Document ID: FAA-2018-0453-0007
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
Posted Date: 2019-09-26T04:00Z

[Federal Register Volume 84, Number 187 (Thursday, September 26, 2019)]
[Rules and Regulations]
[Pages 50727-50730]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-20897]

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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; Amendment 
39-19732; AD 2019-18-05]
RIN 2120-AA64

Airworthiness Directives; De Havilland Aircraft of Canada Limited 
(Type Certificate Previously Held by Bombardier, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (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 (Type Certificate 
Previously Held by Bombardier, Inc.) Model DHC-8-400 series airplanes. 
This AD was prompted by reports of the nose landing gear (NLG) locking 
in a partially extended position due to loose bushings on the lock link 
of the NLG locking mechanism. This AD requires repetitive inspections 
of the bushings and the lower lock link of the NLG for discrepancies, 
and corrective actions if necessary. This AD also requires replacement 
of the lower lock link of the NLG, which terminates the repetitive 
inspections. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective October 31, 2019.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of October 31, 
2019.

ADDRESSES: For service information identified in this final rule, 
contact De Havilland Aircraft of Canada Ltd., Q-Series Technical Help 
Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; 
telephone: 416-375-4000; fax: 416-375-4539; email: thd@dehavilland.com; 
internet: https://dehavilland.com. You may view this 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. It is also available on the 
internet at http://www.regulations.gov by searching for and locating 
Docket No. FAA-2018-0453.

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 final rule, the regulatory evaluation, 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.

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: 

Discussion

    The FAA issued a notice of proposed rulemaking (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 the lock link of the NLG locking mechanism. The NPRM 
proposed to require inspecting the bushings and the lower lock link of 
the NLG for discrepancies, and corrective actions if necessary.
    The FAA issued a supplemental notice of proposed rulemaking (SNPRM) 
to amend 14 CFR part 39 by adding an AD that would apply to certain 
Bombardier, Inc., Model DHC-8-400 series airplanes. The SNPRM published 
in the Federal Register on June 7, 2019 (84 FR 26601). The FAA issued 
the SNPRM to add a requirement to replace the lower lock link of the 
NLG, which would terminate the repetitive inspections proposed in the 
NPRM. The SNPRM also proposed to reduce the applicability in the NPRM.
    The FAA is 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.
    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian AD CF-2018-01R1, dated 
January 21, 2019 (referred to after this as the Mandatory Continuing 
Airworthiness Information, or ``the MCAI''), to correct an unsafe

[[Page 50728]]

condition for certain De Havilland Aircraft of Canada Limited (Type 
Certificate Previously Held by 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.

    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

    The FAA gave the public the opportunity to participate in 
developing this final rule. The following presents the comments 
received on the SNPRM and the FAA's response to each comment.

Request To Revise Certain Requirements

    Horizon Air asked that the requirement to do the actions specified 
in paragraph (k) of the proposed AD in accordance with paragraph 3.A. 
of the Accomplishment Instructions of Bombardier Service Bulletin 84-
32-154, Revision A, dated November 21, 2018, be removed. Horizon Air 
stated that the job setup specified in paragraph 3.A. of the referenced 
service information does not directly correct the unsafe condition. 
Horizon Air would like only the actions specified in paragraph 3.B. of 
the referenced service information mandated.
    The FAA does not agree with the commenter's request. For some ADs, 
the job setup actions in the associated service information do not 
affect the actions to correct the unsafe condition. However, for this 
AD, the FAA has determined that to adequately perform the corrective 
actions the job setup actions specified in Bombardier Service Bulletin 
84-32-154, Revision A, dated November 21, 2018, must be accomplished. 
Paragraph 3.A., ``Job Set-Up,'' of Bombardier Service Bulletin 84-32-
154, Revision A, dated November 21, 2018, includes specific procedures 
for the NLG to be in the correct configuration for the corrective 
actions to be done and prevent damage to the equipment. Therefore, the 
FAA has not changed this AD in this regard.

Request To Install Post-UTC Aerospace Systems Spare Parts

    Horizon Air asked that installation of NLG drag strut assemblies 
having part number 47300-7A, 47300-9A, or 47300-11A, serviced in 
accordance with UTC Aerospace Systems Vendor Service Bulletin (VSB) 
47300-32-138 R3, be allowed as terminating action for the repetitive 
inspections. Horizon Air stated that UTC Aerospace Systems VSB 47300-
32-138 R3 can be done on units not installed on the airplane.
    The FAA agrees to clarify. NLG drag strut assemblies can be 
serviced (lower lock links replaced and affected parts re-identified) 
by accomplishing UTC Aerospace Systems VSB 47300-32-138 R3, as 
specified in Bombardier Service Bulletin 84-32-154, Revision A, dated 
November 21, 2018. However, operators must still show compliance with 
paragraph 3.A. and Steps 3.B.(1), 3.B.(4) and 3.B.(5) of the 
Accomplishment Instructions of Bombardier Service Bulletin 84-32-154, 
Revision A, dated November 21, 2018, for the removal of a unit which 
has not been serviced, and installation of a serviced spare unit, in 
order to correct the unsafe condition. In addition, paragraph (f) of 
this AD specifies ``Comply with this AD within the compliance times 
specified, unless already done.'' Therefore, if some of the corrective 
actions have been done, only the remaining corrective actions must be 
completed to comply with this AD. The FAA has not changed this AD in 
this regard.

Explanation of Change Made to This Final Rule

    The FAA has revised this final rule to identify the legal name of 
the manufacturer as published in the most recent type certificate data 
sheet for the affected airplane models.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and determined that air safety and the public interest 
require adopting this final rule as proposed, except for minor 
editorial changes. The FAA has determined that these minor changes:
     Are consistent with the intent that was proposed in the 
SNPRM for addressing the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the SNPRM.

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 general visual inspections of the 
bushings and the lower lock link of the NLG for discrepancies. The 
service information also describes procedures for repair or replacement 
of the lock link if any discrepancy is found.
     Service Bulletin 84-32-154, Revision A, dated November 21, 
2018, which describes procedures for replacement of the existing lock 
link with a new 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.

Costs of Compliance

    The FAA estimates that this AD affects 64 airplanes of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
           Action                  Labor cost         Parts cost       Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Inspection.................  2 work-hours x $85                 $0  $170 per inspection    $10,880 per
                              per hour = $170 per                    cycle.                 inspection cycle.
                              inspection cycle.

[[Page 50729]]

 
Replacement................  6 work-hours x $85              5,923  $6,433...............  $411,712
                              per hour = $510.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data that enables the agency to 
provide cost estimates for the on-condition actions specified in this 
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.
    This 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of 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 (AD):

2019-18-05 De Havilland Aircraft of Canada Limited (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-19732; Docket No. 
FAA-2018-0453; Product Identifier 2018-NM-028-AD.

(a) Effective Date

    This AD is effective October 31, 2019.

(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 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. The FAA is 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 (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 any one of paragraphs (h)(1) through (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 the introductory text of 
paragraph (h) of this AD.

[[Page 50730]]

Figure 1 to the Introductory Text of Paragraph (h)--Compliance Times for
       Next Inspection on Repaired or Replaced NLG Lower Lock Link
------------------------------------------------------------------------
             Flight cycles                       Compliance time
------------------------------------------------------------------------
Airplanes on which the NLG lower lock    Before the accumulation of
 link has accumulated 7,200 or fewer      8,000 flight cycles on the NLG
 flight cycles since the NLG lower link   lower lock link since the
 was repaired or replaced.                repair or replacement.
Airplanes on which the NLG lower lock    Within 800 flight cycles on the
 link has accumulated more than 7,200     NLG lower lock link after the
 flight cycles since the NLG lower link   effective date of this AD.
 was repaired or replaced.
------------------------------------------------------------------------

    (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 
aircraft maintenance manual (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 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 January 21, 2019, 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.
    (3) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (n)(3) and (4) of this AD.

(n) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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) Bombardier Service Bulletin 84-32-153, Revision A, dated 
February 27, 2018.
    (ii) Bombardier Service Bulletin 84-32-154, Revision A, dated 
November 21, 2018.
    (3) For service information identified in this AD, contact De 
Havilland Aircraft of Canada Ltd., Q-Series Technical Help Desk, 123 
Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone: 416-
375-4000; fax: 416-375-4539; email: thd@dehavilland.com; internet: 
https://devahilland.com.
    (4) You may view this 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email fedreg.legal@nara.gov, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.;

    Issued in Des Moines, Washington, on September 9, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-20897 Filed 9-25-19; 8:45 am]
 BILLING CODE 4910-13-P