AD 2000-20-51

[Federal Register Volume 65, Number 216 (Tuesday, November 7, 2000)]
[Rules and Regulations]
[Pages 66604-66607]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-28236]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-51-AD; Amendment 39-11960; AD 2000-20-51]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company Model R22 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 2000-20-51, which was sent 
previously to all known U.S. owners and operators of Robinson 
Helicopter Company (RHC) Model R22 helicopters by individual letters. 
This AD requires checking the yoke half assembly (yoke) for any crack 
and replacing a cracked yoke assembly before further flight. This AD 
also requires replacing certain yokes with airworthy yokes before 
further flight after January 1, 2001. This AD is prompted by the 
discovery of cracks in the yoke. The actions specified by this AD are 
intended to detect crack formation and growth, which could result in 
separation of the yokes from the main rotor drive shaft and subsequent 
loss of control of the helicopter.

DATES: Effective November 22, 2000, to all persons except those persons 
to whom it was made immediately effective by Emergency AD 2000-20-51, 
issued on October 4, 2000, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before January 8, 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-51-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected].

FOR FURTHER INFORMATION CONTACT: Fredrick A. 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: On October 4, 2000, the FAA issued Emergency 
AD 2000-20-51, for RHC Model R22 helicopters, which requires checking 
the yoke for any crack and replacing a cracked yoke assembly before 
further flight. The Emergency AD also requires replacing certain yokes 
with airworthy yokes before further flight after January 1, 2001. That 
action was prompted by the discovery of cracks in the yokes. The 
cracked yokes were still in service and functioned for an unknown 
duration. Several lots of the yokes were machined from 2024-T3 aluminum 
billet, which has poor stress corrosion properties in the transverse 
grain directions. Clamping the yokes in place causes a preload tension 
in areas that have exposed transverse grain. When these areas are 
exposed to a corrosive environment, such as salty air, stress corrosion 
causes crack formation and growth. This condition, if not

[[Page 66605]]

corrected, could result in separation of the yokes from the main rotor 
drive shaft and subsequent loss of control of the helicopter.
    The FAA has reviewed RHC R22 Service Bulletin SB-88A, dated 
September 13, 2000, which describes procedures for determining the lot 
number for yokes, P/N A203-5, and replacing any affected yoke with 
yoke, P/N A203-7.
    Since the unsafe condition described is likely to exist or develop 
on other RHC Model R22 helicopters of the same type design, the FAA 
issued Emergency AD 2000-20-51 to detect crack formation and growth, 
which could result in separation of the yokes from the main rotor drive 
shaft and subsequent loss of control of the helicopter. The AD requires 
the following:
     Before further flight and thereafter before the first 
flight of each day, check the identified area of each yoke for a crack. 
The visual check required by the AD may be performed by an owner/
operator (pilot) but must be entered into the aircraft records showing 
compliance with paragraph (a) of the AD in accordance with 14 CFR 43.11 
and 91.417(a)(2)(v). The AD allows a pilot to perform this check 
because it involves only a visual check for a crack in the yoke and can 
be performed equally well by a pilot or a mechanic.
     If a yoke has a crack, before further flight, replace the 
yokes with airworthy yokes, P/N A203-7. Both yokes must be replaced 
with yoke, P/N A203-7.
     Before further flight after January 1, 2001, determine the 
lot identifier for each yoke, P/N A203-5, and replace any affected 
yokes, P/N A203-5, with yokes, P/N A203-7.
    Determining that the installed yokes are not in the lots affected 
by this AD or replacing both yokes, P/N A203-5, with yokes, P/N A203-7, 
is terminating action for the requirements of this AD. The short 
compliance time involved is required because the previously described 
critical unsafe condition can adversely affect the structural integrity 
and controllability of the helicopter. Therefore, checking the yoke for 
any crack and replacing any cracked yoke are required before further 
flight, and this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on October 4, 2000 to all known U.S. owners and operators of RHC 
Model R22 helicopters. These conditions still exist, and the AD is 
hereby published in the Federal Register as an amendment to section 
39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it 
effective to all persons. However, one minor editorial correction is 
made in this AD. The note concerning existing alternative methods of 
compliance was incorrectly numbered in the emergency AD. This AD 
corrects that Note number as NOTE 3. The FAA has determined that this 
change will neither increase the economic burden on any operator nor 
increase the scope of the AD.
    The FAA estimates that 1305 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 0.3 work hour per 
helicopter to check both yokes and 0.5 work hour to replace both yokes. 
The average labor rate is $60 per work hour. Required parts will cost 
approximately $150 per helicopter (two yokes). Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$258,390, assuming each helicopter is inspected once and both yokes are 
replaced on all helicopters.

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 mailed 
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. 2000-SW-51-AD.'' The postcard will be date 
stamped and returned to the commenter.
    The regulations adopted herein will 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 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 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 
FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham 
Blvd., Room 663, Fort Worth, Texas.

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 
to read as follows:

2000-20-51  Robinson Helicopter Company: Amendment 39-11960. Docket 
No. 2000-SW-51-AD.

    Applicability: Model R22 helicopters, with a yoke half assembly 
(yoke), Part number(P/

[[Page 66606]]

N) A203-5, 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 (f) 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 failure of a yoke, separation of a yoke from the main 
rotor drive shaft, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Before further flight and thereafter before the first flight 
of each day, check each yoke for a crack. See Figure A.
    (b) If a yoke is cracked, before further flight, replace the 
yokes with airworthy yokes, P/N A203-7. Both yokes must be replaced 
with yokes, P/N A203-7.
    (c) Before further flight after January 1, 2001,
    (1) Determine the Lot identifier of each yoke.
    (2) If the Lot identifier is from 24 through 43, if it is a 
letter code, or if it is illegible, replace yokes, P/N A203-5, with 
airworthy yokes, P/N A203-7. Yoke, P/N A203-7, cannot be installed 
with yoke, P/N A203-5.

    Note 2: Robinson Helicopter Company R22 Service Bulletin SB-88A, 
dated September 13, 2000, pertains to the subject of this AD.

    (d) The visual check required by paragraph (a) may be performed 
by an owner/operator (pilot) holding at least a private pilot 
certificate and must be entered into the aircraft records showing 
compliance with paragraph (a) in accordance with 14 CFR 43.11 and 
91.417(a)(2)(v).
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[GRAPHIC] [TIFF OMITTED] TR07NO00.026

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    (e) Determining that the installed yokes, P/N A203-5, are not in 
the lots affected by this AD, or replacing yokes, P/N A203-5, with 
yokes, P/N A203-7, is terminating action for the requirements of 
this AD.
    (f) 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, 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.

    (g) Special flight permits will not be issued.
    (h) This amendment becomes effective on November 22, 2000, to 
all persons except those persons to whom it was made immediately 
effective by Emergency AD 2000-20-51, issued October 4, 2000, which 
contained the requirements of this amendment.


[[Page 66607]]


    Issued in Fort Worth, Texas, on October 27, 2000.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-28236 Filed 11-6-00; 8:45 am]
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