[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