[Federal Register Volume 61, Number 225 (Wednesday, November 20, 1996)] [Proposed Rules] [Pages 59034-59036] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-29609] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 94-SW-20-AD] Airworthiness Directives; Bell Helicopter Textron, Inc. Model 412 and 412EP Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. (BHTI) Model 412 and 412EP helicopters. This proposal would require creation of a component history card using a Retirement Index Number (RIN) system; would establish a system for tracking increases to the accumulated RIN; and would establish a maximum accumulated RIN for certain main rotor masts (masts) and main rotor spline plates (spline plates). This proposal is prompted by fatigue analyses and tests that show certain masts and spline plates fail earlier than originally anticipated because of an unanticipated high number of takeoffs and external load lifts utilizing high power settings, in addition to the time-in-service (TIS) accrued under normal operating conditions. The actions specified by the proposed AD are intended to prevent fatigue failure of the mast or spline plate, which could result in failure of the main rotor system and subsequent loss of control of the helicopter. DATES: Comments must be received by January 21, 1997. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Assistant Chief Counsel, Attention: Rules Docket No. 94-SW-20-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 Department, P.O. Box 482, Fort Worth, Texas, 76101. FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer, FAA, Rotorcraft Certification Office, Rotorcraft Directorate, Fort Worth, Texas 76193-0170, telephone (817) 222-5157, 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-20-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. [[Page 59035]] 94-SW-20-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Discussion This notice proposes the adoption of a new AD that is applicable to BHTI Model 412 and 412EP helicopters. This proposal would require, within the next 100 hours TIS, creation of a component history card using a RIN system for certain masts and spline plates used on the Model 412 and 412EP helicopters; would establish a system for tracking increases to the accumulated RIN; and would establish a retirement life of 80,000 RIN for certain helicopter masts and spline plates, and a retirement life of 60,000 RIN for certain other helicopter masts and spline. Fatigue analyses and tests by the manufacturer show that certain masts and spline plates fail earlier than originally anticipated because of an unanticipated high number of takeoffs and external load lifts utilizing high power settings in addition to the TIS accrued under normal operating conditions. This condition, if not corrected, could result in fatigue failure of the mast or spline plate, which could result in failure of the main rotor system and subsequent loss of control of the helicopter. The FAA has reviewed BHTI Alert Service Bulletin (ASB) No. 412-94- 81, Revision B, dated March 4, 1996, which describes procedures for creation of a component history card within the next 100 hours TIS for Model 412 and 412EP helicopters. The ASB also describes utilizing either a retirement life of 10,000 hours TIS or a maximum accumulated RIN of 80,000, whichever occurs first, for the BHTI Model 412 helicopter mast and spline plate; and a retirement life of 10,000 hours TIS or a maximum accumulated RIN of 60,000, whichever occurs first, for the BHTI Model 412EP helicopter mast and spline plate. Since an unsafe condition has been identified that is likely to exist or develop on other BHTI Model 412 and 412EP helicopters of the same type design, the proposed AD would require creation of a component history card using a RIN system for certain masts and spline plates, establishing a system for tracking increases to the accumulated RIN, and establishing a retirement life of 80,000 RIN for certain helicopter masts and spline plates, and a retirement life of 60,000 RIN for certain other helicopter masts and spline plates. Spline plates and masts used on Model 412EP helicopters will be vibro-etched with ``412HP''. This identifier does not indicate FAA approval or certification of a Model 412HP helicopter. The FAA estimates that 294 helicopters of U.S. registry would be affected by this proposed AD, and that it would take (1) 8 work hours per helicopter to replace the mast and 10 work hours per helicopter to replace the spline plate; (2) 2 work hours per helicopter to create the component history card or equivalent record (record); (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 $21,635 per mast and $5,675 per spline plate. Based on these figures, the total cost impact of the proposed AD on U.S. operators for the first year is estimated to be $1,602,790, and each subsequent year to be $1,573,390. These costs assume replacement of the mast and spline plate in one-sixth of the fleet each year, creation and maintenance of the records for all the fleet the first year, and creation of one-sixth of the fleet'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 USC 106(g), 40113, 44701. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: Bell Helicopter Textron Inc.: Docket No. 94-SW-20-AD. Applicability: Model 412 and Model 412EP helicopters with main rotor mast (mast), part number (P/N) 412-040-101-105, -109, -117, - 121, -125, -127, or -129, and main rotor spline plate (spline plate) P/N 412-010-167-105 or P/N 412-010-177-101, -105, -109, -113, or - 117, 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 100 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously. To prevent fatigue failure of the mast and spline plate, which could result in failure of the main rotor system and subsequent loss of control of the helicopter, accomplish the following: (a) Create a component history card or an equivalent record for each affected mast and spline plate. Record the accumulated Retirement Index Number (RIN) on the mast and spline plate component history card(s) as follows: (1) If the numbers of takeoffs (at any gross weight) and external load lift events are known, and those numbers do not include any external load operation in which the load was 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 was 200 feet or greater (high power lift event), increase the accumulated RIN by one for each takeoff and external load lift. (2) If the numbers of takeoffs (at any gross weight) and external load lifts are known, and the number of external load lifts includes a high power lift event, increase the accumulated RIN by two for each takeoff and two for each external load lift. (3) For each hour time-in-service (TIS) for which the numbers of takeoffs and external [[Page 59036]] load lifts are unknown, and the number of external load lifts does not include a high power lift event, increase the accumulated RIN by 10 for each hour TIS. (4) For each hour TIS for which the numbers of takeoffs and external load lifts are unknown, but the number of external load lifts does include a high power lift event, increase the accumulated RIN by 20 for each hour TIS. (5) For each hour TIS for which the numbers of takeoffs and external load lifts are unknown, and it is unknown whether the external load lifts include any high-power lift event, increase the accumulated RIN by 20 for each hour TIS. (b) After compliance with paragraph (a) of this AD, during each operation thereafter, maintain a count of each lift or takeoff performed and at the end of each day's operations, increase the accumulated RIN on the component history card as follows: (1) Increase the RIN by 1 for each takeoff. (2) Increase the RIN by 1 for each external load lift, or increase the RIN by 2 for each external load 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. (c) Retire the mast and spline plate in accordance with the following: (1) For the mast, part number (P/N) 412-040-101-105, 109, -117, or -127, used on the Model 412 helicopter upon reaching 10,000 hours TIS or 80,000 maximum RIN, whichever occurs first. (2) For the mast, P/N 412-040-101-121, -125, or -129, used on the Model 412EP helicopter, upon reaching 10,000 hours TIS or 60,000 maximum RIN, whichever occurs first. (3) For the spline plate, P/N 412-010-167-105 or P/N 412-010- 177-101, or -109, used on the Model 412 helicopter, at 10,000 hours TIS or 80,000 maximum RIN, whichever occurs first. (4) For the spline plate, P/N 412-010-167-105 or P/N 412-010- 177-101, -105, -113, or -117, used on the Model 412EP helicopter, at 10,000 hours TIS or 60,000 maximum RIN, whichever occurs first. (d) For spline plate, P/N 412-010-167-105 or P/N 412-010-177- 101, -105, -113, or -117, installed on Model 412EP helicopters, at the next scheduled teardown inspection, beside the P/N on the side of the spline plate, vibro-etch ``412HP'' and annotate in the component history card or equivalent record ``412HP/EP only'' to reflect that this spline plate can only be installed on the Model 412EP helicopter, and not on any other Model 412 helicopter. Retire the spline plates that have been vibro-etched with ``412HP'' on or before accumulating 10,000 hours TIS or 60,000 RIN, whichever occurs first. Note 2: Bell Helicopter Textron, Inc. Alert Service Bulletin No. 412-94-81, Revision B, dated March 4, 1996, pertains to this subject. (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, 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 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 November 6, 1996. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 96-29609 Filed 11-19-96; 8:45 am] BILLING CODE 4910-13-U