AD Amdt-39-11010

[Federal Register Volume 64, Number 16 (Tuesday, January 26, 1999)]
[Rules and Regulations]
[Pages 3819-3821]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-1351]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-20-AD; Amendment 39-11010; AD 98-11-15]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 212 
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) 98-11-15, which was sent 
previously to all known U.S. owners and operators of Bell Helicopter 
Textron, Inc. (BHTI) Model 212 helicopters by individual letters. This 
AD requires inspecting the trunnion assembly or tail rotor flapping 
stop (flapping stop), whichever is applicable, installing a trunnion 
assembly or flapping stop, if necessary; and replacing the tail rotor 
yoke (yoke). This amendment is prompted by an accident involving a BHTI 
Model 205A-1 helicopter in which the yoke failed during flight. This 
condition, if not corrected, could lead to failure of the yoke, loss of 
the tail rotor, and subsequent loss of control of the helicopter.

DATES: Effective February 10, 1999, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 98-11-
15, issued on May 19, 1998, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 10, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before March 29, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-20-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.
    The applicable service information may be obtained from Bell 
Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, 
telephone (817) 280-3391, fax (817) 280-6466. This information may be 
examined at the FAA, Office of the Regional Counsel, Southwest Region, 
2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Sandra Shelly, Aerospace Engineer, 
FAA, Rotorcraft Certification Office, Rotorcraft Directorate, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5177, fax 
(817) 222-5783.

SUPPLEMENTARY INFORMATION: On May 19, 1998, the FAA issued priority 
letter AD 98-11-15, applicable to BHTI Model 212 helicopters, which 
requires, before further flight, reviewing historical records of the 
helicopter and the yoke assembly to detect any usage or event that may 
have imposed an excessive bending load on the yoke. If such usage or 
event occurred, before further flight, this AD requires replacing the 
yoke assembly with an airworthy yoke assembly that has zero-hours TIS, 
or that has passed an x-ray diffraction inspection in accordance with 
Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) 212-96-100, 
Revision A, dated May 18, 1998, or ASB 212-96-101, dated September 3, 
1996, whichever is applicable, as well as installing an airworthy 
trunnion assembly or an airworthy flapping stop, depending on which 
part-numbered yoke assembly is installed. If no usage or event that may 
have imposed an excessive bending load on the yoke has occurred, the 
yoke must be replaced within 180 calendar days. Thereafter, at 
intervals not to exceed 25 hours TIS, or before further flight after 
any incident that may have imposed an excessive bending load on the 
yoke, this AD requires inspecting the trunnion assembly or the tail 
rotor flapping stop, whichever is applicable, for yielding. If yielding 
is detected, the yoke assembly and trunnion assembly or flapping stop, 
whichever is applicable, must be replaced. That action was prompted by 
an accident involving a BHTI Model 205A-1 helicopter in which the yoke 
failed during flight. The Model 205A-1 helicopter is similar in design 
to the Model 212 helicopter. Investigation of the accident revealed 
that the yoke assembly service life may be reduced due to unforeseen 
static and dynamic

[[Page 3820]]

loading of the tail rotor. This condition, if not corrected, could lead 
to failure of the yoke, loss of the tail rotor, and subsequent loss of 
control of the helicopter.
    The FAA has reviewed Bell Helicopter Textron, Inc. Alert Service 
Bulletin (ASB) No. 212-96-100, Revision A, dated May 18, 1998, which 
specifies inspections of the yoke assembly and trunnion assembly, and 
replacement of certain trunnion assemblies; and ASB 212-96-101, dated 
September 3, 1996, which specifies inspections of the yoke assembly, 
and installation of a tail rotor flapping stop.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other BHTI Model 212 helicopters of the same type 
design, this AD requires, before further flight, reviewing historical 
records of the helicopter and the yoke assembly to detect any usage or 
event that may have imposed an excessive bending load on the yoke. If 
such usage or event occurred, before further flight, this AD requires 
replacing the yoke assembly with an airworthy yoke assembly that has 
zero-hours TIS, or that has passed an x-ray diffraction inspection in 
accordance with ASB 212-96-100, Revision A, dated May 18, 1998, or ASB 
212-96-101, dated September 3, 1996, whichever is applicable, as well 
as installing an airworthy trunnion assembly or an airworthy flapping 
stop, depending on which part-numbered yoke assembly is installed. If 
no such usage or event has occurred, the yoke must be replaced within 
180 calendar days. Thereafter, at intervals not to exceed 25 hours TIS, 
or before further flight after any incident that may have imposed an 
excessive bending load on the yoke, this AD requires inspecting the 
trunnion assembly or the tail rotor flapping stop, whichever is 
applicable, for yielding. If yielding is detected, the yoke assembly 
and trunnion assembly or flapping stop, whichever is applicable, must 
be replaced. The actions are required to be accomplished in accordance 
with the service bulletins described previously. The short compliance 
time involved is required because the previously described critical 
unsafe condition can adversely affect the controllability and 
structural integrity of the helicopter, and the yoke assembly may need 
to be replaced 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 May 19, 1998 to all known U.S. owners and operators of BHTI 
Model 212 helicopters. These conditions still exist, and the AD is 
hereby published in the Federal Register as an amendment to Sec. 39.13 
of the Federal Aviation Regulations (14 CFR 39.13) to make it effective 
to all persons.
    The FAA estimates that 250 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 9 work hours per 
helicopter to accomplish the inspections and installations, and that 
the average labor rate is $60 per work hour. Required parts will cost 
approximately $6,637 for each yoke, $1,028 for each trunnion assembly, 
and $936 for each flapping stop per helicopter. Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$2,051,250 if both the yoke and the trunnion assembly are replaced in 
the entire fleet.

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. 98-SW-20-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, Incorporation by 
reference, 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:

AD 98-11-15 Bell Helicopter Textron Inc.: Amendment 39-11010. Docket 
No. 98-SW-20-AD.

    Applicability: Model 212 helicopters, with tail rotor yoke 
assembly, part number (P/N) 212-010-704-all dash numbers, P/N 212-010-
744-all dash numbers, or P/N 212-011-702-all dash

[[Page 3821]]

numbers, 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 (d) 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.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the tail rotor yoke (yoke), loss of the 
tail rotor, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Before further flight, review all historical records of the 
helicopter and the tail rotor yoke assembly (yoke assembly) for any 
static or dynamic incident history that could have imposed an 
excessive bending load on the yoke. If such a history exists, comply 
with paragraph (b) of this AD before further flight.

    Note 2: Examples of excessive bending loads include exposure to 
high wind gusts (such as those from rotor wash or prop blast), 
improper ground handling (in which the tail rotor blade has been 
used as a hand hold), improper feathering bearing removal (in which 
the yoke is not properly supported when pressing out bearings), a 
static ground strike of some type (such as being struck by a 
vehicle), or an incident in which a damaged tail rotor blade was 
replaced due to a blade strike.

    (b) Within the next 180 calendar days, remove the yoke assembly 
and replace it with an airworthy yoke assembly having zero hours 
time-in-service (TIS), or with an airworthy yoke assembly 
(regardless of TIS) that has passed an x-ray diffraction inspection 
in accordance with Bell Helicopter Textron, Inc. Alert Service 
Bulletin (ASB) 212-96-100, Revision A, dated May 18, 1998, or ASB 
212-96-101, dated September 3, 1996, whichever is applicable. When 
the yoke assembly is replaced, for helicopters with a yoke assembly, 
P/N 212-011-702-all dash numbers, install an airworthy tail rotor 
flapping stop, P/N 212-011-713-103 and for helicopters with yoke 
assemblies, P/N 212-010-704-all dash numbers or P/N 212-010-744-all 
dash numbers, install an airworthy trunnion assembly, P/N 212-010-
738-001. If any incident as described in paragraph (a) of this AD 
occurs after the effective date of this AD and prior to compliance 
with this paragraph, then compliance with this paragraph is required 
before further flight.

    Note 3: Yoke assemblies that have passed an x-ray diffraction 
inspection at BHTI will have the letters ``FM'' vibro-etched on them 
following the serial number.

    (c) After accomplishing the requirements of paragraph (b) of 
this AD, thereafter, at intervals not to exceed 25 hours TIS, or 
before further flight after any incident as described in paragraph 
(a) of this AD, inspect the trunnion assembly and replace the yoke 
assembly and trunnion assembly, if required, in accordance with Part 
III, Paragraph 1, of ASB 212-96-100, Revision A, dated May 18, 1998; 
or inspect the tail rotor flapping stop and replace the yoke 
assembly and flapping stop, if required, in accordance with Part 
III, Paragraphs 1, 2, and 3, of ASB 212-96-101, dated September 3, 
1996, whichever is applicable.
    (d) 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, Rotorcraft Certification Office, 
Rotorcraft Directorate. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Rotorcraft Certification 
Office, Rotorcraft Directorate.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Certification Office.

    (e) Special flight permits may be issued in accordance with 
Secs. 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.
    (f) The inspection shall be done in accordance with ASB 212-96-
100, Revision A, dated May 18, 1998, or ASB 212-96-101, dated 
September 3, 1996, whichever is applicable. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, 
Texas 76101, telephone (817) 280-3391, fax (817) 280-6466. Copies 
may be inspected at the FAA, Office of the Regional Counsel, 
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on February 10, 1999, to 
all persons except those persons to whom it was made immediately 
effective by Priority Letter AD 98-11-15, issued May 19, 1998, which 
contained the requirements of this amendment.

    Issued in Fort Worth, Texas, on January 13, 1999.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-1351 Filed 1-25-99; 8:45 am]
BILLING CODE 4910-13-P