Given the task definition and input, reply with output. In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Why did Schwarzenegger's plane have to make an unscheduled landing?, Context: Schwarzenegger's private jet made an emergency landing at Van Nuys Airport on June 19, 2009, after the pilot reported smoke coming from the cockpit, according to a statement released by the governor's press secretary. No one was harmed in the incident.
smoke