[Federal Register Volume 59, Number 154 (Thursday, August 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18906]


[[Page Unknown]]

[Federal Register: August 11, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-SW-01-AD; Amendment 39-8978; AD 94-15-07]

 

Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 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 Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 
206L-1, 206L-3, and 206L-4 series helicopters. This action requires a 
one-time inspection for cracks in a portion of the main rotor blade 
(blade) trailing edge and the inboard trim tab, and replacement of the 
blade or trim tab as necessary. This amendment is prompted by reports 
of cracks in the blade trailing edge near the inboard trim tab. The 
actions specified in this AD are intended to prevent failure of a main 
rotor blade and subsequent loss of control of the helicopter.

DATES: Effective August 26, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 26, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before October 11, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 94-SW-01-AD, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137-4298.
    The service information referenced in this AD may be obtained from 
Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101. 
This information may be examined at the FAA, Office of the Assistant 
Chief Counsel, 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: Ms. Sharon Miles, Aerospace Engineer, 
Rotorcraft Certification Office, FAA, Rotorcraft Directorate, ASW-170, 
2601 Meacham Blvd., Fort Worth, Texas 76137-4298, telephone (817) 222-
5172, fax (817) 222-5959.

SUPPLEMENTARY INFORMATION: This amendment adopts a new airworthiness 
directive (AD) that is applicable to Bell Helicopter Textron, Inc. 
(BHTI) Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 series 
helicopters. Reports indicate that cracks have occurred in the blade 
trailing edge at the inboard trim tab radius affecting the upper and 
lower trim tabs. In one instance, the crack propagated through the 
trailing edge strip, through both the upper and lower blade skins, and 
forward to the blade spar. Field and laboratory investigations revealed 
that the cracks started at sanding or grinding marks in the trim tab 
radius areas. The FAA has reviewed the reports and determined that 
cracks in the blade trailing edge or the inboard trim tab could create 
an unsafe condition. This condition, if not corrected, could result in 
failure of a main rotor blade and subsequent loss of control of the 
helicopter.
    The FAA has reviewed and approved BHTI Alert Service Bulletin 206-
93-77 and Alert Service Bulletin 206L-93-92, both dated November 17, 
1993, which describe procedures for a one-time inspection for cracks in 
a portion of the blade trailing edge and the inboard trim tab within 50 
hours' time-in-service (TIS), and replacing the blade or inboard trim 
tab as necessary; or reworking the blade trailing edge and trim tab.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other BHTI Model 206A, 206B, 206L, 206L-1, 206L-3, 
and 206L-4 series helicopters of the same type design, this AD is being 
issued to prevent failure of a main rotor blade and subsequent loss of 
control of the helicopter. This AD requires, within 50 hours' TIS, a 
one-time inspection for cracks in each blade's trailing edge and 
inboard trim tab, and replacement of the blade or inboard trim tab as 
necessary or rework of the blade trailing edge and trim tab. The 
actions are required to be accomplished in accordance with the service 
bulletins described previously.
    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 Number 94-SW-01-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. 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 94-15-07  Bell Helicopter Textron, Inc. (BHTI): Amendment 39-
8978. Docket Number 94-SW-01-AD.

    Applicability: Model 206A and 206B helicopters, equipped with 
main rotor blade (blade), part number (P/N) 206-010-200-133, having 
a serial number with prefix ``A'', and Model 206L, 206L-1, 206L-3, 
and 206L-4 helicopters, equipped with blade, P/N 206-015-001-107, 
having a serial number beginning with prefix ``A'', except for those 
blades with serial numbers listed as exempt in the ``Helicopters 
Affected'' section of BHTI Alert Service Bulletin 206-93-77, for 
Models 206A and 206B and in Alert Service Bulletin 206L-93-92, for 
Models 206L, 206L-1, 206L-3, and 206L-4, both dated November 17, 
1993, certificated in any category.
    Compliance: Required within 50 hours' time-in-service after the 
effective date of this airworthiness directive (AD), unless 
accomplished previously.
    To prevent failure of a main rotor blade and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Conduct a one-time inspection for cracks in each blade's 
inboard trim tab and trailing edge in accordance with steps 1, 2, 
and 3 of Part I of the Accomplishment Instructions of applicable 
Alert Service Bulletin (ASB) 206-93-77 or ASB 206L-93-92, both dated 
November 17, 1993.
    (1) If the blade skin is cracked, remove the blade and replace 
it with an airworthy blade before further flight.
    (2) If only the trim tab is cracked, remove the affected blade 
from the helicopter. Remove the trim tab and adhesive from the blade 
and inspect the upper and lower blade skins with a 10-power or 
higher magnifying glass in accordance with Part II of the 
Accomplishment Instructions of the applicable ASB, dated November 
17, 1993.
    (i) If the blade skin under the trim tab is cracked, remove the 
blade and replace it with an airworthy blade before further flight.
    (ii) If no crack is detected in the blade skin, polish out all 
marks on the blade in accordance with Part II, step 4 of the 
Accomplishment Instructions of the applicable ASB, dated November 
17, 1993, and inspect and install a new trim tab in accordance with 
Part II, steps 5-9 of the Accomplishment Instructions of the 
applicable ASB, dated November 17, 1993.
    (3) If no crack is found in the inboard trim tab or the blade 
trailing edge by the inspections required by paragraphs (1) and (2), 
before further flight, inspect the plan-form radii of the trim tab 
where the trim tab intersects the trailing edge in accordance with 
Part I, steps 4-6, of the Accomplishment Instructions of the 
applicable ASB, dated November 17, 1993.
    (i) If a crack is found in the plan-form radii of the inboard 
trim tab, before further flight, remove the blade and replace it 
with an airworthy blade.
    (ii) If no crack is found in the plan-form radii of the trim 
tab, polish and refinish the blade in accordance with Part I, steps 
8-11, of the Accomplishment Instructions of the applicable ASB, 
dated November 17, 1993.
    (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, Rotorcraft Certification Office, 
FAA, 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.

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

    (c) 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.
    (d) The inspection, rework, and replacement, if necessary, shall 
be done in accordance with BHTI Alert Service Bulletin 206-93-77 or 
Alert Service Bulletin 206L-93-92 as applicable, both dated November 
17, 1993. 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. Copies may be 
inspected at the FAA, Office of the Assistant Chief Counsel, 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.
    (e) This amendment becomes effective on August 26, 1994.

    Issued in Fort Worth, Texas, on July 14, 1994.
James D. Erickson,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-18906 Filed 8-10-94; 8:45 am]
BILLING CODE 4910-13-P