[Federal Register Volume 61, Number 174 (Friday, September 6, 1996)]
[Rules and Regulations]
[Pages 47041-47046]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22575]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-SW-08-AD; Amendment 39-9740; AD 96-18-15]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron, A Division of
Textron Canada Ltd. Model 222, 222B, 222U, and 230 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD) 96-01-08, which superseded Priority Letter AD 95-23-02, both of
which were applicable to certain serial-numbered Bell Helicopter
Textron, A Division of Textron Canada Ltd. (BHT) Model 222, 222B, 222U,
and 230 helicopters, that currently requires an initial check of both
surfaces of each tail rotor blade (blade) for cracks; an inspection of
the blade skin if a crack of a specified size or location is found in
the paint; and replacement of the blade if a crack is found in the
blade skin. This AD requires the same actions as required by the
existing AD, but expands the applicability to include additional blade
part numbers (P/N). This amendment is prompted by three incidents in
which a crack developed in the stainless steel blade skins due to
sanding marks on the blades that occurred during the manufacturing
process on BHT Model 230 helicopters, which are similar in design to
the Model 222, 222B and 222U helicopters. The actions specified by this
AD are intended to prevent failure of a blade due to a fatigue crack,
loss of the tail rotor and tail rotor gear box, and subsequent loss of
control of the helicopter.
DATES: Effective September 23, 1996.
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-08-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137.
FOR FURTHER INFORMATION CONTACT: Mr. Charles Harrison, Aerospace
Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA,
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-
5960.
SUPPLEMENTARY INFORMATION: On November 3, 1995, the FAA issued priority
letter AD 95-23-02, applicable to certain serial-numbered BHT Model
222, 222B, 222U, and 230 helicopters, to require an initial check of
both surfaces of each blade for cracks; an inspection of the blade skin
if a crack of a specified size or location was found in the paint; and
replacement of the blade if a crack was found in the blade skin. That
action was prompted by two incidents in which a crack developed in the
stainless steel blade skins on BHT Model 230 helicopters. In one of
these incidents, the blade failed during flight. Subsequent
investigation revealed fatigue cracks originating from sanding marks on
the blade skin. The cracks were located just outboard of the stainless
steel blade doubler. That condition, if not corrected, could result in
failure of a blade due to a fatigue crack, loss of the tail rotor and
tail rotor gear box, and subsequent loss of control of the helicopter.
Subsequent to the issuance of the priority letter AD, the FAA issued AD
96-01-08 to publish the
[[Page 47042]]
priority letter in the Federal Register and to correct an error in the
applicability paragraph of the priority letter AD, which incorrectly
stated the serial number (S/N) of one of the affected models. The Model
230 helicopters affected by the AD include S/N 23001 through 23038. The
priority letter AD incorrectly stated S/N 23001 through 23034.
Since the issuance of AD 96-01-08, a crack has been discovered in
the tail rotor blade of another serial-numbered Model 230 helicopter,
that originated from a small indentation that occurred during the
manufacturing process. As a result of this discovery, additional part-
numbered blades have been determined to be affected.
Since the unsafe condition described is likely to exist or develop
on other BHT Model 222, 222B, 222U, and 230 helicopters of the same
type design, this AD supersedes AD 96-01-08 to require, before further
flight, an initial visual check of both painted surfaces of each blade
for cracks. If a crack of a specified size and location is found in the
paint, removal of the paint and a visual inspection using a 10-power or
higher magnifying glass is required before further flight. If this
closer inspection reveals a crack in the blade skin, replacement of the
blade with an airworthy blade is required. If no crack is found in the
blade skin, the area from which the paint was removed is coated with a
light-weight oil or an equivalent corrosion preventive compound, and
then repetitive visual checks are required at intervals not to exceed 3
hours time-in-service (TIS). The initial visual check that is required
before further flight and the repetitive checks may be performed by a
pilot, but must be entered into the aircraft records showing compliance
with paragraph (a) of this AD in accordance with sections 43.11 and
91.417 (a)(2)(v) of the Federal Aviation Regulations (14 CFR sections
43.11 and 91.417 (a)(2)(v)). This AD allows a pilot to perform this
check because it involves only a visual check for cracking in the
painted surface of the blade skin, and can be performed equally well by
a pilot or a mechanic.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for 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 No. 96-SW08-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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive (AD), Amendment 39-9740, to read as follows:
AD 96-18-15 Bell Helicopter Textron, a Division of Textron Canada
Ltd.: Amendment 39-9740. Docket No. 96-SW08-AD. Supersedes AD 96-01-
08, issued December 21, 1995, Docket No. 95-SW-33-AD.
Applicability: Model 222 helicopters, serial numbers (S/N) 47006
through 47089, and Model 222B helicopters, S/N 47131 through 47156,
with tail rotor blades, part numbers (P/N) 222-016-001-101, -107, -
111, -113, -115, and -119; Model 222U helicopters, S/N 47501 through
47574, with tail rotor blades, P/N 222-016-001-107, -111, and -115;
and Model 230 helicopters, S/N 23001 through 23038, with tail rotor
blades, P/N 222-016-001-111 and -115, 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 (g) 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 before further flight, unless accomplished
previously. To prevent failure of a tail rotor blade (blade) due to
a fatigue crack (see Figure 1), loss of the tail rotor and tail
rotor gear box, and subsequent
[[Page 47043]]
loss of control of the helicopter, accomplish the following:
(a) Clean the painted surfaces of the blades in an area
approximately 6 inches spanwise on either side of the doubler tip.
Visually check both surfaces of each blade for cracks by pushing the
blade tip away from the surface being checked until it contacts the
flapping stop and then holding the blade firmly against the stop.
Pay particular attention to the area reaching from the doubler tip
to 1 inch outboard, centering on an area 2 inches aft of the blade
leading edge (see Figure 2).
(b) The visual check required by paragraph (a) may be performed
by an owner/operator (pilot) holding at least a private pilot
certificate, and must be entered into the aircraft records showing
compliance with paragraph (a) of this AD in accordance with sections
43.11 and 91.417(a)(2)(v) of the Federal Aviation Regulations (14
CFR sections 43.11 and 91.417(a)(2)(v)).
(c) If the visual check described in paragraph (a) reveals any
crack outboard of the doubler tip (Station 14.250), or any chordwise
crack inboard of the doubler tip that is longer than 1 inch (see
Figure 3), accomplish the following:
(1) Remove the paint from the skin in the cracked area using the
following procedures (see Figure 4):
Note 2: Paint cracking that follows the contour of the doubler
is common and requires no action.
(2) Using a 180 or 220 grit abrasion paper, sand by hand with
spanwise strokes until greenish- or yellow-colored primer or bare
metal begins to be exposed.
(3) Using spanwise or circular sanding motions, continue hand-
sanding the remaining greenish- or yellow-colored primer in the
cracked area using a 320 or 400 grit paper until sufficient metal
has been exposed to allow inspection (see area indicated in Figure
4).
(d) Inspect the blade skin for cracks in the area that was
exposed in accordance with paragraph (c) using a 10-power or higher
magnifying glass.
(1) If no crack is found in the blade skin, coat the bare metal
area with a light-weight oil or an equivalent corrosion preventive
compound.
(2) If any crack is discovered, remove the blade and replace it
with an airworthy blade.
(e) Perform the requirements of this AD upon installation of a
replacement blade.
(f) Perform the visual checks of paragraph (a) of this AD and
the subsequent inspections, if appropriate, at intervals not to
exceed 3 hours TIS.
Note 3: A light-weight oil or equivalent corrosion preventive
compound may be applied after accomplishing the repetitive
requirements of paragraph (f) of this AD.
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(g) 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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Rotorcraft Certification Office.
(h) Special flight permits to accomplish the requirements of
this AD will not be issued.
(i) This amendment becomes effective on September 23, 1996.
Issued in Fort Worth, Texas, on August 26, 1996.
Daniel P. Salvano,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-22575 Filed 9-5-96; 8:45 am]
BILLING CODE 4910-13-U
