Lawyers acting for a teenager accused of attempting to hijack a Jetstar flight have revealed plans to argue he was suffering a mental impairment at the time – telling a court the child later told police the people on the plane were “heroes” and he wanted to thank them.The now 19-year-old boy, who cannot be named for legal reasons, appeared in a Children’s Court on Wednesday morning as prosecutors launched a bid to have the case sent to a higher court.The teenager is accused of attempting to take control of a commercial flight at Avalon Airport in Geelong on March...