COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters AD/BELL 206/115 Horizontal Stabilizer P/N 206-023-119-151 13/89 TX Applicability: Model 206L, 206L-1 and 206L-3. Requirement: 1. Inspect the horizontal stabilizer to determine if the raised external doubler is installed. The doubler is visible on the top of the stabilizer surface extending approx 100 mm (4") outward from either side of the tail boom, and covers the upper surface of the horizontal stabilizer from within 12 mm (1/2") of the forward leading edge to the trailing edge. 2. Remove from service any stabilizer that does not have the doubler installed. Note 1: Installation of an external doubler will not bring the stabilizer into conformity nor provide an equivalent level of safety. Note 2: FAA AD 89-20-13 refers. Compliance: Prior to further flight after 20 October 1989. Background: The FAA has determined that the subject stabilizers have been either incorrectly manufactured or repaired. The stabilizers may not have the required overall skin thickness, may not have a required external doubler and otherwise may not conform to the approved type design. There has been a failure where the stabilizer separated from the aircraft and struck the tail rotor.