Icon A5 N838BA accident near Duluth, Minnesota

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.

NTSB analysis

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.

Text from the NTSB. Open the NTSB docket for CEN20LA207 for the full record.