AD 2000-18-52 Airworthiness Directives; Bell Helicopter Textron, Inc.-Manufactured Model OH-13E, OH-13H, and OH-13S Helicopters

Models named: OH-13E, OH-13H, OH-13S. Read the applicability below — it usually turns on serial or part numbers too.

Bell Helicopter Textron, Inc. (BHTI)-manufactured Model OH-13E, OH-13H, and OH-13S helicopters, with main rotor blade grips, part number (P/N) 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, 47-120-252-11, 74-120-252-11, and 74-120-135-5, 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 otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent failure of a main rotor blade grip (grip), separation of a main rotor blade, and subsequent loss of control of the helicopter, accomplish the following: (a) Within 100 hours time-in-service (TIS) since initial installation on any helicopter or within 10 hours TIS for grips with 100 or more hours TIS, conduct a liquid penetrant or eddy current inspection of the grip threads for a crack. Thereafter, conduct the liquid penetrant or eddy current inspection at intervals not to exceed 200 hours TIS. If a crack is detected, before further flight, replace the cracked grip with an airworthy grip. (b) On or before 1200 hours TIS, replace each grip with an airworthy grip. This AD establishes a retirement life of 1200 hours TIS for grips, P/N 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, 47-120-252-11, 74-120-252-11, and 74-120-135-5. (c) 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. 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office. (d) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on November 30, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-18-52, issued September 1, 2000, which contained the requirements of this amendment. Issued in Fort Worth, Texas, on November 2, 2000. Mark R. Schilling, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 00-29050 Filed 11-14-00; 8:45 am] BILLING CODE 4910-13-U