Airworthiness directives: Sikorsky,

[Federal Register: September 17, 1999 (Volume 64, Number 180)]

[Rules and Regulations]

[Page 50442-50443]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr17se99-7]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-44-AD; Amendment 39-11317; AD 99-19-30]

RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corp. Model S76A, B, and C Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

SUMMARY: This amendment adopts a new airworthiness directive (AD) applicable to Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, B, and C helicopters. This action requires conducting a visual inspection to detect disbonding of the attachment angle between the tail gearbox forward fairing (fairing) and the pylon and replacing or repairing the attachment angles as necessary. This amendment is prompted by incidents, two in flight and eight on the ground, of fairing bonding failures. The actions specified in this AD are intended to prevent separation of the fairing, damage to the tail rotor blades, and subsequent loss of control of the helicopter.

DATES: Effective October 4, 1999.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 4, 1999.

Comments for inclusion in the Rules Docket must be received on or before November 16, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-44-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: Manager, Commercial Tech Support, 6900 Main Street, P. O. Box 9729, Stratford, Connecticut 06497-9129, phone (203) 386-7860, fax (203) 386-4703. 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: Jeffrey Lee, Aerospace Engineer, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7161, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: This amendment adopts a new airworthiness directive (AD) applicable to Sikorsky Model S-76A, B, and C helicopters. This action requires, within 50 hours time-in-service (TIS), conducting a visual inspection for disbonding on any attachment angle between the fairing and the pylon. Thereafter, a visual inspection is required at intervals not to exceed 1500 hours TIS. If a bonding failure of one square inch or larger is found on the attachment angle, this AD requires repairing or replacing the attachment angle. This amendment is prompted by incidents, two in flight and eight on the ground, of fairing bonding failures. The actions specified in this AD are intended to prevent a separation of the fairing, damage to the tail rotor blades, and subsequent loss of control of the helicopter.

The FAA has reviewed Sikorsky Alert Service Bulletin 76-55-16, dated May 12, 1999 (ASB), which describes procedures for inspecting for disbonding on the attachment angle between the fairing and the pylon and either repairing or replacing, as necessary, the attachment angle. The ASB also describes a recurring 1500-hour TIS inspection.

Since an unsafe condition has been identified that is likely to exist or develop on other Sikorsky Model S-76A, B, and C helicopters of the same type design, this AD is being issued to prevent separation of the fairing, damage to the tail rotor blades, and subsequent loss of control of the helicopter. This AD requires visually inspecting the attachment angle on each fairing for disbonding and repairing or replacing the attachment angle as appropriate. The actions are required to 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, visually inspecting the attachment angle on each fairing for disbonding and repairing or replacing the attachment angle, as appropriate, within 50 hours TIS, is required and this AD must be issued immediately.

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.

The FAA estimates that 150 helicopters will be affected by this AD, that it will take approximately 4 work hours to accomplish the inspection and 8 work hours to replace the attachment angle. The average labor rate is $60 per work hour. Required parts will cost approximately $880 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $240,000.

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

[[Page 50443]]

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 filedin 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. 99-SW-44-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, 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:

   AD 99-19-30 Sikorsky Aircraft Corporation: Amendment 39-11317. Docket No. 99-SW-44-AD.

   Applicability: Model S-76A, B, and C helicopters, 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 separation of the tail gearbox forward fairing (fairing), damage to the tail rotor blades, and subsequent loss of control of the helicopter, accomplish the following:

   (a) Within 50 hours time-in-service (TIS), conduct a visual inspection of the attachment angle on each fairing, in accordance with the Accomplishment Instructions, paragraph A, of Sikorsky Aircraft Corp. Alert Service Bulletin 76-55-16, dated May 12, 1999 (ASB).

   (b) Thereafter, at intervals not to exceed 1500 hours TIS, conduct a visual inspection of the attachment angle on each fairing in accordance with the Accomplishment Instructions, paragraph A, of the ASB.

   (c) If the visual inspection in paragraphs (a) or (b) reveals a disbond area that equals or exceeds 1.0 square inch, prior to further flight, repair or replace the attachment angle with an airworthy attachment angle in accordance with the Accomplishment Instructions, paragraph B, of the ASB.

   (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. 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.

   (e) 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.

   (f) The inspection, repair, or replacement shall be done in accordance with the Accomplishment Instructions in Sikorsky Aircraft Corp. Alert Service Bulletin 76-55-16, dated May 12, 1999. 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: Manager, Commercial Tech Support, 6900 Main Street, P. O. Box 9729, Stratford, Connecticut 06497-9129, phone (203) 386-7860, fax (203) 386-4703. 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 October 4, 1999.

   Issued in Fort Worth, Texas, on September 7, 1999. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

   [FR Doc. 99-23959Filed9-16-99; 8:45 am]

   BILLING CODE 4910-13-U