Hawker Beechcraft Model 60 (Duke) SAIB CE-10-10

This Special Airworthiness Information Bulletin is issued to inform you of an airworthiness concern on Hawker Beechcraft Model 60 (Duke) Series twin-engine powered airplanes.
At this time, this airworthiness concern is not an unsafe condition that would warrant Airworthiness Directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.
 

Background
After attempting to takeoff, a Hawker Beechcraft Model 60 (Duke) airplane impacted terrain that resulted in the airplane being destroyed. The flap actuators recovered at the crash site indicated that the left flap was fully retracted and the right flap was fully extended, which may have contributed to the accident. Further examination of the flap actuators revealed evidence of torsional-induced overload on the output shaft and corrosion on the output drive shaft subassembly, key location, and roller bearings.
The roller bearings showed evidence of binding. Proper rigging is essential to assure the correct operation of the flap system. If the flap bottoms out in the flap track before the flap limit switch deactivates the motor, it will stress the actuator, the 90-degree output shaft, and key. Repeated cycles with this condition may result in fractures in the key and output shaft.

SAIB attached