[Federal Register Volume 86, Number 208 (Monday, November 1, 2021)]
[Rules and Regulations]
[Pages 60162-60164]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-23656]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0613; Project Identifier MCAI-2020-01431-T; 
Amendment 39-21801; AD 2021-23-03]
RIN 2120-AA64


Airworthiness Directives; De Havilland Aircraft of Canada Limited 
(Type Certificate Previously Held by Bombardier, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain De Havilland Aircraft of Canada Limited Model DHC-8-400, -401, 
and -402 airplanes. This AD was prompted by a report of cracking found 
on a main landing gear (MLG) drag strut assembly. This AD requires a 
records review to determine if an affected MLG drag strut assembly is 
installed, repetitive detailed inspections for cracking of affected 
strut assemblies, a one-time magnetic particle inspection for cracking, 
and on-condition actions if necessary. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective December 6, 2021.

ADDRESSES:

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-
0613; 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, any comments received, and other information. The 
address for Docket Operations is U.S. Department of

[[Page 60163]]

Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Aziz Ahmed, Aerospace Engineer, 
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7329; fax 516-
794-5531; email [email protected].

SUPPLEMENTARY INFORMATION:

Background

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued TCCA AD CF-2020-43, dated October 21, 
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, -401, 
and -402 airplanes. You may examine the MCAI in the AD docket at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0613.
    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain De Havilland 
Aircraft of Canada Limited Model DHC-8-400, -401, and -402 airplanes. 
The NPRM published in the Federal Register on August 3, 2021 (86 FR 
41794). The NPRM was prompted by a report of cracking found on an MLG 
drag strut assembly. The NPRM proposed to require a records review to 
determine if an affected MLG drag strut assembly is installed, 
repetitive detailed inspections for cracking of affected strut 
assemblies, a one-time magnetic particle inspection for cracking, and 
on-condition actions if necessary. The FAA is issuing this AD to 
address cracking of the MLG drag strut assembly and possible failure 
under compression loads during landing or ground operations, which 
could result in asymmetric MLG configuration and potential runway 
excursion. See the MCAI for additional background information.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The FAA has considered the comment 
received. The Air Line Pilots Association, International (ALPA) 
indicated its support for the NPRM.

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety and the public interest 
require adopting this final rule as proposed, except for minor 
editorial changes. The FAA has determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Costs of Compliance

    The FAA estimates that this AD will affect 34 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
               Labor cost                   Parts cost         Cost per product         Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 11 work-hours x $85 per hour = Up               $0  Up to $935................  Up to $31,790.
 to $935.
----------------------------------------------------------------------------------------------------------------

    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
----------------------------------------------------------------------------------------------------------------
               Labor cost                   Parts cost         Cost per product         Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 10 work-hours x $85 per hour = Up              * $  Up to $850................  Up to $850.
 to $850.
----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data that would enable the agency to provide parts cost estimates for the
  actions specified in this AD.

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

    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.

[[Page 60164]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of 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 adding the following new airworthiness 
directive:

2021-23-03 De Havilland Aircraft of Canada Limited (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-21801; Docket No. 
FAA-2021-0613; Project Identifier MCAI-2020-01431-T.

(a) Effective Date

    This airworthiness directive (AD) is effective December 6, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to De Havilland Aircraft of Canada Limited Model 
DHC-8-400, -401, and -402 airplanes, certificated in any category, 
serial numbers 4001, 4003, and subsequent.

(d) Subject

    Air Transport Association (ATA) of America Code 32, Landing 
Gear.

(e) Unsafe Condition

    This AD was prompted by a report of cracking found on a main 
landing gear (MLG) drag strut assembly. The FAA is issuing this AD 
to address cracking of the MLG drag strut assembly and possible 
failure under compression loads during landing or ground operations, 
which could result in asymmetric MLG configuration and potential 
runway excursion.

(f) Compliance

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

(g) Records Review, Repetitive Inspections, and On-Condition Actions

    Within 30 days after the effective date of this AD: Review the 
applicable airplane maintenance records to determine if any affected 
MLG drag strut assembly identified in figure 1 to the introductory 
text of paragraph (g) of this AD is installed. If any affected MLG 
drag strut assembly is installed, do the actions specified in 
paragraphs (g)(1) and (2) of this AD.

  Figure 1 to the Introductory Text of Paragraph (g)--Affected MLG Drag
                             Strut Assembly
------------------------------------------------------------------------
                 Part No.                            Serial No.
------------------------------------------------------------------------
46301-13..................................  MBM0056
                                            MBM0073
                                            MBM0076
                                            MBM0130
                                            MBM0136
                                            MBM0145
                                            MBM0179
                                            MBM0204
                                            MBM0208
                                            MBM0302
                                            MBM0303
                                            MBM0324
                                            MBM0405
                                            MBM0408
                                            MBM0412
                                            MBM0417
                                            MBM0423
------------------------------------------------------------------------

    (1) Within 80 flight hours after accomplishing the records 
review required by paragraph (g) of this AD, do a detailed 
inspection for cracking of the affected MLG drag strut assembly, and 
do all applicable on-condition actions before further flight, in 
accordance with a method approved by the Manager, New York ACO 
Branch, FAA. Repeat the inspection thereafter at intervals not to 
exceed 80 flight hours until the magnetic particle inspection 
required by paragraph (g)(2) of this AD is done.
    Note 1 to paragraph (g)(1): Guidance on the inspections and on-
condition actions required by this AD can be found in Transport 
Canada Civil Aviation (TCCA) AD CF-2020-43, dated October 21, 2020.
    (2) Within 1,600 flight hours or 12 months after the effective 
date of this AD, whichever occurs first, perform a magnetic particle 
inspection for cracks of the entire tubular section of the affected 
MLG drag strut assembly, and do all on-condition actions before 
further flight, in accordance with a method approved by the Manager, 
New York ACO Branch, FAA. Performing the magnetic particle 
inspection required by this paragraph terminates the repetitive 
detailed inspections required by paragraph (g)(1) of this AD.

(h) Parts Installation Prohibition

    As of the effective date of this AD, no person may install an 
affected MLG drag strut assembly identified in figure 1 to the 
introductory text of paragraph (g) of this AD on any airplane unless 
the inspections and applicable on-conditions specified in paragraphs 
(g)(1) and (2) of this AD are done before further flight.

(i) 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 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.

(j) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) TCCA AD CF-2020-43, dated October 21, 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-2021-0613.
    (2) For more information about this AD, contact Aziz Ahmed, 
Aerospace Engineer, Airframe and Propulsion Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7329; fax 516-794-5531; email [email protected].
    (3) For information about TCCA AD CF-2020-43, dated October 21, 
2020, contact TCCA, Transport Canada National Aircraft 
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; 
telephone 888-663-3639; email [email protected]; internet https://tc.canada.ca/en/aviation. 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.

(k) Material Incorporated by Reference

    None.

    Issued on October 26, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-23656 Filed 10-29-21; 8:45 am]
BILLING CODE 4910-13-P