The crew was completing a local training mission at Oakland International Airport. After touchdown, the pilot-in-command started the braking procedure when control was lost. The airplane veered off runway before coming to rest. While all four crew members were uninjured, the aircraft was damaged beyond repair.
Probable cause (official findings): The pilot-in-command failed to maintain directional control due to improper operation of powerplant controls which caused an asymmetrical thrust reversal after landing. Crew unfamiliar with early warning reverse circuit. Poor flight supervision on part of the instructor.