[Federal Register Volume 64, Number 10 (Friday, January 15, 1999)]
[Rules and Regulations]
[Pages 2560-2562]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-907]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-37-AD; Amendment 39-10999; AD 98-17-15]
RIN 2120-AA64
Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
76A, B, and C 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) 98-17-15 which was sent
previously to all known U.S. owners and operators of Sikorsky Aircraft
Corporation Model S-76A, B, and C helicopters by individual letters.
This AD requires, before further flight, a one-time visual inspection
of the swashplate assembly uniball bearing
[[Page 2561]]
retainer (retainer) for missing bolts, an inspection with a magnet to
detect aluminum bolts, and replacing missing or aluminum bolts with
airworthy steel bolts. This amendment is prompted by reports of the
installation of aluminum bolts on swashplate assemblies. This
condition, if not corrected, could result in failure of the swashplate
assembly, loss of the main rotor, and subsequent loss of control of the
helicopter.
DATES: Effective February 1, 1999, to all persons except those persons
to whom it was made immediately effective by Priority Letter AD 98-17-
15, issued on August 13, 1998, which contained the requirements of this
amendment.
Comments for inclusion in the Rules Docket must be received on or
before March 16, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-37-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
FOR FURTHER INFORMATION CONTACT: Robert Mann, Aerospace Engineer, FAA,
Boston Aircraft Certification Office, ANE-150, 12 New England Executive
Park, Burlington, Massachusetts 01803, telephone (781) 238-7190, fax
(781) 238-7199.
SUPPLEMENTARY INFORMATION: On August 13, 1998, the FAA issued Priority
Letter AD 98-17-15, applicable to Sikorsky Aircraft Corporation Model
S-76A, B, and C helicopters, which requires, before further flight, a
one-time visual inspection of the swashplate assembly retainer for
missing bolts and a one-time inspection of each retainer bolt using a
magnet to detect the installation of aluminum retainer bolts. If
retainer bolts are missing or aluminum bolts are found, the AD requires
that they be replaced with airworthy steel bolts. That action was
prompted by reports of the installation of aluminum bolts on swashplate
assemblies, part numbers 76104-08000-044, -045, -046, and 76104-08500-
041 and -043. This condition, if not corrected, could result in failure
of the swashplate assembly, loss of control of the main rotor, and
subsequent loss of control of the helicopter.
The FAA has reviewed Sikorsky Aircraft Corporation Service Bulletin
76-65-47, dated July 31, 1998 (SB). The SB describes procedures for a
one-time visual inspection of the swashplate assembly retainer for
missing bolts, an inspection with a magnet to determine whether steel
bolts are installed, and replacing missing or aluminum bolts with
airworthy steel bolts.
Since the unsafe condition described is likely to exist or develop
on other Sikorsky Aircraft Corporation Model S-76A, B, and C
helicopters of the same type design, the FAA issued Priority Letter AD
98-17-15 to prevent failure of the swashplate assembly, loss of the
main rotor, and subsequent loss of control of the helicopter. The AD
requires, before further flight, a one-time visual inspection of the
swashplate assembly retainer for missing bolts, an inspection with a
magnet to detect aluminum bolts, and replacing missing or aluminum
bolts with airworthy steel bolts.
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 August 13, 1998 to all known U.S. owners and operators of
Sikorsky Aircraft Corporation Model S-76A, B, and C helicopters. These
conditions still exist, and the AD is hereby published in the Federal
Register as an amendment to section 39.13 of the Federal Aviation
Regulations (14 CFR 39.13) to make it effective to all persons.
The FAA estimates that 157 helicopters of U.S. registry will be
affected by this AD, that it will take approximately 3 work hours per
helicopter to accomplish the required actions, and that the average
labor rate is $60 per work hour. Required parts will cost approximately
$3 per swashplate assembly. Based on these figures, the total cost
impact of the AD on U.S. operators is estimated to be $28,731, assuming
one inspection and replacement of all retainer bolts in all the
helicopters.
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, both before and after the closing date for comments, 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 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. 98-SW-37-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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, 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:
[[Page 2562]]
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:
AD 98-17-15 Sikorsky Aircraft Corporation: Amendment 39-10999.
Docket No. 98-SW-37-AD.
Applicability: Model S-76A, B, and C helicopters, serial numbers
prior to 760488, with swashplate assembly, part numbers 76104-08000-
044, -045, -046, or 76104-08500-041 or -043, 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
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 use the authority
provided in paragraph (c) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition, or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any helicopter from the applicability of this AD.
Compliance: Required before further flight, unless accomplished
previously.
To prevent failure of the swashplate assembly, loss of control
of the main rotor, and subsequent loss of control of the helicopter,
accomplish the following:
(a) Conduct a one-time visual inspection of the swashplate
assembly uniball bearing retainer (retainer) to determine whether
any retainer bolts are missing. Replace any missing retainer bolt
with an airworthy AN3-5A bolt.
(b) Conduct a one-time inspection of each swashplate assembly
retainer bolt (12 installed) with a magnet to verify that a steel
bolt is installed. The steel bolts will attract the magnet, the
aluminum bolts will not. Replace any aluminum bolt, one at a time,
with an airworthy AN3-5A bolt.
Note 2: Sikorsky Aircraft Corporation Service Bulletin 76-65-47,
dated July 31, 1998, pertains to the subject of this AD.
(c) 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.
(d) Special flight permits will not be issued.
(e) This amendment becomes effective on February 1, 1999, to all
persons except those persons to whom it was made immediately
effective by Priority Letter AD 98-17-15, issued August 13, 1998,
which contained the requirements of this amendment.
Issued in Fort Worth, Texas, on January 7, 1999.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-907 Filed 1-14-99; 8:45 am]
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