An American Airlines mechanic was arrested Thursday on a sabotage charge accusing him of disabling a navigation system on a flight with 150 people aboard before it was scheduled to take off from Miami International Airport earlier this summer. The reason, according to a criminal complaint affidavit filed in Miami federal court: Abdul-Majeed Marouf Ahmed Alani, a veteran employee, was upset over stalled union contract negotiations. None of the passengers and crew on the flight to Nassau were injured because the tampering with the so-called air data module caused an error alert as the pilots powered up the plane’s engines...