[Federal Register Volume 61, Number 94 (Tuesday, May 14, 1996)]
[Rules and Regulations]
[Pages 24218-24220]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11958]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-SW-01-AD; Amendment 39-9616; AD 96-06-12]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron, Inc. Model
47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B,
47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1,
47J, 47J-2, 47J-2A, and 47-K 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) 96-06-12 which was sent
previously to all known U.S. owners and operators of Bell Helicopter
Textron, Inc. (Bell) Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A,
47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A,
47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47-K helicopters by
individual letters. This AD requires a visual inspection of each tail
rotor blade (blade) tip, abrasion strip, blade skin, and blade butt for
corrosion or delamination. This amendment is prompted by reports that a
number of Model 47 helicopter blades were manufactured using a clad
aluminum alloy material instead of a bare aluminum alloy material. The
actions specified by this AD are intended to prevent premature
delamination or separation of the blade tip block or the abrasion
strip, which could lead to failure of the blade and subsequent loss of
control of the helicopter.
[[Page 24219]]
DATES: Effective May 29, 1996, to all persons except those persons to
whom it was made immediately effective by priority letter AD 96-06-12,
issued on March 13, 1996, which contained the requirements of this
amendment.
Comments for inclusion in the Rules Docket must be received on or
before July 15, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Assistant Chief Counsel, Attention:
Rules Docket No. 96-SW-01-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137.
FOR FURTHER INFORMATION CONTACT: Mr. Tony Nguyen, Aerospace Engineer,
Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5177; fax
(817) 222-5960.
SUPPLEMENTARY INFORMATION: On March 13, 1996, the FAA issued priority
letter AD 96-06-12, applicable to Bell Model 47B, 47B-3, 47D, 47D-1,
47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-
3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47-
K helicopters, which requires, prior to the first flight of each day,
and at intervals not to exceed 10 hours time-in-service (TIS) if the
helicopter is operated for more than 10 hours in any one day, a visual
inspection of each blade tip, abrasion strip, blade skin, and blade
butt for corrosion or delamination. That action was prompted by reports
that a number of Model 47 helicopter blades were manufactured using a
clad aluminum alloy material instead of a bare aluminum alloy material.
The shear and peel strength of bonded clad aluminum alloy is less than
the shear and peel strength of bonded bare aluminum alloy. This
condition, if not corrected, could result in premature delamination or
separation of the blade tip block or the abrasion strip, which could
lead to failure of the blade and subsequent loss of control of the
helicopter.
Since the unsafe condition described is likely to exist or develop
on other Bell Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-
1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5,
47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47-K helicopters of the same
type design, the FAA issued priority letter AD 96-06-12 to prevent
premature delamination or separation of the blade tip block or the
abrasion strip, which could lead to failure of the blade and subsequent
loss of control of the helicopter. The AD requires, prior to the first
flight of each day, and at intervals not to exceed 10 hours TIS, if the
helicopter is operated for more than 10 hours in any one day, a visual
inspection of each blade tip, abrasion strip, blade skin, and blade
butt for corrosion or delamination. If any of the inspections reveal
corrosion or delamination, removal of the blades and replacement with
airworthy blades is required.
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 March 13, 1996 to all known U.S. owners and operators of Bell
Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-
3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1,
47J, 47J-2, 47J-2A, and 47-K 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. 96-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, 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.
[[Page 24220]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive
to read as follows:
AD 96-06-12 Bell Helicopter Textron, Inc.: Amendment 39-9616.
Docket No. 96-SW-01-AD.
Applicability: Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A,
47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-
4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47-K helicopters,
with tail rotor blade assembly, part number (P/N) 047-642-117-105,
serial numbers (S/N) A-1943 through A-2068, 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 (f) 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 premature delamination or separation of the tail
rotor blade (blade) tip block or the abrasion strip, which could
lead to failure of the blade and subsequent loss of control of the
helicopter, accomplish the following:
(a) Prior to the first flight of each day, visually inspect each
blade tip, abrasion strip, blade skin and blade butt as follows:
(1) Inspect each blade tip for corrosion or delamination
adjacent to the abrasion strip and tip block.
(2) Inspect each abrasion strip for corrosion or delamination,
paying particular attention to the abrasion strip leading edge.
(3) Inspect each blade skin for corrosion, paying particular
attention to any areas of paint cracking or damage. Inspect all
bonded joints for corrosion or delamination.
(4) Inspect each blade butt around the bearings for corrosion or
delamination.
(b) Thereafter, conduct the visual inspections specified in
paragraph (a) of this AD at intervals not to exceed 10 hours time-
in-service.
(c) If the inspections required by paragraphs (a) and (b) of
this AD reveal any corrosion or delamination, replace the blade with
an airworthy blade before further flight.
(d) Installation of any airworthy tail rotor blade assembly
which has been FAA-approved for the particular Model 47 helicopter,
except for P/N 047-642-117-105 with S/N A-1943 through A-2068,
constitutes a terminating action for the requirements of this AD.
(e) Installation of tail rotor blade assembly, P/N 047-642-117-
105M, including those with S/N A-1943 through A-2068, constitutes a
terminating action for the requirements of this AD.
Note 2: Bell Helicopter Textron Alert Service Bulletin No. 47-
96-21, dated January 29, 1996, pertains to this AD.
(f) 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.
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.
(g) 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.
(h) This amendment becomes effective on May 29, 1996, to all
persons except those persons to whom it was made immediately
effective by Priority Letter AD 96-06-12, issued March 13, 1996,
which contained the requirements of this amendment.
Issued in Fort Worth, Texas, on May 3, 1996.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-11958 Filed 5-13-96; 8:45 am]
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