AD 2000-02-12 Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

Models named: 407. Read the applicability below — it usually turns on serial or part numbers too.

Model 407 helicopters, with oil cooler blower shaft bearing (bearing), part number (P/N) 407-340-339-101 or -103, 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 (d) 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 bearing failure, loss of tail rotor drive, and a subsequent forced landing, accomplish the following: (a) Within 10 hours time-in-service (TIS), inspect the forward and aft bearings for roughness by hand-rotating the driveshaft with the oil cooler driveshaft connected. Replace any rough bearing before further flight. (b) Within 25 hours TIS, inspect the forward and aft bearings for roughness by hand-rotating the driveshaft with the oil cooler driveshaft disconnected at both ends. Replace any rough bearing before further flight. After the inspection, lubricate the bearings with MIL-G-25013 grease. (c) Following the inspection of paragraph (b) and at intervals not to exceed 25 hours TIS, repeat the inspection of paragraph (a). Replace any rough bearing before further flight. After each recurring inspection, lubricate the bearings with MIL-G-25013 grease. (d) 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, Regulations Group, 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, Regulations Group. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group. (e) Special flight permits will not be issued. (f) This amendment becomes effective on March 3, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-02-12, issued January 21, 2000, which contained the requirements of this amendment. Note 3: The subject of this AD is addressed in Transport Canada (Canada) AD CF-2000-02, dated January 14, 2000. Issued in Fort Worth, Texas, on February 10, 2000. Larry M. Kelly, Acting Manager, Rotorcraft Directorate Aircraft Certification Service. [FR Doc. 00-3793 Filed 2-16-00; 8:45 am] BILLING CODE 4910-13-P