NTSB Safety Alert – Aluminum Propeller Blades: Prevent Fractures with Proper Inspections and Maintenance
Aluminum propeller blades can be susceptible to fatigue, cracking, and fracture if a small nick, pit, or corrosion on the surface or edge is not found and repaired during preflight inspection or maintenance. Such damage can concentrate stress from normal airplane operation loads, resulting in fatigue crack initiation and growth followed by propeller blade fracture. Aluminum is more commonly used for airplane propeller blades than composite propeller blades or wood. Fatigue cracking and fracture of a propeller blade can damage the airframe, and engine, and cause a possible loss of control. Airplanes utilized for aerial application and coastal operations, as well