[Federal Register Volume 59, Number 164 (Thursday, August 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-20753]


[[Page Unknown]]

[Federal Register: August 25, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-11-AD; Amendment 39-9013; AD 94-17-18]

 

Airworthiness Directives; Robinson Helicopter Company Model R44 
Series Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Robinson Helicopter Company (RHC) Model R44 series 
helicopters. This action requires removal and replacement of specific 
components of the cyclic control system. This amendment is prompted by 
an accident involving an R44 in which the probable cause was determined 
to be fatigue failure of the cyclic stick assembly. The actions 
specified in this AD are intended to prevent failure of the cyclic 
stick assembly and loss of control of the helicopter.

DATES: Effective September 9, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before October 24, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 94-SW-11-AD, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.

FOR FURTHER INFORMATION CONTACT: Ms. Lirio Liu, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, ANM-123L, 3229 E. Spring Street, 
Long Beach, California 90806-2425, telephone (310) 988-5229, fax (310) 
988-5210.

SUPPLEMENTARY INFORMATION: This amendment adopts a new airworthiness 
directive (AD) that is applicable to RHC Model R44 series helicopters. 
On July 31, 1993, a RHC Model R44 crashed shortly after takeoff. The 
helicopter had accumulated 174 hours time-in-service at the time of the 
accident. The National Transportation Safety Board (NTSB) determined 
the probable cause for the accident as fatigue failure of the cyclic 
stick assembly. After reviewing the NTSB report, the FAA finds it 
necessary to take action to remove the cyclic control system involved 
in this accident from eligibility for further flight. Of the six Model 
R44 series helicopters in the field, five have been modified to 
incorporate a revised FAA-approved cyclic control system design. The 
sixth helicopter, serial number (S/N) 0011, has not been modified. The 
cyclic control system controls the attitude of the helicopter. If it 
fails, the operator loses the ability to control inputs to the rotor. 
This condition, if not corrected, could result in failure of the cyclic 
stick assembly and loss of control of the helicopter.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other RHC Model R44 series helicopters of the same 
type design, this AD is being issued to prevent failure of the cyclic 
stick assembly and loss of control of the helicopter.
    The FAA has found that the original cyclic control system design 
fully meets existing FAA design standards, but has limited damage 
tolerance characteristics and does not display slow crack growth 
properties. When initial damage or a flaw is introduced, the cyclic 
stick assembly can fail due to fatigue prior to its retirement time of 
4,000 hours time-in-service. This AD requires immediate removal and 
replacement of specific components of the cyclic control system in 
accordance with the applicable maintenance manual.
    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. 94-SW-11-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, 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

AD 94-17-18  Robinson Helicopter Company: Amendment 39-9013. Docket 
No. 94-SW-11-AD.
    Applicability: Model R44 series helicopters, certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the cyclic stick assembly and loss of 
control of the helicopter, accomplish the following:
    (a) Before further flight after the effective date of this AD, 
remove the following cyclic control system parts and replace with 
the corresponding replacement parts in accordance with the 
applicable maintenance manual: 

------------------------------------------------------------------------
 Remove part                                                            
    Nos.                        Replace with part Nos.                  
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A205-3        A205-5 Revision J or higher.                              
C175-1        C175-2 Revision H or higher.                              
C176-1        C176-2 Revision B or higher.                              
C177-1        C177-2 Revision F or higher.                              
C319-1        C319-3 Revision I or higher.                              
C320-1        C320-1 Revision L or higher.                              
C958-4        C958-5 Revision E or higher.                              
A101-4        D173-1 Revision A or higher.                              
C338-1        C338-4 Revision C or higher.                              
A211-2        C211-3 Revision I or higher.                              
A137-1        A137-2 Revision C or higher.                              
------------------------------------------------------------------------

    (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. 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: 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 will not be issued.
    (d) This amendment becomes effective on September 9, 1994.

    Issued in Fort Worth, Texas, on August 18, 1994.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-20753 Filed 8-24-94; 8:45 am]
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