Airworthiness Directives; Bell Helicopter Textron, Inc. Model 206A, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4 Helicopters

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-SW-07-AD; Amendment 39-9031; AD 94-20-03]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

206A, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4 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) applicable to Bell Helicopter Textron, Inc. (BHTI) Model 206A,

206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4 helicopters, that

currently requires an inspection of the main rotor hub trunnion

(trunnion) for a mislocated master spline and replacement of any

trunnion that has a mislocated master spline. This amendment is

prompted by a report that certain main rotor hub trunnions (trunnions)

were manufactured with a mislocated master spline. The actions

specified by this AD are intended to identify and require replacement

of any trunnion with a mislocated master spline to prevent pitch link

misalignment, altered cyclic stick control position, loss of the main

rotor system, and subsequent loss of control of the helicopter.

DATES: Effective October 11, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of October 11, 1994.

Comments for inclusion in the Rules Docket must be received on or

before November 7, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Rules Docket No. 94-SW-07-AD, 2601 Meacham Boulevard, Room 663, Fort

Worth, Texas 76137-4298.

The service information referenced in this AD may be obtained from

Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101.

This information may be examined at the FAA, Office of the Assistant

Chief Counsel, 2601 Meacham Boulevard, Room 663, Fort Worth, Texas; or

at the Office of the Federal Register, 800 North Capitol Street, NW.,

suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Ms. Sharon Miles, Aerospace Engineer, Rotorcraft Certification Office,

FAA, Southwest Region, Rotorcraft Directorate, 2601 Meacham Boulevard,

Fort Worth, Texas 76137-4298, telephone (817) 222-5172, fax (817) 222-

5959.

SUPPLEMENTARY INFORMATION: On November 18, 1993, the FAA issued

Priority Letter AD 93-22-11, applicable to Bell Helicopter Textron,

Inc. (BHTI) Model 206A, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4

helicopters, to require an inspection of the main rotor hub trunnion

(trunnion), part number (P/N) 206-011-113-103 and P/N 206-011-120-103,

for proper positioning of the trunnion master spline and replacement of

any trunnion that had a mislocated master spline. That action was

prompted by a manufacturer's report that certain trunnions were

manufactured with a mislocated master spline. The manufacturer's data

showed that when the trunnion master spline is mislocated, the main

rotor mast does not align properly, so the operator's input to the

cyclic stick does not produce the desired result in the main rotor

system. After reviewing the manufacturer's data, the FAA determined

that any mislocated trunnion master spline creates an unsafe condition.

This condition, if not corrected, could result in pitch link

misalignment, altered cyclic stick control position, loss of the main

rotor system, and subsequent loss of control of the helicopter.

Since the issuance of that AD, BHTI has issued a revised Alert

Service Bulletin (ASB) for Model 206L, 206L-1, 206L-3, and 206L-4

helicopters. ASB 206L-93-90, Revision A, dated November 9, 1993,

changed Figure 3 to show that the center line of the trunnion should go

through the crown rather than the inset of the master spline. ASB 206-

93-75, dated October 19, 1993, which is applicable to Model 206A, 206B,

and 206B-1 helicopters, has a correct Figure 3 showing that the center

line of the trunnion should go through the inset rather than the crown

of the master spline.

Since an unsafe condition has been identified that is likely to

exist or develop on other BHTI Model 206 helicopters of this same type

design, this AD supersedes Priority Letter AD 93-22-11 to require,

within the next 50 hours time-in-service (TIS) or 90 calendar days

after the effective date of this AD, whichever occurs first, an

inspection of the trunnion for proper positioning of the trunnion

master spline, and replacement of any trunnion that has a mislocated

master spline. The actions are required to be accomplished in

accordance with the BHTI ASB 206-93-75, dated October 19, 1993, for

Model 206A, 206B, and 206B-1 helicopters, and BHTI ASB 206L-93-90,

Revision A, dated November 9, 1993, for Model 206L, 206L-1, 206L-3, and

206L-4 helicopters, described previously. Due to the criticalness of

correct alignment of the trunnion master spline and a compliance time

that is short for some operators of frequently-used helicopters, this

rule must be issued immediately to correct an unsafe condition in

aircraft.

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and opportunity for prior

public comment hereon are impracticable, and 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 Number 94-SW-07-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, Incorporation by

reference, 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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

(AD), Amendment 39-9031, to read as follows:

AD 94-20-03 Bell Helicopter Textron, Inc., (BHTI): Amendment 39-

9031. Docket Number 94-SW-07-AD. Supersedes Priority Letter AD 93-

22-11, issued November 18, 1993.

Applicability: Model 206A, 206B, 206B-1, 206L, 206L-1, 206L-3,

and 206L-4 helicopters, equipped with main rotor hub trunnion

(trunnion), part number (P/N) 206-011-113-103 or P/N 206-011-120-

103, certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent pitch link misalignment, altered cyclic stick control

position, loss of the main rotor system, and subsequent loss of

control of the helicopter, accomplish the following:

(a) Within the next 50 hours time-in-service (TIS) or 90

calendar days after the effective date of this airworthiness

directive (AD), whichever occurs first, inspect the trunnion master

spline for proper positioning in accordance with Parts I and II of

the Accomplishment Instructions contained in BHTI Alert Service

Bulletin 206-93-75, dated October 19, 1993, for Model 206A, 206B,

and 206B-1 helicopters, and BHTI Alert Service Bulletin 206L-93-90,

Revision A, dated November 9, 1993, for Model 206L, 206L-1, 206L-3,

and 206L-4 helicopters.

(b) If the master spline is not in the proper position, before

further flight remove and replace the trunnion with an airworthy

trunnion in accordance with the provisions of the applicable

maintenance manual.

(c) 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,

FAA, 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: Information concerning the existence of approved

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

obtained from the Rotorcraft Certification Office.

(d) Special flight permits may be issued in accordance with

Sec. Sec. 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 provided there is no

interference between the pitch link clevices and the swashplate

outer ring or pitch horn lugs, through full motion of the cyclic and

collective controls.

(e) The inspection and replacement, if necessary, shall be done

in accordance with BHTI Alert Service Bulletin No. 206-93-75, dated

October 19, 1993, and Alert Service Bulletin No. 206L-93-90,

Revision A, dated November 9, 1993. This incorporation by reference

was approved by the Director of the Federal Register in accordance

with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from

Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas

76101. Copies may be inspected at the FAA, Office of the Assistant

Chief Counsel, 2601 Meacham Boulevard, Room 663, Fort Worth, Texas;

or at the Office of the Federal Register, 800 North Capitol Street,

NW., suite 700, Washington, DC.

(f) This amendment becomes effective on October 11, 1994.

Issued in Fort Worth, Texas, on September 16, 1994.

Larry M. Kelly,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 94-23441 Filed 9-22-94; 8:45 am]

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