Primary finding
Probable cause
The pilot’s failure to remove an object from the airplane’s exterior, which impacted the propeller blades when he applied full power, causing them to fracture and damage the airplane.
Investigator assessment
Analysis narrative
The pilot taxied the amphibian airplane downwind on the water for takeoff. When facing into the wind, he applied full power; about 5 seconds later, he heard a "loud bang." The propeller blades separated and penetrated the fuselage, resulting in substantial damage to the airplane's fuselage. The pilot reported that, immediately before the accident flight, he had placed a portable speaker on the top of the airplane and did not recall removing the speaker before departure. The pilot stated, "the speaker must have rolled over the engine compartment and into the propellers." It is likely that the audio speaker, which was left on the airplane, struck the propeller blades, which resulted in the propeller blades separating from the propeller and penetrating the fuselage.
Source record
Factual narrative
On June 3, 2020, about 1630 central daylight time, an ICON A5 amphibian airplane, N838BA, was substantially damaged when it was involved in an accident near the Sky Harbor Airport (DYT), Duluth, Minnesota. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he taxied downwind on the water for takeoff. When facing into the wind, he applied full power and about 5 seconds later, heard a "loud bang". He shut down the engine, climbed out, looked back, and saw that all 3 propeller blades were missing. At this point, the airplane started to sink. He and his passenger donned life jackets and evacuated the airplane. Substantial damage was noted to the airplane's fuselage, including holes in the hull. Several days later, the pilot recalled that before he taxied out, they washed the airplane. During the wash, he had placed a portable speaker on the top of the airplane to listen to some music while they worked. He did not recall putting the speaker away before departure. The pilot added, "that the speaker must have rolled over the engine compartment and into the propellers ..." During a telephone conversation with the National Transportation Safety Board Investigator In Charge, the pilot stated that he has not since located the speaker.