What happened
On January 31, 2017, a Diamond DA-20 Katana operated by Salt Aviation began taxiing for a PPL(A) proficiency check flight. The crew, consisting of a student pilot and an instructor, departed from the airfield and entered the EPMO CTR. Shortly after takeoff, the crew noticed a significant degradation in the aircraft's performance. Despite the loss of performance, all cockpit instruments provided normal readings, and the crew reported no unusual vibrations or abnormal sounds. Due to the degraded climb/flight capabilities, the crew decided to return to the airport, landing without further complications.
The investigation
The investigation focused on the cause of the performance loss observed during the flight. A subsequent inspection of the aircraft revealed a crack along the leading edge of one of the composite propeller blades. This structural failure had resulted in a loss of blade stiffness, which directly caused the observed reduction in engine/propeller efficiency. The investigation examined the history of the propeller and the methods used to move the aircraft on the ground. It was noted that this was the second such propeller failure on this specific aircraft, with a similar incident occurring in November 2016.
Findings
- The primary cause of the damage was improper handling of the aircraft while maneuvering it on the ground, specifically by pulling the aircraft by the propeller blade.
- A contributing factor was a lack of awareness among personnel regarding the specific structural properties and operational characteristics of composite propellers.