[Federal Register Volume 89, Number 137 (Wednesday, July 17, 2024)]
[Rules and Regulations]
[Pages 58058-58061]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-15656]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0756; Project Identifier MCAI-2023-00549-T; 
Amendment 39-22769; AD 2024-12-05]
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 superseding Airworthiness Directive (AD) 2021-25-12 
and AD 2022-11-11, which applied to certain De Havilland Aircraft of 
Canada Limited Model DHC-8-401 and -402 airplanes. AD 2021-25-12 
required repetitive lubrications of the trailing arm of the nose 
landing gear (NLG). AD 2021-25-12 also required revising the existing 
maintenance or inspection program to include new and revised 
airworthiness limitations. AD 2022-11-11 required a modification to the 
NLG shock strut assembly. This AD continues to require the actions 
specified in AD 2021-25-12 and AD 2022-11-11 and requires replacement 
of the pivot pin and tow fitting assembly with a new, improved pivot 
pin and tow fitting assembly and prohibits the installation of affected 
parts. This AD was prompted by a determination that the pivot pin and 
tow fitting assembly of the NLG must be replaced. 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.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of July 
8, 2022 (87 FR 33627, June 3, 2022).
    The Director of the Federal Register approved the incorporation by 
reference of certain other publications listed in this AD as of January 
5, 2022 (86 FR 72174, December 21, 2021).

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-0756; 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 material 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;

[[Page 58059]]

email dehavilland.com">thd@dehavilland.com; website dehavilland.com.
     You may view this material 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. It is also available at regulations.gov under 
Docket No. FAA-2024-0756.

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:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2021-25-12, Amendment 39-21856 (86 FR 
72174, December 21, 2021) (AD 2021-25-12); and AD 2022-11-11, Amendment 
39-22061 (87 FR 33627, June 3, 2022) (AD 2022-11-11). AD 2021-25-12 and 
AD 2022-11-11 applied to certain DeHavilland Aircraft of Canada Limited 
Model DHC-8-401 and -402 airplanes. AD 2021-25-12 required repetitive 
lubrications of the trailing arm of the NLG. AD 2021-25-12 also 
required revising the existing maintenance or inspection program to 
include new and revised airworthiness limitations (life limits for 
certain bolts). AD 2022-11-11 required modification to the NLG shock 
strut assembly. The FAA issued AD 2021-25-12 and AD 2022-11-11 to 
address failure of the pivot pin retention bolt, which could result in 
a loss of directional control or loss of an NLG tire during takeoff or 
landing, which could lead to runway excursions.
    The NPRM published in the Federal Register on March 22, 2024 (89 FR 
20367). The NPRM was prompted by AD CF-2023-22, dated March 30, 2023 
(Transport Canada AD CF-2023-22) (also referred to as the MCAI), issued 
by Transport Canada, which is the aviation authority for Canada. 
Transport Canada AD CF-2023-22 superseded Transport Canada AD CF-2009-
29R4, October 1, 2021 (Transport Canada AD CF-2009-29R4). The MCAI 
states that it requires the removal of pivot pin part number (P/N) 
47127-1 or P/N 47127-3 and tow fitting assembly P/N 47160-1, and their 
replacement with pivot pin P/N 47127-5 and tow fitting assembly P/N 
47160-3, as terminating action to the requirements of Transport Canada 
AD CF-2009-29R4. The pivot pin P/N 47127-5 is now attached directly to 
the new tow fitting lug and no longer requires the use of a retention 
bolt. Transport Canada AD CF-2023-22 also prohibits the installation of 
certain parts.
    In the NPRM, the FAA proposed to continue to require the actions 
specified in AD 2021-25-12 and AD 2022-11-11 and to require replacement 
of the pivot pin and tow fitting assembly with a new, improved pivot 
pin and tow fitting assembly and prohibit the installation of affected 
parts. In the NPRM, the FAA also proposed to remove airplanes from the 
applicability of AD 2021-25-12 and AD 2022-11-11. 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-2024-0756.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the cost to the public.

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 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 84-32-173, dated November 15, 2022, including Collins 
Aerospace Service Bulletin 47100-32-153, dated November 10, 2022. This 
material specifies procedures for replacing the pivot pin retention 
mechanism and tow fitting assembly with a new, improved pivot pin and 
tow fitting assembly, which consists of removing pivot pin linkage 
components and replacing pivot pin P/N 47127-1 or P/N 47127-3 and tow 
fitting assembly P/N 47160-1 with pivot pin P/N 47127-5 and tow fitting 
assembly P/N 47160-3.
    This AD also requires De Havilland Aircraft of Canada Limited 
Service Bulletin 84-32-161, Revision B, dated March 31, 2021, including 
UTC Aerospace Systems Service Bulletin 47100-32-145, Revision 3, dated 
March 26, 2021, which the Director of the Federal Register approved for 
incorporation by reference as of July 8, 2022 (87 FR 33627, June 3, 
2022).
    This AD also requires De Havilland Aircraft of Canada Limited 
Service Bulletin 84-32-167, dated August 12, 2021; and De Havilland 
Aircraft of Canada Limited Temporary Revision ALI-0223, dated October 
15, 2020, which the Director of the Federal Register approved for 
incorporation by reference as of January 5, 2022 (86 FR 72174, December 
21, 2021).
    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 will affect 41 airplanes of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
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                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Retained actions from AD 2021-25-12 *.  1 work-hour x $85 per         Negligible             $85          $3,485
                                         hour = $85.
Retained actions from AD 2022-11-11...  4 work-hours x $85 per                $8             348          14,268
                                         hour = $340.
New actions...........................  4 work-hours x $85 per            25,804          26,144       1,071,904
                                         hour = $340.
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* Table does not include estimated costs for revising the maintenance or inspection program.

    The FAA has determined that revising the maintenance or inspection 
program takes an average of 90 work-hours per operator, although the 
FAA recognizes that this number may vary from operator to operator. In 
the past, the FAA has

[[Page 58060]]

estimated that this action takes 1 work-hour per airplane. Since 
operators incorporate maintenance or inspection program changes for 
their affected fleet(s), the FAA has determined that a per-operator 
estimate is more accurate than a per-airplane estimate. Therefore, the 
FAA estimates the total cost per operator to be $7,650 (90 work-hours x 
$85 per work-hour).
    The FAA estimates the following costs to do any necessary on-
condition actions 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 these on-condition actions:

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
                                                             Cost per
              Labor cost                   Parts cost        product
------------------------------------------------------------------------
2 work-hours x $85 per hour = $170....              $8             $178
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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 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

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:
0
a. Removing Airworthiness Directive (AD) 2021-25-12, Amendment 39-21856 
(86 FR 72174, December 21, 2021); and AD 2022-11-11, Amendment 39-22061 
(87 FR 33627, June 3, 2022); and
0
b. Adding the following new AD:

2024-12-05 De Havilland Aircraft of Canada (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-22769; Docket No. 
FAA-2024-0756; Project Identifier MCAI-2023-00549-T.

(a) Effective Date

    This airworthiness directive (AD) is effective August 21, 2024.

(b) Affected ADs

    This AD replaces AD 2021-25-12, Amendment 39-21856 (86 FR 72174, 
December 21, 2021) (AD 2021-25-12); and AD 2022-11-11, Amendment 39-
22061 (87 FR 33627, June 3, 2022) (AD 2022-11-11).

(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) Reason

    This AD was prompted by reports of a certain bolt at the pivot 
pin link being found missing or having stress corrosion cracking and 
a determination that the pivot pin and tow fitting assembly of the 
nose landing gear (NLG) must be replaced. The FAA is issuing this AD 
to address failure of the pivot pin retention bolt. The unsafe 
condition, if not addressed, could result in a loss of directional 
control or loss of an NLG tire during takeoff or landing, which 
could lead to runway excursions.

(f) Compliance

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

(g) Retained Maintenance or Inspection Program Revision, With No 
Changes

    This paragraph restates the requirements of paragraph (g) of AD 
2021-25-12, with no changes. For airplanes with pivot pin retention 
bolt part number (P/N) NAS6204-14D installed on the NLG assembly: 
Within 30 days after January 5, 2022 (the effective date of AD 2021-
25-12), or within 30 days after installation of pivot pin retention 
bolt part number P/N NAS6204-14D, whichever occurs later, revise the 
existing maintenance or inspection program, as applicable, to 
incorporate the information for Structures Safe Life Task 32-21-01-
701 and Task 32-21-01-702, as specified in De Havilland Aircraft of 
Canada Limited Temporary Revision ALI-0223, dated October 15, 2020. 
The initial compliance time for doing the tasks is at the applicable 
time specified in De Havilland Aircraft of Canada Limited Temporary 
Revision ALI-0223, dated October 15, 2020, or within 30 days after 
January 5, 2022, whichever occurs later; except, if replacement of 
bolt P/N NAS6204-14D was performed before January 5, 2022, as 
specified in De Havilland Aircraft of Canada Service Bulletin 84-32-
161, the initial compliance time for Task 32-21-01-702 (bolt P/N 
NAS6204-14D replacement) is within 3 months after January 5, 2022, 
or within 800 flight cycles after performing the replacement, 
whichever occurs later.

(h) Retained No Alternative Actions or Intervals, With No Changes

    This paragraph restates the requirements of paragraph (h) of AD 
2021-25-12, with no changes. After the existing maintenance or 
inspection program has been revised as required by paragraph (g) of 
this AD, no alternative actions (e.g., replacements) or intervals 
may be used unless the actions and intervals are approved as an 
alternative method of compliance (AMOC) in accordance with the 
procedures specified in paragraph (n)(1) of this AD.

[[Page 58061]]

(i) Retained Repetitive Lubrications, With No Changes

    This paragraph restates the requirements of paragraph (i) of AD 
2021-25-12, with no changes. For airplanes with pivot pin retention 
bolt P/N NAS6204-14D installed on the NLG assembly: Within 30 days 
or 400 flight cycles, whichever occurs first after January 5, 2022 
(the effective date of AD 2021-25-12), and thereafter at intervals 
not exceeding 400 flight cycles, lubricate the trailing arm of the 
NLG, including doing a general visual inspection of the NLG pivot 
pin mechanism for discrepancies (i.e., bolt P/N NAS602-14D is 
missing or has damage (e.g., stress corrosion or stress corrosion 
cracking)) and, as applicable, replacing the bolt before further 
flight, in accordance with paragraph 3.B. of the Accomplishment 
Instructions of De Havilland Aircraft of Canada Limited Service 
Bulletin 84-32-167, dated August 12, 2021.

(j) Retained Modification, With No Changes

    This paragraph restates the requirements of paragraph (g) of AD 
2022-11-11, with no changes. For any airplane having an NLG shock 
strut assembly, P/N 47100-XX (where XX represents any number), that 
has special bolt P/N 47205-1 or 47205-3: Within 1,600 flight cycles 
or 9 months after July 8, 2022 (the effective date of AD 2022-11-
11), whichever occurs first, modify the NLG shock strut assembly, in 
accordance with paragraph 3.B., ``Procedure,'' of the Accomplishment 
Instructions of De Havilland Aircraft of Canada Limited Service 
Bulletin 84-32-161, Revision B, dated March 31, 2021, including UTC 
Aerospace Systems Service Bulletin 47100-32-145, Revision 3, dated 
March 26, 2021.
    Note 1 to paragraph (j): After installing pivot pin retention 
bolt part number NAS6204-14D, paragraphs (g), (h), and (i) of this 
AD apply to pivot pin retention bolt part number NAS6204-14D.

(k) New Replacement

    Within 8,000 flight hours or 48 months, whichever occurs first, 
after the effective date of this AD, remove pivot pin linkage 
components and replace pivot pin P/N 47127-1 or P/N 47127-3 and tow 
fitting assembly P/N 47160-1 with pivot pin P/N 47127-5 and tow 
fitting assembly P/N 47160-3, in accordance with Section 3.B. of the 
Accomplishment Instructions of De Havilland Aircraft of Canada 
Limited Service Bulletin 84-32-173, dated November 15, 2022, 
including Collins Aerospace Service Bulletin 47100-32-153, dated 
November 10, 2022. Accomplishing the replacement required by this 
paragraph terminates the requirements of paragraphs (g), (h), (i), 
and (j) of this AD.

(l) Credit for Previous Actions

    This paragraph provides credit for actions required by paragraph 
(j) of this AD, if those actions were performed before July 8, 2022 
(the effective date of AD 2022-11-11), using De Havilland Aircraft 
of Canada Limited Service Bulletin 84-32-161, dated April 7, 2020, 
including UTC Aerospace Systems Service Bulletin 47100-32-145, dated 
April 3, 2020; or De Havilland Aircraft of Canada Limited Service 
Bulletin 84-32-161, Revision A, dated January 27, 2021, including 
UTC Aerospace Systems Service Bulletin 47100-32-145, Revision 2, 
dated January 4, 2021.

(m) Parts Installation Prohibition

    As of the effective date of this AD, no person may install pivot 
pin P/N 47127-1 or P/N 47127-3 as a replacement part for pivot pin 
P/N 47127-5 on De Havilland Aircraft of Canada Limited Model DHC-8-
401 and DHC-8-402 airplanes.

(n) Additional AD Provisions

    (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 of the 
International Validation Branch, mail it to the address identified 
in paragraph (o)(2) of this AD. Information may be emailed to: 9-
[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.

(o) Additional Information

    (1) For more information about this AD, contact Deep Gaurav, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 518-228-7300; email [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the address specified in 
paragraph (p)(6) of this AD.

(p) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the material listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless this AD specifies otherwise.
    (3) The following material was approved for IBR on August 21, 
2024.
    (i) De Havilland Aircraft of Canada Limited Service Bulletin 84-
32-173, dated November 15, 2022, including Collins Aerospace Service 
Bulletin 47100-32-153, dated November 10, 2022.
    Note 2 to paragraph (p)(3)(i): De Havilland issued De Havilland 
Aircraft of Canada Limited Service Bulletin 84-32-173, dated 
November 15, 2022, with Collins Aerospace Service Bulletin 47100-32-
153, dated November 10, 2022, attached as one ``merged'' file for 
the convenience of affected operators.
    (ii) [Reserved]
    (4) The following material was approved for IBR on July 8, 2022 
(87 FR 33627, June 3, 2022).
    (i) De Havilland Aircraft of Canada Limited Service Bulletin 84-
32-161, Revision B, dated March 31, 2021, including UTC Aerospace 
Systems Service Bulletin 47100-32-145, Revision 3, dated March 26, 
2021.
    Note 3 to paragraph (p)(4)(i): De Havilland issued De Havilland 
Service Bulletin 84-32-161, Revision B, dated March 31, 2021, with 
UTC Aerospace Systems Service Bulletin 47100-32-145, Revision 3, 
dated March 26, 2021, attached as one ``merged'' file for the 
convenience of affected operators.
    (ii) [Reserved]
    (5) The following material was approved for IBR on January 5, 
2022 (86 FR 72174, December 21, 2021).
    (i) De Havilland Aircraft of Canada Limited Service Bulletin 84-
32-167, dated August 12, 2021.
    (ii) De Havilland Aircraft of Canada Limited Temporary Revision 
ALI-0223, dated October 15, 2020.
    (6) For De Havilland material 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.
    (7) You may view this material 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.
    (8) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations, or email [email protected].

    Issued on July 10, 2024.
James D. Foltz,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-15656 Filed 7-16-24; 8:45 am]
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