Document ID: FAA-2022-0287-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
Posted Date: 2022-03-24T04:00Z

[Federal Register Volume 87, Number 57 (Thursday, March 24, 2022)]
[Proposed Rules]
[Pages 16661-16667]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05964]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0287; Project Identifier MCAI-2020-01602-T]
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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[[Page 16662]]

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain De Havilland Aircraft of Canada Limited Model DHC-8-400 
series airplanes. This proposed AD was prompted by reports of broken P-
clamps on the pressure relief line and the motive flow line in the fuel 
tanks, and a subsequent determination that certain service information 
lacked instructions for maintaining appropriate clearance between 
certain fuel tubes and their support brackets, and may also have led to 
incorrect installation of certain TeflonTM sleeves. This 
proposed AD was also prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. This proposed AD 
would require inspecting the motive flow line, vent line, and related 
parts, and adding support or additional clearance if necessary. This 
proposed AD would also require inspection, and replacement or 
relocation if necessary, of affected TeflonTM sleeves on the 
vent line, and installation of TeflonTM sleeves on the vent 
line at additional wing stations. This proposed AD would also require 
revising the existing maintenance or inspection program, as applicable, 
to incorporate new or more restrictive airworthiness limitations. 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 May 9, 
2022.

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 at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0287; 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.

FOR FURTHER INFORMATION CONTACT: Joseph Catanzaro, Aerospace Engineer, 
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7366; 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 ADDRESSES. Include ``Docket No. FAA-2022-0287; Project Identifier 
MCAI-2020-01602-T'' 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 NPRM.

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 
Joseph Catanzaro, Aerospace Engineer, Airframe and Propulsion Section, 
FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; telephone 516-228-7366; 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.

Background

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued TCCA AD CF-2017-05R2, dated September 
20, 2019 (CF-2017-05R2) (also 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-2022-0287.
    This proposed AD was prompted by reports of broken P-clamps on the 
pressure relief line and the motive fuel line in the fuel tanks, as 
well as fouling conditions between the motive flow line and the 
collector tank partition wall in both fuel tanks. Later, certain 
service information designed to mitigate these issues was found to not 
contain instructions to support the motive flow line and vent line at 
wing stations -371.019 and 371.019 in the fuel tanks or to maintain 
appropriate clearance between the fuel tubes and their support brackets 
at wing stations -371.019 and -209.109 in the left-hand fuel tank and 
wing stations 371.019 and 209.019 in the right-hand fuel tank. 
Bombardier issued Modification Summaries (ModSums) to provide 
instructions for addressing the initial reports of inadequate 
clearance. Bombardier later issued revised service information to 
address this inadequate support and clearance on all affected 
airplanes. Subsequently, the manufacturer determined that certain 
service information was missing instructions to relocate certain 
TeflonTM sleeves and certain other service information may 
have caused TeflonTM sleeves to be incorrectly installed on 
the vent line. The FAA is proposing this AD to address adverse impacts 
on the integrity of the electrical bonding paths throughout the fuel 
line, which could lead to arcing between the vent line and airplane 
structure, and could result in

[[Page 16663]]

possible fuel tank ignition in the event of a lightning strike.
    See the MCAI for additional background information.

Related Service Information Under 1 CFR Part 51

    De Havilland Aircraft of Canada Limited has issued the following 
Bombardier service information.
     Bombardier Service Bulletin 84-28-18, Revision B, dated 
April 20, 2017, which describes procedures for increasing the hole size 
in the collector tank partition wall, inspecting the motive flow line 
for damage, and replacing the associated grommet and motive flow line.
     Bombardier Service Bulletin 84-28-19, Revision D, dated 
February 16, 2018, which describes procedures for replacing the 
affected single nut plate brackets and standoffs at the affected left-
hand (LH) and right-hand (RH) wing stations on the motive flow line and 
pressure relief line; inspecting the motive flow line and vent line at 
certain wing stations in the fuel tanks to ensure that these fuel tubes 
are adequately supported; and inspecting the fuel tubes to verify that 
an appropriate clearance has been maintained between the fuel tubes and 
their support brackets.
     Bombardier Service Bulletin 84-28-24, dated November 27, 
2017, which describes procedures for installing TeflonTM 
sleeves on the vent line at the specified wing stations in the LH and 
RH fuel tanks, inspecting the TeflonTM sleeve installation 
on the vent line at those wing stations in the LH and RH fuel tanks, 
and repositioning the TeflonTM sleeves.
     Bombardier Service Bulletin 84-28-25, dated November 27, 
2017, which describes procedures for inspecting the TeflonTM 
sleeve installation on the vent line in the LH and RH fuel tanks for 
correct installation and damage, and replacing and repositioning the 
TeflonTM sleeves.
    De Havilland Aircraft of Canada Limited has also issued the 
following Bombardier service information, which describes procedures 
for replacing the affected single nut plate brackets and standoffs on 
the motive flow line and vent line at LH and RH wing stations. These 
documents are distinct since they apply to different airplane 
configurations.
     Bombardier Repair Drawing 8/4-28-018, Issue 1, dated 
October 30, 2017.
     Bombardier Repair Drawing 8/4-28-018, Issue 2, dated June 
12, 2018.
     Bombardier Repair Drawing 8/4-28-018, Issue 3, dated June 
21, 2018.
     Bombardier Repair Drawing 8/4-28-018, Issue 4, dated July 
27, 2018.
    De Havilland Aircraft of Canada Limited has also issued the 
following Bombardier service information, which describes fuel systems 
limitations. These documents are distinct because they apply to 
different airplane configurations.
     (Bombardier) Q400 Dash 8 Temporary Revision (TR) ALI-0192, 
dated April 24, 2018, to Section 4--28 Fuel System Limitation, of Part 
2, of the Bombardier Q400 Dash 8 Maintenance Requirements Manual (MRM), 
PSM 1-84-7.
     (Bombardier) Q400 Dash 8 TR ALI-0193, dated April 24, 
2018, to Section 5--00 Critical Design Configuration Control 
Limitations, of the Bombardier Q400 Dash 8 MRM, PSM 1-84-7.
    De Havilland Aircraft of Canada Limited has also issued the 
following Bombardier service information, which describes new or more 
restrictive airworthiness limitations for fuel tank systems. These 
documents are distinct because they apply to different airplane 
configurations.
     (Bombardier) Q400 Dash 8 Airplane Maintenance Manual (AMM) 
TR 28-145, dated November 21, 2017.
     (Bombardier) Q400 Dash 8 AMM TR 28-146, dated November 21, 
2017.
     (Bombardier) Q400 Dash 8 AMM TR 28-147, dated November 21, 
2017.
     (Bombardier) Q400 Dash 8 AMM TR 28-148, dated November 24, 
2017.
     (Bombardier) Q400 Dash 8 AMM TR 28-149, dated November 27, 
2017.
     (Bombardier) Q400 Dash 8 Maintenance Task Card Manual 
(MTCM) Maintenance Task Card 000-28-520-704 (Config A01), Detailed 
Inspection of the TeflonTM Sleeve on the Fuel Tank Vent Line 
(LH), Revision 42, Amendment 0002, dated November 21, 2017.
     (Bombardier) Q400 Dash 8 MTCM Maintenance Task Card 000-
28-620-704 (Config A01), Detailed Inspection of the TeflonTM 
Sleeve on the Fuel Tank Vent Line (RH), Revision 42, Amendment 0002, 
dated November 21, 2017.
    This service information 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.

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 AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described. This proposed AD would 
allow using Bombardier Repair Drawing 8/4-28-018 as a method of 
compliance for the actions required by paragraph (h)(2) of this 
proposed AD, provided the replacement of the affected single nut plate 
brackets and standoffs on the motive flow line, vent line, pressure 
relief line, and scavenge line at LH and RH wing stations Yw  209.019, Yw  317.019, and Yw  371.019, 
is also done.
    This proposed AD would also require revising the existing 
maintenance or inspection program, as applicable, to incorporate new or 
more restrictive airworthiness limitations for fuel tank systems.
    This proposed AD would require revisions to certain operator 
maintenance documents to include new actions (e.g., inspections) and 
Critical Design Configuration Control Limitations (CDCCLs). Compliance 
with these actions and CDCCLs is required by 14 CFR 91.403(c). For 
airplanes that have been previously modified, altered, or repaired in 
the areas addressed by this proposed AD, the operator may not be able 
to accomplish the actions described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must request 
approval for an alternative method of compliance according to paragraph 
(n)(1) of this proposed AD.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 52 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

[[Page 16664]]

                                     Estimated Costs for Required Actions *
----------------------------------------------------------------------------------------------------------------
              Labor cost                      Parts cost            Cost per product     Cost on  U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 93 work-hours x $85 per hour =   Up to $7,862...........  Up to $15,767..........  Up to $819,884.
 Up to $7,905.
----------------------------------------------------------------------------------------------------------------
* 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 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 has received no definitive data on which to base the cost 
estimates for the on-condition actions specified in this proposed AD.

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) Would not affect intrastate aviation in Alaska, and
    (3) Would 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:

De Havilland Aircraft of Canada Limited (Type Certificate Previously 
Held by Bombardier, Inc.): Docket No. FAA-2022-0287; Project 
Identifier MCAI-2020-01602-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 9, 2022.

(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, serial 
numbers (S/Ns) 4001, 4003, and subsequent.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel System; 
and 05, Time Limits/Maintenance Checks.

(e) Unsafe Condition

    This AD was prompted by reports of broken P-clamps on the 
pressure relief line and the motive flow line in the fuel tanks, and 
a subsequent determination that certain service information lacked 
instructions for maintaining appropriate clearance between certain 
fuel tubes and their support brackets, and may also have led to 
incorrect installation of certain TeflonTM sleeves. The 
FAA is issuing this AD to address adverse impacts on the integrity 
of the electrical bonding paths throughout the fuel line, which 
could lead to arcing between the vent line and airplane structure, 
and could result in possible fuel tank ignition in the event of a 
lightning strike.

(f) Compliance

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

(g) Definition

    For the purposes of this AD, ``prohibited tasks'' are defined as 
any task identified in paragraph (l) of this AD and any procedure or 
task that specifies fuel tank access using non-manufacturer-approved 
procedures.

(h) Modifications

    (1) For airplanes having S/N 4001 and 4003 through 4525 
inclusive: Within 6,000 flight hours or 36 months after the 
effective date of this AD, whichever occurs first, increase the hole 
size in the collector tank partition wall, inspect the motive flow 
line for damage, and replace the associated grommet and motive flow 
line, in accordance with paragraph 3.B. of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-28-18, Revision B, 
dated April 20, 2017.
    (2) For airplanes having S/N 4001 and 4003 through 4533 
inclusive, on which Bombardier Service Bulletin 84-28-19, dated 
August 16, 2016; or Revision A, dated November 4, 2016, has not been 
done: Within 6,000 flight hours or 36 months after the effective 
date of this AD, whichever occurs first, replace the affected single 
nut plate brackets and standoffs at the affected left-hand (LH) and 
right-hand (RH) wing stations on the motive flow line and pressure 
relief line, in accordance with paragraphs 3.B. and 3.C. of 
Bombardier Service Bulletin 84-28-19, Revision D, dated February 16, 
2018.
    (3) Accomplishing Bombardier Repair Drawing 8/4-28-018, Issue 1, 
dated October 30, 2017; Issue 2, dated June 12, 2018; Issue 3, dated 
June 21, 2018; or Issue 04, dated July 27, 2018, is an alternative 
method of compliance (AMOC) only for the replacement of the affected 
single nut plate brackets and standoffs on the motive flow line and 
vent line at LH and RH wing stations Yw  209.019 and Yw 
 317.019 required by paragraph (h)(2) of this AD.
    (4) Accomplishing Bombardier Repair Drawing 8/4-28-018, Issue 1, 
dated October 30, 2017; Issue 2, dated June 12, 2018; Issue 3, dated 
June 21, 2018; or Issue 04, dated July 27, 2018, prior to the 
effective date of this AD, along with the replacement of the

[[Page 16665]]

affected single nut plate brackets and standoffs on the motive flow 
line, vent line, pressure relief line, and scavenge line at LH and 
RH wing stations Yw  209.019, Yw  317.019, 
and Yw  371.019, is an acceptable method of compliance 
for the actions required by paragraph (h)(2) of this AD.
    (5) For airplanes having S/N 4001 and 4003 through 4533 
inclusive, on which Bombardier Service Bulletin 84-28-19, dated 
August 16, 2016; or Revision A, dated November 4, 2016, has been 
done: Within 6,000 flight hours or 36 months after the effective 
date of this AD, whichever occurs first, inspect the motive flow 
line and vent line at wing stations -371.019 and 371.019 in the LH 
and RH fuel tanks, respectively, to ensure that these fuel tubes are 
adequately supported, and inspect the fuel tubes to verify that an 
appropriate clearance has been maintained between the fuel tubes and 
their support brackets, in accordance with paragraph 3.B., step 
(13), and paragraph 3.C., of Bombardier Service Bulletin 84-28-19, 
Revision D, dated February 16, 2018.
    (6) For airplanes having S/N 4001 and 4003 through 4572 
inclusive: Within 8,000 flight hours or 48 months after the 
effective date of this AD, whichever occurs first, install 
TeflonTM sleeves on the vent line at wing stations Yw 
 209.019 and Yw  371.019 in the LH and RH 
fuel tanks, inspect the TeflonTM sleeve installation on 
the vent line at wing stations Yw  317.019 in the LH and 
RH fuel tanks, and if any sleeve is incorrectly installed, 
reposition the TeflonTM sleeves before further flight, in 
accordance with paragraphs 3.B. and 3.C. of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-28-24, dated November 
27, 2017.
    (7) Prior to accomplishment of the actions required by paragraph 
(h)(6) of this AD, the applicable actions specified in paragraph 
(h)(2) or (5) of this AD must be done. Accomplishment of Bombardier 
Modification Summary (ModSum) 4Q113904 on an airplane prior to the 
effective date of this AD is acceptable for compliance with this 
paragraph.
    (8) For airplanes having S/N 4001 and 4003 through 4575 
inclusive: Within 8,000 flight hours or 48 months after the 
effective date of this AD, whichever occurs first, inspect the 
TeflonTM sleeve installation on the vent line in the LH 
and RH fuel tanks for correct installation and damage, and if the 
sleeves are incorrectly installed or damage is found, before further 
flight, replace and reposition the TeflonTM sleeves, as 
applicable, in accordance with paragraphs 3.B. and 3.C. of the 
Accomplishment Instructions of Bombardier Service Bulletin 84-28-25, 
dated November 27, 2017.
    (9) Prior to accomplishment of the actions required by paragraph 
(h)(8) of this AD, the applicable actions specified in paragraph 
(h)(2) or (5) of this AD must be done. Accomplishment of Bombardier 
ModSum 4Q113904 on an airplane prior to the effective date of this 
AD is acceptable for compliance with this paragraph.

(i) Verification and Rework for Existing Maintenance Program

    (1) For airplanes having S/N 4001 and 4003 through 4575 
inclusive, on which the actions required by paragraph (h)(6) or (8) 
of this AD have been done before the effective date of this AD, or 
that have complied with paragraph (m)(4) of this AD: Within 60 days 
after the effective date of this AD, review the airplane maintenance 
records to confirm if any of the prohibited tasks (defined in 
paragraph (g) of this AD) were accomplished during or after 
compliance with paragraph (h)(6) or (8) of this AD or paragraph 
(m)(4) of this AD.
    (i) If any of the prohibited tasks were accomplished during or 
after compliance with paragraph (h)(6) or (m)(4) of this AD, or if 
it cannot be conclusively confirmed that they were not accomplished 
during or after compliance with paragraph (h)(6) or paragraph (m)(4) 
of this AD: Within 8,000 flight hours or 48 months after the 
effective date of this AD, whichever occurs first, do the actions 
required by paragraph (h)(6) of this AD and, as applicable, comply 
with the requirements of paragraph (h)(7) of this AD.
    (ii) If any of the prohibited tasks were accomplished during or 
after compliance with paragraph (h)(8) of this AD, or if it cannot 
be conclusively confirmed that they were not accomplished during or 
after compliance with paragraph (h)(8) of this AD: Within 8,000 
flight hours or 48 months after the effective date of this AD, 
whichever occurs first, do the actions required by paragraph (h)(8) 
of this AD and, as applicable, comply with the requirements of 
paragraph (h)(9) of this AD.
    (2) For airplanes having S/N 4573 and subsequent, with an 
airplane date of manufacture, as identified on the identification 
plate of the airplane, dated before the effective date of this AD: 
Within 60 days after the effective date of this AD, review the 
airplane maintenance records to confirm if any of the prohibited 
tasks (defined in paragraph (g) of this AD) were accomplished on or 
after the airplane date of manufacture. If any of the prohibited 
tasks were accomplished on or after the airplane date of 
manufacture, or if it cannot be conclusively confirmed that they 
were not accomplished on or after the airplane date of manufacture, 
within 8,000 flight hours or 48 months after the effective date of 
this AD, whichever occurs first, obtain and follow instructions for 
rework 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) Maintenance or Inspection Program Revision

    For all airplanes: Within 30 days after the effective date of 
this AD, revise the existing maintenance or inspection program, as 
applicable, to incorporate the information specified in (Bombardier) 
Q400 Dash 8 Temporary Revision (TR) ALI-0192 and TR ALI-0193, both 
dated April 24, 2018, into Section 4--28 Fuel System Limitation, or 
Section 5--00 Critical Design Configuration Control Limitations, as 
applicable, of Part 2, of the Bombardier Q400 Dash 8 Maintenance 
Requirements Manual, PSM 1-84-7. The initial compliance time for 
doing the tasks in (Bombardier) Q400 Dash 8 TR ALI-0192, dated April 
24, 2018, is at the applicable time specified in paragraph (j)(1) or 
(2) of this AD, whichever occurs later:
    (1) Prior to the accumulation of 18,000 total flight cycles or 
within 108 months since issuance of the original airworthiness 
certificate or original export certificate of airworthiness, 
whichever occurs first.
    (2) Within 90 days after the effective date of this AD.

(k) No Alternative Actions, Intervals, or Critical Design Configuration 
Control Limitations (CDCCLs)

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

(l) Maintenance Task Prohibitions

    For all airplanes: As of the effective date of this AD, comply 
with the prohibitions specified in paragraphs (l)(1) and (2) of this 
AD.
    (1) It is prohibited to use the Bombardier airplane maintenance 
manual (AMM) tasks identified in paragraphs (l)(1)(i) through (v) of 
this AD, which are specified in the Bombardier Q400 Dash 8 AMM, PSM 
1-84-2, Revision 59 dated October 5, 2017, or earlier revisions of 
these tasks. TRs including these AMM tasks, dated November 27, 2017, 
or earlier, are also prohibited for use except as specified in 
paragraph (l)(1)(i) through (v) of this AD.
    (i) Task 28-10-00-280-806 Detailed Inspection of the 
TeflonTM Sleeve on the Fuel Tank Vent Line, LH and RH 
(FSL#284000-406), with the exception of (Bombardier) Q400 Dash 8 AMM 
TR 28-145, dated November 21, 2017.
    (ii) Task 28-12-06-000-801 Removal of the Outboard Vent Line, 
with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-146, dated 
November 21, 2017.
    (iii) Task 28-12-06-400-801 Installation of the Outboard Vent 
Line, with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-147, 
dated November 21, 2017.
    (iv) Task 28-12-01-000-801 Removal of the Inboard Vent Line, 
with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-148, dated 
November 24, 2017.
    (v) Task 28-12-01-400-801 Installation of the Inboard Vent Line, 
with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-149, dated 
November 27, 2017.
    (2) It is prohibited to use the Bombardier Q400 Dash 8 
Maintenance Task Card Manual (MTCM) task cards identified in 
paragraphs (l)(2)(i) and (ii) of this AD that are specified in the 
Bombardier Q400 Dash 8 MTCM, PSM 1-84-7TC, Revision 42 dated 
November 5, 2017, or earlier revisions or amendments of these task 
cards. MTCM task card revisions or amendments dated November 21, 
2017, or earlier, are also prohibited for use, except as specified 
in paragraphs (l)(2)(i) and (ii) of this AD.

[[Page 16666]]

    (i) Bombardier Q400 Dash 8 MTCM Maintenance Task Card 000-28-
520-704 (Config A01), Detailed Inspection of the TeflonTM 
Sleeve on the Fuel Tank Vent Line (LH), with the exception of 
(Bombardier) Q400 Dash 8 MTCM Maintenance Task Card 000-28-520-704 
(Config A01), Detailed Inspection of the TeflonTM Sleeve 
on the Fuel Tank Vent Line (LH), Revision 42, Amendment 0002, dated 
November 21, 2017.
    (ii) Bombardier Q400 Dash 8 MTCM Maintenance Task Card 000-28-
620-704 (Config A01), Detailed Inspection of the TeflonTM 
Sleeve on the Fuel Tank Vent Line (RH), with the exception of 
(Bombardier) Q400 Dash 8 MTCM Maintenance Task Card 000-28-620-704 
(Config A01), Detailed Inspection of the TeflonTM Sleeve 
on the Fuel Tank Vent Line (RH), Revision 42, Amendment 0002, dated 
November 21, 2017.

(m) Credit for Previous Actions

    (1) This paragraph provides credit for actions required by 
paragraph (h)(1) of this AD, if those actions were performed before 
the effective date of this AD using Bombardier Service Bulletin 84-
28-18, dated April 20, 2016; or Revision A, dated November 14, 2016.
    (2) This paragraph provides credit for actions required by 
paragraph (h)(2) of this AD, if those actions were performed before 
the effective date of this AD using Bombardier Service Bulletin 84-
28-19, Revision B, dated July 28, 2017, or Revision C, dated 
September 1, 2017.
    (3) This paragraph provides credit for actions required by 
paragraph (h) (5) of this AD, if those actions were performed before 
the effective date of this AD using paragraphs 3.A. and 3.C and 
paragraph 3.B., step (13) of Bombardier Service Bulletin 84-28-19, 
Revision B, dated July 28, 2017, or Revision C, dated September 1, 
2017
    (4) This paragraph provides credit for actions required by 
paragraph (h)(6) of this AD, if, before the effective date of this 
AD, the ModSums identified in paragraph (m)(4)(i), (ii), or (iii) of 
this AD were incorporated, and provided the conditions identified in 
figure 1 to paragraph (m)(4) of this AD have been met.
[GRAPHIC] [TIFF OMITTED] TP24MR22.057

    (i) Incorporation of both a modsum identified in paragraph 
(m)(4)(i)(A) of this AD and a modsum identified in paragraph 
(m)(4)(i) (B) of this AD.
    (A) One of the modsums identified in paragraphs (m)(4)(i)(A)(1) 
through (9) of this AD.
    (1) Bombardier ModSum IS4Q2800023, Revision A, dated February 7, 
2017.
    (2) Bombardier ModSum IS4Q2800023, Revision B, dated April 11, 
2017.
    (3) Bombardier ModSum IS4Q2800023, Revision C, dated August 30, 
2017.
    (4) Bombardier ModSum IS4Q2800023, Revision D, dated October 11, 
2017.
    (5) Bombardier ModSum IS4Q2800023, Revision E, dated October 19, 
2017.
    (6) Bombardier ModSum IS4Q2800023, Revision F, dated October 20, 
2017.
    (7) Bombardier ModSum IS4Q2800023, Revision G, dated November 
24, 2017.
    (8) Bombardier ModSum IS4Q2800023, Revision H, dated November 
29, 2017.
    (9) Bombardier ModSum IS4Q2800023, Revision J, dated December 
12, 2017.
    (B) One of the modsums identified in paragraphs (m)(4)(i)(B)(1) 
through (5) of this AD.
    (1) Bombardier ModSum IS4Q2800025, Revision A, dated October 20, 
2017.
    (2) Bombardier ModSum IS4Q2800025, Revision B, dated November 3, 
2017.
    (3) Bombardier ModSum IS4Q2800025, Revision C, dated November 
21, 2017.
    (4) Bombardier ModSum IS4Q2800025, Revision D, dated November 
23, 2017.
    (5) Bombardier ModSum IS4Q2800025, Revision E, dated November 
29, 2017.
    (ii) Incorporation of both a modsum identified in paragraph 
(m)(4)(ii)(A) of this AD and a modsum identified in paragraph 
(m)(4)(ii)(B) of this AD.
    (A) Bombardier ModSum IS4Q2800030, Revision A, dated November 3, 
2017; or Bombardier ModSum IS4Q2800030, Revision B, dated November 
21, 2017.
    (B) One of the modsums identified in paragraphs (m)(4)(ii)(B)(1) 
through (5) of this AD.
    (1) Bombardier ModSum IS4Q2800025, Revision A, dated October 20, 
2017.
    (2) Bombardier ModSum IS4Q2800025, Revision B, dated November 3, 
2017.
    (3) Bombardier ModSum IS4Q2800025, Revision C, dated November 
21, 2017.
    (4) Bombardier ModSum IS4Q2800025, Revision D, dated November 
23, 2017,
    (5) Bombardier ModSum IS4Q2800025, Revision E, dated November 
29, 2017.
    (iii) Incorporation of a modsum identified in paragraphs 
(m)(4)(iii)(A) through (C) of this AD.
    (A) Bombardier ModSum IS4Q2800027, Revision A, dated October 27, 
2017.
    (B) Bombardier ModSum IS4Q2800027, Revision B, dated November 9, 
2017.
    (C) Bombardier ModSum IS4Q2800027, Revision C, dated November 
15, 2017.

(n) 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,

[[Page 16667]]

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 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.

(o) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) TCCA AD CF-2017-05R2, dated September 20, 2019, 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-2022-0287.
    (2) For more information about this AD, contact Joseph 
Catanzaro, Aerospace Engineer, Airframe and Propulsion Section, FAA, 
New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; telephone 516-228-7366; email [email protected].
    (3) 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 March 15, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-05964 Filed 3-23-22; 8:45 am]
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