AD 2000-08-04

[Federal Register Volume 65, Number 76 (Wednesday, April 19, 2000)]
[Rules and Regulations]
[Pages 20895-20896]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-9818]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-70-AD; Amendment 39-11690; AD 2000-08-04]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company Model R44 
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), 
applicable to Robinson Helicopter Company (RHC) Model R44 helicopters. 
This action requires replacing certain serial number (S/N) sprag 
clutches with an airworthy sprag clutch as specified in this AD. This 
amendment is prompted by several reports of sprag clutch failures. The 
actions specified by this AD are intended to prevent a sprag clutch 
failure, loss of main rotor RPM during autorotation, and subsequent 
loss of control of the helicopter.

DATES: Effective May 4, 2000. Comments for inclusion in the Rules 
Docket must be received on or before June 19, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-70-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Elizabeth Bumann, Aviation Safety 
Engineer, FAA, Los Angeles Aircraft Certification Office, 3960 
Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-
5265; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: On April 5, 1999, the FAA issued AD 99-07-
18, Amendment 39-11127 (64 FR 17964, April 13, 1999), to require 
inserting a Special Pilot Caution into the Rotorcraft Flight Manual 
(RFM) to alert pilots of the potential for the sprag clutch failing to 
overrun during autorotation maneuvers. The Special Pilot Caution was an 
interim measure until permanent corrective action was developed by the 
manufacturer. The FAA now believes that the affected sprag clutches 
need to be replaced within 30 days or 50 hours time-in-service (TIS), 
whichever occurs first. Since the sprag clutch is such a critical 
component of the rotor drive system, this AD requires replacing sprag 
clutch part number (P/N) C188-3, S/N 0003 through 0505, inclusive, with 
sprag clutch, P/N C188-3, S/N 0506 and higher. This amendment is 
prompted by several reports of clutch assemblies, including one from 
wreckage of an accident, with cracked or fractured sprag ends. The 
actions specified by this AD are intended to prevent a sprag clutch 
failure, loss of main rotor RPM during autorotation, and subsequent 
loss of control of the helicopter.
    The FAA has reviewed RHC Service Bulletin SB-36, dated November 5, 
1999, which describes replacing the sprag clutch, P/N C188-3, S/N 0453 
through 0505, inclusive, with sprag clutch, P/N C188-3, S/N 0506 and 
subsequent. RHC Service Bulletin SB-32, dated March 22, 1999, affected 
this same P/N, S/N 0003 through 0452.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Robinson R44 helicopters of the same type 
design, this AD is being issued to prevent a sprag clutch failure, loss 
of main rotor RPM during autorotation, and subsequent loss of control 
of the helicopter. The short compliance time involved is required 
because the previously described critical unsafe condition can 
adversely affect the controllability of the helicopter after an actual 
engine failure. Therefore, replacing sprag clutch, P/N C188-3, S/N 0003 
through 0505, inclusive, with sprag clutch, P/N C188-3, S/N 0506 and 
higher, is required within 30 calendar days or 50 hours time-in-service 
after the effective date of this AD, whichever occurs first, 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 200 helicopters will be affected by this 
proposed AD, that it will take approximately 4 work hours to replace a 
sprag clutch, and that the average labor rate is $60 per work hour. 
Required parts will cost approximately $3,600 per helicopter. Based on 
these figures, the total cost impact of the AD on U.S. operators is 
estimated to be $768,000.

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 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. 99-SW-70-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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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

[[Page 20896]]

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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

AD 2000-08-04    Robinson Helicopter Company: Amendment 39-11690. 
Docket No. 99-SW-70-AD.

    Applicability: Model R44 Helicopters, serial number (S/N) 0001 
through 0541, inclusive, 0543, 0550, 0556, and 0565 with sprag 
clutch, part number (P/N) C188-3, S/N 0003 through 0505, inclusive, 
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: Within 30 calendar days or 50 hours time-in-service, 
whichever occurs first, unless accomplished previously.
    To prevent sprag clutch failure, loss of main rotor RPM during 
autorotation, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Replace sprag clutch, P/N C188-3, S/N 0003 through 0505, 
inclusive, with sprag clutch P/N C188-3, S/N 0506 or higher.
    (b) Remove from the Rotorcraft Flight Manual the Special Pilot 
Caution, dated March 22, 1999, contained in Robinson Helicopter 
Company R44 Service Bulletin SB-32 dated March 22, 1999, or the 
Special Pilot Caution insert in the Normal Procedures Section of the 
Rotorcraft Flight Manual between pages P.4-8 and P.4-9 required by 
AD 99-07-18, Docket No. 99-SW-25-AD, Amendment 39-11127 (64 FR 
17964, April 13, 1999), as applicable.
    (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. 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 2: 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.

    (d) 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.
    (e) This amendment becomes effective on May 4, 2000.

    Issued in Fort Worth, Texas, on April 11, 2000.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-9818 Filed 4-18-00; 8:45 am]
BILLING CODE 4910-13-U