[Federal Register Volume 66, Number 122 (Monday, June 25, 2001)]
[Proposed Rules]
[Pages 33653-33654]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-15795]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-67-AD]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company Model R44 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for Robinson Helicopter Company (RHC) Model R44 helicopters. This 
proposal would require establishing a life limit of 2200 hours time-in-
service (TIS) for affected horizontal stabilizers. This proposal is 
prompted by engineering analysis, which indicates that certain 
vertical-to-horizontal stabilizer attach channels (channels) will crack 
sooner than the original life limit of the horizontal stabilizer. The 
actions specified by the proposed AD are intended to prevent a crack 
through a channel, separation of the stabilizers, and subsequent loss 
of directional control of the helicopter.

DATES: The FAA must receive any comments on this proposal by August 24, 
2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2000-SW-67-AD, Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. You may also send comments electronically to 
the Rules Docket at the following address: [email protected]. 
Comments may be inspected at the Office of the Regional Counsel between 
9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Fred Guerin, Aviation Safety Engineer, 
FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 
Paramount Blvd., Lakewood, California 90712, telephone (562) 627-5232, 
fax (562) 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 will 
be considered before taking action on the proposed rule. The proposals 
contained in this document 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 mailed 
comments submitted in response to this proposal must submit a self-
addressed, stamped postcard on which the following statement is made: 
``Comments to Docket No. 2000-SW-67-AD.'' The postcard will be date 
stamped and returned to the commenter.

Discussion

    This document proposes adopting a new AD for RHC Model R44 
helicopters to require establishing a life limit of 2200 hours TIS for 
affected horizontal stabilizers and removing, inspecting, and replacing 
certain channels with airworthy channels. This proposal is prompted by 
engineering analysis which indicates that a fatigue crack may develop 
through the inboard attachment hole for the nutplate, part number (P/N) 
NAS697A4, on channels, P/N D283-1 and -2, sooner than the original life 
limit of 4,000 hours TIS. This condition, if not corrected, could 
result in a fatigue crack on the channels, P/N D283-1 and -2, that 
attach the vertical and horizontal stabilizers, separation of the 
vertical and horizontal stabilizers after 2200 hours TIS, and 
subsequent loss of directional control of the helicopter.
    The FAA has reviewed RHC Service Bulletin No. SB-39, dated 
September 12, 2000 (SB), which specifies replacing affected channels 
during overhaul at 2200 hours TIS. The FAA agrees that channels, P/N 
D283, with nutplate, P/N NAS697A4, are considered unairworthy after 
2200 hours TIS.
    We have identified an unsafe condition that is likely to exist or 
develop on other RHC Model R44 helicopters of these same type designs. 
The proposed AD would require the following before 2200 hours TIS:

 Removing the vertical stabilizer to inspect the nutplate on 
channels, P/N D283-1 and -2.
 Replacing channels installed with nutplate, P/N NAS697A4, with 
channels, P/N D296-1 and -2.

    This proposal would revise the Limitations section of the 
maintenance manual by establishing a life limit of 2200 hours TIS for 
stabilizer, P/N CO44-1, with channels, P/N D283-1 or -2, installed.

Regulatory Impact

    We estimate that 3 helicopters of U.S. registry would be affected 
by this proposed AD and that it would take approximately \1/2\ work 
hour per helicopter to inspect the horizontal stabilizer and replace 
channels. The average labor rate is $60 per work hour. The manufacturer 
states in the SB that there will be no charge for the parts. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $90.
    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

[[Page 33654]]

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under 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), 40113, 44701.


Sec. 39.13  [Amended]

    2. The FAA amends Sec. 39.13 by adding the following new 
airworthiness directive:

Robinson Helicopter Company: Docket No. 2000-SW-67-AD.

    Applicability: Model R44 helicopters, with horizontal stabilizer 
assembly (assembly), part number (P/N) C044-1; horizontal stabilizer 
serial number (S/N) 0009 through 0224, except S/N 0018, 0090, 0094, 
0111, 0129, 0144, 0161, 0178, 0201, and 0223, 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 
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 (c) 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 a crack through a vertical-to-horizontal stabilizer 
attach channel (channel), which can cause separation of the 
stabilizers and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Before accumulating 2200 hours time-in-service (TIS) on the 
assembly:
    (1) Remove the vertical stabilizer to inspect the nutplate on 
channels, P/N D283-1 and -2.
    (2) If the nutplates are P/N MS21086L4, no further action is 
required by this AD.
    (3) If the nutplates are P/N NAS697A4, replace the channels with 
airworthy channels, P/N D296-1 or -2.

    Note 2: Robinson Helicopter Company Service Bulletin SB-39, 
dated September 12, 2000, pertains to the subject of this AD.

    (b) This AD revises the Limitations section of the maintenance 
manual by establishing a retirement life of 2200 hours TIS for 
assembly, P/N CO44-1, with channels, P/N D283-1 or -2, with 
nutplates, P/N NAS697A4, installed.
    (c) 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, Los Angeles Aircraft Certification 
Office (LAACO), FAA. Operators shall submit their requests through 
an FAA Principal Maintenance Inspector, who may concur or comment 
and then send it to the Manager, LAACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the LAACO.

    (d) Special flight permits may be issued in accordance with 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 June 12, 2001.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 01-15795 Filed 6-22-01; 8:45 am]
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