Shortly after departure on a local flight, the private pilot observed that the Velocity’s engine temperature was higher than it had been on the previous day’s flight.
After reducing power, the engine began to surge, which prompted him to return to the airport in Rosamond, California.
Unable to maintain altitude, he elected to land in a vacant field.
The left wing sustained substantial damage during the landing.
A post-accident examination of the engine revealed that the No. 1 connecting rod assembly had failed.
Although the reason for the failure could not be determined, the fracture surfaces exhibited signatures of fatigue consistent with a malfunction of the connecting rod bearing, such as improper bearing size, rotation of the bearing during service, or operation of a severely worn bearing.
Such conditions would result in higher-than-normal operating stress, and likely contributed to the propogation of the fatigue cracking.
Probable cause: A partial loss of engine power due to failure of the No. 1 connecting rod as a result of multiple fatigue cracks for reasons that could not be determined.
NTSB Identification: WPR16LA047
This January 2016 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
