What happened
Shortly after takeoff, while at an altitude of approximately 50 to 75 feet above the runway, one of the two blades from the left propeller separated from the assembly. Following the separation, an FAA designee assumed control of the aircraft type and performed an emergency landing with the landing gear extended on the grass area adjacent to the runway.
During the landing sequence, the aircraft traveled off the runway surface and came to a stop in an upright position. Upon halting, the nose landing gear collapsed.
The investigation
An examination of the left propeller was conducted following the accident. Investigators determined that the blade No. 1 hub arm failed due to fatigue.
A review of the maintenance records for the propeller indicated that the component had been last overhauled on October 18, 1985. At the time of the event, the propeller had accumulated a total of 2,979.7 hours since its manufacture and 963.2 hours of operation since its most recent overhaul.