Ad/Bell 206/153 Amdt 3 - Tail Rotor Blade Trailing Edge Skin Cracks (Cth)
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 206/153 Amdt 2 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 Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters
| AD/BELL 206/153 Amdt 3 | Tail Rotor Blade Trailing Edge Skin Cracks | 11/2005 |
Applicability: | Model 206A and 206B helicopters, equipped with tail rotor blade, part numbers Agusta-Bell Model AB206A/B helicopters, equipped with tail rotor blades, part numbers 206-016-201-131 or 206-016-201-133; with serial numbers identified in Model AB206A/B Alert Bolletino Technico (ABT) 206-237. |
Requirement: | Part A: Identification of Affected Tail Rotor Blades 1. Verify if the rotorcraft is equipped with tail rotor blades identified in the “Component Affected” or “Helicopters Affected” section of the applicable ASB or ABT, listed in the Applicability part of this Directive. If the rotorcraft is equipped with an affected blade, enter the part number and serial number into the journey logbook. If not equipped with an affected blade, indicate that the rotorcraft is not equipped with blades affected by this Directive. 2. If any spare blade is listed in the “Component Affected” or “Helicopters Affected” section of the applicable ASB or ABT, the blade is to be identified with a “Blue Diamond” decal as per Part II, of the applicable ASB or ABT. Part B: Initial and Recurring Check for Tail Rotor Blade Cracks Check the affected tail rotor blade for cracking in accordance with the instructions in Part I of the applicable ASB or ABT listed in the Applicability part of this Directive. If a crack is found, before further flight, replace the affected blade. Part C: Schedule 100 hour / Annual Inspection For Tail Rotor Blade Cracks Perform a detail visual inspection of the tail rotor blade using a magnifying glass, in accordance with Part II of the applicable ASB or ABT listed in the Applicability part of this Directive. If a crack is found, before further flight, replace the affected blade. |
| Part D: Terminating Inspection for Bell Helicopter Textron tail rotor blades Send the affected tail rotor blades to the repair facility identified in Part III of the applicable ASB listed in the Applicability part of this Directive. Tail rotor blades found with unacceptable blade skin thickness are to be removed from service. Part E: New Skin Damage Limits for Bell Helicopter Textron tail rotor blades Inspect the tail rotor blades in accordance with Part IV of ASB 206-04-100 Revision C or ASB 206L-04-127 Revision C, or later Transport Canada approved revisions, as applicable. Part F: One-Time Inspections for Bell Helicopter Textron tail rotor blades Inspect the maintenance records of the affected blades to determine if the blades had been previously repaired following the inspection required by the previous issues of this Directive. If it has been repaired, contact the repair organisation to determine if the weight of the trailing edge root weight package had changed. If the weight package was increased, the tail rotor blade is to be sent for rebalancing in accordance with Part III of ASB 206-04-100 Revision C or ASB 206L-04-127 Revision C, or later Transport Canada approved revisions, as applicable. Note: Transport Canada AD CF-2004-05R2 refers. | |
Compliance: | Part A.1. Before further flight after 6 May 2004, unless already accomplished. Part A.2. Before the installation of a spare blade. Part B. Before further flight after 6 May 2004, unless the initial inspection is already accomplished. Repeat thereafter at intervals specified in applicable ASB or ATB. Part C. At the next, and recurring, 100 hour scheduled inspection or annual inspection after 6 May 2004, whichever occurs first. Part D. Before 27 April 2007. Part E. At the next 100-hour scheduled inspection or annual inspection after 27 October 2005, whichever occurs first; or if damage is identified. Part F. At the next 100-hour scheduled inspection or annual inspection after 27 October 2005, whichever occurs first. |
| This Directive shall be entered on the Maintenance Release as maintenance required. The Requirement Part A.1.action, and Requirement Part B. “Recurring 3-Flight Hour Check,” identified in the applicable ASB or ABT listed in Applicability part of this Directive, may be performed and certified by the Pilot in Command who has been trained to do the Requirement Part A.1. action and Requirement Part B. inspection by an appropriately qualified person. In this case, a copy of the applicable ASB or ABT and this Directive is to be carried in the aircraft. The compliance times for Parts A, B, C, and D remain unchanged from the previous issue of this Directive. | |
| This Amendment becomes effective on 27 October 2005. | |
Background: | Transport Canada received reports of three occurrences of skin cracks originating near the tail rotor blade trailing edge balance weight. Two of the occurrences resulted in loss of the weight and a strip of material along the trailing edge, leading to an imbalance, which caused fracture of three of the four tail rotor gearbox attachments. One of these occurrences resulted in the gearbox shifting that caused failure of the drive shaft, which resulted in loss of yaw control. Amendment 1 introduced Agusta-Bell AB206A/B helicopters to the requirements of this Directive. Amendment 2 introduced terminating action requiring affected blades to be inspected for acceptable tail rotor blade skin thickness. Amendment 3 is issued in response to a revision of the related Transport Canada AD, which introduces more stringent tail rotor skin damage limits, and re-balance requirements. Amendment 2 of this Directive became effective on 30 September 2004. Amendment 1 of this Directive became effective on 6 May 2004. The original issue of this Directive became effective on 26 March 2004. |
David Villiers
Delegate of the Civil Aviation Safety Authority
16 September 2005
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