
[Federal Register Volume 82, Number 181 (Wednesday, September 20, 2017)]
[Rules and Regulations]
[Pages 43829-43832]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-19660]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0334; Product Identifier 2017-NM-008-AD; Amendment 
39-19039; AD 2017-19-09]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are superseding Airworthiness Directive (AD) 2014-25-01, 
which applied to certain Bombardier, Inc., Model DHC-8-400 series 
airplanes. AD 2014-25-01 required modifying the nose landing gear (NLG) 
trailing arm and installing a new pivot pin retention mechanism. This 
AD instead requires modifying the NLG shock strut assembly. This AD was 
prompted by reports of discrepancies of a certain bolt at the pivot pin 
link, resulting in corrosion of the bolt. We are issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective October 24, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 24, 
2017.

ADDRESSES: For service information identified in this final rule, 
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, 1601 Lind Avenue 
SW., Renton, WA. For information on the availability of this material 
at the FAA, call 425-227-1221. It is also available on the Internet at 
http://www.regulations.gov by searching for and locating Docket No. 
FAA-2017-0334.

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-2017-
0334; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD, the regulatory

[[Page 43830]]

evaluation, any comments received, and other information. The address 
for the Docket Office (telephone 800-647-5527) is Docket Management 
Facility, 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: Fabio Buttitta, Aerospace Engineer, 
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600 
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7303; 
fax 516-794-5531.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 2014-25-01, Amendment 39-18042 (79 FR 73808, 
December 12, 2014) (``AD 2014-25-01''). AD 2014-25-01 applied to 
certain Bombardier, Inc., Model DHC-8-400 series airplanes. The NPRM 
published in the Federal Register on May 9, 2017 (82 FR 21484). The 
NPRM was prompted by reports of discrepancies of a certain bolt at the 
pivot pin link, resulting in corrosion of the bolt. The NPRM proposed 
to require modifying the NLG shock strut assembly. We are issuing this 
AD to prevent failure of the pivot pin retention bolt, which could 
result in a loss of directional control or loss of an NLG tire during 
takeoff or landing.
    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2009-29R2, dated December 21, 2016 (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:

    Two in-service incidents have been reported on DHC-8 Series 400 
aircraft in which the nose landing gear (NLG) trailing arm pivot pin 
retention bolt (part number NAS6204-13D) was damaged. One incident 
involved the left hand NLG tire which ruptured on take-off. 
Investigation determined that the retention bolt failure was due to 
repeated contact of the castellated nut with the towing device 
including both the towbar and the towbarless rigs. The loss of the 
retention bolt allowed the pivot pin to migrate from its normal 
position and resulted in contact with and rupture of the tire. The 
loss of the pivot pin could compromise retention of the trailing arm 
and could result in a loss of directional control due to loss of 
nose wheel steering. The loss of an NLG tire or the loss of 
directional control could adversely affect the aircraft during take-
off or landing.
    To prevent the potential failure of the pivot pin retention 
bolt, Bombardier Aerospace has developed a modification which 
includes a new retention bolt, a reverse orientation of the 
retention bolt and a rework of the weight on wheel (WOW) proximity 
sensor cover to provide clearance for the re-oriented retention 
bolt.
    Since the original issue of this [Canadian] AD [which 
corresponds to AD 2010-13-04, Amendment 39-16335 (75 FR 35622, June 
23, 2010)], there have been several reports of pivot pin retention 
bolts found missing or damaged. Additional investigation determined 
that the failures were caused by high contact stresses on the 
retention bolt due to excessive frictional torque on the pivot pin 
and an adverse tolerance condition at the retention bolt.
    Revision 1 of this [Canadian] AD mandated the installation of a 
new pivot pin retention mechanism.
    Since the issuance of Revision 1 of this [Canadian] AD, there 
have been reports of chrome peeling on special bolt part number 
47205-1 at the pivot pin link resulting in corrosion of the bolt 
substrate layer.
    Revision 2 of this [Canadian] AD mandates the installation of 
new special bolt part number 47205-3 with additional processing for 
increased chrome plating adhesion on aeroplanes equipped with nose 
landing gear shock strut assembly part number 47100-19 or any 
assembly with Bombardier (BA) Service Bulletin (SB) 84-32-110 
incorporated. In addition, Revision 2 of this [Canadian] AD mandates 
the installation of a new pivot pin retention mechanism that 
includes new special bolt part number 47205-3 on aeroplanes equipped 
with nose landing gear shock strut assembly part number 47100-9, 
47100-11, 47100-13, 47100-15, or 47100-17 without BA SB 84-32-110 
incorporated. The corrective actions of Revision 2 of this 
[Canadian] AD cancel and replace the corrective actions of Revision 
1 of this [Canadian] AD.

    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-2017-
0334.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM and 
the FAA's response to each comment.

Support for the NPRM

    The Air Line Pilots Association, International concurred with the 
intent of the NPRM.

Request To Exclude Setup and Closeout Sections

    Horizon Air asked that we revise paragraph (g) of the proposed AD 
to exclude the ``Job Set-up'' and ``Close Out'' sections of Bombardier 
Service Bulletin 84-32-145, Revision A, dated October 18, 2016. Horizon 
Air stated that incorporating those sections as a requirement of the AD 
restricts an operator's ability to perform other maintenance in 
conjunction with incorporation of the referenced service information.
    We agree with the commenter's request for the reason provided. We 
have revised paragraph (g) of this AD to require accomplishment of only 
paragraph 3.B., ``Procedure'' of the Accomplishment Instructions of 
Bombardier Service Bulletin 84-32-145, Revision A, dated October 18, 
2016.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the change described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    Bombardier, Inc., has issued Bombardier Service Bulletin 84-32-145, 
Revision A, dated October 18, 2016. The service information describes 
procedures for modifying the NLG shock strut assembly by installing a 
new, improved pivot pin retention mechanism and a new retention bolt. 
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

    We estimate that this AD affects 52 airplanes of U.S. registry.
    We also estimate that it takes about 2 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $85 per work-hour. Required parts will cost about $0 per product. 
Based on these figures, we estimate the cost of this AD on U.S. 
operators to be $8,840, or $170 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I,

[[Page 43831]]

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 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 to 
the Director of the System Oversight Division.

Regulatory Findings

    We determined that 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. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979);
    3. Will not affect intrastate aviation in Alaska; and
    4. 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 removing Airworthiness Directive (AD) 
2014-25-01, Amendment 39-18042 (79 FR 73808, December 12, 2014), and 
adding the following new AD:

2017-19-09 Bombardier, Inc.: Amendment 39-19039; Docket No. FAA-
2017-0334; Product Identifier 2017-NM-008-AD.

(a) Effective Date

    This AD is effective October 25, 2017.

(b) Affected ADs

    This AD replaces AD 2014-25-01, Amendment 39-18042 (79 FR 73808, 
December 12, 2014).

(c) Applicability

    This AD applies to Bombardier, Inc., Model DHC-8-400, -401, and 
-402 airplanes, certificated in any category, serial numbers 4001, 
4003 through 4533 inclusive, and 4535, equipped with any nose 
landing gear (NLG) shock strut assembly having part number 47100-9, 
47100-11, 47100-13, 47100-15, 47100-17, or 47100-19.

(d) Subject

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

(e) Reason

    This AD was prompted by reports of discrepancies of a certain 
bolt at the pivot pin link, resulting in corrosion of the bolt. We 
are issuing this AD to prevent failure of the pivot pin retention 
bolt, which could result in a loss of directional control or loss of 
an NLG tire during takeoff or landing.

(f) Compliance

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

(g) Installation of Improved Pivot Pin Retention Mechanism and Bolt

    Within 6,000 flight hours or 36 months after the effective date 
of this AD, whichever occurs first: Install a new pivot pin 
retention mechanism to the NLG shock strut assembly, and replace the 
existing pivot pin retention bolt with a new bolt, in accordance 
with paragraph 3.B., ``Procedure,'' of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-32-145, Revision A, 
dated October 18, 2016.

(h) 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 84-32-145, dated 
July 26, 2016.

(i) 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: As of the effective date of 
this AD, 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.

(j) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian Airworthiness Directive CF-2009-29R2, dated December 
21, 2016, 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-2017-0334.
    (2) For more information about this AD, contact Fabio Buttitta, 
Aerospace Engineer, Airframe and Mechanical Systems Section, FAA, 
New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; telephone 516-228-7303; 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 (k)(3) and (k)(4) of this AD.

(k) 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 84-32-145, Revision A, dated 
October 18, 2016.
    (ii) Reserved.
    (3) For service information identified in this AD, 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.
    (4) You may view this service information at the FAA, Transport 
Standards Branch,

[[Page 43832]]

1601 Lind Avenue SW., Renton, WA. For information on the 
availability of this material at the FAA, call 425-227-1221.
    (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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on September 7, 2017.
Jeffrey E. Duven,
Director, System Oversight Division, Aircraft Certification Service.
[FR Doc. 2017-19660 Filed 9-19-17; 8:45 am]
BILLING CODE 4910-13-P


