62-23-02: Main Rotor Mast Thrust Bearing

62-23-02 BELL: Amdt. 498 Part 507 Federal Register October 23, 1962. Applies to Model 47 Series Helicopters Equipped with Main Rotor Mast Thrust Bearing, P/N 47-130-110-1. Compliance required as indicated. Excessive wear and evidence of impending failure of the main rotor mast thrust bearing have occurred. To preclude progression of bearing deterioration to a hazardous degree, accomplish the following: (a) Within the next 25 hours' time in service following the effective date of this AD and thereafter at periods not to exceed 25 hours, conduct a close visual inspection of the engine oil filter. (b) If metal particles are found during any inspection of the engine oil filter, the following shall be accomplished prior to further flight: (1) The source of the contaminant shall be located and eliminated and other components of the engine and transmission which may be jeopardized by metal particles shall be inspected and overhauled as prescribed by the appropriate Bell maintenance manual; and (2) The main rotor mast thrust bearing, P/N 47-130-110-1, shall be thoroughly inspected and replaced with a like component if found not to be in a serviceable condition. (c) Clean engine oil filter carefully before reinstalling. NOTE: For the purpose of this AD, the operations outlined under (a) and (c) are considered to be preventive maintenance and may, therefore, be accomplished by persons specified in Section 18.10(c) of the Civil Air Regulations. This directive effective October 29, 1962. Revised September 16, 1966.