Airworthiness Directives; Robinson Helicopter Company Model R22 Helicopters

[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)] [Proposed Rules] [Pages 58578-58580] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 95-28396]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-SW-23-AD]

Airworthiness Directives; Robinson Helicopter Company Model R22 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Robinson Helicopter Company (Robinson) Model R22 helicopters. This proposal would require replacement of the upper V-belt sheave (sheave). This proposal is prompted by three reports of cracks in the flange of the sheave. The actions specified in this AD are intended to prevent failure of the sheave, which could result in damage to other drive system components, and subsequent loss of control of the helicopter.

DATES: Comments must be received by January 29, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-SW-23-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 Robinson Helicopter Company, 2901 Airport Drive, Torrance, California 90505. 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: Ms. Elizabeth Bumann, Aerospace Engineer, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd., Lakewood, California 90712, telephone (310) 627-5265, FAX (310) 627-5210.

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. 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-23-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-23-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

This document proposes the adoption of a new AD that is applicable to Robinson Model R22 helicopters. In 1990, Robinson changed the sheave, part number (P/N) A170-1I or J, and P/N A170-2J, from a casting to a machined part. This change included some dimensional modifications, one of which was a reduction in the thickness of the sheave flange. Two reported cases of cracks in the thinner flange prompted Robinson to issue Robinson Helicopter Company R22 Service Bulletin SB-71, dated June 18, 1992, describing pre-flight owner/ operator checks of the sheave for cracks until replacement with a modified sheave, P/N A170-1K or P/N A170-2K, is accomplished. This service bulletin was not reviewed or approved by the FAA prior to its issuance by Robinson. Another report of cracks in the thinner-flanged sheave prompted Robinson to issue Robinson Helicopter Company R22 Service Bulletin SB-77, dated April 25, 1995, describing procedures for removal and replacement of the thinner-flanged sheave. Any crack in the sheave creates an unsafe condition. That condition, if not corrected, could result in failure of the sheave, which could result in damage to other drive system components, and subsequent loss of control of the helicopter. The FAA has reviewed and approved the design engineering aspects of Robinson Helicopter R22 Service Bulletin SB-77, dated April 25, 1995, which describes procedures for removal and replacement of sheave, P/N A170-1I or J, or P/N A170-2J. Since an unsafe condition has been identified that is likely to exist or develop on other Robinson Model R22 helicopters of the same type design, the proposed AD would require replacement of the affected sheave with a sheave having a thicker flange within the next 100 hours time-in-service (TIS) or 60 calendar days, whichever occurs first. The actions would be required to be accomplished in accordance with the service bulletin described previously. The FAA estimates that 650 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,216 per helicopter for the sheave, P/N A170-1, and $2,298 per helicopter for the sheave, P/N A170-2. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $1,298,050, assuming replacement of the sheave in all 650 helicopters, and assuming that one-half of the helicopters have the sheave, P/N A170-1, installed, and one-half of the helicopters have the sheave, P/N A170-2, installed. 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; 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

[[Page 58580]] 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), 40101, 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

Robinson Helicopter Company: Docket No. 95-SW-23-AD. Applicability: Model R22 helicopters with upper V-belt sheave (sheave), part number (P/N) A170-1I or J, or P/N A170-2J, 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 (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.

Note 2: Determination of whether the affected sheave has been installed can be accomplished by measuring the depth from the edge of the forward retainer plate to the flange of the sheave in an area located between the webs as shown in Figure 2 of Robinson Helicopter Company R22 Service Bulletin SB-77, dated April 25, 1995. If the depth is greater than 0.30 inch, then either sheave, P/N A170-1I or J, or sheave, P/N A170-2J, is installed.

Compliance: Required as indicated, unless accomplished previously. To prevent failure of the sheave, which could result in damage to other drive system components, and subsequent loss of control of the helicopter, accomplish the following: (a) Within the next 100 hours time-in-service (TIS) or 60 calendar days, whichever occurs first after the effective date of this AD, replace the sheave, P/N A170-1I or J, or P/N A170-2J, with an airworthy sheave, P/N A170-1, or P/N A170-2, having a dimension equal to or less than 0.30 inch measured from the edge of the forward retainer plate to the flange of the sheave in an area located between the webs, in accordance with paragraphs 2 through 15 of the Compliance Procedures of Robinson Helicopter Company R22 Service Bulletin SB-77, dated April 25, 1995. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Los Angeles 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, Los Angeles 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 Los Angeles Aircraft Certification Office.

(c) 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 26, 1995. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 95-28396 Filed 11-27-95; 8:45 am] BILLING CODE 4910-13-U