Cellphones a flight risk? Could be on some Boeing planes, US aviation authority says

US government officials in 2014 revealed an alarming safety issue: passenger cellphones and other types of radio signals could pose a crash threat to some models of Boeing 737 and 777 aircraft.

More than 1,300 planes registered in the US were equipped with cockpit screens vulnerable to interference from Wi-fi, mobile phones and even outside frequencies such as weather radar, according to the US Federal Aviation Administration, which gave airlines until November 2019 to replace the units made by Honeywell International.

Today, potentially hundreds of planes worldwide are still flying with the unsafe systems cited in the FAA report. Flight-critical data including airspeed, altitude and navigation could disappear and “result in loss of airplane control at an altitude insufficient for recovery”, the FAA said in the safety bulletin, known as an airworthiness directive.

Honeywell has not heard of any blanking display screens caused by mobile phones or other radio frequencies while an airplane was in flight, spokeswoman Nina Krauss said.

When airlines and Honeywell argued that radio signals were unlikely to cause safety problems during flight, though, the FAA countered that it had run tests on in-service planes – and the aircraft flunked.