[Federal Register Volume 85, Number 212 (Monday, November 2, 2020)]
[Proposed Rules]
[Pages 69276-69279]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-24040]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0975; Product Identifier 2020-NM-061-AD]
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-8-400, -
401, and -402 airplanes. This proposed AD was

[[Page 69277]]

prompted by a report of main landing gear (MLG) retractions after 
striking an obstacle or severe wheel imbalance after a tire failure. 
This proposed AD would require inspections for correct height of the 
lock link over-center stop pin and for correct gaps of the left-hand 
and right-hand MLG downlock proximity sensors, replacement of the shim 
if necessary, and corrective actions, and installation of a new 
improved proximity sensor electronic unit (PSEU) with software changes. 
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 December 
17, 2020.

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 https://www.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.
    For service information identified in this NPRM, contact De 
Havilland Aircraft of Canada Limited, Q-Series Technical Help Desk, 123 
Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-
4000; fax 416-375-4539; email [email protected]; internet https://dehavilland.com. 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.

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-2020-
0975; 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, any comments received, and other information. The street 
address for Docket Operations is listed above. Comments will be 
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Darren Gassetto, Aerospace Engineer, 
Mechanical Systems and Administrative Services Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7323; fax 516-794-5531; 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 the ADDRESSES section. Include ``Docket No. FAA-2020-0975; 
Product Identifier 2020-NM-061-AD'' 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 the 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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposed AD.

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 
Darren Gassetto, Aerospace Engineer, Mechanical Systems and 
Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7323; fax 516-
794-5531; 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.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian AD CF-2016-31R1, dated March 
24, 2017 (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 on the internet at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2020-0975.
    This proposed AD was prompted by a report of MLG retractions after 
striking an obstacle or severe wheel imbalance after a tire failure. 
The FAA is proposing this AD to address loss of MLG downlock signal 
caused by the vibrations from those events, which leads to de-
energizing the MLG solenoid sequence valve (SSV) and subsequent removal 
of hydraulic pressure from the MLG downlock actuator. Loss of the 
hydraulic pressure in the downlock actuator, combined with the 
vibrations, can cause the stabilizer brace to unlock and the MLG to 
subsequently retract. See the MCAI for additional background 
information.

Related Service Information Under 1 CFR Part 51

    De Havilland Aircraft of Canada Limited has issued Bombardier 
Service Bulletin 84-32-140, Revision B, dated January 30, 2018. This 
service information describes set-up procedures for proper 
configuration of the MLG prior to performing subsequent procedures for 
inspections for correct height of the lock link over-center stop pin 
and for correct gaps of the left-hand and right-hand MLG downlock 
proximity sensors, and replacement of the shim.
    De Havilland Aircraft of Canada Limited has also issued Bombardier 
Service Bulletin 84-32-143, Revision B, dated November 16, 2016, which 
describes procedures for installation of a new, improved PSEU, PSEU 
30145-0601, with software changes.
    De Havilland Aircraft of Canada Limited has also issued Bombardier 
Service Bulletin 84-32-149, dated November 16, 2016, which describes 
procedures for installation of a new, improved PSEU, PSEU 30145-0602, 
with software changes.
    These documents are distinct since they apply to different airplane 
configurations. This service information is reasonably available 
because the interested parties have access to it

[[Page 69278]]

through their normal course of business or by the means identified in 
the 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, 
the FAA has been notified of the unsafe condition described in the MCAI 
and service information referenced above. The FAA is proposing this AD 
because the FAA evaluated all the relevant information and determined 
the unsafe condition described previously is likely to exist or develop 
on other products of the same type design.

Proposed Requirements of This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    The FAA estimates that this proposed AD affects 57 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 12 work-hours x $85 per   Up to $4,750..............  Up to $5,770.............  Up to $328,890.
 hour = Up to $1,020.
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    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
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                                                             Cost per
              Labor cost                   Parts cost        product
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1 work-hour x $85 per hour = $85......            $374             $459
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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 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) 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 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 (AD):

De Havilland Aircraft of Canada Limited (Type Certificate Previously 
Held by Bombardier, Inc.): Docket No. FAA-2020-0975; Product 
Identifier 2020-NM-061-AD.

(a) Comments Due Date

    The FAA must receive comments by December 17, 2020.

(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-8-400, -
401, and -402 airplanes, certificated in any category, having serial 
number 4001, and 4003 through 4534 inclusive.

(d) Subject

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

(e) Reason

    This AD was prompted by a report of main landing gear (MLG) 
retractions after striking an obstacle or severe wheel imbalance 
after a tire failure. The FAA is issuing this AD to address loss of 
MLG downlock signal caused by the vibrations from those events, 
which leads to de-energizing the MLG solenoid sequence valve and 
subsequent removal of hydraulic pressure from the MLG downlock 
actuator. Loss of the hydraulic pressure in the downlock actuator, 
combined with the vibrations, can cause the stabilizer brace to 
unlock and the MLG to subsequently retract.

(f) Compliance

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

[[Page 69279]]

(g) Downlock Sensor Rigging and Reduced Lock Link Over-Center

    Within 9 months after the effective date of this AD: Verify both 
the height of the lock link over-center stop pin and the gap of the 
left-hand and right-hand MLG downlock proximity sensors, and perform 
corrective actions as required, in accordance with paragraphs 3.A. 
and 3.B. of the Accomplishment Instructions of Bombardier Service 
Bulletin 84-32-140, Revision B, dated January 30, 2018. Do all 
applicable corrective actions before further flight.

(h) Installation of Proximity Sensor Electronic Unit (PSEU) 30145-0601

    Within 18 months after the effective date of this AD, install 
PSEU 30145-0601 in accordance with paragraphs 3.A. and 3.B. of the 
Accomplishment Instructions of Bombardier Service Bulletin 84-32-
143, Revision B, dated November 16, 2016.

(i) Installation of PSEU 30145-0602

    Installing PSEU 30145-0602 in accordance with paragraphs 3.A. 
and 3.B. of the Accomplishment Instructions of Bombardier Service 
Bulletin 84-32-149, dated November 16, 2016, also accomplishes the 
requirements of paragraphs (g) and (h) of this AD.

(j) Credit for Previous Actions

    (1) This paragraph provides credit for actions required by 
paragraph (g) of this AD, if those actions were performed before the 
effective date of this AD using the service information as specified 
in paragraphs (j)(1)(i) and (ii) of this AD.
    (i) Bombardier Service Bulletin 84-32-140, dated August 5, 2016.
    (ii) Bombardier Service Bulletin 84-32-140, Revision A, dated 
June 12, 2017.
    (2) This paragraph provides credit for actions required by 
paragraphs (g) and (h) of this AD, if PSEU 30145-0601 was installed 
before the effective date of this AD using the service information 
as specified in paragraphs (j)(2)(i) and (ii) of this AD.
    (i) Bombardier Service Bulletin 84-32-143, dated June 30, 2016.
    (ii) Bombardier Service Bulletin 84-32-143, Revision A, dated 
August 5, 2016.

(k) 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 local Flight Standards District 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 
local flight standards district office/certificate holding district 
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.

(l) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian AD CF-2016-31R1, dated March 24, 2017, 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-2020-0975.
    (2) For more information about this AD, contact Darren Gassetto, 
Aerospace Engineer, Mechanical Systems and Administrative Services 
Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7323; fax 516-794-5531; email 
[email protected].
    (3) For information about AMOCs, contact 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.
    (4) For service information identified in this AD, contact De 
Havilland Aircraft of Canada Limited, Q-Series Technical Help Desk, 
123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 
416-375-4000; fax 416-375-4539; email [email protected]; internet 
https://dehavilland.com. 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.

    Issued on October 26, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-24040 Filed 10-30-20; 8:45 am]
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