AD 99-05-07 Airworthiness Directives; Bell Helicopter Textron, Inc. Model 214B and 214B-1 Helicopters

Models named: 214B, 214B-1. Read the applicability below — it usually turns on serial or part numbers too.

Model 214B and 214B-1 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.

Required within 25 hours time-in-service (TIS), unless accomplished previously. [[Page 10209]] To prevent fatigue failure of the pillow block bearing bolts (bearing bolts), part number (P/N) 20-057-12-48D or -50D, which could result in failure of the main rotor system and subsequent loss of control of the helicopter, accomplish the following: (a) Create a Retirement Index Number (RIN) component history card or an equivalent record for the bearing bolts, P/N 20-057-12- 48D or -50D. (b) Calculate and record on the component history card the historical accumulated RIN for the bearing bolts as follows: (1) When the type of operation (internal or external load lift), actual flight hours, and number of external load lifts or takeoffs per hour are known, multiply the actual flight hours by the appropriate factor in the following table for external load lift operation: ------------------------------------------------------------------------ Average number of external load lift events per flight hour Factor ------------------------------------------------------------------------ 0-2.00..................................................... 6.8 2.01-5.00.................................................. 13.6 5.01-16.00................................................. 27.2 16.01--27.00............................................... 40.8 Above 27.00................................................ 54.4 ------------------------------------------------------------------------ When the type of operation is internal load and no external lifting is involved, each hour of actual operating time is equal to 6.8 RIN. (2) When the actual flight hours on the bolts are known, but the type of operation (internal or external load lift) is unknown, multiply the actual flight hours by a factor of 40.8. (3) When the actual flight hours on the bolts are unknown, assume 75 flight hours per month. (4) When the flight hours on the bolts are assumed, but the type of operation (internal or external load lift) is known, (i) Multiply the number of flight hours assumed for internal load operations by a factor of 6.8. (ii) Multiply the number of flight hours assumed for external load operations by a factor of 40.8. (5) When the flight hours on the bolts are assumed and the type of operation (internal or external load lift) is unknown, multiply the assumed flight hours by a factor of 40.8. (c) After compliance with paragraphs (a) and (b) 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 bearing bolts 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. Note 2: Bell Helicopter Textron, Inc. Alert Service Bulletin No. 214-94-54, dated November 7, 1994, pertains to the subject of this AD. (d) Remove the bearing bolts from service on or before attaining an accumulated RIN of 17,000. The bearing bolts are no longer retired based upon flight hours. If any of the four bolts require replacement for any reason, then all four bolts must be replaced at that time. 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, 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. (g) This amendment becomes effective on May 3, 1999. Issued in Fort Worth, Texas, on February 19, 1999. Henry A. Armstrong, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 99-5039 Filed 3-2-99; 8:45 am] BILLING CODE 4910-13-U