[Federal Register Volume 89, Number 96 (Thursday, May 16, 2024)]
[Rules and Regulations]
[Pages 42792-42795]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-08577]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2137; Project Identifier MCAI-2022-01389-T; 
Amendment 39-22737; AD 2024-08-04]
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.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 
airplanes. This AD was prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. This AD requires 
revising the existing maintenance or inspection program, as applicable, 
to incorporate new or more restrictive airworthiness limitations. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective June 20, 2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-2137; 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.

[[Page 42793]]

    Material Incorporated by Reference:
     For De Havilland material, 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 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-2023-2137.

FOR FURTHER INFORMATION CONTACT: Fatin Saumik, 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 by adding an AD that would apply to all De Havilland 
Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. The NPRM 
published in the Federal Register on October 27, 2023 (88 FR 73775). 
The NPRM was prompted by AD CF-2022-59, dated October 27, 2022, issued 
by Transport Canada, which is the aviation authority for Canada 
(referred to after this as the MCAI). The MCAI states that new or more 
restrictive airworthiness limitations have been developed.
    In the NPRM, the FAA proposed to require revising the existing 
maintenance or inspection program, as applicable, to incorporate new or 
more restrictive airworthiness limitations. The FAA is issuing this AD 
to address new or more restrictive maintenance interval limitations. 
Failure to adhere to the specified interval limitations may result in 
reduced structural integrity of the airplane.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-2137.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from an individual who supported the 
NPRM without change.
    The FAA received additional comments from De Havilland Aircraft of 
Canada Limited and Horizon Air. The following presents the comments 
received on the NPRM and the FAA's response to each comment.

Request To Update the Number of Affected Airplanes

    De Havilland requested that the Costs of Compliance section of the 
NPRM be updated to show the correct number of affected airplanes.
    The FAA agrees. The Costs of Compliance section of this AD has been 
updated to show 52 affected airplanes.

Request To Require Tasks as Mandated in the MCAI

    Horizon Air requested that the proposed AD directly mandate 
maintenance review board report (MRBR) tasks instead of Aircraft 
Maintenance Manual (AMM) tasks. Horizon noted that Transport Canada AD 
CF-2022-59 mandates MRBR tasks directly, and that using the AMM tasks 
would put an additional burden on the operator to monitor multiple 
sources for the same tasks. The commenter also asserted that AMM task 
77-31-00-710-803, which would be required by the proposed AD, adds MRBR 
tasks 731100-203, 733100-201, 740000-201, 750000-201, 772100-202, and 
793000-201. These tasks are not identified in Section 7-00, PSM 1-84-
7--Maintenance Requirements Manual--Part 2 ALI.
    The FAA does not agree because the FAA has decided to not mandate 
MRBRs that are part of Candidate Certification Maintenance Requirements 
(CCMRs), which are required by Transport Canada AD CF-2022-59. Instead 
of mandating the CCMR as done in the Transport Canada AD, the FAA, 
after coordination with Transport Canada, determined the corresponding 
AMM task numbers will be used. With the AMM tasks, operators must check 
for all engine fault codes at once, which involves reading codes from 
the engine fault code indicator. Although this involves more tasks, it 
does not add a significant number of steps. Requiring the AMM task does 
not pose a significant burden on the operator. This AD has not been 
changed with regard to this request.

Request To Limit Required Tasks to Procedure Section

    Horizon Air requested that the proposed AD require only the 
procedure section of the AMM, with provisions for equivalent tooling 
and materials, rather than requiring the entire AMM maintenance task, 
including the job set-up, specific tools, equipment, and close-out 
sections. The commenter stated that mandating the entire AMM 
maintenance task procedure may restrict the operator's ability to 
perform other maintenance along with AMM tasks.
    The FAA does not agree. The job set-up and close-out procedures are 
essential for ensuring the safety of maintenance personnel, and for 
ensuring the correct completion of the AMM task. This AD has not been 
changed with regard to this request.

Request To Allow Further AMM Revisions

    Horizon Air requested clarification of whether future revisions of 
the AMM are allowed. Horizon noted that the proposed AD did not address 
whether task changes such as additions, removals, and interval 
adjustments could cause an operator to be out of compliance with the 
rule as issued.
    The FAA agrees to clarify. Using the current revision of the AMMs 
or other revisions that incorporate the information specified in 
paragraph (g) of this AD is acceptable for compliance with this AD. 
This AD does not mandate using a specific revision of the AMM, provided 
that the revision used complies with the requirements of paragraph (g) 
of this AD.

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, considered the 
comments received, 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, and any other changes described previously, this AD is adopted 
as proposed in the NPRM. None of the changes will increase the economic 
burden on any operator.

Costs of Compliance

    The FAA estimates that this AD affects 52 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:
    The FAA has determined that revising the maintenance or inspection 
program takes an average of 90 work-hours per operator, although the 
agency recognizes that this number may vary from operator to operator. 
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 
agency

[[Page 42794]]

estimates the average total cost per operator to be $7,650 (90 work-
hours x $85 per work-hour).

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.

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 adding the following new airworthiness 
directive:

2024-08-04 De Havilland Aircraft of Canada Limited (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-22737; Docket No. 
FAA-2023-2137; Project Identifier MCAI-2022-01389-T.

(a) Effective Date

    This airworthiness directive (AD) is effective June 20, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all De Havilland Aircraft of Canada Limited 
Model DHC-8-401 and -402 airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 05, Time Limits/
Maintenance Checks.

(e) Reason

    This AD was prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. The FAA is 
issuing this AD to address new or more restrictive maintenance 
interval limitations. Failure to adhere to the specified interval 
limitations may result in reduced structural integrity of the 
airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    Within 60 days after the effective date of this AD, revise the 
existing maintenance or inspection program, as applicable, to 
incorporate the information specified in figure 1 to paragraph (g) 
of this AD. The initial compliance time for each task in the AMM 
Task column of figure 1 to paragraph (g) of this AD is at the time 
specified in the initial compliance time column of figure 1 to 
paragraph (g) of this AD or within 12 months after the effective 
date of this AD, whichever occurs later.

Figure 1 to Paragraph (g)--Maintenance or Inspection Program Revision

  Figure 1 to Paragraph (g)--Maintenance or Inspection Program Revision
------------------------------------------------------------------------
                        Initial          Interval
   Effectivity      compliance time     limitation         AMM task
------------------------------------------------------------------------
All..............  10,000 total      10,000 FH......    21-31-00-710-801
                    flight hours
                    (FH).
All..............  20,000 total FH.  20,000 FH......    21-31-00-710-803
All..............  20,000 total FH.  20,000 FH......    21-31-00-710-804
All..............  35,000 total FH.  35,000 FH......    22-11-00-720-803
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-801
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-802
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-805
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-807
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-803
All..............  30,000 total FH.  30,000 FH......    26-20-00-900-804
All..............  20,000 total FH.  20,000 FH......    26-20-00-710-801
All..............  20,000 total FH.  20,000 FH......    28-21-00-710-801
All..............  10,000 total FH.  10,000 FH......    29-12-00-720-803
All..............  4,950 total FH..  4,950 FH.......    29-12-00-720-805
All..............  4,950 total FH..  4,950 FH.......    29-12-00-720-802
All..............  4,950 total FH..  4,950 FH.......    29-12-00-720-804
All..............  30,000 total FH.  30,000 FH......    30-11-00-710-802
All..............  5,280 total FH..  5,280 FH.......    31-41-00-710-802
All..............  1,760 total FH..  1,760 FH.......    32-11-00-210-802
All..............  30,000 total FH.  30,000 FH......    52-24-00-210-802
All..............  4,400 total FH..  4,400 FH.......    61-20-00-710-802
All..............  150 total FH....  150 FH.........    77-31-00-710-803
------------------------------------------------------------------------


[[Page 42795]]

(h) No Alternative Actions or Intervals

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections) or intervals may be used unless the 
actions or intervals are approved as an alternative method of 
compliance (AMOC) in accordance with the procedures specified in 
paragraph (i)(1) of this AD.

(i) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (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 International 
Validation Branch, send it to the attention of the person identified 
in paragraph (j)(2) of this AD. Information may be emailed to: [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.

(j) Additional Information

    (1) Refer to Transport Canada AD CF-2022-59, dated October 27, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2023-2137.
    (2) For more information about this AD, contact Fatin Saumik, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone: 516-228-7300; email: [email protected].

(k) Material Incorporated by Reference

    None.

    Issued on April 17, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-08577 Filed 5-15-24; 8:45 am]
BILLING CODE 4910-13-P