[Federal Register Volume 61, Number 174 (Friday, September 6, 1996)]
[Rules and Regulations]
[Pages 47047-47049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22573]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-SW-11-AD; Amendment 39-9741; AD 96-12-26 ]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. 
Manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-
1F, UH-1H, UH-1L, and UH-1P 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) AD 96-12-26 which was sent 
previously to all known U.S. owners and operators of Bell Helicopter 
Textron, Inc. (BHTI) manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-
1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters by 
individual letters. This AD requires a visual inspection of each tail 
rotor (T/R) blade (blade) for peeling, flaking, or bubbling paint that 
may indicate corrosion; an inspection for corrosion, if necessary; and 
replacement of the T/R blade with an airworthy blade if corrosion is 
discovered. This amendment is prompted by an FAA determination, based 
on the manufacturer's data, that certain serial-numbered T/R blades 
were manufactured with internal leading edge doublers fabricated from 
clad aluminum instead of bare aluminum material. The actions specified 
by this AD are intended to prevent debonding of the main spar internal 
leading edge doubler, which could lead to failure of a T/R blade and 
subsequent loss of control of the helicopter.


[[Page 47048]]


DATES: Effective September 23, 1996, to all persons except those 
persons to whom it was made immediately effective by priority letter AD 
96-12-26 issued on June 5, 1996, which contained the requirements of 
this amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before November 5, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 96-SW-11-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.

FOR FURTHER INFORMATION CONTACT: Mr. Charles Harrison, Aerospace 
Engineer, Rotorcraft Certification Office, 2601 Meacham Blvd., Fort 
Worth, Texas 76137, telephone (817) 222-5447, fax (817) 222-5960.

SUPPLEMENTARY INFORMATION: On June 5, 1996, the FAA issued priority 
letter AD 96-12-26, applicable to BHTI-manufactured Model AH-1, HH-1K, 
TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P 
helicopters, which requires a visual inspection of each T/R blade for 
peeling, flaking, or bubbling paint that may indicate corrosion; an 
inspection for corrosion, if necessary; and, replacement of the T/R 
blade with an airworthy blade if corrosion is discovered. That action 
was prompted by an FAA determination, based on the manufacturer's data, 
that certain serial-numbered T/R blades were manufactured with internal 
leading edge doublers fabricated from clad aluminum instead of bare 
aluminum material. This condition, if not corrected, could result in 
debonding of the main spar leading edge doubler, which could lead to 
failure of a T/R blade and subsequent loss of control of the 
helicopter.
    Since the unsafe condition described is likely to exist or develop 
on other BHTI-manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-
1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters of the same type 
design, the FAA issued priority letter AD 96-12-26, to inspect for 
debonding of the main spar internal leading edge doubler, which could 
lead to failure of a T/R blade and subsequent loss of control of the 
helicopter. The AD requires, within 10 hours time-in-service (TIS) 
after the effective date of this AD, and thereafter at intervals of not 
more than 7 calendar days, a visual inspection of the each T/R blade 
for peeling, flaking, or bubbling paint that may indicate corrosion, or 
corrosion along the bond lines viewed from the root and tip ends of the 
blade, and at the abrasion strip bond line on both sides of the blade 
from the root to the tip. If peeling, flaking, or bubbling paint is 
discovered, the paint in the affected area must be removed and the 
blade must be inspected for corrosion. If corrosion is discovered in 
the affected areas, the blade must be removed and replaced with an 
airworthy blade.
    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 June 5, 1996 to all known U.S. owners and operators of BHTI-
manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-
1F, UH-1H, UH-1L, and UH-1P 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.

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. 96SW-11-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, 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 USC 106(g), 40113, 44701.

[[Page 47049]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

AD 96-12-26  California Department of Forestry; Erickson Air Crane 
Co.; Garlick Helicopters; Hawkins and Powers Aviation, Inc.; 
International Helicopters, inc.; Smith Helicopters; Southwest 
Florida Aviation; West Coast Fabrications; Western International 
Aviation, Inc.; Williams Helicopter Technology, Inc.; and UNC 
Helicopters: Amendment 39-9741. Docket No. 96-SW-11-AD.

    Applicability: Bell Helicopter Textron, Inc.manufactured Model 
AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, 
and UH-1P helicopters, with tail rotor (T/R) blade (blade), part 
number (P/N) 204-011-702-015 or -121, serial numbers (S/N) A-20262 
through A-20268, A-20270 through A-20282, A-20284 through A-20287, 
A-20289 through A-20422, A-20424 through A-20428, A-20430 through A-
20433, A-20435 through A-20464, A-20466 through A-20497, A-20499 
through A-21019, A-21027 through A-21031, A-21041, A-21047, A-21049 
and A-21059, 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 debonding of the main spar internal leading edge 
doubler, which could lead to failure of a T/R blade and subsequent 
loss of control of the helicopter, accomplish the following:
    (a) Within 10 hours time-in-service (TIS) after the effective 
date of this AD, and thereafter at intervals of not more than 7 
calendar days, clean each T/R blade using a mild detergent and water 
to remove soot and grime.
    (b) Visually inspect each T/R blade for peeling, flaking, or 
bubbling paint, or corrosion along the bond lines viewed from the 
root and tip ends of the blade, and at the abrasion strip bond line 
on both sides of the blade from the root to the tip.
    (c) If the visual inspection indicates peeling, flaking, or 
bubbling paint, remove the paint from the affected area and perform 
a visual inspection for corrosion.
    (1) If no corrosion is noted, refinish the blade.
    (2) If corrosion is noted in the bond lines of the affected 
areas, remove the blade and replace it with an airworthy blade. 
Replacement with an airworthy blade that has a serial number not 
listed in the Applicability section of this AD constitutes a 
terminating action for this AD.

    Note 2: Bell Helicopter Textron, Inc. ASB No. 204-9648, Revision 
A, dated February 12, 1996, which pertains to Model 204B 
helicopters, also pertains to this AD.

    (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, FAA. 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 3: 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) This amendment becomes effective on September 23, 1996, to 
all persons except those persons to whom it was made immediately 
effective by priority letter AD 96-12-26, issued June 5, 1996, which 
contained the requirements of this amendment.

    Issued in Fort Worth, Texas, on August 26, 1996.
Daniel P. Salvano,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-22573 Filed 9-5-96; 8:45 am]
BILLING CODE 4910-13-U