Cessna 150J N151GW accident near Minersville, Utah

Probable cause

The failure of the propeller blade due to fatigue that originated from an impact pit sustained at an unknown time. Contributing to the accident was the failure of unknown maintenance personnel to detect and repair the impact pit before painting the propeller, which obscured the damage.

NTSB analysis

According to the pilot, who had recently purchased the airplane, he inspected the airplane’s propeller for damage before departing on a multi-leg cross country flight. During the second leg of the flight, one of the propeller blades separated about 17 inches from the hub. The pilot shut down the engine and was able to perform a forced landing on a rural road. The airplane sustained substantial damage to its airframe and engine mount from excessive vibrations caused by the propeller blade separation.

The maintenance records for the airplane and propeller were incomplete, and the propeller’s maintenance and operational history could not be determined. Examination of the propeller revealed fracture features consistent with a fatigue crack that initiated from an impact pit on the blade face. The impact pit was one of several areas of damage consistent with debris impacts that were subsequently painted over and obscured with black paint. Measurement of the pit at the origin of the fatigue crack revealed it was within tolerance for a field repair; however, there was no indication any repair was performed. There was insufficient information to determine when the damage occurred or how long the fatigue crack had been present.

Text from the NTSB. Open the NTSB docket for WPR25LA096 for the full record.