Airworthiness Directive · Amendment 39-18649 · Tail rotor drive shaft
Agusta S.p.A. Helicopters
This AD applies to Agusta S.p.A. Model A109A, A109A II, A109C, A109E, A109K2, A109S, and AW109SP helicopters with a tail rotor drive shaft assembly (drive shaft) part number 109-8412-02-1 or 109-8412-02-3 installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model A109A, A109A II, A109C, A109E, A109K2, A109S, and AW109SP helicopters. This AD requires visually inspecting the tail rotor drive shaft assembly (drive shaft) for a crack. This AD was prompted by the discovery of three cracks on the drive shaft of a Model A109S helicopter. The actions of this AD are intended to detect a crack on the drive shaft to prevent failure of the driveshaft, failure of the tail rotor, and subsequent loss of helicopter control.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 50 hours time-in-service:
(1) Visually inspect each drive shaft in accordance with the Compliance Instructions, paragraph 4, of AgustaWestland Bollettino Tecnico (BT) No. 109-147, dated March 25, 2015; BT No. 109EP-143, dated March 25, 2015; BT No. 109K-68, dated March 25, 2015; BT No. 109S-067, dated March 25, 2015; or BT No. 109SP-094, dated March 25, 2015, as applicable for your model helicopter.
(2) If there is a crack, replace the drive shaft before further flight.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
