As Jason Thrasher lowered his helicopter to a park with seven firefighters aboard, he saw what he thought was another firefighting chopper battling a blaze that was threatening homes.The California Department of Forestry and Fire Protection pilot suddenly identified the object as a four-rotor drone only 10 feet from his windshield, forcing him to make a hard left to avoid a collision about 500 feet above ground, according to a report he filed the next day. "If that drone came through my windshield, I have no idea what could have happened," Thrasher said in a phone interview.