AD 2002-13-05 Airworthiness Directives; MD Helicopters, Inc. Model 369D, 369E, 369F, and 369FF Helicopters

The following MD Helicopters, Inc. helicopter models, certificated in any category:   Helicopter model With Modified In accordance with (1) 369D, 369E, 369F, 369FF Tailboom, serial number (S/N) 5001-5032 Aerometals Supplemental Type Certificate (STC) SH5055NM (2) 369D and 369E Tail Rotor Gearbox Attach Bolts Aerometals STC SH4801NM 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 loss of the tail rotor gearbox due to attaching bolts of inadequate grip length and subsequent loss of control of the helicopter, accomplish the following: (a) Within 25 hours time-in-service (TIS): (1) For each tail rotor gearbox attaching bolt (bolt): (i) Determine the part number (P/N). (ii) If the P/N cannot be determined or if the bolt is not P/N NAS1304-26, before further flight, replace the bolt with bolt, P/N NAS1304-26. (iii) Torque the bolt to 100-110 in-lbs and apply a slippage mark. (2) Remove the tailboom control rod and determine the number of bolt threads protruding from each nutplate on the internal surface of the aft tailboom frame casting, P/N 369D23503, as shown in Figure 1 of this AD. At least one thread must protrude. If more than four threads protrude, add an additional washer, P/N AN960D416, under the bolt head. Torque the bolt to 100-110 in-lbs, and reapply a slippage mark. See Figure 1: ER21JA03.000 (b) Between 2 and 10 hours TIS after accomplishing the requirements of paragraph (a) of this AD, inspect the torque on each bolt by applying 100 in-lbs. If any bolt movement occurs, retorque the bolt to 100-110 in-lbs. Reapply a slippage mark to the bolt regardless of the outcome of the torque test. Reinspect the torque between 2 and 10 hours TIS thereafter until no bolt movement occurs. Note 2: Aerometals Service Bulletin SB-001, dated August 3, 2000, pertains to the subject of this AD. (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, Los Angeles Aircraft Certification Office (LAACO), FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, LAACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the LAACO. (d) Special flight permits will not be issued. (e) This amendment becomes effective on February 25, 2003. Issued in Fort Worth, Texas, on January 11, 2003. David A. Downey, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 03-1189 Filed 1-17-03; 8:45 am] BILLING CODE 4910-13-U