Document ID: FAA-2012-0337-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Bell Helicopter Textron Canada Helicopters
Posted Date: 2012-03-29T04:00Z

[Federal Register Volume 77, Number 61 (Thursday, March 29, 2012)]
[Proposed Rules]
[Pages 18970-18973]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-7542]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0337; Directorate Identifier 2010-SW-090-AD]
RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron Canada 
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 the 
Bell Helicopter Textron Canada Limited (BHTC) Model 407 helicopters. 
This proposed AD is prompted by a review of the tailboom-attachment 
installation, which revealed that the torque value of the bolts 
specified in the BHTC Model 407 Maintenance Manual and applied during 
manufacturing was incorrect and exceeded the torque range recommended 
for the bolts. This proposed AD would require you to replace tailboom-
attachment hardware (attachment hardware), and perform initial and 
recurring determinations of

[[Page 18971]]

the torque on the nuts of the tailboom-attachment bolts (bolts) at all 
four attachment locations. The actions required by this proposed AD are 
intended to prevent an over-torque of a bolt, bolt failure, loss of the 
tailboom, and subsequent loss of control of the helicopter.

DATES: We must receive comments on this proposed AD by May 29, 2012.

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.
     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 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 
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 AD, 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 copies of the referenced service information at the FAA, Office 
of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Sharon Miles, Aerospace Engineer, FAA, 
Regulations and Policy Group, 2601 Meacham Blvd., Fort Worth, Texas 
76137; telephone: (817) 222-5122; fax: (817) 222-5961; email: 
sharon.y.miles@faa.gov.

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 AD No. CF-2010-33, dated September 30, 2010 (AD CF-2010-33), to 
correct an unsafe condition for the BHTC Model 407 helicopter, serial 
numbers (S/Ns) 53000 through 53990. Transport Canada advises that a 
review of the tailboom-attachment installation determined that the 
torque value of the bolts specified in the BHTC Model 407 Maintenance 
Manual and applied during manufacturing exceeded the torque range 
recommended for the bolts. Transport Canada states that this situation, 
if not corrected, could lead to a bolt failure, detachment of the 
tailboom, and subsequent loss of control of the helicopter.
    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.

FAA's Determination

    We are proposing this AD because we evaluated all known relevant 
information and determined that an unsafe condition exists and is 
likely to exist or develop on other products of the same type design.

Related Service Information

    BHTC has issued Alert Service Bulletin No. 407-10-93, Revision A, 
dated August 30, 2010 (ASB), which specifies installing new attachment 
hardware with a reduced torque value. This ASB specifies performing a 
torque check of the newly installed bolts and nuts every one to five 
flight hours until torque stabilizes at all locations, and thereafter 
at intervals not to exceed 300 flight hours. Transport Canada 
classified this ASB as mandatory and issued AD CF-2010-33 to ensure the 
continued airworthiness of these helicopters.

Proposed AD Requirements

    This proposed AD would require for helicopters with 7000 hours or 
less time-in-service (TIS), at the next 600 hours scheduled inspection, 
or 90 days, whichever comes first; and for helicopters with more than 
7000 hours TIS, within 150 hours TIS or 90 days, whichever comes first, 
the following actions:
     Remove the left upper bolt, washers, and nut. Install a 
new bolt, part number (P/N) NAS627-30; washers, P/N 140-007-29S25E6 and 
P/N NAS1149G0732P; and new nut, P/N 42FLW-720. Repeat this action for 
the opposite right upper attachment hardware.
     Remove the left lower bolt, washers, and nut. Install a 
new bolt, P/N NAS626-26; washer, P/N 140-007-25S22E6, washer(s), P/N 
NAS1149G0663P; and new nut, P/N 42FLW-624. Repeat this action for the 
opposite right lower attachment hardware.
     After installation of the new attachment hardware, at 
intervals of not less than 1 hour TIS but not exceeding 5 hours TIS, 
determine the torque of each nut until torque stabilizes at each 
attachment location. Thereafter, determine the torque of each nut at 
recurring intervals not to exceed 300 hours TIS. If the proper torque 
has not been retained since the last torquing, remove and inspect the 
tailboom assembly for damage, corrosion, improper assembly, and 
condition. If the tailboom assembly is airworthy, replace the 
attachment hardware and determine that the torque has stabilized at 
each attachment location. Replace any unairworthy tailboom assembly 
with an airworthy tailboom assembly before further flight.

Differences Between This Proposed AD and the Transport Canada AD

    The differences between this proposed AD and the Transport Canada 
AD are as follows:
     This proposed AD uses the term ``hours time-in-service'' 
to describe compliance times, and the Transport Canada AD uses the term 
``air time'';

[[Page 18972]]

     For helicopters with 7000 hours or less TIS, the Transport 
Canada AD requires accomplishing the actions in the AD at the next 
scheduled 600-hour inspection or by December 31, 2010, whichever occurs 
first. This proposed AD requires accomplishing the actions at the next 
scheduled 600-hour inspection or 90 days, whichever occurs first.
     This proposed AD uses the term ``determine the torque'' 
when referring to the torque on a nut, and the Transport Canada AD uses 
the term ``perform a torque check.''

Costs of Compliance

    We estimate that this proposed AD would affect 552 helicopters of 
U.S. registry. We estimate it would take about 2.0 work-hours per 
helicopter to replace the hardware and 1.0 work-hour per helicopter to 
determine the recurring torque value at an average labor rate of $85 
per work hour. Required parts would cost about $498 per helicopter. 
Based on these figures, we estimate for the first year the total cost 
per helicopter to be $923, and the total cost impact on U.S. operators 
to be $509,496. This estimated total cost assumes attachment hardware 
will be replaced on all affected helicopters, the torque will be 
considered stabilized after determining the torque value once, and the 
300-hour TIS recurring torque determination will be accomplished twice 
a year.

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

    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]

    2. The FAA amends Sec.  39.13 by adding the following new 
Airworthiness Directive (AD):

Bell Helicopter Textron Canada (BHTC): Docket No. FAA-2012-0337; 
Directorate Identifier 2010-SW-090-AD.

(a) Applicability

    BHTC Model 407 helicopters, serial numbers 53000 through 53990, 
certificated in any category.

(b) Unsafe Condition

    This proposed AD defines the unsafe condition as an incorrect 
torque value of the tailboom attachment bolt (bolt) specified in the 
BHTC Model 407 Maintenance Manual and applied during manufacturing, 
which exceeds the torque range recommended for the bolts. This 
condition could result in an over-torque of the bolt, bolt failure, 
loss of the tailboom, and subsequent loss of control of the 
helicopter.

(c) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless accomplished 
previously.

(d) Required Actions

    (1) For helicopters with 7000 hours or less time-in-service 
(TIS), at the next 600 hours scheduled inspection, or 90 days, 
whichever comes first; and for helicopters with more than 7000 hours 
TIS, within 150 hours TIS or 90 days, whichever comes first, replace 
the tailboom-attachment hardware (attachment hardware) as follows:
    (i) Remove the left upper bolt, washers, and nut.
    (ii) Install a new bolt, part number (P/N) NAS627-30; washer, P/
N 140-007-29S25E6; washer(s), P/N NAS1149G0732P; and new nut, P/N 
42FLW-720 in accordance with paragraphs 2.a) through paragraph 3.e) 
of the ``Accomplishment Instructions: Replacement of tailboom 
attachment bolts and nuts'' section and Figure 2 in the BHTC Alert 
Service Bulletin No. 407-10-93, Revision A, dated August 30, 2010 
(ASB).
    (iii) Remove the opposite right upper bolt, washers, and nut, 
and accomplish the requirements in paragraph (d)(1)(ii) of this AD.
    (iv) Remove the left lower bolt, washers, and nut.
    (v) Install a new bolt, (P/N) NAS626-26; washer, P/N 140-007-
25S22E6; washer(s), P/N NAS1149G0663P; and new nut, P/N 42FLW-624 in 
accordance with paragraphs 6.a) through 7.e) of the ``Accomplishment 
Instructions: Replacement of tailboom attachment bolts and nuts'' 
section and Figure 2 in the ASB.
    (vi) Remove the right lower bolt, washers, and nut, and 
accomplish the requirements in paragraph (d)(1)(v) of this AD.
    (2) After installation of the new attachment hardware, at 
intervals of not less than 1 hour TIS but not exceeding 5 hours TIS, 
determine the torque of each nut until the torque stabilizes at each 
attachment location, referring to Figure 2 of the ASB. Apply the 
minimum specified torque of the range, plus the minimum acceptable 
tare torque of 14 inch/lbs (1.58 Nm) for the upper nuts, and 9.5 
inch/lbs (1.07 Nm) for the lower nuts.
    (3) At intervals not to exceed 300 hours TIS, determine the 
torque of each of the four attachment nuts, referring to Figure 2 of 
the ASB. Apply the minimum specified torque of the range plus the 
minimum acceptable tare torque of 14 inch/lbs (1.58 Nm) for the 
upper nuts, and 9.5 inch/lbs (1.07 Nm) for the lower nuts. If the 
proper torque has not been retained since the last torque 
determination, remove and inspect the tailboom assembly for damage, 
corrosion, improper assembly, and condition. If the tailboom 
assembly is airworthy, replace the attachment hardware in accordance 
with the requirements in paragraphs (d)(1)(i) through (d)(1)(vi) and 
determine that the torque has stabilized in accordance with 
paragraph (2) of this AD. Replace any unairworthy tailboom assembly 
with an airworthy tailboom assembly.

(e) Alternative Methods of Compliance (AMOC)

    (1) The Manager, Safety Management Group, FAA, may approve AMOCs 
for this AD. Send your proposal to: Sharon Miles,

[[Page 18973]]

2601 Meacham Blvd., Fort Worth, Texas 76137; telephone: (817) 222-
5122; fax: 817-222-5961; email: sharon.y.miles@faa.gov.
    (2) For operations conducted under a Part 119 operating 
certificate or under 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.

(f) Additional Information

    The subject of this AD is addressed in the Transport Canada 
Civil Aviation (TCCA) AD CF-2010-33, dated September 30, 2010.

 (g) Subject

    Joint Aircraft Service Component (JASC) Code: 5302, Rotorcraft 
tailboom.

    Issued in Fort Worth, Texas, on March 21, 2012.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 2012-7542 Filed 3-28-12; 8:45 am]
BILLING CODE 4910-13-P