Safety Notice SN003 – Tail Rotor Spindle Installation
Safety Notice – SN003
Date: May 12, 2006 To: All Safari and Baby Belle Owners
Subject: Tail Rotor Spindle Orientation Compliance Time: Before Next Flight
Background:
It is possible to install the tail rotor spindle with the delta hinge 90 degrees out of correct orientation. While the blades and pitch change mechanism will operate correctly, there will be increased vibration and a high potential for failure.
It should be noted that no rotors that were assembled at the factory have ever been identified as having the wrong spindle orientation: however, there is one instance where factory personnel inspected a tail rotor that had been re-assembled by a builder. The spindle had been reversed. This was corrected, but the spindle failed shortly thereafter during hover testing.
There is also evidence that another tail rotor failure occurred as a direct result of the owner rebuilding the rotor assembly incorrectly.
Compliance:
The assembly should be inspected to verify that the spindle is correctly oriented as shown in the accompanying picture. The delta pin should be oriented towards the rod ends on the tail rotor pitch arm which is also towards the leading edge (LE) of the blades. In the event that the spindle has been installed backwards (ie. delta pin towards the trailing edge (TE) of the blades), the helicopter should be immediately grounded and the owner should contact the factory for assistance before operating the helicopter.
Note: All spindles are now clearly marked for correct installation as shown above.