Operational Alert: 149
Date: June 4, 2001
Subject: Two-blade Warp Drive propellers on 100 HP 912S's
Models Affected: S-6S, S-6SXL, S-6ES, S-6XL, S-7, S-9, S-10 with Rotax 912S Engine
It has been determined that the two-blade Warp Drive propeller is not enough propeller to absorb the horsepower from the 912S. Even short-term use may result in fractures at the hub end of the blades. It is recommended to stop use of the two-blade propeller and replace it with the three-blade Warp Drive or a two-blade Sensenich wood propeller. With use of the three-blade Warp Drive a thorough inspection of the propeller hub and blade roots is required every 25 hours. Please take action before your next flight.
Thank you for your attention to this matter. Hopefully we have not inconvenienced you to any great degree.