Airworthiness Directives; Sikorsky Aircraft Corporation Model S- 61A, D, E, L, N, NM, R, and V Helicopters

[Federal Register Volume 62, Number 182 (Friday, September 19, 1997)]
[Rules and Regulations]
[Pages 49132-49133]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24075]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-SW-18-AD; Amendment 39-10026; AD 97-19-06]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
61A, D, E, L, N, NM, R, and V Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing priority letter 
airworthiness directive (AD), applicable to Sikorsky Aircraft 
Corporation Model S-61A, D, E, L, N, NM, R, and V helicopters, that 
currently requires inspecting certain main rotor blade assemblies 
(blades) to determine if a blade has a blade trailing edge pocket 
assembly (pocket assembly) that was anodized by Poly-Metal Company 
during a specified time period, and if so, replacing it with an 
airworthy blade. This amendment requires the same actions as the 
existing AD, but corrects two serial numbers in the list of the 
applicable blades. This amendment is prompted by the manufacturer's 
issuance of a service bulletin with a revised list of blade serial 
numbers. The actions specified by this AD are intended to prevent 
disbonding and separation of portions of the blade, subsequent 
excessive vibrations, and loss of control of the helicopter.

DATES: Effective October 6, 1997. The incorporation by reference of 
certain publications listed in the regulations is approved by the 
Director of the Federal Register as of October 6, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before November 18, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 97-SW-18-AD, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.
    The service information referenced in this AD may be obtained from 
Sikorsky Aircraft Corporation, Attn: Mr. Paul Dionne, CAR Office, 6900 
Main Street, P.O. Box 9729, Stratford, Connecticut 06497-9129, 
telephone (203) 386-7860, fax (203) 386-4703. This information may be 
examined at the FAA, Office of the Assistant Chief Counsel, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Bob Mann, Aerospace Engineer, 
Boston Aircraft Certification Office, ANE-150, 12 New England Executive 
Park, Burlington, MA 01803, telephone (617) 238-7190, fax (617) 238-
7199.

SUPPLEMENTARY INFORMATION: On April 30, 1997, the FAA issued priority 
letter AD 97-10-04 to require, before further flight, inspecting 
certain blades to determine the anodizing date for certain pocket 
assemblies installed on the blade, and if a blade has a pocket assembly 
that was anodized by Poly-Metal Company from October 1, 1996 through 
December 31, 1996, replacing it with an airworthy blade. That action 
was prompted by the discovery of a manufacturing defect that may cause 
disbonding and separation of portions of a blade. This defect is the 
result of an anodizing process, used during the manufacture of the 
pocket assembly, that did not meet the Type Design specifications. That 
condition, if not corrected, could result in disbonding and separation 
of portions of the blade, subsequent excessive vibrations, and loss of 
control of the helicopter.
    Since the issuance of that AD, Sikorsky Aircraft Corporation has 
issued Sikorsky Alert Service Bulletin (ASB) No. 61B15-29A, Revision A, 
dated May 9, 1997, which corrects two of the blade serial numbers 
listed in the ASB that were referenced in the priority letter AD.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Sikorsky Aircraft Corporation Model S-61A, D, 
E, L, N, NM, R, and V helicopters of the same type design, this AD 
supersedes AD 97-10-04 to require, before further flight, inspecting 
certain blades to determine the anodizing date for certain pocket 
assemblies installed on the blade, and if a blade has a pocket assembly 
that was anodized by Poly-Metal Company during the period of October 1, 
1996, through December 31, 1996, replacing it with an airworthy blade. 
The actions are required to be accomplished in accordance with the 
service bulletin described previously.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

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. 97-SW-18-AD.'' The postcard will be date stamped and 
returned to the commenter.

[[Page 49133]]

    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, 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 
(AD), Amendment 39-10026, to read as follows:

97-19-06 Sikorsky Aircraft Corporation: Amendment 39-10026. Docket 
No. 97-SW-18-AD. Supersedes priority letter AD 97-10-04.

    Applicability: Model S-61A, D, E, L, N, NM, R, and V 
helicopters, certificated in any category, with a main rotor blade 
assembly (blade), part number (P/N) S6115-20501 or P/N 61170-20201, 
installed, having one of the following four-digit or eight-digit 
serial numbers:

1282-1554                             3305-3106                         
2183                                  3317-3115                         
2380-2498                             3343-3147                         
2495                                  3343-3648                         
2500                                  3364-3180                         
2520                                  3451-3239                         
2521                                  3491-3278                         
2644                                  3499-3936                         
2673                                  3511-3293                         
2716-2683                             3512-3292                         
2721                                  3517-3311                         
2751                                  3525-3310                         
2781-2644                             3637-3459                         
2800-2671                             3694-3481                         
2817                                  3748-3543                         
2819                                  3752-3527                         
2839                                  3753-3528                         
2883                                  3840-3620                         
2919-2771                             3966-3737                         
3008                                  4216-4392                         
3016-2850                             4787-4793                         
3019                                  4800-4794                         
3138                                  4835-4790                         
3168-3585                             5484-5363                         
3192-2999                             5974-5816                         
3215-3012                             5981-5813                         
3216-3023                             7069-6583                         
3242-3044                             7779-7033                         
3249-3052                             8099-8054                         
3250-3043                                                               
                                                                        

    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 (b) 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 disbonding and separation of portions of the blade, 
subsequent excessive vibrations, and loss of control of the 
helicopter, accomplish the following:
    (a) Inspect each blade having one of the affected serial numbers 
in accordance with Section 2A of the Accomplishment Instructions of 
Sikorsky Alert Service Bulletin (ASB) No. 61B15-29A, Revision A, 
dated May 9, 1997, to determine the anodizing date for all blade 
trailing edge pocket assemblies (pocket assemblies) installed on the 
blade in locations as specified in the Planning Information Section, 
paragraph 1D(3) of the ASB, that were anodized by Poly-Metal 
Company. Remove any blade having a pocket assembly anodized by Poly-
Metal Company during the period from October 1, 1996 through 
December 31, 1996, and replace the blade with an airworthy blade.
    (b) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Boston Aircraft Certification Office.

    (c) A one-time only special flight permit may be issued to 
operate the helicopter to a location where the requirements of this 
AD can be accomplished, after inspecting all pocket assemblies for 
disbonding.
    (d) The inspection shall be done in accordance with Sikorsky ASB 
No. 61B15-29A, Revision A, dated May 9, 1997. This incorporation by 
reference was approved by 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: Mr. Paul Dionne, 
CAR Office, 6900 Main Street, P.O. Box 9729, Stratford, Connecticut 
06497-9129, telephone (203) 386-7860, fax (203) 386-4703. Copies may 
be inspected at the FAA, Office of the Assistant Chief Counsel, 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.
    (e) This amendment becomes effective on October 6, 1997.

    Issued in Fort Worth, Texas, on September 3, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-24075 Filed 9-18-97; 8:45 am]
BILLING CODE 4910-13-P

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