AD 97-19-09

This amendment adopts a new airworthiness directive (AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214ST helicopters, that requires creation of a component history card or equivalent record using a Retirement Index Number (RIN) system; establishes a system for tracking increases to the accumulated RIN; and establishes a maximum accumulated RIN for the pillow block bearing bolts (bearing bolts). This amendment is prompted by fatigue analyses and tests that show certain bearing bolts fail sooner than originally anticipated because of the unanticipated high number of takeoffs and external load lifts utilizing high-power settings in addition to the time-in-service (TIS) accrued under other operating conditions. The actions specified by this AD are intended to prevent fatigue failure of the bearing bolts, which could result in failure of the main rotor system and subsequent loss of control of the helicopter.

Final rule

97-19-09 BELL HELICOPTER TEXTRON INC.: Amendment 39-10129. Docket No. 94- SW-28-AD.

Applicability: All Model 214ST helicopters with pillow block bearing bolts (bearing bolts), part number (P/N) 20-057-12-48D or -50D, 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 configurationon 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 bearing bolts, 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 the bearing bolts, P/N 20-057-12-48D or -50D.

(b) To determine the accumulated Retirement Index Number (RIN) to date on parts in service, multiply the factored flight hour total to date by 13.6 (round-off the result to the next higher whole number). Record on the component history card or equivalent record the accumulated RIN.

NOTE 2: Bell Helicopter Textron, Inc. Alert Service Bulletin 214ST-94-69, dated November 7, 1994, pertains to this AD.

(c) After compliance with paragraphs (a) and (b) of this AD, during each operation thereafter, maintain a count of each takeoff and external load lift performed, and at the end of each day's operations, increase the accumulated RIN on the component history cards or equivalent record as follows:

(1) Increase the RIN by 2 for each takeoff.

(2) Increase the RIN by 2 for each external load lift, 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 bearing bolts from service on or before attaining an accumulated RIN of 17,000. If any of the four bearing bolts are replaced, then all four bolts must be replaced at that time. The bolts are no longer retired based upon flight hours. This AD revises the Airworthiness Limitations section of the maintenance manual by establishing a new retirement life for the bearing bolts of 17,000 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.

(g) This amendment becomes effective on October 16, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to BHTI Model 214ST helicopters was published in the Federal Register on December 23, 1996 (61 FR 67503). That action proposed to require creation of a component history card using a RIN system; establishing a system for tracking increases to the accumulated RIN; and establishing a maximum accumulated RIN for the bearing bolts.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule with three non-substantive changes. The words "based on condition" were deleted from paragraph (d) of the AD. If any of the four bearing bolts are replaced for any reason, all four bearing bolts must be replaced. The words "or equivalent record" are added to paragraphs (b) and (c). The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 6 helicopters of U.S. registry will be affected by this AD, that it will take approximately (1) 24 work hours per helicopter to replace the affected bearing bolts 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); (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 will cost approximately $2,000 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators for the first year is estimated to be $7,760 and each subsequent year to be $7,160. These costs assume replacement of the bearing bolts 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 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.

For the reasons discussed above, I certify that this action (1) is not a " significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positiveor negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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.

39.13 - [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: