[Federal Register Volume 60, Number 211 (Wednesday, November 1, 1995)]
[Proposed Rules]
[Pages 55495-55496]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-27000]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-SW-26-AD]


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
214ST Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Bell Helicopter Textron, Inc. 
(BHTI) Model 214ST helicopters with certain tailboom assemblies and a 
certain emergency float kit installed. This proposal would require 
initial and repetitive inspections of the tailboom for cracks until 
modifications of the tailboom are accomplished. This proposal is 
prompted by several reports of cracks in the lower aft skin of the 
tailboom assembly. The actions specified by the proposed AD are 
intended to prevent cracks in the tailboom assembly, which could result 
in structural failure of the tailboom and subsequent loss of control of 
the helicopter.

DATES: Comments must be received by January 2, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 95-SW-26-AD, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137. Comments may be inspected at this location between 9:00 
a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Bell Helicopter Textron, Inc., Attention: Customer 
Support, 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.

FOR FURTHER INFORMATION CONTACT: Mr. Tom Henry, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5158, fax 
(817) 222-5959.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 95-SW-26-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Office of the Assistant Chief Counsel, Attention: Rules 
Docket No. 95-SW-26-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 
76137.

Discussion

    This document proposes to adopt a new AD that is applicable to BHTI 
Model 214ST helicopters, serial number (S/N) 28101 through 28132, with 
a tailboom assembly, part number (P/N) 214-031-003-111 or 214-031-003-
277, and with an emergency float kit, P/N 214-706-120, installed. There 
have been reports of cracks found in five Model 214ST helicopter 
tailbooms with the emergency float kit installed. The cracks were found 
in the lower aft skin between boom stations 243.76 and 284.38. This 
condition, if not corrected, could result in structural failure of the 
tailboom and subsequent loss of control of the aircraft.
    The FAA has reviewed Bell Helicopter Textron, Inc. Alert Service 
Bulletin 214ST-95-72 (ASB), dated July 24, 1995, which describes 
procedures for a visual inspection of the affected tailboom area of 
Model 214ST helicopters with emergency float kits installed. The ASB 
also describes a modification to the helicopters that adds internal 
stiffeners and doublers to the tailboom, and replaces the existing 
access door frame, P/N 214-030-325, with a redesigned frame of 
increased thickness.
    Since an unsafe condition has been identified that is likely to 
exist or develop on certain other BHTI Model 214ST helicopters of the 
same type design, the proposed AD would require, for Model 214ST 
helicopters, S/N 28101 through 28132, with a tailboom assembly, P/N 
214-031-003-111 or 214-031-003-277, and with an emergency float kit, P/
N 214-706-120, installed, inspections of the tailboom assembly for 
cracks within 250 hours time-in-service (TIS) or at the next 180-day 
float inspection, and thereafter, at each 180-day float inspection 
until certain modifications of the tailboom are accomplished. The 
modifications, which are to be accomplished if any crack is found in 
the tailboom or on or before accumulating an additional 500 hours TIS 
after the effective date of this AD, whichever occurs first, include 
installing stiffeners and doublers in the tailboom, and replacing the 
access door frame with a thicker access door frame. The actions would 
be required to be accomplished in accordance with the procedures 
contained in BHTI Alert Service Bulletin (ASB) 214ST-95-72, dated July 
24, 1995.
    The FAA estimates that six helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 20 work 

[[Page 55496]]
hours per helicopter to accomplish the modifications, approximately 3 
work hours per helicopter to accomplish the 250 hours TIS inspection, 
and that the average labor rate is $60 per work hour. Required parts 
would cost approximately $1,100 per helicopter. Based on these figures, 
the total cost impact of the proposed AD on U.S. operators is estimated 
to be $14,880.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:
Bell Helicopter Textron, Inc. (BHTI): Docket No. 95-SW-26-AD.

    Applicability: Model 214ST helicopters, serial number (S/N) 
28101 through 28132, with a tailboom assembly, part number (P/N) 
214-031-003-111 or 214-031-003-277 and with an emergency float kit, 
P/N 214-706-120, 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 cracks in the tailboom assembly, structural failure 
of the tailboom and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Within the next 250 hours time-in-service (TIS) or at the 
next 180-day float inspection, whichever occurs first, and 
thereafter at intervals not to exceed each 180-day float inspection, 
visually inspect the tailboom assembly for cracks in accordance with 
the maintenance procedures contained in Part 1 of the Accomplishment 
Instructions of BHTI Alert Service Bulletin 214ST-95-72, dated July 
24, 1995.
    (b) Upon discovery of a crack or on or before accumulating an 
additional 500 hours TIS after the effective date of this AD, 
whichever occurs first, modify the tailboom assembly in accordance 
with Part 2 of the Accomplishment Instructions of BHTI Alert Service 
Bulletin No. 214ST-95-72, dated July 24, 1995.
    (c) Modification of the tailboom assembly in accordance with 
paragraph (b) constitutes terminating action for the requirements of 
this AD.
    (d) 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. 
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 2: 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.

    Issued in Fort Worth, Texas, on October 23, 1995.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 95-27000 Filed 10-31-95; 8:45 am]
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