82 FR 31535 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 129 (July 7, 2017)

We propose to adopt a new airworthiness directive (AD) for Bell Model 407 helicopters. This proposed AD would require repetitive inspections of the tail rotor (TR) driveshaft segment assemblies and a torque check of the TR adapter retention nuts. This proposed AD is prompted by a report of an in-flight failure of the TR drive system. The proposed actions are intended to detect and correct an unsafe condition on these products.

[Federal Register Volume 82, Number 129 (Friday, July 7, 2017)]
[Proposed Rules]
[Pages 31535-31537]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-14231]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0667; Directorate Identifier 2016-SW-053-AD]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron Canada Limited 
(Bell) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
Bell Model 407 helicopters. This proposed AD would require repetitive 
inspections of the tail rotor (TR) driveshaft segment assemblies and a 
torque check of the TR adapter retention nuts. This proposed AD is 
prompted by a report of an in-flight failure of the TR drive system. 
The proposed actions are intended to detect and correct an unsafe 
condition on these products.

DATES: We must receive comments on this proposed AD by September 5, 
2017.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.

[[Page 31536]]

     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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-
0667; or in person at the Docket Operations Office between 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, the Transport Canada AD, the economic 
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 service information identified in this proposed rule, contact 
Bell Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, 
Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or (800) 363-8023; fax 
(450) 433-0272; or at http://www.bellcustomer.com/files/. You may 
review the referenced service information at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, 
Fort Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: David Hatfield, Aviation Safety 
Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 
Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email 
[email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to participate in this rulemaking by submitting 
written comments, data, or views. We also invite comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    We will file in the docket all comments that we receive, as well as 
a report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    Transport Canada, which is the aviation authority for Canada, has 
issued Canadian AD No. CF-2016-21, dated July 7, 2016 (AD CF-2016-21), 
to correct an unsafe condition for Bell Model 407 helicopters. 
Transport Canada advises that a Model 407 helicopter experienced in-
flight failure of the TR drive system, which resulted in loss of 
directional control. The helicopter landed safely with substantial 
damage to the TR segmented shaft and adapter splines, coupling, and 
hanger bearings. According to Transport Canada, the splines connecting 
the adapter part number (P/N) 406-040-328-105 to the shaft assembly P/N 
407-040-330-107 were ``severely worn and no longer capable of 
performing their function.'' The investigation further revealed other 
Model 407 helicopters with the same axial and radial play or looseness 
of some splined connections. AD CF-2016-21 states that these parts 
should be clamped together with threaded fasteners with no detectable 
looseness. Transport Canada advises that undetected looseness at the 
splined connection could result in wear of the parts and eventual loss 
of directional control of the helicopter.
    For these reasons, AD CF-2016-21 requires a repetitive inspection 
of the TR driveshaft assemblies for play and a one-time torque 
verification of the TR adapter retention nuts.

FAA's Determination

    These helicopters have been approved by the aviation authority of 
Canada and are approved for operation in the United States. Pursuant to 
our bilateral agreement with Canada, Transport Canada, its technical 
representative, has notified us of the unsafe condition described in 
its AD. We are proposing this AD because we evaluated all known 
relevant information and determined that an unsafe condition is likely 
to exist or develop on other products of the same type design.

Related Service Information Under 1 CFR Part 51

    We reviewed Bell Alert Service Bulletin (ASB) 407-16-113, dated 
February 12, 2016 (ASB 407-16-113), which specifies procedures for 
inspecting the TR driveshaft assemblies for noticeable rotational or 
axial play between each adapter and TR driveshaft. ASB 407-16-113 also 
specifies procedures for performing a torque check of each TR adapter 
retention nut on the four TR driveshaft segments.
    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.

Proposed AD Requirements

    This proposed AD would require inspecting each TR driveshaft 
segment assembly for rotational and axial play between the adapter and 
the TR driveshaft and determining the installation torque of each 
adapter retention nut. For helicopters with 4,000 or more hours time-
in-service (TIS), the driveshaft assembly inspection would be required 
within 50 hours TIS. For helicopters with less than 4,000 hours TIS, 
the driveshaft assembly inspection would be required within 100 hours 
TIS. Thereafter, these inspections would be required at intervals not 
to exceed 330 hours TIS. The torque verification of the adapter 
retention nuts would be a one-time inspection.
     If there is play or looseness in the TR driveshaft, the 
proposed AD would require correcting the discrepant splined fitting 
before further flight.
     The proposed AD would also require replacing the adapter 
retention nut anytime the adapter is re-assembled.

Costs of Compliance

    We estimate that this proposed AD would affect 667 helicopters of 
U.S. Registry. We estimate that operators may incur the following costs 
in order to comply with this proposed AD. At an average labor rate of 
$85 per hour, inspecting the TR driveshaft segments and adapters for 
play would require about 1 work-hour, for a cost per helicopter of $85, 
and a total cost of $56,695 to the U.S. fleet per inspection cycle. 
Determining the torque of the four adapter retention nuts would require 
about 3 work-hours for a cost per helicopter of $255 and a total cost 
of $170,085 to the U.S. fleet.
    If required, repairing a worn driveshaft adapter would require 
about 3 work-hours, and required parts would cost about $1,259, for a 
cost per helicopter of $1,514.
    Replacing an adapter retention nut would require about 1 work-hour, 
and required parts cost are negligible, for a cost of $85 per 
helicopter and $56,695 for the U.S. fleet per inspection cycle.

[[Page 31537]]

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, 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 to the extent that 
it justifies making a regulatory distinction; 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this proposed AD and placed it in the AD docket.

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):

Bell Helicopter Textron Canada Limited (Bell): Docket No. FAA-2017-
0667; Directorate Identifier 2016-SW-053-AD.

(a) Applicability

    This AD applies to Bell Model 407 helicopters, certificated in 
any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as a loose tail rotor (TR) 
driveshaft splined connection, which if not corrected could result 
in wear in the splines, failure of the TR drive system, and 
subsequent loss of directional control of the helicopter.

(c) Comments Due Date

    We must receive comments by September 5, 2017.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    For helicopters with less than 4,000 hours time-in-service 
(TIS), within 100 hours TIS, and for helicopters with 4,000 or more 
hours TIS, within 50 hours TIS:
    (1) Inspect each TR driveshaft segment assembly for rotational 
and axial play between the adapter and the TR driveshaft at the four 
positions depicted in Figure 1 of Bell Alert Service Bulletin (ASB) 
407-16-113, dated February 12, 2016 (ASB 407-16-113). If there is 
any axial or rotational play, remove the adapter from the TR 
driveshaft segment assembly and inspect the adapter, washers, and TR 
driveshaft for damage. Replace the adapter retention nut and apply a 
torque of 30 to 50 inch-pounds (5.7 to 7.9 Nm). Replace any part 
with damage or repair the part if the damage is within the maximum 
repair damage limitations.
    (2) Determine the torque of each TR adapter retention nut at 
each of the four segment assembly positions depicted in Figure 1 of 
Bell ASB 407-16-113. If the torque is less than 30 inch-pounds (5.7 
Nm), remove the adapter from the TR driveshaft segment assembly and 
inspect the adapter, washers, and TR driveshaft for damage. Replace 
the adapter retention nut and apply a torque of 30 to 50 inch-pounds 
(5.7 to 7.9 Nm). Replace any part with damage or repair the part if 
the damage is within the maximum repair damage limitations.
    (3) Repeat the actions specified in paragraph (e)(1) of this AD 
at intervals not to exceed 330 hours TIS.

(f) Special Flight Permits

    Special flight permits are prohibited.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Safety Management Group, FAA, may approve AMOCs 
for this AD. Send your proposal to: David Hatfield, Aviation Safety 
Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-
5110; email [email protected].
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(h) Additional Information

    The subject of this AD is addressed in Transport Canada AD No. 
CF-2016-21, dated July 7, 2016. You may view the Transport Canada AD 
on the Internet at http://www.regulations.gov in the AD Docket.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 6510 Tail Rotor 
Drive Shaft.

    Issued in Fort Worth, Texas, on June 27, 2017.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2017-14231 Filed 7-6-17; 8:45 am]
 BILLING CODE 4910-13-P