AD 2011-15-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Textron | Various | Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters |
| aircraft | Bell | 407 427 | Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters |
Unsafe Condition
Certain hydraulic servo actuators may have a loose nut, shaft, and clevis assembly due to improper lock-washer installation, which could result in a malfunction of the servo in the flight control system and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect certain hydraulic servo actuators to determine whether the shaft turns independently of the nut or the clevis assembly. If the shaft turns independently, replace the servo with an airworthy servo. If the shaft does not turn independently, inspect the lock washers. If any lock washer tab is not bent flush against a flat surface of the nut or clevis assembly, bend it flush. Reidentify the servo by metal-impression stamping or vibro-etching '67.01' onto the modification plate. Before installing a servo with a part number or serial number identified in this AD, inspect it following the AD requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight for certain affected servos and within 25 hours time-in-service for certain other affected servos identified by a serial number.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bell Helicopter Textron Canada Model 407 and 427 helicopters.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2011-15-51, which was sent previously to all known U.S. owners and operators of the specified Bell Model 407 and 427 helicopters by individual letters. This AD requires inspecting certain hydraulic servo actuators to determine whether the shaft turns independently of the nut or the clevis assembly. If the shaft turns independently, this AD requires replacing the servo with an airworthy servo. If the shaft does not turn independently, the AD requires inspecting to determine the condition of the lock washers. Based on the condition of the lock washers, the AD requires either replacing the servo with an airworthy servo, or if any tab of the lock washer is not flush against a flat surface of the nut or clevis assembly, bending it flush against a flat surface. The AD also requires reidentifying the servo by metal-impression stamping or by vibro- etching "67.01" onto the modification plate. Also, the AD requires before installing a servo with a part number or serial number identified in this AD, not identified by "67-01" on the modification plate, inspecting it by following the requirements of this AD. This AD is prompted by a report that a quality escape by a supplier has occurred and certain servos may have a loose nut, shaft, and clevis assembly due to improper lock-washer installation. An investigation after an accident revealed the clevis nut on the servo was loose. The actions specified by this AD are intended to prevent a malfunction of a servo in the flight control system and subsequent loss of control of the helicopter.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 76, Number 208 (Thursday, October 27, 2011)]
[Rules and Regulations]
[Pages 66609-66613]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2011-27687]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2011-1035; Directorate Identifier 2011-SW-038-AD;
Amendment 39-16817; AD 2011-15-51]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron Canada (Bell)
Model 407 and 427 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) 2011-15-51, which was sent
previously to all known U.S. owners and operators of the specified Bell
Model 407 and 427 helicopters by individual letters. This AD requires
inspecting certain hydraulic servo actuators to determine whether the
shaft turns independently of the nut or the clevis assembly. If the
shaft turns independently, this AD requires replacing the servo with an
airworthy servo. If the shaft does not turn independently, the AD
requires inspecting to determine the condition of the lock washers.
Based on the condition of the lock washers, the AD requires either
replacing the servo with an airworthy servo, or if any tab of the lock
washer is not flush against a flat surface of the nut or clevis
assembly, bending it flush against a flat surface. The AD also requires
reidentifying the servo by metal-impression stamping or by vibro-
etching ``67.01'' onto the modification plate. Also, the AD requires
before installing a servo with a part number or serial number
identified in this AD, not identified by ``67-01'' on the modification
plate, inspecting it by following the requirements of this AD. This AD
is prompted by a report that a quality escape by a supplier has
occurred and certain servos may have a loose nut, shaft, and clevis
assembly due to improper lock-washer installation. An investigation
after an accident revealed the clevis nut on the servo was loose. The
actions specified by this AD are intended to prevent a malfunction of a
servo in the flight control system and subsequent loss of control of
the helicopter.
DATES: Effective November 14, 2011, to all persons except those persons
to whom it was made immediately effective by Emergency AD 2011-15-51,
issued on July 8, 2011, which contained the requirements of this
amendment.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 14, 2011.
Comments for inclusion in the Rules Docket must be received on or
before December 27, 2011.
ADDRESSES: Use one of the following addresses to submit comments on
this AD:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
You may get the service information identified in this AD from 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 <a href="http://www.bellcustomer.com/files/">http://www.bellcustomer.com/files/</a>.
Examining the Docket: You may examine the docket that contains the
AD, any comments, and other information on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>, or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Operations office (telephone (800) 647-5527) is
located in Room W12-140 on the ground floor of the West Building at the
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Matt Wilbanks, Aviation Safety
Engineer, 2601 Meacham Blvd, Fort Worth, Texas 76137, telephone (817)
222-5051, fax (817) 222-5961.
SUPPLEMENTARY INFORMATION: On July 8, 2011, the FAA issued Emergency AD
2011-15-51 for the specified model helicopters, which requires
inspecting certain servos to determine whether the shaft turns
independently of the nut or the clevis assembly. If the shaft turns
independently, the AD requires replacing the servo with an airworthy
servo. If the shaft does not turn independently, the AD requires
inspecting to determine the condition of the lock washers. If at least
one lock washer is not bent flush against a flat surface of the nut and
at least one tab of the lock washer is not bent flush against a flat
surface of the clevis assembly, the AD requires replacing the servo
with an airworthy servo. If any tab of the lock washer is not bent
flush against either a flat surface of the nut or clevis assembly, the
AD requires bending the tab flush against a flat surface. The AD also
requires reidentifying the servo by metal-impression stamping or by
vibro-etching ``67.01'' onto the modification plate. Also, the AD
requires before installing a servo with a part number or serial number
identified in this AD, not identified by ``67-01'' on the modification
plate, inspecting and reidentifying it by following the requirements of
this AD. That action was prompted by a report that a quality escape by
a supplier has occurred and certain servos may have a loose nut,
[[Page 66610]]
shaft, and clevis assembly due to improper lock-washer installation. An
investigation after an accident revealed the clevis nut on the servo
was loose. This condition, if not corrected, could result in a
malfunction of a servo in the flight control system and subsequent loss
of control of the helicopter.
Transport Canada, the airworthiness authority for Canada, notified
the FAA that an unsafe condition may exist on these helicopter models.
Transport Canada advises that a quality escape by a supplier has
occurred, and a number of servos may have a loose nut, shaft, and
clevis assembly. Transport Canada states in its AD that the loose
connection is due to improper lock-washer installation, which is not
traceable or identifiable except by inspection. The authority also
states a disconnect of the affected parts may lead to loss of control
of the helicopter.
Bell has issued Alert Service Bulletin (ASB) 407-11-96 and 427-11-
35, both dated June 29, 2011, which specify the part numbers and serial
numbers of the affected servos and refer to ASB 407-05-70, Revision A,
dated November 10, 2005; ASB 427-05-12, Revision A, dated November 14,
2005; with HR Textron Service Bulletin (SB) 41011300-67-01, Revision 2,
dated November 9, 2005; HR Textron SB 41011400-67-01, Revision 2, dated
November 9, 2005; and HR Textron SB 41011700-67-01, Revision 2, dated
November 9, 2005, attached. The ASBs also specify reidentifying the
servos with a ``67-01'' on the modification plate indicating the
inspection procedures were followed.
Transport Canada classified the ASBs as mandatory and issued AD No.
CF-2011-17, dated June 30, 2011, to ensure the continued airworthiness
of these helicopters.
This helicopter model is manufactured in Canada and is type
certificated for operation in the United States under the provisions of
14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the
applicable bilateral agreement, Transport Canada has kept us informed
of the situation described above. We have examined the findings of
Transport Canada, reviewed all available information, and determined
that AD action is necessary for helicopters of this type design that
are certificated for operation in the United States.
Since the unsafe condition described is likely to exist or develop
on other Bell Model 407 and 427 helicopters of these same type designs,
the FAA issued Emergency AD 2011-15-51 to prevent a malfunction of a
servo in the flight control system and subsequent loss of control of
the helicopter. The AD requires before further flight for certain
affected servos and within 25 hours time-in-service for certain other
affected servos, identified by a serial number, retracting the boot and
inspecting the servo as follows:
<bullet> Applying only hand pressure, determining whether the nut,
shaft, or clevis assembly turns independently. If the shaft turns
independently of the nut or the clevis assembly, before further flight,
replacing the servo with an airworthy servo.
<bullet> If the shaft does not turn independently, inspecting to
determine whether at least one tab of a lock washer is bent flush
against a flat surface of the nut and at least one tab of the lock
washer is bent flush against a flat surface of the clevis assembly.
<bullet> If at least one lock washer tab is not aligned and bent
flush with a flat surface of the nut and at least one lock washer tab
is not aligned and bent flush with a flat surface of the clevis
assembly, before further flight, replacing the servo with an airworthy
servo.
<bullet> If any tab of the lock washer is not bent flush against
either a flat surface of the nut or clevis assembly, bend the tab flush
against a flat surface.
<bullet> Reidentifying the servo by metal-impression stamping or by
vibro-etching ``67.01'' onto the modification plate.
<bullet> Before installing a servo with a P/N and S/N identified in
this AD, not identified by ``67-01'' on the modification plate,
inspecting it by following the requirements of this AD.
This AD differs from the Transport Canada AD in that we do not
require that the servo be returned to the manufacturer. Also, we do not
limit the applicability to specific serial-numbered helicopters. We
have specified the inspection requirements rather than referring to the
applicable service bulletins. The AD requires that the servo be
replaced before further flight, and the Transport Canada AD refers to
the ASB, which requires that the servo be replaced within 300 hours
time-in-service.
The short compliance time involved is required because the
previously described critical unsafe condition can adversely affect the
controllability of the helicopter. Therefore, inspecting the servos for
specified conditions and replacing any affected servo, as necessary,
are required before further flight, and this AD must be issued
immediately.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual letters
issued on July 8, 2011, to all known U.S. owners and operators of Bell
Model 407 and 427 helicopters. These conditions still exist, and the AD
is hereby published in the Federal Register as an amendment to 14 CFR
39.13 to make it effective to all persons.
We estimate that this AD will affect 582 helicopters of U.S.
registry, and inspecting or replacing an affected servo will take about
2 work hours to inspect and 2 work hours to replace per helicopter at
an average labor rate of $85 per work hour. Required parts will cost
about $33,000 per helicopter. Based on these figures, we estimate the
total cost impact of the AD on U.S. operators to be $164,940, assuming
2 servos are replaced on the entire fleet.
Comments Invited
This AD is a final rule that involves requirements that affect
flight safety and was not preceded by notice and an opportunity for
public comment; however, we invite you to submit any written data,
views, or arguments regarding this AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2011-1035; Directorate
Identifier 2011-SW-038-AD'' at the beginning of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of the AD. We will consider all
comments received by the closing date and may amend the AD in light of
those comments.
We will post all comments we receive, without change, to <a href="http://www.regulations.gov">http://www.regulations.gov</a>, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact
with FAA personnel concerning this AD. Using the search function of our
docket Web site, you can find and read the comments to any of our
dockets, including the name of the individual who sent the comment. You
may review the DOT's complete Privacy Act Statement in the Federal
Register published on April 11, 2000 (65 FR 19477-78).
Regulatory Findings
We have 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 the regulation:
[[Page 66611]]
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); and
3. 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. See the AD docket to examine the economic evaluation.
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive to
read as follows:
2011-15-51 Bell Helicopter Textron, Inc. (Bell): Amendment 39-
16817; Docket No. FAA-2011-1035; Directorate Identifier 2011-SW-038-
AD.
Applicability: Model 407 helicopters with a hydraulic servo
actuator assembly (servo), part number (P/N) 206-076-062-105, or -
107 and Model 427 helicopters, with servo, P/N 206-076-062-109 or -
111, installed, certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To detect loose or misaligned parts of the servo that could lead
to failure of the servo and subsequent loss of control of the
helicopter, do the following:
(a) Before further flight, for those helicopters with a servo
serial number (S/N) on the modification plate listed in Table 1 of
Bell Alert Service Bulletin (ASB) No. 407-11-96, dated June 29,
2011, for the Model 407 helicopters or Table 1 of ASB 427-11-35,
dated June 29, 2011, for the Model 427 helicopters, do the
following:
(1) Retract the boot depicted as ``230'' in Figure 1 of this AD:
Note 1: Bell ASB 427-05-12, Revision A, dated November 14, 2005;
HR Textron SBs 41011300-67-01, 41011400-67-01, and 41011700-67-01,
all Revision 2, all dated November 9, 2005, which are not
incorporated by reference, contain information pertaining to the
subject of this AD.
[[Page 66612]]
[GRAPHIC] [TIFF OMITTED] TR27OC11.000
(2) Applying only hand pressure, determine whether the nut,
shaft, or clevis assembly, depicted as ``225,'' ``215,'' and
``205,'' respectively, in Figure 1 of this AD, turns independently.
If the shaft turns independently of the nut or the clevis assembly,
before further flight, replace the servo with an airworthy servo.
(3) If the shaft does not turn independently, inspect to
determine whether at least one tab of the lock washer is bent flush
against a flat surface of the nut and at least one tab of the lock
washer is bent flush against a flat surface of the clevis assembly.
(i) If at least one lock washer tab is not aligned and bent
flush with a nut flat surface and at least one lock washer tab is
not aligned and bent flush with a flat surface of the clevis
assembly, before further flight, replace the servo with an airworthy
servo.
(ii) If any tab of the lock washer is not bent flush against
either a flat surface of the nut or clevis assembly, bend the tab
flush against a flat surface.
(4) After accomplishing paragraph (a)(1) through (a)(3) of this
AD, reidentify the servo by metal-impression stamping or by vibro-
etching ``67-01'' onto the modification plate.
(b) For those servo P/Ns with a S/N less than the S/Ns listed in
the following Table A of this AD but NOT specifically included in
the list of S/Ns in Table 1 referenced in paragraph (a) of this AD,
within 25 hours
[[Page 66613]]
time-in-service, inspect the nut, shaft, and clevis assembly and
accomplish the requirements of paragraphs (a)(1) through (a)(4) of
this AD.
Table A
----------------------------------------------------------------------------------------------------------------
Helicopter model Servo P/N Servo prefix ``HR,'' S/N
----------------------------------------------------------------------------------------------------------------
407................................ 41011300-101 (BHT 206-076-062- Less than 807.
105).
----------------------------------------------------------------------------
41011400-101 (BHT 206-076-062- Less than 2248.
107).
----------------------------------------------------------------------------
427................................ 41011300-101 (BHT 206-076-062- Less than 807.
111).
41011700-101 (BHT 206-076-062- Less than 230.
109).
----------------------------------------------------------------------------------------------------------------
(c) Before installing a servo with a P/N and S/N identified in
paragraphs (a) or (b) of this AD, not identified by ``67-01'' on the
modification plate, inspect the servo by following the requirements
of this AD.
(d) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Contact the Manager, Safety Management Group, FAA, ATTN: Matt
Wilbanks, Aviation Safety Engineer, 2601 Meacham Blvd, Fort Worth,
Texas 76137, telephone (817) 222-5051, fax (817) 222-5961, for
information about previously approved alternative methods of
compliance.
(e) The Joint Aircraft System/Component (JASC) Code is: 6730:
Rotorcraft Servo System.
(f) The affected servo serial numbers are listed in Table 1 of
Bell Alert Service Bulletin (ASB) No. 407-11-96, dated June 29,
2011, for the Model 407 helicopters or Table 1 of ASB 427-11-35,
dated June 29, 2011, for the Model 427 helicopters. The Director of
the Federal Register approved this incorporation by reference in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from 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 <a href="http://www.bellcustomer.com/files/">http://www.bellcustomer.com/files/</a>. Copies may be inspected at the FAA, Office of the Regional
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 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: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
(g) This amendment becomes effective on November 14, 2011, to
all persons except those persons to whom it was made immediately
effective by Emergency AD 2011-15-51, issued July 8, 2011, which
contained the requirements of this amendment.
Note 2: The subject of this AD is addressed in Transport Canada
AD CF-2011-17, dated June 30, 2011.
Issued in Fort Worth, Texas, on September 19, 2011.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2011-27687 Filed 10-26-11; 8:45 am]
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