AD 98-23-18 Airworthiness Directives; Bell Helicopter Textron, Inc. Model 214B, 214B-1, and 214ST Helicopters

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

Model 214B, 214B-1, and 214ST 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 40 hours time-in-service, unless accomplished previously. To detect cracks in a barrel nut, which could lead to failure of a main rotor grip, pitch horn, or tailboom, and subsequent loss of control of the helicopter, accomplish the following: (a) For each barrel nut, determine if the manufacturer was Kaynar Technologies Inc. (Kaynar) in accordance with paragraph 1.a. of the Accomplishment Instructions of Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) No. 214-97-59, applicable to Model 214B and B-1 helicopters, or Bell Helicopter Textron, Inc. ASB No. 214ST- 97-78, applicable to Model 214ST helicopters, both dated July 17, 1997. (b) For each Kaynar-manufactured barrel nut, part number (P/N) NAS577B-10A, determine if it is a ``thick'' flange barrel nut (installed edge distance of 0.115-inch) or a ``thin flange barrel nut (installed edge distance of 0.155-inch) in accordance with paragraph 1.b of the Accomplishment Instructions of the applicable ASB, dated July 17, 1997. (c) For each barrel nut identified as a Kaynar-manufactured ``thin'' flange barrel nut, using a 10-power or higher magnifying glass, perform a visual inspection for cracks in the threaded portion of each barrel nut or lubrication residue in the threaded portion of each barrel nut or its corresponding attaching bolt. Note 2: If a ``thick'' flange Kaynar-manufactured barrel nut, P/ N NAS577B-10A, is installed, compliance with paragraphs (d) and (e) of this AD is not required. (d) For each barrel nut that cannot be positively identified, and for each Kaynar-manufactured ``thin'' flange barrel nut in which a crack or lubrication residue was discovered as a result of the inspection required by paragraph (c) of this AD, replace the barrel nut and the corresponding attaching bolt with an airworthy barrel nut and attaching bolt before further flight. If an unairworthy barrel nut is found at the right-hand upper tailboom attachment location, also replace the left-hand upper barrel nut and corresponding bolt, and inspect both upper tailboom and fuselage longeron fittings for damage or deformation. (e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be [[Page 63402]] used if approved by the Manager, FAA, Rotorcraft Directorate, Rotorcraft Certification Office. 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) The identification and determination of the barrel dimensions shall be done in accordance with Bell Helicopter Textron, Inc. ASB No. 214-97-59 or Bell Helicopter Textron, Inc. ASB No. 214ST-97-78, both dated July 17, 1997. 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, telephone (817) 280-3391, fax (817) 280-6466. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on November 30, 1998. Issued in Fort Worth, Texas on November 4, 1998. Mark R. Schilling, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 98-30165 Filed 11-12-98; 8:45 am] BILLING CODE 4910-13-U