47-32-06 BELL: (Was Mandatory Note 6 of AD-1H-1.) Applies Only to Model 47B Serial Numbers 5, 8, 9, 10, 11, 12, 15, 16, 20, 21, 22, 24, 25, 26, 27, 30, 31, 35, 36, 37, 39, 41, 42, 43, 45, 51 and 52.
Compliance required before next flight.
Replace the 14ST pillow blocks 47-120-111-1, on the main rotor hub, with 4340 steel pillow blocks, 47-120-111-5, and inspect the hub assembly in accordance with Bell Service Bulletin 47C45 (Revised) dated May 27, 1947. In order to avoid possible structural failure of pillow blocks if extreme misapplication of flight controls are applied, reference "Flight Manual" 47B Series, Section II, paragraph 14B.