[Federal Register Volume 61, Number 199 (Friday, October 11, 1996)]
[Proposed Rules]
[Pages 53337-53339]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-26128]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-SW-34-AD]
Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-
64F Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to Sikorsky Aircraft-manufactured S-
64F helicopters. This proposal would require inspections, and
replacement, if necessary, of the main gearbox second stage lower
planetary plate (plate). This proposal is prompted by two incidents in
which the second stage planetary plate was found cracked. The actions
specified by the proposed AD are intended to prevent failure of the
plate due to fatigue cracking, which could lead to failure of the main
gearbox and subsequent loss of control of the helicopter.
DATES: Comments must be received by December 10, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Assistant Chief Counsel, Attention:
Rules Docket No. 95-SW-34-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137. Comments may be inspected at this location between 9:00
a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be
obtained from Erickson Air-Crane Co., 3100 Willow Springs Rd., P.O. Box
3247, Central Point, Oregon 97502. This information may be examined at
the FAA, Office of the Assistant Chief Counsel, 2601 Meacham Blvd.,
Room 663, Fort Worth, Texas.
FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer,
FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 2601
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5114, fax
(817) 222-5961.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed 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 above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
[[Page 53338]]
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 95-SW-34-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Office of the Assistant Chief Counsel, Attention: Rules
Docket No. 95-SW-34-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas
76137.
Discussion
This document proposes the adoption of a new AD that is applicable
to Model S-64F helicopters. During the overhaul of a main gearbox
assembly, Erickson Air-Crane Co., the type certificate holder, found a
plate that was cracked. Subsequent field boroscope inspections
performed on other S-64F helicopters revealed a second plate that was
also cracked. This condition, if not corrected, could lead to failure
of the plate due to fatigue cracking, which could lead to failure of
the main gearbox and subsequent loss of control of the helicopter.
The FAA has reviewed Erickson Air-Crane Co. Service Bulletin No.
64F35-2A, which describes procedures for the inspection and
replacement, if necessary, of the plate.
Since an unsafe condition has been identified that is likely to
exist or develop on other Sikorsky Aircraft-manufactured Model S-64F
helicopters of the same type design, the proposed AD would require a
daily inspection of main gearboxes containing a plate with more than
2,000 hours time-in-service (TIS) for main gearbox oil filter magnesium
contamination and, if magnesium contamination is discovered,
replacement of the main gearbox assembly. For main gearbox assemblies
containing a plate with more than 2,000 hours TIS, this AD also
requires an inspection of the plate within the next 100 hours TIS after
the effective date of this AD, and thereafter at intervals not to
exceed 500 hours TIS; and replacement of the plate if necessary. This
AD also requires, at the next overhaul of the main gearbox assembly,
inspection and rework of plates that are not cracked. The actions would
be required to be accomplished in accordance with the service bulletin
described previously.
The FAA estimates that 6 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 8 work
hours per helicopter to accomplish the borescope inspection and 140
work hours to remove and replace the main gearbox assembly, if
necessary, and that the average labor rate is $60 per work hour.
Required parts would cost $8,000. Based on these figures, the total
cost impact of the proposed AD on U.S. operators is estimated to be
$101,280; $2,880 to accomplish the inspections, and $98,400 to replace
the plate in the main gearbox assembly in all 6 helicopters, if
necessary.
The regulations proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that 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);
and (3) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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:
Erickson Air-Crane Co.: Docket No. 95-SW-34-AD.
Applicability: Sikorsky Aircraft-manufactured Model S-64F
helicopters, with main gearbox second stage lower planetary plate,
part number (P/N) 6435-20516-101 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 as indicated, unless accomplished
previously.
To prevent failure of the main gearbox second stage lower
planetary plate (plate) due to fatigue cracking, which could lead to
failure of the main gearbox and subsequent loss of control of the
helicopter, accomplish the following:
(a) For main gearbox assemblies containing plate, P/N 6435-
20516-101, with 2,000 hours time-in-service (TIS) or more:
(1) Prior to the first flight of each day, inspect the main oil
filter for magnesium contamination, and if magnesium contamination
is discovered, replace the main gearbox assembly.
(2) Within the next 100 hours TIS after the effective date of
this AD, and thereafter at intervals not to exceed 500 hours TIS,
inspect or replace the main gearbox assembly in accordance with the
Accomplishment Instructions of Section 2, Paragraph B, of Erickson
Service Bulletin No. 64F35-2A dated November 8, 1995.
(b) At the next overhaul of the main gearbox assembly, inspect
and rework the plate, P/N 6435-20516-101, in accordance with Section
2, Paragraphs C(1) and (3) through (11) of Erickson Service Bulletin
No. 64F35-2A, dated November 8, 1995.
(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, Rotorcraft Certification Office,
Rotorcraft Directorate, FAA. Operators shall submit their requests
through an FAA Principal Maintenance Inspector, who may concur or
comment and then send it to the Manager, Rotorcraft Certification
Office.
Note 2: Information concerning the existence of approved
alternative methods of
[[Page 53339]]
compliance with this AD, if any, may be obtained from the Rotorcraft
Certification Office.
(d) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the helicopter to a location where
the requirements of this AD can be accomplished.
Issued in Fort Worth, Texas, on October 4, 1996.
Eric Bries,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-26128 Filed 10-10-96; 8:45 am]
BILLING CODE 4910-13-U
