
[Federal Register Volume 82, Number 88 (Tuesday, May 9, 2017)]
[Proposed Rules]
[Pages 21484-21487]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-09325]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0334; Directorate Identifier 2017-NM-008-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede Airworthiness Directive (AD) 2014-25-
01, for certain Bombardier, Inc., Model DHC-8-400 series airplanes. AD 
2014-25-01 currently requires modifying the nose landing gear (NLG) 
trailing arm and installing a new pivot pin retention mechanism. Since 
we issued AD 2014-25-01, we have received reports of discrepancies of a 
certain bolt at the

[[Page 21485]]

pivot pin link, resulting in corrosion of the bolt. This proposed AD 
would instead require modifying the NLG shock strut assembly. We are 
proposing this AD to address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by June 23, 2017.

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: 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 
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 Airplane Directorate, 1601 Lind Avenue SW., Renton, 
WA. For information on the availability of this material at the FAA, 
call 425-227-1221.

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 proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Operations office (telephone 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Fabio Buttitta, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; telephone 516-228-7303; fax 516-794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2017-0334; 
Directorate Identifier 2017-NM-008-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD 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 proposed AD.

Discussion

    On November 28, 2014, we issued AD 2014-25-01, Amendment 39-18042 
(79 FR 73808, December 12, 2014) (``AD 2014-25-01''), for certain 
Bombardier, Inc., Model DHC-8-400 series airplanes. AD 2014-25-01 was 
prompted by a report of several missing or damaged pivot pin retention 
bolts. AD 2014-25-01 requires modifying the NLG trailing arm and 
installing a new pivot pin retention mechanism. We issued AD 2014-25-01 
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 take-off 
or landing.
    Since we issued AD 2014-25-01, we have received reports of missing 
or damaged pivot pin retention bolts and chrome peeling on special bolt 
part number 47205-1 at the pivot pin link, resulting in corrosion of 
the bolt substrate layer. Therefore, we have determined that the 
actions required by AD 2014-25-01 do not address the identified unsafe 
condition.
    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.

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

[[Page 21486]]

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.

FAA's Determination and Requirements of This Proposed AD

    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.

Costs of Compliance

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

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. 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.

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 removing Airworthiness Directive (AD) 
2014-25-01, Amendment 39-18042 (79 FR 73808, December 12, 2014), and 
adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2017-0334; Directorate Identifier 
2017-NM-008-AD.

(a) Comments Due Date

    We must receive comments by June 23, 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 missing or damaged pivot pin 
retention bolts and chrome peeling on 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 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 Aircraft Certification Office (ACO), ANE-170, 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, send it to ATTN: 
Program Manager, Continuing Operational Safety, FAA, New York ACO, 
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, ANE-170, 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

[[Page 21487]]

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 Branch, ANE-171, 
FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, 
Suite 410, Westbury, NY 11590; telephone 516-228-7303; fax 516-794-
5531.
    (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. You may view this service information at 
the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at 
the FAA, call 425-227-1221.

    Issued in Renton, Washington, on May 2, 2017.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-09325 Filed 5-8-17; 8:45 am]
 BILLING CODE 4910-13-P


