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Proposed Rule

Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NRPM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C helicopters. That AD currently requires, before further flight, performing a fluorescent penetrant inspection (FPI) of the main rotor shaft assembly (shaft). Also, a recurring FPI and visual inspection for a cracked shaft are required by that AD. That AD also requires replacing the shaft with an airworthy shaft before further flight if a crack is found. This action would require replacing certain serial numbered shafts with an airworthy shaft before further flight. This proposal is prompted by a further investigation and a determination that the inspections can be safely eliminated if certain serial numbered shafts are removed from service before further flight. The actions specified by the proposed AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.

DATES:

Comments must be received by April 16, 2001.

ADDRESSES:

Submit comments to Docket No. 2001-SW-05-AD in one of the following ways:

  • Mail comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-05-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send a request for a copy of the NPRM to that address. If you want us to acknowledge receipt of your mailed comments, you must include a self-addressed, stamped postcard on which the Docket Number is written. We will date-stamp your postcard and mail it back to you.
  • E-mail comments to 9-asw-adcomments@faa.gov.

You may examine this Docket (including any comments and service information) at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137 between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

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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.

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SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to submit any written relevant data, views, or arguments. Submit your comments as specified under the ADDRESSES caption. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it. We will file a report in the Docket that summarizes each FAA contact with the public during the comment period that is related to the substantive part of this rule.

We will consider comments received by the closing date. The proposals or format contained in this document may be changed because of the comments received.

Discussion

On November 3, 2000, the FAA issued AD 2000-23-51, to require a one-time FPI of the shaft. That AD was prompted by the discovery of a cracked shaft having 477 hours time-in-service. On November 9, 2000, the FAA issued superseding Emergency AD 2000-23-52 to require an initial and recurring FPI and a daily visual inspection of the shaft and replacing any shaft found cracked with an airworthy shaft. The requirements of that AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.

Since the issuance of that AD, further investigation and engineering analysis have revealed that daily visual inspections are unnecessary and that certain shafts require an immediate and repetitive FPI and a new retirement life while certain others require replacing before further flight. The inspections and new retirement life for certain serial numbered shafts are addressed in AD 2001-03-51, Docket 2001-SW-01-AD. This AD would require, before further flight, replacing certain shafts installed on the Sikorsky Model S-76A helicopters. The FAA has reviewed Sikorsky Aircraft Corporation Alert Service Bulletin No. 76-66-32A (319A), Revision A, dated January 17, 2001, which specifies removing certain shafts from service and implementing a recurring FPI for certain other shafts.

We have identified an unsafe condition that is likely to exist or develop on other Sikorsky Model S-76A helicopters of the same type design. The proposed AD would require, before further flight, replacing each shaft, part number 76351-09030-all dash numbers, serial number B015-00700 through B015-00706, with an airworthy shaft.

Regulatory Impact

We estimate that 3 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 5 work hours per helicopter to replace the shafts, and that the average labor rate is $60 per work hour. Required parts would cost approximately $19,000 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $57,900.

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

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. You can get a copy of the draft regulatory evaluation prepared for this action from the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the mailing address listed under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. FAA amends § 39.13 by removing Amendment 39-12095 (66 FR 8507, February 1, 2001), and by adding the following new airworthiness directive (AD):

Federal Aviation Administration (FAA), Docket No. 2001-SW-05-AD, Sikorsky Aircraft Corporation

[Subject: Model S-76A, S-76B, and S-76C Main Rotor Shaft Assembly]

(a) Comment Due DateFAA must receive comments by April 16, 2001.
(b) Affected DocumentsThis AD supersedes AD 2000-23-52, Amendment 39-12095, Docket No. 2000-SW-61-AD.
(c) ApplicabilitySikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C helicopters with main rotor shaft assembly (shaft), part number (P/N) 76351-09030—all dash numbers, installed, certificated in any category.
(d) Unsafe ConditionTo prevent failure of the shaft and subsequent loss of control of the helicopter.
(e) ComplianceRequired before further flight, unless accomplished previously.
(f) Required ActionsReplace each affected shaft, serial number B015-00700 through B015-00706, with an airworthy shaft.
(g) Other Provisions(1) Alternative Methods of Compliance (AMOC): (i) You may use an AMOC or adjust the time you need to meet the requirements of this AD if your alternative provides an acceptable level of safety and if the Manager, Boston Aircraft Certification Office (ACO), approves your alternative.
(ii) Submit your request for approval through an FAA Principal Maintenance Inspector, who may add comments and then forward it to the Manager, Boston ACO.
(iii) You can get information about the existence of already approved AMOC's by contacting the FAA, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7156, fax (781) 238-7199.
(2) Modifications, Alterations, or Repairs:
This AD applies to each helicopter identified in the applicability paragraph, even if it has been modified, altered, or repaired in the area subject to this AD. If that change in any way affects accomplishing the required actions, you must request FAA approval for an AMOC. Your request should assess the effect of the change on the unsafe condition addressed by this AD.
(3) Special Flight Permits:
The FAA may issue you a special flight permit under 14 CFR 21.197 and 21.199 to operate your helicopter to a location where you can comply with this AD.
(h) Material Incorporated by ReferenceNone.
(i) Related InformationSikorsky Alert Service Bulletin No. 76-66-32A (319A), Revision A, dated January 17, 2001, pertains to the subject of this AD.
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Issued in Fort Worth, Texas, on March 5, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 01-6389 Filed 3-14-01; 8:45 am]

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