So we’ve all been told, “ensure your small portable electronic devices are turned off or switched into airplane mode.” But why does that even matter? Does it really disrupt Pilot/ATC communications?
Well, we now have an answer according to studies conducted at the Gransby Institute for Technological Studies. Over a period of three years from 2012 to 2015, researches tested 95% of all cell phone models (approximately 3,400 phones) that had been manufactured since 2009 with the capability to be switched into airplane mode. Of the 3,400 cell phone devices 3,399 of them had no effect on any portion of the aircraft or crew. However, the remaining 1 device was actually found to highly compromise the safety of flight operations. In one specific occurrence, the phone was live tested on a Delta Airlines flight from Hartsfield-Jackson Atlanta International airport en-route to Los Angeles International Airport. With the permission of the crew, the device was tested through various phases of flight with only one issue that could be directly linked to the phone.
The issue occurred at cruising altitude in a McDonnell Douglas MD88 airliner. Atmospheric conditions that prevailed for the flight were excellent and were not listed as contributory in the findings. With the go ahead from the Captain, the researches switched the device out of airplane mode at approximately 36,000 feet. Within 5 seconds of the phone being active, the Delta flight crew reported experiencing light to moderate chop. The flight crew was very alarmed by the findings and quickly had the research group enable airplane mode. Immediately after enabling airplane mode, the flight crew reported the ride as smooth. The test continued at various altitudes between 20,000 and 36,000 feet over the course of the flight. At one point during the testing, the chop became so severe that crew was forced to declare an emergency and divert to Las Vegas, NV.
Within one week after completion of the test flight, Captain John Hammsfield (lead officer on the Delta Airlines flight), testified before the United States Senate Commerce Subcommittee on Aviation Operations, Safety, and Security. In his detailed testimony before the committee, Captain Hammsfield pleaded for the Senate to “ban all portable electronic devices in aviation.” He described the flight as “the most terrifying event of his career” and has since resigned from Delta. He plans to become an advocate for aviation safety and vows never to fly again until cell phones are permanently banned from the skies.