AD 96-31523

[Federal Register Volume 61, Number 240 (Thursday, December 12, 1996)] [Proposed Rules] [Pages 65367-65369] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-31523]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-29-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model 214B, 214B-1, and 214ST 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 214B, 214B-1, and 214ST helicopters, that currently establishes a retirement life of 60,000 high-power events for the main rotor trunnion (trunnion). This proposal would require changing the method of calculating retirement life for the trunnion from high power events to a maximum accumulated Retirement Index Number (RIN). This proposal is prompted by fatigue analyses and tests that show certain trunnions fail sooner than originally anticipated because of the unanticipated higher number of lifts or takeoffs (torque events) performed with those trunnions in addition to the time-in-service (TIS) accrued under other operating conditions. The actions specified by the proposed AD are intended to prevent fatigue failure of the trunnion, which could result in loss of the main rotor and subsequent loss of control of the helicopter.

DATES: Comments must be received by February 10, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Assistant Chief Counsel, Attention: Rules Docket No. 94-SW-29-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., Attention: Product Support Department, P.O. Box 482, Fort Worth, Texas 76101.

FOR FURTHER INFORMATION CONTACT: Mr. Charles Harrison, Aerospace Engineer, FAA, Rotorcraft Certification Office, Rotorcraft Directorate, Fort Worth, Texas 76193-0170, telephone (817) 222-5447, 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-29-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.

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94-SW-29-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On July 20, 1994, the FAA issued AD 94-15-14, Amendment 39-8985 (59 FR 40798, August 10, 1994), to require changing the method of calculating the retirement life for the trunnion, part number (P/N) 214-010-230-101, from flight hours to high-power events calculated using the number of takeoffs and external load lifts. That action was prompted by fatigue analyses and tests that show certain trunnions fail sooner than originally anticipated because of the unanticipated high number of lifts and takeoffs (torque events) performed with those trunnions in addition to the time-in-service (TIS) accrued under other operating conditions. The requirements of that AD are intended to prevent fatigue failure of the trunnion, which could result in loss of the main rotor and subsequent loss of control of the helicopter. Since the issuance of that AD, BHTI has issued BHTI Information Letter GEN-94-54, dated April 15, 1994, Subject: Retirement Index Number (RIN) For Cycle Lifed Components, which introduces a different method of accounting for fatigue damage on components that have shortened service lives as a result of frequent torque events. Additionally, BHTI has issued BHTI Alert Service Bulletin (ASB) 214-94- 55, which is applicable to the Model 214B helicopters, and ASB 214ST- 94-70, which is applicable to the Model 214ST helicopters, both of which are dated November 7, 1994 and describe procedures for converting flight hours and total number of torque events into a RIN for the trunnion, P/N 214-010-230-101. Although ASB 214-94-55 does not state that it applies to Model 214B-1 helicopters, this was an oversight by the manufacturer. That ASB was intended to apply to both Model 214B and 214B-1 helicopters. Since an unsafe condition has been identified that is likely to exist or develop on other BHTI Model 214B, 214B-1, and 214ST helicopters of the same type design, the proposed AD would supersede AD 94-15-14 to require creation of a component history card using the RIN system; a system for tracking increases to the accumulated RIN; and would establish a maximum accumulated RIN for the trunnion of 120,000 at which the trunnion must be removed from service. The FAA estimates that 8 helicopters of U.S. registry would be affected by this proposed AD, and that it would take: (1) 10 work hours to replace the affected trunnion due to the new method of determining the retirement life required by this AD; (2) 2 work hours per helicopter to create the component history card or equivalent record (record); and (3) 10 work hours per helicopter to maintain the record each year, and that the average labor rate is $60 per work hour. Required parts would cost approximately $11,000. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $17,360 for the first year and $16,520 for each subsequent year. These costs assume replacement of the trunnion in one helicopter each year, creation and maintenance of the records for all the fleet the first year, and creation of one helicopter's records and maintenance of the records for all the fleet each subsequent year. The regulations proposed herein would 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 economic 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), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-8985 (59 FR 40798, August 10, 1994), and by adding a new airworthiness directive (AD), to read as follows:

Bell Helicopter Textron, Inc. (BHTI): Docket No. 94-SW-29-AD. Supersedes AD 94-15-14, Amendment 39-8985.

Applicability: Model 214B, 214B-1, and 214ST helicopters, with main rotor trunnion (trunnion), part number (P/N) 214-010-230-101, 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 (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 within 25 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously. To prevent fatigue failure of the trunnion, which could result in loss of the main rotor and subsequent loss of control of the helicopter, accomplish the following: (a) Create a component history card or an equivalent record for the trunnion, P/N 214-040-230-101. (b) Determine and record on a component history card or equivalent record the accumulated Retirement Index Number (RIN) to- date on the trunnion by multiplying the accumulated high-power event total to-date by 2 or as follows: (1) For Model 214B, multiply the flight hour total to-date by 24 (round up any resulting fraction to the next higher whole number), or (2) For Model 214ST, multiply the factored flight hour total to- date by 24 (round up any resulting fraction to the next higher whole number).

Note 2: BHTI Alert Service Bulletin (ASB) No. 214-94-55, which is applicable to Model 214B and 214 B-1 helicopters, and ASB No. 214ST-94-70, which is applicable to Model 214ST helicopters, both dated November 7, 1994, pertain to this AD.

(c) After complying with paragraphs (a) and (b) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs performed and, at the end of each day's operations, increase the accumulated RIN on the component history card as follows:

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(1) For the Model 214B and 214B-1 helicopters, (i) Increase the RIN by 1 for each takeoff. (ii) Increase the RIN by 1 for each external lift, or increase the RIN by 2 for each external load lift operation in which the load is picked up at a higher elevation and released at a lower elevation, and the difference in elevation between the pickup point and the release point is 200 feet or greater. (2) For the Model 214ST helicopters, (i) Increase the RIN by 2 for each takeoff. (ii) Increase the RIN by 2 for each external load lift operation, or increase the RIN by 4 for each external load lift operation in which the load is picked up at a higher elevation and released at a lower elevation, and the difference in elevation between the pickup point and the release point is 200 feet or greater. (d) Remove the trunnion, P/N 214-010-230-101, from service on or before attaining an accumulated RIN of 120,000. The trunnion is no longer retired based upon flight hours. This AD revises the Airworthiness Limitation section of the maintenance manual by establishing a new retirement life for the trunnion of 120,000 RIN. (e) 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, 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 3: 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 December 4, 1996. Eric Briese, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 96-31523 Filed 12-11-96; 8:45 am] BILLING CODE 4910-13-U