Document ID: chunk:federal_register_of_legislation:F2007L04510:body:0:p1
Version: federal_register_of_legislation:F2007L04510
Segment Type: other
Provision Reference: 
Character Range: 0–3064

AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BELL 412/44 Amdt 1 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron 412 Series Helicopters
AD/BELL 412/44 Amdt 2  Tail Rotor Blade Fwd Tip Weight      13/2007
                       Retention Block and Aft Tip Closure

Applicability:  Model 412, 412CF, and 412EP helicopters with a tail rotor blade part number
                212-010-750-009 through -129, all serial numbers, except serial numbers with a prefix of "A" or "AFS" and the number 11926, 13351, 13367, 13393, 13400, 13402, 13515, 13540, 13568, 13595 through 13602, 13619, and subsequent assigned numbers, installed.
Requirement:    1. Inspect the tail rotor blade forward tip weight retention block and aft tip closure for adhesive bond voids.  Remove any tail rotor blade with a void in excess of that allowed by the Component Repair and Overhaul Manual limitations.

                2. Inspect the forward tip weight retention block attachment countersink screws in four locations to determine if the head of each countersink screw is flush with the surface of the abrasion strip.  The locations of these four screws are depicted on Figure 1 of Bell Helicopter Textron Inc. Alert Service Bulletin (ASB)
                412-00-106 Revision D or 412CF-00-13 Revision D, or later FAA approved revisions, as applicable.  If any of these screws are set below the surface of the abrasion strip or are covered with filler material, install shear pins in accordance with the Accomplishment Instructions, Part A, Shear Pin Installation paragraphs, of ASB  412-00-106 Revision D or 412CF-00-13 Revision D, or later FAA approved revisions, as applicable.

                3. Install the aft tip closure rivets, re-identify the modified blade by adding an "FM", and dynamically balance the tail rotor hub assembly in accordance with the Accomplishment Instructions, Part B, Aft Tip Closure Rivet Installation paragraphs, of ASB 412-00-106 Revision D or 412CF-00-13 Revision D, or later FAA approved revisions, as applicable.

                Note:  FAA AD 2007-22-02 Amdt 39-15238 refers.
Compliance:     Within 100 hours time in service after 20 December 2007, unless already accomplished.
                This Amendment becomes effective on 20 December 2007.

Background:  The FAA received reports of five occurrences of missing tail rotor blade forward tip weight retention blocks or aft tip