AD 2001-03-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-76B | Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76B and S-76C Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-76C | Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76B and S-76C Helicopters |
Unsafe Condition
Failure of the main rotor shaft due to cracks, which could lead to loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct initial and recurring fluorescent penetrant inspections (FPI) in the specified area of the main rotor shaft. Replace each affected main rotor shaft with an airworthy one before reaching 1,000 hours time-in-service (TIS).
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight for initial FPI, and thereafter at intervals not exceeding 20 hours TIS or 80 landings, whichever occurs first. Replace each affected shaft on or before 1,000 hours TIS.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Aircraft Corporation Model S-76B and S-76C helicopters with main rotor shaft assembly (part number 76351-09630, all dash numbers), and specific serial numbers listed in the AD.
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) 2001-03-51, which was sent previously to all known U.S. owners and operators of Sikorsky Aircraft Corporation (Sikorsky) Model S-76B and S-76C helicopters by individual letters. This AD requires, for certain main rotor shafts, initial and recurring fluorescent penetrant inspections. Replacing each affected main rotor shaft (shaft) on or before reaching 1,000 hours time-in- service (TIS) is also required. This amendment is prompted by four reports of shaft cracks. The actions specified by this AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 66, Number 44 (Tuesday, March 6, 2001)]
[Rules and Regulations]
[Pages 13422-13424]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-5165]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-SW-01-AD; Amendment 39-12134; AD 2001-03-51]
RIN 2120-AA64
Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
76B and S-76C 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) 2001-03-51, which was sent
previously to all known U.S. owners and operators of Sikorsky Aircraft
Corporation (Sikorsky) Model S-76B and S-76C helicopters by individual
letters. This AD requires, for certain main rotor shafts, initial and
recurring fluorescent penetrant inspections. Replacing each affected
main rotor shaft (shaft) on or before reaching 1,000 hours time-in-
service (TIS) is also required. This amendment is prompted by four
reports of shaft cracks. The actions specified by this AD are intended
to prevent failure of the shaft and subsequent loss of control of the
helicopter.
DATES: Effective March 21, 2001, to all persons except those persons to
whom it was made immediately effective by Emergency AD 2001-03-51,
issued on January 30, 2001, 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 March 21, 2001.
Comments for inclusion in the Rules Docket must be received on or
before May 7, 2001.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 2001-SW-01-AD, 2601 Meacham Blvd., Room
663, Fort Worth, Texas 76137. You may also send comments electronically
to the Rules Docket at the following address: <a href="/cdn-cgi/l/email-protection#9ca5b1fdefebb1fdf8fff3f1f1f9f2e8efdcfafdfdb2fbf3ea"><span class="__cf_email__" data-cfemail="c2fbefa3b1b5efa3a6a1adafafa7acb6b182a4a3a3eca5adb4">[email protected]</span></a>.
The applicable service information may be obtained from Sikorsky
Aircraft Corporation, Attn: Manager, Commercial Tech Support, 6900 Main
Street, Stratford, Connecticut 06614, phone (203) 386-3001, fax (203)
386-5983. This information may be examined at the FAA, Office of the
Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort
Worth, Texas; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Wayne Gaulzetti, Aviation Safety
Engineer, Boston Aircraft Certification Office, 12 New England
Executive Park, Burlington, MA 01803, telephone (781) 238-7156, fax
(781) 238-7199.
SUPPLEMENTARY INFORMATION: On January 30, 2001, the FAA issued
Emergency AD 2001-03-51 for Sikorsky Model S-76B and S-76C helicopters,
which requires, for certain shafts, initial and recurring fluorescent
penetrant inspections. Replacing each affected shaft on or before
reaching 1,000 hours TIS is also required. That action was prompted by
four reports of shaft cracks. This condition, if not corrected, could
result in failure of the shaft and subsequent loss of control of the
helicopter.
The FAA has reviewed Sikorsky Alert Service Bulletin (ASB) No. 76-
66-32A, Revision A, dated January 17, 2001, which specifies identifying
main gear box assemblies containing certain shafts, conducting a
recurring fluorescent penetrant inspection (FPI), and removing certain
main gear box assemblies containing certain shafts.
Since the unsafe condition described is likely to exist or develop
on other Sikorsky Model S-76B and S-76C helicopters of the same type
designs, the FAA issued Emergency AD 2001-03-51 to prevent failure of
the shaft and subsequent loss of control of the helicopter. The AD
requires, for certain main rotor shafts, an FPI before further flight
and thereafter at intervals not to exceed 20 hours TIS or 80 landings,
whichever occurs first. Replacing each affected shaft on or before
reaching 1,000 hours TIS is also required. The actions must be
accomplished in accordance with the ASB described previously. The short
compliance time involved is required because the previously described
critical unsafe condition can adversely affect the structural integrity
of the helicopter. Therefore, FPI's and removal of each affected shaft
are required at the specified time intervals, 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 January 30, 2001, to all known U.S. owners and operators of
[[Page 13423]]
Sikorsky Model S-76B and S-76C 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.
The FAA estimates that 7 helicopters of U.S. registry will be
affected by this AD. It will take approximately 4 work hours per
helicopter to accomplish each FPI and 5 work hours to replace each
shaft. The average labor rate is $60 per work hour. Required parts will
cost approximately $25,000 per shaft. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to be $178,780
(assuming 1 FPI per helicopter and 1 shaft replacement on each
helicopter). Additional FPI's would cost $240 per inspection and
additional shaft replacements would cost $25,300 per helicopter.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications should identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available in the Rules Docket for examination by interested persons. A
report that summarizes each FAA-public contact concerned with the
substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their mailed
comments submitted in response to this rule must submit a self-
addressed, stamped postcard on which the following statement is made:
``Comments to Docket No. 2001-SW-01-AD.'' The postcard will be date
stamped and returned to the commenter.
The regulations adopted herein 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ADDRESSES.
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
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. Section 39.13 is amended by adding a new airworthiness directive
to read as follows:
2001-03-51 Sikorsky Aircraft Corporation: Amendment 39-12134.
Docket No. 2001-SW-01-AD.
Applicability: Model S-76B and S-76C helicopters, with main
rotor shaft assembly (shaft), part number (P/N) 76351-09630 all dash
numbers, serial number (S/N) C213-00274, C213-00275, C213-00276,
C213-00277, C213-00278, C213-00279, C213-00280, C213-00282, C213-
00292, C213-00294, C213-00295, C213-00296, C213-00297, C213-00299,
and C213-00300, installed, certificated in any category.
Note 1: This AD applies to each helicopter identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For helicopters that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (d) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the shaft and subsequent loss of control
of the helicopter, accomplish the following:
(a) Before further flight and thereafter at intervals not to
exceed 20 hours time-in-service (TIS) or 80 landings, whichever
occurs first, conduct a fluorescent penetrant inspection (FPI) in
the area above the uppers shaft output seal and below the lower hub
attachment flange in accordance with the Accomplishment
Instructions, paragraphs 3.B.(1) through 3.B.(5), of Sikorsky
Aircraft Corporation (Sikorsky) Alert Service Bulletin (ASB) No. 76-
66-32A, Revision A, dated January 17, 2001. Contacting Sikorsky is
not required by this AD. If a crack is found, replace the shaft with
an airworthy shaft before further flight.
Note 2: Accomplishing the FPI before further flight is not
required if previously accomplished in accordance with the
Accomplishment Instructions, paragraphs 3.C.(1) through 3.C.(5), of
Sikorsky ASB No. 76-66-31B, Revision B, dated November 7, 2000.
(b) On or before 1000 hours TIS, replace each affected shaft
with an airworthy shaft.
(c) This AD revises the Limitations section of the maintenance
manual by establishing a retirement life of 1000 hours TIS for the
affected shafts.
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Boston Aircraft Certification
Office, FAA. Operators shall submit their requests through an FAA
Principal Maintenance Inspector, who may concur or comment and then
send it to the Manager, Boston Aircraft Certification Office.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Boston Aircraft Certification Office.
(e) Special flight permits may be issued in accordance with 14
CFR 21.197 and 21.199 to operate the helicopter to a location where
the requirements of this AD can be accomplished if the FPI or a
visual inspection, using a 10X or higher magnifying glass, does not
reveal a crack.
(f) The FPI shall be done in accordance with the Accomplishment
Instructions, paragraphs 3.B.(1) through 3.B.(5), of Sikorsky
Aircraft Corporation Alert Service Bulletin No. 76-66-32A, Revision
A, dated January 17, 2001. This incorporation by
[[Page 13424]]
reference was approved the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from Sikorsky Aircraft Corporation, Attn: Manager,
Commercial Tech Support, 6900 Main Street, Stratford, Connecticut
06614, phone (203) 386-3001, fax (203) 386-5983. 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
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
(g) This amendment becomes effective on March 21, 2001, to all
persons except those persons to whom it was made immediately
effective by Emergency AD 2001-03-51, issued January 30, 2001, which
contained the requirements of this amendment.
Issued in Fort Worth, Texas, on February 20, 2001.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 01-5165 Filed 3-5-01; 8:45 am]
BILLING CODE 4910-13-M
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