any discrepancy is discovered in 
the cam assembly, before further flight, replace with a new cam 
assembly, in accordance with Section 3.B. Part B, of the 
Accomplishment Instructions of De Havilland Aircraft of Canada 
Service Bulletin 84-32-159, dated June 28, 2019.
    (2) Within 2,400 flight hours or 12 months, whichever occurs 
first, after the effective date of this AD, do a general visual 
inspection for discrepancies of the alternate release cable 
assemblies (P/N 48503-3) on the left and right MLG, in accordance 
with Section 3.B., Part A, of the Accomplishment Instructions of De 
Havilland Aircraft of Canada Service Bulletin 84-32-159, dated June 
28, 2019. Thereafter, repeat the inspection at intervals not to 
exceed 2,400 flight hours or 12 months, whichever occurs first. If 
any discrepancy is found, before further flight, replace the 
alternate release cable assembly with a redesigned alternate release 
cable assembly P/N 48503-5, in accordance with in accordance with 
Section 3.B. of the Accomplishment Instructions of De Havilland 
Aircraft of Canada Service Bulletin 84-32-172, dated August 16, 
2022, including Collins Aerospace Service Bulletin 48500-32-152, 
dated July 18, 2022. Accomplishing the replacement required by 
paragraph (i) of this AD terminates the inspections required by this 
paragraph.

(i) Replacement

    Within 5,500 flight hours or 30 months, whichever occurs first, 
after the effective date of this AD, replace the left and right MLG 
alternate release cable assemblies, P/N 48503-3, with the redesigned 
alternate release cable assembly, P/N 48503-5, in accordance with 
Section 3.B. of the Accomplishment Instructions of De Havilland 
Aircraft of Canada Service Bulletin 84-32-172, dated August 16, 
2022, including

[[Page 35791]]

Collins Aerospace Service Bulletin 48500-32-152, dated July 18, 
2022.

(j) Maintenance Task Requirement

    As of the effective date of this AD, when installing an MLG 
alternate extension system cam assembly and when installing an 
alternate release cable assembly, the following aircraft maintenance 
manual (AMM) tasks must be used, as applicable:
    (1) For the alternate release cable assembly: AMM TASK 32-34-16-
400-804, ``Installation of the Alternate Extension Cables--Center 
Fuselage to Nacelle'' as specified in De Havilland Aircraft of 
Canada Limited Temporary Revision 32-603, dated December 1, 2022.
    (2) For the MLG alternate extension system cam assembly: AMM 
TASK 32-34-26-400-801, ``Installation of the MLG Alternate-Extension 
Cam-Mechanism Assembly'' of Subject 32-34-26, ``Cam Mechanism 
Assembly--MLG Alternative Extension'' in Chapter 32, ``Landing 
Gear,'' of the De Havilland Aircraft of Canada Limited Aircraft 
Maintenance Manual, Revision 76, dated March 5, 2022.

(k) Parts Installation Prohibition

    As of the effective date of this AD, no person may install, on 
any airplane, an alternate release cable assembly P/N 48503-3.

(l) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, East 
Certification 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 East 
Certification Branch, mail it to ATTN: Program Manager, Continuing 
Operational Safety, at the address identified in paragraph (m)(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, East 
Certification 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.

(m) Additional Information

    (1) Refer to Transport Canada AD CF-2022-69, dated December 16, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2023-1047.
    (2) For more information about this AD, contact Gabriel Kim, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; email [email protected].

(n) 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-
32-159, dated June 28, 2019.
    (ii) De Havilland Aircraft of Canada Limited Service Bulletin 
84-32-172, dated August 16, 2022, including Collins Aerospace 
Service Bulletin 48500-32-152, dated July 18, 2022.

    Note 1 to paragraph (n)(2)(ii): De Havilland issued De Havilland 
Service Bulletin 84-32-172, dated August 16, 2022, with Collins 
Aerospace Service Bulletin 48500-32-152, dated July 18, 2022, 
attached as one ``merged'' file for the convenience of affected 
operators.
    (iii) De Havilland Aircraft of Canada Limited Temporary Revision 
32-603, dated December 1, 2022.
    (iv) AMM TASK 32-34-26-400-801, ``Installation of the MLG 
Alternate-Extension Cam-Mechanism Assembly,'', of Subject 32-34-26, 
``Cam Mechanism Assembly--MLG Alternative Extension'' in Chapter 32, 
``Landing Gear,'' of the De Havilland Aircraft of Canada Limited 
Aircraft Maintenance Manual, Revision 76, dated March 5, 2022.
    (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 North America (toll-free): 855-310-1013, Direct: 
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 May 25, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-11590 Filed 5-31-23; 8:45 am]
BILLING CODE 4910-13-P