Bell Helicopter Textron 412 Series Helic
Bell Helicopter Textron 412 Series Helicopters
Bell Helicopter Textron 412 Series Helicopters
| AD/BELL 412/40 Amdt 1 | Main Rotor Yoke | 3/2006 |
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| Applicability: | Model 412 and 412EP helicopters, serial numbers 33001 through 33213, 34001 through 34036 and 36001 through 36204; and Model 412CF helicopters, serial numbers 46400 through 46499; and All Model AB 412 helicopters: equipped with a main rotor yoke assembly part number 412-010-101-123 or -127. |
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| Requirement: | Action in accordance with Bell Helicopter Textron Alert Service Bulletins No.412-98-93, or No. 412CF-98-5, or Agusta Alert Technical Bulletin No. 412-74, as applicable.Note: FAA AD 99-23-23 and ENAC AD 1999-179 refer. |
| Compliance: | As specified in the Requirement documents, as applicable. |
| This Amendment becomes effective on 16 March 2006. | |
| Background: | The manufacturer determined that main rotor yokes which measured less than 0.478" across a specific portion of the flexure area, does not have a sufficient fatigue margin of safety and have therefore reduced the life by 500 hours time in service.Amendment 1 is issued to include the Agusta Model AB 412 helicopter in applicability. |
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David Villiers
Delegate of the Civil Aviation Safety Authority
2 February 2006