Despite the belief that electronic gear does not really interfere with equipment on an aircraft, pilots claim that there is evidence to the contrary.

Pilots and crews told the International Air Transport Association that between 2003 and 2009, mobile phones, iPods, laptops and other equipment all caused problems. More than 26 of the incidents affected flight controls, including the autopilot, autothrust and landing gear. Another 17 concerned navigations systems, there were 15 incidents of interference affecting communications systems and 13 triggered warnings including “engine indications”.

In one case an electronic devices are believed to have caused the autopilot to switch off at 4,500ft. An IATA report stresses that it does not verify that electronic devices caused the problems, however, but records the impressions of pilots and crew. Mobile phones are believed to have been responsible for 40 per cent of the incidents. In one case a GPS unit in the cabin gave an incorrect reading because two laptops were being used nearby. Electronic interference was also blamed for rapidly changing altitude measurements on a separate flight. Passengers were asked to switch off their devices and the readings returned to normal.

So if the Apple fanboy sitting next to you refuses to turn off his iPad it is probably in the best interests of flight safety to give him a clip around the ears. Even if he has turned it off, you might be doing humanity a favour.