Amateur-built BIG PIET N973BP accident near Gainesboro, Tennessee

Probable cause

Separation of the spinner cap for reasons that could not be determined based on available evidence, which resulted in contact and subsequent separation of the wooden propeller blade tip.

NTSB analysis

The pilot reported that about 2 hours into a cross-country flight, he experienced an airplane vibration and determined a section of the propeller departed the airplane. He shut the engine down due to severe vibration. He intended to land at the nearest airport but realized the airplane would not reach the runway and set up for a landing on a grass field. The airplane landed hard and the landing gear split, buckling the lower longerons. The airplane then slid into the airport perimeter fence. Examination of the wreckage revealed that the left wing was damaged, and the fuselage frame was bent. The propeller spinner was not located at the accident site and one propeller blade was missing the blade tip.

The wood propeller was sent to the propeller manufacturer for further investigation. Examination determined the portion of the missing blade separated as a result of a strike to the propeller by an object. The examination could not definitively identify the spinner as the object that struck the blade; however , it is likely the missing spinner departed the airplane inflight and impacted the propeller blade. The reason the spinner departed the airplane could not be determined based on available evidence.

Text from the NTSB. Open the NTSB docket for ERA19LA228 for the full record.