Airworthiness Directives; Bell Helicopter Textron, Inc. Model 206A and 206B Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-16-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

206A and 206B Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of Proposed Rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing

airworthiness directive (AD), applicable to Bell Helicopter Textron,

Inc. (BHTI) Model 206A and 206B helicopters, that currently requires an

inspection of the main transmission input driveshaft assembly

(driveshaft) at intervals of 300 hours time-in-service (TIS); the

application of a zinc chromate primer inspection visual aid; and, daily

visual checks of the driveshaft. This action would require inspections

of the driveshaft at intervals of 300 hours TIS; the application of a

self-adhesive temperature indicator visual inspection aid; and,

preflight visual owner/operator (pilot) checks of the driveshaft. This

proposal is prompted by recent studies that indicate that self-adhesive

temperature indicators are a more reliable means of detecting overheat

conditions on grease-lubricated couplings than the zinc chromate

primers that are currently in use. The actions specified by the

proposed AD are intended to prevent failure of the driveshaft due to

coupling wear or overheating, which could result in loss of power to

the main rotor and a subsequent forced emergency landing.

DATES: Comments must be received by November 7, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Office of the Assistant Chief Counsel, Attention:

Rules Docket No. 94-SW-16-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., Product Support Dept.,

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. Jurgen Priester, Aerospace

Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA,

Fort Worth, Texas 76193-0170, telephone (817) 222-5159; 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. 94-SW-16-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. 94-SW-16-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas

76137.

Discussion

On January 26, 1981, the FAA issued AD 81-04-08, Amendment 39-4037

(46 FR 12469, February 17, 1981), to require an inspection of the

driveshaft at intervals of 300 hours TIS; the application of a zinc

chromate primer

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inspection visual aid; and, daily visual checks of the driveshaft that

may be performed by the pilot. That action was prompted by reports of

excessive wear and failures of the driveshaft. The requirements of that

AD are intended to prevent failure of the driveshaft due to coupling

wear or overheating, which would result in loss of power to the main

rotor and a forced emergency landing.

Since the issuance of that AD, manufacturer's studies have shown

that self-adhesive temperature indicators are a more reliable means of

detecting overheat conditions on grease-lubricated couplings than zinc

chromate primers. BHTI has issued Alert Service Bulletin (ASB) No. 206-

93-76, Revision B, dated September 6, 1994, which describes procedures

for the application of a self-adhesive temperature indicator, as well

as for repetitive visual checks of the driveshaft for grease leakage

from the grease-lubricated couplings, overheating, and security of the

clamps and bolts used to attach the driveshaft to transmission and

engine couplings. The checks described in this proposal before the

first flight of each day may be performed by a pilot, but must be

entered into the aircraft records showing compliance with the AD in

accordance with sections 43.11 and 91.417(a)(2)(v) of the Federal

Aviation Regulations. This notice proposes to allow a pilot to perform

these checks because they involve only a visual check for grease

leakage, overheating, and security of the clamps and bolts used to

attach the driveshaft to transmission and engine couplings. These

checks can be performed equally well by a pilot or a mechanic. They

involve checking items similar to those items that a pilot checks

during a preflight check. This notice proposes that a mechanic inspect

the driveshaft and driveshaft couplings at intervals of 300 hours TIS.

Since an unsafe condition has been identified that is likely to

exist or develop on other BHTI Model 206A and 206B helicopters of the

same type design, the proposed AD would supersede AD 81-04-08 to

require inspections of the driveshaft at intervals of 300 hours TIS;

the application of a self-adhesive visual over-temperature indicator;

and, preflight visual pilot checks of the driveshaft. The actions would

be accomplished in accordance with BHTI ASB No. 206-93-76, Revision B,

dated September 6, 1994, described previously.

The FAA estimates that 4,312 helicopters of U.S. registry would be

affected by this proposed AD, that it would take approximately one and

one-half work hours per helicopter to accomplish the proposed actions,

and that the average labor rate is $60 per work hour. Required parts

would be provided by the manufacturer at no charge, but installation

materials would cost approximately $10 per helicopter. Based on these

figures, the total cost impact of the proposed AD on U.S. operators is

estimated to be $431,200.

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

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 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 U.S.C. 106(g), 40101, 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-4037 (46 FR

12469, February 17, 1981), and by adding a new airworthiness directive

(AD), to read as follows:

Bell Helicopter Textron, Inc.: Docket No. 94-SW-16-AD. Supersedes AD

81-04-08, Amendment 39-4037.

Applicability: Model 206A and 206B helicopters, 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 (e) 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 failure of the main transmission input driveshaft

assembly (driveshaft) due to coupling wear or overheating, which

could result in loss of power to the main rotor and a subsequent

forced emergency landing, accomplish the following:

(a) Before the first flight of each day after the effective date

of this AD, visually check the driveshaft, part number (P/N) 206-

040-100-13, for: (1) Grease leakage from the driveshaft coupling, P/

N 206-040-108-005; and (2) visual damage and security of the clamps

and bolts used to attach the driveshaft to the transmission and

engine couplings. After compliance with paragraph (d) of this AD,

also check the self-adhesive visual over-temperature indicators

(over-temperature indicators) for overheating, deterioration,

debonding, or discoloration in accordance with Part II of the

Accomplishment Instructions of Bell Helicopter Textron, Inc. (BHTI)

Alert Service Bulletin (ASB) No. 206-93-76, Revision B, dated

September 6, 1994. If any grease leakage exists, or if there are

indications of overheating, disassemble and inspect the driveshaft

in accordance with the applicable maintenance manual, and replace

the over-temperature indicators in accordance with Part III of the

Accomplishment Instructions of BHTI ASB 206-93-76, Revision B, dated

September 6, 1994.

(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 this AD in accordance with sections 43.11 and

91.417(a)(2)(v) of the Federal Aviation Regulations.

(c) Inspect and lubricate the driveshaft assembly, P/N 206-040-

100-13, and driveshaft grease-lubricated couplings, P/N 206-040-108-

005, in accordance with the helicopter's maintenance manual and

according to the compliance schedule that follows, and thereafter,

inspect and lubricate at intervals not to exceed 300 hours time-in-

service (TIS):

(1) For helicopters with 250 hours TIS or more, compliance is

required within the next 50 hours TIS; or,

[[Page 46792]]

(2) For helicopters with less than 250 hours TIS, compliance is

required prior to attaining 300 hours TIS.

(d) Install the over-temperature indicators at the next 300

hours TIS driveshaft coupling inspection and lubrication in

accordance with Part I of the Accomplishment Instructions of BHTI

ASB 206-93-76, Revision B, dated September 6, 1994.

(e) 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,

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 2: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Rotorcraft Certification Office.

(f) 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 August 31, 1995.

Daniel P. Salvano,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 95-22338 Filed 9-7-95; 8:45 am]

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