Mumbai Police have arrested a Class 12 student from Gujarat who allegedly posted a tweet claiming that an aircraft of airline Akasa Air "will go down", an official said on Monday. After the tweet, the private airline had lodged a complaint at the Airport Police Station here, based on which an FIR was registered against unidentified persons under Indian Penal Code Sections 505 (statements conducing to public mischief) and 506(2) (criminal intimidation), he said.