...our research has found that these items can interrupt the normal operation of key cockpit instruments, especially Global Positioning System (GPS) receivers, which are increasingly vital to safe landings. Two different studies by NASA further support the idea that passengers' electronic devices dangerously produce interference in a way that reduces the safety margins for critical avionics systems. There is no smoking gun to this story: there is no definitive instance of an air accident known to have been caused by a passenger's use of an electronic device.