2004-20-07: Main rotor yoke (yoke)

2004-20-07 Bell Helicopter Textron Canada: Amendment 39-13812. Docket No. 2004-SW-04-AD. \n\n\tApplicability: The following helicopter models, certificated in any category: \n\n\nModel \nSerial number (S/N) \n With main rotor hub (hub) assembly part number installed\n(1) 222\n(2) 222B\n(3) 222U\n(4) 230\n47006-47089\n47131-47156\n47501-47574\n47501-47574\n222-011-101-ALL or 222-012-101-ALL.\n222-011-101-ALL or 222-012-101-ALL. \n222-011-101-ALL or 222-012-101-ALL.\n222-012-101-ALL\n\n \n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent failure of the yoke and subsequent loss of control of the helicopter, accomplish the following: \n\t(a) Within 50 hours time-in-service (TIS) or by the next scheduled inspection for the hub assembly, whichever occurs first, and thereafter at intervals not to exceed 25 hours TIS, using a 10X or higher magnifying glass, visually inspect the main rotor yoke (yoke) for a crack, fretting or buffer deterioration in the four areas around the flapping bearing attachment bushings as shown in the following Figure 1 of this AD: \n\n\n\n\n\tNote 1: Bell Helicopter Textron Alert Service Bulletin (ASB) Nos. 222-03-97 for the Model 222 and 222B, 222U-03-68 for the Model 222U, and 230-03-28 for the Model 230, all dated September 23, 2003, pertain to the subject of this AD. \n\n\t(1) If a crack is found, before further flight, replace the yoke with an airworthy yoke. \n\n\t(2) If fretting or buffer deterioration is found on the yoke in the areas shown in Figure 1 of this AD, before further flight, disassemble the hub assembly and further inspect the yoke with a 10X or higher magnifying glass in the four areas shown in Figures 2 and 3 of this AD. \n\n\t(i) If a crack is found on any part, before further flight, replace the part with an airworthy part. \n\n\t(ii) If fretting or buffer deterioration is found on any part, before further flight, repair any unairworthy part or replace the part with an airworthy part. \n\n\n\n\n\n\t(b) Within 50 hours TIS or by the next scheduled inspection for each hub assembly, whichever occurs first, and thereafter at intervals not to exceed 50 hours TIS, determine the torque of the four main rotor flapping bearing retaining bolts or nuts. While holding the bolt head, apply 100 foot-pounds (135Nm) of torque to the nut in the tightening direction. \n\n\t(1) If 100 foot-pounds (135Nm) of torque is reached without movement of the nut, before further flight, torque the nut to 125 foot-pounds. \n\n\t(2) If any nut moves before reaching 100 foot-pounds (135Nm) of torque, before further flight, remove both flapping bearings from the hub assembly. Inspect the yoke, the bolt and nut, and the trunnion supports with a 10X or higher magnifying glass, for a crack, fretting, or buffer deterioration. \n\n\t(i) If a crack is found on any part, before further flight, replace the part with an airworthy part. \n\n\t(ii) If fretting or buffer deterioration is found on anypart, before further flight, repair any unairworthy part or replace the part with an airworthy part. \n\n\t(c) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group, FAA, for information about previously approved alternative methods of compliance. \n\n\t(d) This amendment becomes effective on November 9, 2004. \n\n\tNote 2: The subject of this AD is addressed in Transport Canada (Canada) AD CF-2003-27, dated November 17, 2003.