A 2006 analysis of the database identified 125 reports of interference from electronic gadgets, of which 77 were defined as "highly correlated". In one incident a 30-degree error in navigation equipment was immediately corrected when a passenger turned off a portable DVD player. This problem reoccurred when the device was switched back on. Fight crew have reported a number of similar cases in which they have watched readings on navigations systems change apparently in response to passengers being asked to turn specific devices on and off. In another report, the International Air Transport Association (IATA) identified 75 separate incidents of possible electronic interference that pilots believe were linked to mobile phones and other electronic devices between 2003 and 2009.
In the competitive world of aviation, some airlines such as Virgin Atlantic and Delta Airlines have started advertising the use of technologies that allow greater use of mobile devices on flights. In-flight mobile phone systems such as OnAir and AeroMobile use miniature on-board base stations called picocells which allow devices to transmit at lower power levels. Transmissions are processed, transmitted to a satellite and then on to the normal ground networks. This, says AeroMobile chief executive Kevin Rogers, enables the use of mobiles “as a roaming service just like when you go to a foreign country, except that in a foreign country you don’t need a satellite link.” Some airlines are now starting to fit AeroMobile equipment during production.
These systems allow you to use your phone while at cruise altitude, but not during take-off and landing. Rogers thinks that this might change one day, but at the moment it is still difficult to “prove categorically that there is indeed no interference – so airlines tend to err on the side of caution and be conservative.”
But as Rogers adds: “Many phones are always left on anyway. If there was a real risk of interference of a mobile phone or an iPad with the aircraft’s systems, people would not be allowed to take them on the aircraft at all.”
Some air authorities remain unconvinced, however. In-air mobile services cannot be used in US airspace, for example. The US Federal Aviation Administration has come under pressure to relax its rules and last year set up a group of experts to study the question. A decision is expected by the end of this year.
Richard Taylor, a spokesman of the UK’s Civil Aviation Authority, believes it is just a matter of time before we see more widespread use of mobile devices on aircraft, but that calls will remain banned during take-off or landing for the foreseeable future.
“When regulators like us are convinced that an aircraft can be used safely even with portable electronic devices being used in the cabin, that the signal being emitted from the cabin at any stage of the flight can be safely absorbed without affecting any of the aircraft systems, of course the rules will be relaxed,” he says. “But it’s up to the manufacturers, and of course to the airlines, to prove that they are operating the aircraft safely.”
Perhaps that day may come soon. However, having learnt how difficult it is to prove definitively that planes are safe from interference, I'll be making sure my phone is properly switched off in future. After all, when I'm en route to my holiday in the sun, I don't want my handset to be responsible for tricking the pilot into landing in some rainy old place. Or for something even worse.