The Federal Aviation Administration (FAA) said on Friday it was requiring U.S. operators of 143 Boeing Co (BA.N) 737 Classic series airplanes to check for possible wire failures stemming from an investigation into an Indonesia crash in January. The FAA is issuing an airworthiness directive requiring operators to verify the flap synchro wire, which plays a role in the operation of the aircraft’s auto-throttle system, is securely connected to a safety sensor. The wire failure could go undetected by a computer on the affected airplanes and pose a safety risk. The FAA said the issue impacts 1,041 737-300, -400 and -500 Classic series airplanes worldwide. The 737 Classic planes are all more than two decades. Boeing did not immediately comment.