Document ID: FAA-2018-0453-0004
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Bombardier,Inc., Airplanes
Posted Date: 2019-06-07T04:00Z

[Federal Register Volume 84, Number 110 (Friday, June 7, 2019)]
[Proposed Rules]
[Pages 26601-26605]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-11879]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0453; Product Identifier 2018-NM-028-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: We are revising an earlier proposal for certain Bombardier, 
Inc., Model DHC-8-400 series airplanes. This action revises the notice 
of proposed rulemaking (NPRM) by adding a requirement to replace the 
lower lock link of the nose landing gear (NLG), which would terminate 
the repetitive inspections proposed in the NPRM. This action also 
reduces the applicability in the NPRM. We are proposing this 
airworthiness directive (AD) to address the unsafe condition on these 
products. Since these actions would impose an additional burden over 
those in the NPRM, we are reopening the comment period to allow the 
public the chance to comment on these changes.

DATES: The comment period for the NPRM published in the Federal 
Register on May 30, 2018 (83 FR 24694), is reopened.
    We must receive comments on this SNPRM by July 22, 2019.

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 http://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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this NPRM, contact 
Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, 
Toronto, Ontario M3K 1Y5, Canada; telephone: 416-375-4000; fax: 416-
375-4539; email: thd.qseries@aero.bombardier.com; internet: http://www.bombardier.com. You may view this referenced service information at 
the FAA, Transport Standards 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 http://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0453; 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 SNPRM, the regulatory evaluation, any comments received, and other 
information. The street address for Docket Operations (phone: 800-647-
5527) 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, New York ACO 
Branch, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7323; fax 516-794-5531.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite 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-2018-0453; 
Product Identifier 2018-NM-028-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy

[[Page 26602]]

aspects of this SNPRM. We will consider all comments received by the 
closing date and may amend this SNPRM based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this SNPRM.

Discussion

    We issued an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to certain Bombardier, Inc., Model DHC-8-400 series 
airplanes. The NPRM published in the Federal Register on May 30, 2018 
(83 FR 24694). The NPRM was prompted by reports of the NLG locking in a 
partially extended position due to loose bushings on a lock link of the 
NLG locking mechanism. The NPRM proposed to require repetitive 
inspections of the bushings and the lower lock link of the NLG for 
discrepancies, and corrective actions if necessary. We are issuing this 
AD to address excessive free play at the lock link of the NLG locking 
mechanism, and consequent inability to fully retract or deploy the NLG, 
which could result in collapse of the NLG and affect the safe landing 
of the airplane.

Actions Since the NPRM Was Issued

    Since we issued the NPRM, we have determined that to adequately 
address the unsafe condition, it is necessary to require replacement of 
the NLG lower lock link with a new lower lock link having a new 
configuration.
    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian AD CF-2018-01R1, dated 
February 4, 2018 (referred to after this as the Mandatory Continuing 
Airworthiness Information, or ``the MCAI''), to correct an unsafe 
condition for certain Bombardier, Inc., Model DHC-8-400 series 
airplanes. The MCAI states:

    A landing incident took place whereby the aeroplane's nose 
landing gear (NLG) was locked in a partially-extended position, 
leading to gear collapse upon NLG touch down. The investigation 
revealed that the NLG was locked in this position due to the 
bushings on the lock link of the NLG locking mechanism becoming 
loose. This condition was present due to insufficient interference 
fit which resulted in some bushing outer diameter wear and fretting. 
A dislodged bushing will also cause the bushing sealant to break. 
Broken sealant allows moisture ingress and corrosion that can 
accelerate free play buildup. Excessive free play at the lock link 
can result in the inability to fully retract or deploy the NLG, 
resulting in a risk of NLG collapse on landing.
    Bombardier Inc. has developed an inspection to identify and 
correct this condition. [The original version of this Canadian AD 
required] a repetitive inspection [to detect discrepancies] and 
corrective actions based on the inspection findings.
    Revision 1 of this [Canadian] AD is issued to modify the NLG 
with a lower lock with improved bushing retention and greasing 
provisions. Implementing this modification is a terminating action 
to this [Canadian] AD. The modification has been introduced in 
production, therefore the applicability of this [Canadian] AD has 
been reduced. Clarifications have also been made to the retained 
text of the original version.

    Discrepancies include any signs of migration of the bushings, 
broken or missing edge sealant, diagonal paint cracks on the sealant, 
and paint stripe misalignment. You may examine the MCAI in the AD 
docket on the internet at http://www.regulations.gov by searching for 
and locating Docket No. FAA-2018-0453.

Comments

    We gave the public the opportunity to participate in developing 
this proposed AD. We considered the comments received.

Request To Include Revised Service Information

    Horizon Air asked that Bombardier Service Bulletin 84-32-153, 
Revision A, dated February 27, 2018, be incorporated into the proposed 
AD (in the NPRM). Horizon Air added that a credit paragraph should also 
be included for the original issue of the referenced service 
information.
    We partially agree with the commenter's request. We have revised 
this proposed AD to identify Bombardier Service Bulletin 84-32-153, 
Revision A, dated February 27, 2018, as the appropriate source of 
service information for the inspection specified in paragraph (g) of 
this proposed AD. Revision A merely clarifies certain actions and 
corrects a certain task number, and adds no new work. We have added 
paragraph (j) to this proposed AD to provide credit for actions done 
before the effective date of this AD using the original issue of the 
referenced service information. However, for clarification, we have 
included the correct task number for greasing all drag strut joints, 
which is AMM Task 12-20-01-640-802. Bombardier Service Bulletin 84-32-
153, dated September 22, 2017, specifies AMM Task 12-20-01-640-803, 
which is incorrect. We have redesignated subsequent paragraphs 
accordingly.

Request To Add Terminating Action for Repetitive Inspections

    Horizon Air asked that we include an option for terminating action 
for the repetitive inspections required by paragraph (g) of the 
proposed AD (in the NPRM). Horizon Air stated that Bombardier Service 
Bulletin 84-32-154, Revision A, dated November 21, 2018, includes a 
modification that involves reconfiguration of the lower lock link of 
the NLG by adding new bushings with improved retention and greasing 
provisions.
    We partially agree with the commenter's request. We agree to 
include terminating action for the repetitive inspections, but to 
adequately address the unsafe condition, we have determined that it is 
necessary to mandate this action instead of providing it as an option. 
We have added paragraph (k) of this proposed AD to require the 
modification, which would terminate the repetitive inspections 
specified by paragraph (g) of this proposed AD. We have redesignated 
subsequent paragraphs accordingly.

Request To Include Global Alternative Method of Compliance (AMOC)

    Horizon Air asked that we incorporate Global AMOC AARDG-2018/A02 to 
Canadian AD CF-2018-01 into the FAA proposed AD (in the NPRM). Horizon 
Air stated that this global AMOC provides the initial compliance time 
for lower lock links of the NLG that have been repaired based on flight 
cycles accumulated since repair, instead of total flight cycles 
accumulated. Horizon Air added that justification for this AMOC was 
that repair of the lower lock link in accordance with the applicable 
component maintenance manual yields the same bushing retention 
properties as a new part.
    We agree with the commenter's request. Canadian AD CF-2018-01R1 
added compliance times for a repaired or replaced NLG lower lock link. 
Therefore, we have included paragraph (h) in this proposed AD to allow 
the compliance times to be measured from the time of repair or 
replacement of the existing lower lock link for a repair or replacement 
that was done using a specified method.

Request To Exclude Setup and Closeout Actions

    Horizon Air asked that the job setup and closeout actions specified 
in Bombardier Service Bulletin 84-32-153, Revision A, dated February 
27, 2018, be excluded from the requirements of paragraph (g) of the 
proposed AD (in the NPRM). Horizon Air stated that these

[[Page 26603]]

actions do not directly correct the unsafe condition. Horizon Air added 
that incorporating these actions restricts an operator's ability to 
perform other maintenance in conjunction with incorporation of the 
referenced service information.
    We partially agree with the commenter's request. We agree to remove 
the closeout actions, but to adequately perform the corrective actions 
the job setup actions specified in Bombardier Service Bulletin 84-32-
153, Revision A, dated February 27, 2018, must be included. Paragraph 
3.A., ``Job Set-Up,'' of Bombardier Service Bulletin 84-32-153, 
Revision A, dated February 27, 2018, includes specific airplane 
maintenance manual tasks and instructions that properly establish a 
baseline needed to evaluate excessive play at the lower lock link of 
the NLG locking mechanism, and correctly address the unsafe condition. 
In addition, the operator is directed to paragraph 3.A.(5) of the Job 
Setup section in the Accomplishment Instructions of Bombardier Service 
Bulletin 84-32-153, Revision A, dated February 27, 2018, for the 
applicable corrective action. Therefore, we have revised the 
requirements of paragraph (g) accordingly.

Related Service Information Under 1 CFR Part 51

    Bombardier has issued the following service information:
     Service Bulletin 84-32-153, Revision A, dated February 27, 
2018, which describes procedures for an inspection of the bushings and 
the lower lock link of the NLG for discrepancies. The service 
information also describes procedures for repair or replacement of a 
discrepant lock link.
     Service Bulletin 84-32-154, Revision A, dated November 21, 
2018, which describes procedures for replacement of the existing lower 
lock link with a new configuration lock link.
    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 and Requirements of This SNPRM

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.
    Certain changes described above expand the scope of the NPRM. As a 
result, we have determined that it is necessary to reopen the comment 
period to provide additional opportunity for the public to comment on 
this SNPRM.

Costs of Compliance

    We estimate that this proposed AD affects 64 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
         Action                   Labor cost            Parts cost      Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Inspection..............  2 work-hours x $85 per                  $0  $170 per inspection   $10,880 per
                           hour = $170 per                             cycle.                inspection cycle.
                           inspection cycle.
Replacement.............  6 work-hours x $85 per               5,923  $6,433..............  $411,712.
                           hour = $510.
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    We have received no definitive data that enables us to provide 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.
    We are 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.
    This proposed AD is issued in accordance with authority delegated 
by the Executive Director, Aircraft Certification Service, as 
authorized by FAA Order 8000.51C. In accordance with that order, 
issuance of ADs is normally a function of the Compliance and 
Airworthiness Division, but during this transition period, the 
Executive Director has delegated the authority to issue ADs applicable 
to transport category airplanes and associated appliances to the 
Director of the System Oversight Division.

Regulatory Findings

    We 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):

[[Page 26604]]

Bombardier, Inc.: Docket No. FAA-2018-0453; Product Identifier 2018-
NM-028-AD.

(a) Comments Due Date

    We must receive comments by July 22, 2019.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bombardier, Inc., Model DHC-8-400, -401, and 
-402 airplanes, certificated in any category, serial numbers 4001 
through 4585 inclusive, and 4587.

(d) Subject

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

(e) Reason

    This AD was prompted by reports of the nose landing gear (NLG) 
locking in a partially extended position due to loose bushings on a 
lock link of the NLG locking mechanism. We are issuing this AD to 
address excessive free play at the lock link of the NLG locking 
mechanism, and consequent inability to fully retract or deploy the 
NLG, which could result in collapse of the NLG and affect the safe 
landing of the airplane.

(f) Compliance

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

(g) Repetitive Inspections and Corrective Actions

    Except as provided by paragraphs (h) and (i) of this AD: Do a 
general visual inspection for the NLG lower lock link part number 
and discrepancies of the bushings and of the lower lock link of the 
NLG locking mechanism, at the applicable time specified in paragraph 
(g)(1) or (g)(2) of this AD, in accordance with paragraphs 3.A. and 
3.B., or 3.A. and 3.D., as applicable, of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-32-153, Revision A, 
dated February 27, 2018. If any discrepancy is found, before further 
flight, repair or replace the NLG lower lock link, as applicable, in 
accordance with paragraphs 3.B. or 3.D, as applicable, of Bombardier 
Service Bulletin 84-32-153, Revision A, dated February 27, 2018. 
Repeat the inspection thereafter at intervals not to exceed 1,600 
flight cycles on any NLG lower lock link.
    (1) For airplanes on which an NLG lower lock link has 
accumulated 7,200 or fewer total flight cycles as of the effective 
date of this AD: Before the accumulation of 8,000 total flight 
cycles on the NLG lower lock link.
    (2) For airplanes on which an NLG lower lock link has 
accumulated more than 7,200 total flight cycles as of the effective 
date of this AD: Within 800 flight cycles on the NLG lower lock link 
after the effective date of this AD.

(h) Inspections After Repair or Replacement of NLG Lower Lock Link

    For airplanes with an NLG lower lock link that is repaired or 
replaced as specified in paragraph (h)(1), (h)(2), (h)(3), or (h)(4) 
of this AD: The next inspection specified by paragraph (g) of this 
AD is required for the NLG lower lock link on the airplane at the 
applicable time specified in figure 1 to paragraph (h) of this AD.
[GRAPHIC] [TIFF OMITTED] TP07JN19.000

    (1) Repaired as specified in Bombardier Repair Drawing 8/4-32-
0338.
    (2) Repaired as specified in the Goodrich Aerospace Canada Ltd. 
Component Maintenance Manual, Part Number (P/N) 47300, 32-21-03.
    (3) Replaced with a serviceable lock link having P/N 47324-1 
(SCR-093-17-B); or
    (4) Replaced with a new lock link having P/N 47324-1.

(i) Lock Link Excepted From Inspection Requirements

    The inspections specified in this AD are not required for any 
new NLG lower lock link having P/N 47324-3.

(j) Credit for Previous Actions

    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 Bombardier Service Bulletin 84-32-153, dated 
September 22, 2017, provided all drag strut joints were greased, as 
specified in paragraphs 3.B.(1)(h) and 3.D.(1)(c)5 of the 
Accomplishment Instructions of this service information, using AMM 
Task 12-20-01-640-802.

(k) Terminating Action for Repetitive Inspections

    Within 8,000 flight cycles or 48 months on the NLG lower lock 
link after the effective date of this AD, whichever occurs first: 
Replace the existing NLG lower lock link with a new lower lock link 
having P/N 47324-3, in accordance with paragraphs 3.A. and 3.B. of 
the Accomplishment Instructions of Bombardier Service Bulletin 84-
32-154, Revision A, dated November 21, 2018. Replacement of the 
lower lock link on the NLG terminates the repetitive inspections 
required by paragraphs (g) and (h) of this AD for that airplane.

(l) 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 New York ACO 
Branch, 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

[[Page 26605]]

flight standards district office/certificate holding district 
office.
    (2) Contacting the Manufacturer: For any requirement in this AD 
to obtain corrective actions from a manufacturer, the action must be 
accomplished using a method approved by the Manager, New York ACO 
Branch, FAA; or Transport Canada Civil Aviation (TCCA); or 
Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If 
approved by the DAO, the approval must include the DAO-authorized 
signature.

(m) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian AD CF-2018-01R1, dated February 4, 2018, for related 
information. This MCAI may be found in the AD docket on the internet 
at http://www.regulations.gov by searching for and locating Docket 
No. FAA-2018-0453.
    (2) For more information about this AD, contact Darren Gassetto, 
Aerospace Engineer, Mechanical Systems and Administrative Services 
Section, New York ACO Branch, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7323; fax 516-794-5531.

    Issued in Des Moines, Washington, on May 31, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-11879 Filed 6-6-19; 8:45 am]
BILLING CODE 4910-13-P