[Federal Register Volume 88, Number 49 (Tuesday, March 14, 2023)]
[Rules and Regulations]
[Pages 15609-15611]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-05060]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1653; Project Identifier MCAI-2022-01193-T; 
Amendment 39-22370; AD 2023-05-01]
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 adopting a new airworthiness directive (AD) for 
certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series 
airplanes. This AD was prompted by reports of flap power unit (FPU) 
pressure switch failures resulting in flap inoperative events. This AD 
requires replacing the FPU or replacing the FPU pressure switch and 
reidentifying the FPU. This AD also prohibits the installation of 
affected parts. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective April 18, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 18, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2022-1653; 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 service information identified in this final rule, 
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">[email protected]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 in the AD docket at 
regulations.gov under Docket No. FAA-2022-1653.

FOR FURTHER INFORMATION CONTACT: Gabriel Kim, Aerospace Engineer, 
Mechanical Systems and Administrative Services Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone (516) 228-7300; email [email protected].

[[Page 15610]]


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 certain De Havilland 
Aircraft of Canada Limited Model DHC-8-400 series airplanes. The NPRM 
published in the Federal Register on December 23, 2022 (87 FR 78881). 
The NPRM was prompted by AD CF-2022-52, dated September 1, 2022, issued 
by Transport Canada, which is the aviation authority for Canada 
(Transport Canada AD CF-2022-52) (also referred to as the MCAI). The 
MCAI states there have been increasing reports of FPU pressure switch 
failures, part number (P/N) 150135-1 or P/N 162660-1, over the past 
year leading to a high number of flap inoperative events in flight and 
on the ground. An investigation has determined the root cause to be a 
deformation of the FPU pressure switch internal mechanism due to 
hydraulic pressure spikes. If not corrected, a failed FPU pressure 
switch could lead to a failure of the FPU resulting in abnormal flap 
landings and increased landing distances, which could require the use 
of emergency landing procedures and/or airfield diversions. The 
improved pressure switch, P/N 162660-2, has a restrictor insert in the 
pressure switch inlet.
    In the NPRM, the FAA proposed to require replacing the FPU pressure 
switch or the FPU. The NPRM also proposed to prohibit the installation 
of affected parts. 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-2022-1653.

Discussion of Final Airworthiness Directive

Comments

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

Explanation of Additional Changes

    In the NPRM, the FAA inadvertently omitted the operational test of 
the wing flaps specified in Section 3.C. paragraph (2) of De Havilland 
Aircraft of Canada Limited Service Bulletin 84-27-75, dated June 23, 
2022, including Collins Aerospace Service Bulletin 27-0029, dated June 
13, 2022. The MCAI requires this step, which is important to ensure the 
aircraft is airworthy before it is returned to service. The FAA has 
therefore revised paragraphs (g)(1) and (2) of this AD to clarify that 
the operational test is required by this AD.
    The FAA has revised paragraph (g)(2) of this AD to clarify that De 
Havilland Aircraft of Canada Limited Service Bulletin 84-27-75, dated 
June 23, 2022, including Collins Aerospace Service Bulletin 27-0029, 
dated June 13, 2022, is the appropriate service information for 
accomplishing the actions in this AD. The FAA had referred to these 
bulletins separately, but since they are published as one document, the 
FAA corrected the citation.

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, 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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed De Havilland Aircraft of Canada Limited Service 
Bulletin 84-27-75, dated June 23, 2022, including Collins Aerospace 
Service Bulletin 27-0029, dated June 13, 2022. This service information 
specifies procedures for replacing FPU P/N C148656-1 or C148656-2 with 
a new FPU P/N C148656-3, or replacing FPU pressure switch P/N 150135-1 
or 162660-1 within the FPU with a new pressure switch P/N 162660-2 and 
re-identifying the FPU as P/N C148656-3, and accomplishing an 
operational test of the wing flaps. 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.

Costs of Compliance

    The FAA estimates that this AD affects 53 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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              Labor cost                      Parts cost            Cost per product      Cost on U.S. operators
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Up to 6 work-hours x $85 per hour =    Up to $3,000...........  Up to $3,510...........  Up to $186,030.
 $510.
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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 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,

[[Page 15611]]

    (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:

2023-05-01 De Havilland Aircraft of Canada Limited (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-22370; Docket No. 
FAA-2022-1653; Project Identifier MCAI-2022-01193-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 18, 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, serial numbers 4001 
and 4003 through 4633 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code: 27, Flight 
Controls.

(e) Unsafe Condition

    This AD was prompted by reports of flap power unit (FPU) 
pressure switch failures resulting in flap inoperative events. The 
FAA is issuing this AD to address FPU pressure switch failures. The 
unsafe condition, if not addressed, could result in abnormal flap 
landings and increased landing distances, which could require the 
use of emergency landing procedures and/or airfield diversions.

(f) Compliance

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

(g) Requirements

    Within 8,000 flight hours or 48 months after the effective date 
of this AD, whichever occurs first: Do the actions specified in 
either paragraph (g)(1) or (2) of this AD.
    (1) Replace FPU part number (P/N) C148656-1 or C148656-2 with P/
N C148656-3 and do an operational test of the wing flaps in 
accordance with Section 3.B. paragraph (1) and Section 3.C. 
paragraph (2), of the Accomplishment Instructions of De Havilland 
Aircraft of Canada Limited Service Bulletin 84-27-75, dated June 23, 
2022, including Collins Aerospace Service Bulletin 27-0029, dated 
June 13, 2022.
    (2) Replace FPU pressure switch P/N 150135-1 or 162660-1 with P/
N 162660-2, reidentify the FPU as P/N C148656-3, and do an 
operational test of the wing flaps in accordance with Section 3.B. 
paragraph (2) and Section 3.C. paragraph (2), of the Accomplishment 
Instructions of De Havilland Aircraft of Canada Limited Service 
Bulletin 84-27-75, dated June 23, 2022, including Collins Aerospace 
Service Bulletin 27-0029, dated June 13, 2022.

(h) Parts Installation Prohibition

    As of the effective date of this AD, do not install a FPU having 
P/N C148656-1 or C148656-2 or a FPU pressure switch having P/N 
150135-1 or 162660-1 on any airplane.

(i) Additional 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. 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; or De Havilland Aircraft of Canada 
Limited's Transport Canada Design Organization Approval (DOA). If 
approved by the DOA, the approval must include the DOA-authorized 
signature.

(j) Additional Information

    (1) Refer to Transport Canada AD CF-2022-52, dated September 1, 
2022, for related information. This Transport Canada AD may be found 
in the AD docket at regulations.gov under Docket No. FAA-2022-1653.
    (2) For more information about this AD, contact Gabriel Kim, 
Aerospace Engineer, Mechanical Systems and Administrative Services 
Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone (516) 228-7300; email [email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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-
27-75, dated June 23, 2022, including Collins Aerospace Service 
Bulletin 27-0029, dated June 13, 2022.
    Note 1 to paragraph (k)(2)(i): De Havilland issued De Havilland 
Service Bulletin 84-27-75, dated June 23, 2022, with Collins 
Aerospace Service Bulletin 27-0029, dated June 13, 2022, attached as 
one ``merged'' file for the convenience of affected operators.
    (ii) [Reserved]
    (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">[email protected]dehavilland.com; website dehavilland.com.
    (4) 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.
    (5) You may view this material 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 March 2, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-05060 Filed 3-13-23; 8:45 am]
BILLING CODE 4910-13-P


