A former Apple engineer has pleaded guilty to trade secret theft -- one of two people accused of stealing trade secrets from the iPhone maker's nascent self-driving car program. United States federal prosecutors have alleged that Xiaolang Zhang downloaded the plan for a circuit board for Apple's self-driving system after disclosing his intentions to work for a Chinese self-driving car startup and booking a last-minute flight to China. He was arrested at the San Jose airport after he passed through a security checkpoint. Zhang initially pleaded not guilty to the charges, but according to court documents on Monday, he had reached a plea deal with prosecutors and changed his plea to guilty. The plea deal is sealed and sentencing is set for November.