AD Amdt-39-11011

[Federal Register Volume 64, Number 16 (Tuesday, January 26, 1999)]
[Rules and Regulations]
[Pages 3823-3825]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-1430]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-21-AD; Amendment 39-11011; AD 98-11-14]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
205A-1 and 205B Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 98-11-14 which was sent 
previously to all known U.S. owners and operators of Bell Helicopter 
Textron, Inc. (BHTI) Model 205A-1 and 205B 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-
14, 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-21-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

[[Page 3824]]

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: Harry Edmiston, Aerospace Engineer, 
FAA, Rotorcraft Certification Office, Rotorcraft Directorate, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5158, fax 
(817) 222-5783.

SUPPLEMENTARY INFORMATION: On May 19, 1998, the FAA issued Priority 
Letter AD 98-11-14, applicable to BHTI Model 205A-1 and 205B 
helicopters, which requires, before further flight, reviewing 
historical records of the helicopter and 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, the 
priority letter AD requires replacing the yoke assembly with an 
airworthy yoke assembly that has zero-hours time-in-service (TIS) or 
that has passed an x-ray diffraction inspection in accordance with 
BHTI's service bulletins, 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 flapping stop, whichever is applicable, for yielding. If yielding 
is detected, replacing the yoke assembly and trunnion assembly or 
flapping stop, whichever is applicable, is required. That action was 
prompted by an accident involving a BHTI Model 205A-1 helicopter in 
which the yoke failed during flight. Investigation of the accident 
revealed that the yoke assembly service life may be reduced due to 
unforeseen static and dynamic 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. 205-96-68, Revision A, dated May 18, 1998, which 
specifies inspecting the yoke and trunnion assemblies, and replacing 
certain trunnion assemblies; and ASB 205-96-69 and ASB 205B-96-25, both 
dated September 3, 1996, which specify inspecting the yoke assembly and 
installing a flapping stop.
    Since the unsafe condition described is likely to exist or develop 
on other BHTI Model 205A-1 and 205B helicopters of the same type 
design, the FAA issued Priority Letter AD 98-11-14 to prevent failure 
of the yoke, loss of the tail rotor, and subsequent loss of control of 
the helicopter. The AD requires, before further flight, reviewing 
historical records of the helicopter and 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, this AD requires, before further 
flight, 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) 205-96-68, Revision A, dated May 18, 1998, or 
ASB 205-96-69 or ASB 205B-96-25, both 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 flapping stop, whichever is applicable, for yielding. If yielding 
is detected, replacing the yoke assembly and trunnion assembly or 
flapping stop, whichever is applicable, is required. 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 both the controllability and structural integrity of 
the helicopter. Therefore, the previously-stated actions are required 
prior to 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 May 19, 1998 to all known U.S. owners and operators of BHTI 
Model 205A-1 and 205B 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.
    The FAA estimates that 495 helicopters of U.S. registry will be 
affected by this AD; that it will take approximately 9 work hours per 
helicopter to conduct the inspections, install the trunnion assembly or 
flapping stops, and replace the yoke; and that the average labor rate 
is $60 per work hour. Required parts will cost approximately $1,028 for 
a trunnion assembly or $936 for the flapping stops and $6,637 for the 
yoke, per helicopter. Based on these figures, the total cost impact of 
the AD on U.S. operators is estimated to be $4,061,475 to replace both 
the trunnion assembly and the yoke 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-21-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

[[Page 3825]]

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:

98-11-14  Bell Helicopter Textron, Inc.: Amendment 39-11011. Docket 
No. 98-SW-21-AD.

    Applicability: Model 205A-1 helicopters, with tail rotor yoke 
assembly, part number (P/N) 212-011-702-all dash numbers, or P/N 
212-010-704-all dash numbers, or P/N 212-010-744-all dash numbers, 
and Model 205B helicopters, with tail rotor yoke assembly, P/N 212-
011-702-all dash 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. An overload may also occur 
dynamically during a power-on or power-off sudden stoppage incident 
or hard landing.

    (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) 205-96-68, Revision A, dated May 18, 1998, or ASB 
205-96-69 or ASB 205B-96-25, both 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 205-96-68, Revision A, dated May 18, 1998; 
or inspect the flapping stop and replace the yoke assembly and 
flapping stop, if required, in accordance with Part III, Paragraphs 
1, 2, and 3, of ASB 205-96-69 or ASB 205B-96-25, both 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 
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.
    (f) The repetitive inspections shall be done in accordance with 
Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) No. 205-
96-68, Revision A, dated May 18, 1998, which specifies inspections 
of the yoke and trunnion assemblies, and replacement of certain 
trunnion assemblies; and ASB 205-96-69 and ASB 205B-96-25, both 
dated September 3, 1996, which specify inspections of the yoke 
assembly and installation of a flapping stop. 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 from 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 98-11-14, issued May 19, 1998, which 
contained the requirements of this amendment.

    Issued in Fort Worth, Texas, on January 14, 1999.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-1430 Filed 1-25-99; 8:45 am]
BILLING CODE 4910-13-P