The Federal Aviation Administration (FAA) has ordered airlines to replace or modify the cockpit display units fitted in Boeing aircraft after tests indicated mobile phone and computer signals could cause the screens to go blank. The problem with the Honeywell screens was not detected in flight, only during a test on the ground.
"We are issuing this AD [airworthiness directive] to prevent loss of flight-critical information displayed to the flight crew during a critical phase of flight, such as an approach or take-off, which could result in loss of airplane control at an altitude insufficient for recovery, or controlled flight into terrain," it said.
Boeing had recommended airlines change the screens in 2012 but the FAA said that some 1,326 737 and 777 aircraft remained unchanged.