AD 82-20-05

82-20-05 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: Amendment 39- 4466. Applies to Model AS-350 and Model AS-355 series helicopters certificated in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent possible failure or seizure of tail rotor drive shaft bearings (part numbers SKF 6007-2RS1MT47CA/AS704A33.651.010.) accomplish the following:

(a) Within the next 50 hours' time in service after the effective date of this AD, inspect the perpendicularity of each bearing relative to the tail rotor drive shaft in accordance with paragraph 1(C)(1)(a) and figure 1 of Societe Nationale Industrielle Aerospatiale Service Bulletin No. 05.08 for the Model AS-350 helicopter, and Service Bulletin No. 05.02 for the Model AS-355 helicopter, both dated May 27, 1982 (hereinafter referred to as the applicable service bulletin), or an FAA approved equivalent method.

NOTE: Except for helicopter model applicability, the provisions of Service Bulletin Nos. 05.08 and 05.02 are identical.

(1) When perpendicularity of the bearing relative to the shaft is within a runout indication of less than 0.2 mm (.008 in.), inspect the bearing in accordance with paragraph 1(C)(2) of the applicable service bulletin.

(2) When perpendicularity of the bearing relative to the shaft gives a runout indication of 0.2 mm (.008 in.) or more, and the bearing time in service does not exceed 300 hours, inspect the bearing in accordance with paragraph 1(C)(2) of the applicable service bulletin and replace the rubber sleeve with a serviceable sleeve.

(3) When perpendicularity of the bearing relative to the shaft gives a runout indication of 0.2 mm (.008 in.) or more and the bearing has more than 300 hours' time in service, remove the bearing and rubber sleeve from service and install a serviceable sleeve and bearing.

(b) Accomplish paragraph 1(C)(2) of the applicable service bulletin at intervals not to exceed 300 hours' time in service from the last inspection.

(c) For bearings with less than 1,100 hours' time in service on the effective date of this AD, remove the rubber sleeves and bearings from service and install serviceable sleeves and bearings, before or upon achieving 1,200 hours' time in service.

(d) For bearings with 1,100 hours' or more time in service on the effective date of this AD, remove the rubber sleeves and bearings from service and install serviceable sleeves and bearings within 100 hours' time in service after the effective date of this AD.

(e) When the tail rotor drive shaft rear section is disassembled in accomplishing the requirements of this AD, install the drive shaft in accordance with paragraph 1(C)(3) of the applicable service bulletin. When a bearing is replaced, the bearing perpendicularity relative to the tail rotor drive shaft must provide an out-of-round indication of 0.15 mm (.006 in.) or less when examined in accordance with paragraph 1(C)(1)(a) of the applicable service bulletin.

(f) Equivalent means of compliance must be approved by the Manager, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Office, Federal Aviation Administration, c/o American Embassy, Brussels, Belgium, or the Manager, Aircraft Certification Division, ASW-100, Federal Aviation Administration, P.O. Box 1689, Fort Worth, Texas 76101.

This amendment becomes effective October 15, 1982.