Published 2012-05-25 · Federal Register document 2012-12399
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
Publication summary
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (BHTC) Model 427 helicopters which requires replacing certain tailboom attachment hardware and at certain intervals thereafter, determining the torque of that tailboom attachment hardware. This AD was prompted by a review of the tailboom attachment installation, which revealed that the torque value of the bolts specified in the BHTC Model 427 Maintenance Manual and applied during manufacturing was incorrect and exceeded the torque range recommended for the bolts. The actions are intended to prevent an over- torque of the tailboom attachment bolt (bolt), bolt failure, loss of the tailboom, and subsequent loss of control of the helicopter.
Why this record is shown
Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:23:39.502075+00:00. The title, summary and date are source facts.
- Source revision
- federal_register_ad_metadata_2012-08bffa249ae9a205
- Source row
- results[168]
- Raw source SHA-256
- 08bffa249ae9a2053bbfc0d74663d089914e83fb91f9bc4c8409ea28239f6875
Final-rule publication
Recorded publication clauses
- AD identifier printed in this edition
- 2012-10-01
- Effective date printed in this edition
- 2012-06-29
Some source clauses remain unstructured. Read the complete publication for conditions that have not been interpreted here.
Read 9 complete recorded clauses
Applicability wording · Applicability
(a) Applicability
This AD applies to Model 427 helicopters, serial numbers 56001
through 56084, certificated in any category.
Exact source excerpt. Text positions 10183–10316, end exclusive, in the original decoded publication. SHA-256: 29be7fdd0769576ef6981d60f3971a0f0bf4684b1228fc9f04eeff728d28f86a
Unsafe Condition
(b) Unsafe Condition
This AD defines the unsafe condition as an over-torque of the
tailboom attachment bolt (bolt). This condition could result in bolt
failure, loss of the tailboom, and subsequent loss of control of the
helicopter.
Exact source excerpt. Text positions 10316–10558, end exclusive, in the original decoded publication. SHA-256: ba0c94d0529b79c5b8aa86247043d5b7ca60b716a9b15a126bc3d20cd45604cc
Effective Date
(c) Effective Date
This AD becomes effective June 29, 2012.
Exact source excerpt. Text positions 10558–10624, end exclusive, in the original decoded publication. SHA-256: cce9602c107625b8c393566e0b92da26e99c830858060e294587ace8d2bc0bf2
Compliance
(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.
Exact source excerpt. Text positions 10624–10811, end exclusive, in the original decoded publication. SHA-256: 56042b53a75a0db2af067b711f9b82d8091413842e43863752e31aeffdd54a72
Required Actions
(e) Required Actions
(1) Within 150 hours time-in-service (TIS) or 90 days, whichever
occurs 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) NAS627-27; washer, P/
N 140-007-29S25E6; washer(s), P/N NAS1149G0732P; and new nut, P/N
42FLW-720 in accordance with paragraphs 5.a) through 5.d) of the
Accomplishment Instructions in BHTC Alert Service Bulletin No. 427-
10-31, dated March 1, 2010 (ASB).
(iii) Run the nut onto the threads of the mating bolt with a
torque wrench and measure the existing tare torque. Any bolt and nut
used must have a minimum tare torque value of 14 inch/lbs.
(iv) Torque the nut in accordance with paragraphs 5.f) and 5.g)
of the ASB.
(v) Coat the bolt head, nut, and washers with appropriate
corrosion preventive compound to seal the joint.
(vi) At each remaining attachment location, remove the bolt,
washers, and nut, and install the attachment hardware in accordance
with paragraphs (e)(1)(ii) through (e)(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. Thereafter, at intervals not to exceed 300
hours TIS, determine the torque of each nut. When determining the
torque, it is acceptable to use the minimum tare torque of 14 inch/
lbs (1.58 Nm) added to the minimum torque range of 550-560 inch/lbs
(62.1 to 63.3 Nm). If you remove corrosion preventative compound
during the torquing, recoat the bolt head, nut, and washers with
appropriate corrosion preventive compound to seal the joint.
Exact source excerpt. Text positions 10811–12597, end exclusive, in the original decoded publication. SHA-256: 036ce80ed0084e088853f8a5f4808d35c5132bbf1302dc8358f374312e21c682
Alternative Methods of Compliance (AMOCs)
(f) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Safety Management Group, FAA, may approve AMOCs
for this AD. Send your proposal to: Sharon Miles, Aviation Safety
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA,
2601 Meacham Blvd., Fort Worth, Texas 76137; 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.
Exact source excerpt. Text positions 12597–13324, end exclusive, in the original decoded publication. SHA-256: b9951090463c4564dbb043a8f64b5eceac26e6f6dc25770957659655dfc0ac58
Additional Information
(g) Additional Information
The subject of this AD is addressed in Transport Canada AD CF-
2010-32, dated September 30, 2010.
Exact source excerpt. Text positions 13324–13455, end exclusive, in the original decoded publication. SHA-256: 8c13178bbcf38a9347cc5b45dd9a354d602684159e009d82ec9fc60e4f2f00de
Subject
(h) Subject
Joint Aircraft Service Component (JASC) Code: 5302, Rotorcraft
Tailboom.
Exact source excerpt. Text positions 13455–13547, end exclusive, in the original decoded publication. SHA-256: e84338c2b0225ebae4cdedc6f12925cad628340d24f00e8f818b1e081617e3fb
Material Incorporated by Reference
(i) Material Incorporated by Reference
(1) You must use the specified portions of BHTC Alert Service
Bulletin No. 427-10-31, dated March 1, 2010, to do the specified
actions required by this AD. The Director of the Federal Register
approved the incorporation by reference of this service information
under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this 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-
[[Page 31174]]
0272; or at http://www.bellcustomer.com/files/.
(3) You may review a copy of the referenced service information
at the FAA, Office of the Regional Counsel, Southwest Region, 2601
Meacham Blvd., Room 663, Fort Worth, Texas 76137 or 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/code_of_federal_regulations/ibr_locations.html.
Exact source excerpt. Text positions 13547–14610, end exclusive, in the original decoded publication. SHA-256: 3e1d245a9a5999d4ff1566b0624228f1a714a4c4ff4cbb7fdc5a11f004f6f876
No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.
Find all recorded historical references to AD 2012-10-01 · 0 printed reference observations in this pinned collection.
These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.
Why these observations are shown
They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.
Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: bedfc8817d082d1da870b1fd42b53bda54b48f59d27ab4d09248101daabab183. Source manifest: eb2c928590ad0db1ce5ff4a0f25218e9eaae894e806fcb42da3ee8dfcdd7062b.
Official source · 2012-05-25
Publication text
This is the complete recorded text of this dated publication.
Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.
Read the complete official publication text
[Federal Register Volume 77, Number 102 (Friday, May 25, 2012)]
[Rules and Regulations]
[Pages 31172-31174]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-12399]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2012-0084; Directorate Identifier 2010-SW-089-AD;
Amendment 39-17050; AD 2012-10-01]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron Canada Limited
Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We are adopting a new airworthiness directive (AD) for Bell
Helicopter Textron Canada Limited (BHTC) Model 427 helicopters which
requires replacing certain tailboom attachment hardware and at certain
intervals thereafter, determining the torque of that tailboom
attachment hardware. This AD was prompted by a review of the tailboom
attachment installation, which revealed that the torque value of the
bolts specified in the BHTC Model 427 Maintenance Manual and applied
during manufacturing was incorrect and exceeded the torque range
recommended for the bolts. The actions are intended to prevent an over-
torque of the tailboom attachment bolt (bolt), bolt failure, loss of
the tailboom, and subsequent loss of control of the helicopter.
DATES: This AD is effective June 29, 2012.
The Director of the Federal Register approved the incorporation by
reference of certain documents listed in this AD as of June 29, 2012.
ADDRESSES: For service information identified in this 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 the
referenced service information at the FAA, Office of the Regional
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137.
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 AD, any
incorporated-by-reference service information, the economic evaluation,
any comments received, and other information. The street address for
the Docket Operations Office (phone: 800-647-5527) is U.S. Department
of Transportation, Docket Operations Office, M-30, West Building Ground
Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Sharon Miles, Aviation Safety
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA,
2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5110;
email [email protected].
SUPPLEMENTARY INFORMATION:
Discussion
On February 3, 2012, at 77 FR 5425, the Federal Register published
our Notice of Proposed Rulemaking (NPRM), which proposed to amend 14
CFR part 39 to include an AD that would apply to BHTC Model 427
helicopters, serial numbers 56001 through 56084. That NPRM proposed to
require within 150 hours time-in-service (TIS) or 90 days, whichever
occurs first, the following actions:
<bullet> Remove the left upper bolt, washers, and nut. Install the
new bolt, part number (P/N) NAS627-27; washers, P/N 140-007-29S25E6 and
P/N NAS1149G0732P; and new nut, P/N 42FLW-720. Run the nut onto the
threads of the mating bolt with a torque wrench and measure the
existing tare torque. Any bolt and nut used must have a minimum tare
torque value of 14 inch/lbs. Torque the nut and coat the bolt head,
nut, and washers with appropriate corrosion preventive compound to seal
the joint. Repeat these actions at the three remaining bolt locations.
<bullet> 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
intervals not to exceed 300 hours TIS.
The proposed requirements were intended to prevent an over-torque
of the bolt, bolt failure, loss of the tailboom, and subsequent loss of
control of the helicopter.
Transport Canada (TC), which is the aviation authority for Canada,
issued Canadian AD CF-2010-32, dated September 30, 2010 (AD CF-2010-
32), to correct an unsafe condition for the BHTC Model 427 helicopters,
serial numbers (S/Ns) 56001 through 56084, and S/Ns 58001 and 58002. TC
advises that a review of the tailboom attachment installation
determined that the torque value of the bolts specified in the BHTC
Model 427 Maintenance Manual and applied during manufacturing exceeded
the torque range recommended for the bolts. They state that this
situation, if not corrected, could lead to a bolt failure, detachment
of the tailboom, and loss of control of the helicopter.
Comments
We gave the public the opportunity to participate in developing
this AD, but we did not receive any comments on the NPRM.
FAA's Determination
This helicopter model has been approved by the aviation authority
of Canada and is approved for operation in the United States. Pursuant
to our bilateral agreement with Canada, TC, its technical
representative, has notified us of the unsafe condition described in
the TC AD. We are issuing this AD because we evaluated all information
provided by TC and determined the unsafe condition exists and is likely
to exist or develop on other helicopters of this same type design and
that air safety and the public interest require adopting the AD
requirements as proposed.
Differences Between This AD and the TC AD
The differences between this AD and the TC AD are as follows:
<bullet> The TC AD applies to the BHTC Model 427 helicopter, serial
numbers 58001 and 58002; however, this AD is not applicable to the BHTC
Model 427 helicopters with these serial numbers because they are not
eligible for an FAA Certificate of Airworthiness.
Related Service Information
BHTC has issued Alert Service Bulletin No. 427-10-31, dated March
1, 2010 (ASB), which specifies installing new attachment hardware with
a reduced torque value. This ASB specifies determining the torque of
the newly installed bolts and nuts every 1 to 5 flight hours until
torque stabilizes at all locations, and thereafter at intervals not to
exceed 300 flight hours. TC classified this ASB as mandatory and issued
AD CF-2010-32 to ensure
[[Page 31173]]
the continued airworthiness of these helicopters.
Costs of Compliance
We estimate that this AD will affect 28 helicopters of U.S.
Registry.
We estimate that operators may incur the following costs in order
to comply with this AD. It will 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 will cost about $488 per helicopter.
Based on these figures, we estimate the first year total cost per
helicopter to be $913, and the total cost impact on U.S. operators to
be $25,564. This estimated total cost assumes attachment hardware will
be replaced on all affected helicopters, the torque will be considered
stabilized after one torquing, and the recurring 300 hour TIS 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 helicopters identified in this
rulemaking action.
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) Is not a ``significant rule'' under 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 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.
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):
2012-10-01 Bell Helicopter Textron Canada Limited (BHTC): Amendment
39-17050; Docket No. FAA-2012-0084; Directorate Identifier 2010-SW-
089-AD.
(a) Applicability
This AD applies to Model 427 helicopters, serial numbers 56001
through 56084, certificated in any category.
(b) Unsafe Condition
This AD defines the unsafe condition as an over-torque of the
tailboom attachment bolt (bolt). This condition could result in bolt
failure, loss of the tailboom, and subsequent loss of control of the
helicopter.
(c) Effective Date
This AD becomes effective June 29, 2012.
(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
(1) Within 150 hours time-in-service (TIS) or 90 days, whichever
occurs 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) NAS627-27; washer, P/
N 140-007-29S25E6; washer(s), P/N NAS1149G0732P; and new nut, P/N
42FLW-720 in accordance with paragraphs 5.a) through 5.d) of the
Accomplishment Instructions in BHTC Alert Service Bulletin No. 427-
10-31, dated March 1, 2010 (ASB).
(iii) Run the nut onto the threads of the mating bolt with a
torque wrench and measure the existing tare torque. Any bolt and nut
used must have a minimum tare torque value of 14 inch/lbs.
(iv) Torque the nut in accordance with paragraphs 5.f) and 5.g)
of the ASB.
(v) Coat the bolt head, nut, and washers with appropriate
corrosion preventive compound to seal the joint.
(vi) At each remaining attachment location, remove the bolt,
washers, and nut, and install the attachment hardware in accordance
with paragraphs (e)(1)(ii) through (e)(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. Thereafter, at intervals not to exceed 300
hours TIS, determine the torque of each nut. When determining the
torque, it is acceptable to use the minimum tare torque of 14 inch/
lbs (1.58 Nm) added to the minimum torque range of 550-560 inch/lbs
(62.1 to 63.3 Nm). If you remove corrosion preventative compound
during the torquing, recoat the bolt head, nut, and washers with
appropriate corrosion preventive compound to seal the joint.
(f) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Safety Management Group, FAA, may approve AMOCs
for this AD. Send your proposal to: Sharon Miles, Aviation Safety
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA,
2601 Meacham Blvd., Fort Worth, Texas 76137; 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.
(g) Additional Information
The subject of this AD is addressed in Transport Canada AD CF-
2010-32, dated September 30, 2010.
(h) Subject
Joint Aircraft Service Component (JASC) Code: 5302, Rotorcraft
Tailboom.
(i) Material Incorporated by Reference
(1) You must use the specified portions of BHTC Alert Service
Bulletin No. 427-10-31, dated March 1, 2010, to do the specified
actions required by this AD. The Director of the Federal Register
approved the incorporation by reference of this service information
under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this 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-
[[Page 31174]]
0272; or at http://www.bellcustomer.com/files/.
(3) You may review a copy of the referenced service information
at the FAA, Office of the Regional Counsel, Southwest Region, 2601
Meacham Blvd., Room 663, Fort Worth, Texas 76137 or 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/code_of_federal_regulations/ibr_locations.html.
Issued in Fort Worth, Texas, on May 10, 2012.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2012-12399 Filed 5-24-12; 8:45 am]
BILLING CODE 4910-13-P
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