Airworthiness Directives; Bell Helicopter Textron, A Division of Textron Canada Ltd. Model 222, 222B, 222U, and 230 Helicopters

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(AD) 96-01-08, which superseded Priority Letter AD 95-23-02, both of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]

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