Just what would happen if I ignored the safety advice and used a radio or a phone on an airplane?

(Asked by Rory from County Kildare, Ireland)

Before all you regular readers point out that Margot from Brighton asked me a very similar question last month, let me just say that I’m answering this one simply because of the way Rory chose to phrase his question.

In life, we are constantly bombarded by instructions, orders and indefinable ‘rules’ (some of which are written down and legally enforced, while others still are unwritten and socially enforced). I’m sure I’m not the only one who, like Rory from Kildare, wonders what would happen if some of those rules were to be broken.

Being on an airplane is one of those serious occasions when the people around you enact a greatly heightened degree of safety awareness. Frequent fliers among you will no doubt be able to recite a standard safety speech without too much difficulty. As the cabin crew stone-facedly prepare us for the fact that, in the event of a crash, there really isn’t much we can do to save ourselves, they always make a fuss about radios, phones and related equipment, don’t they?

But why is this? Surely something as innocent as a transistor radio or a cellphone can’t hurt a great big aeroplane, and if they can, why are we allowed to have them with us on the flight?

In truth, that is absolutely the case, your radio/phone can’t really damage the plane in any serious way, (death by text message is not going to be a real issue for you) but amazingly, our handheld devices can cause a few problems.

Y’see, a radio receiver houses something called a ‘local oscillator’, which can act as an internal transmitter. This is usually a small signal that helps to clear up the incoming signal for the listener. However, although these oscillators are usually shielded, it honestly doesn’t take much for the signal to escape and play havoc with aircraft navigation technology. In the vast majority of occasions, this simply will not happen, but is it really worth chancing a freak accident?

Mobiles, however, are a slightly different story. They aren’t really dangerous to aircraft technology at all. It is theoretically possible, but so is being burgled by highly trained chimps in ninja outfits…

Essentially, the problem between mobile phones and planes is a logistic/economic one. The phone will search for signal at 30,000 feet and, in doing so, can chance upon hundreds of potential signals at once. This becomes almost impossible for the phone companies to figure out, making it simply a pain in the backside for the companies concerned.

Since there is also a risk (however marginal) to the safety of the passengers and crew, the ban will likely remain in place until someone figures out a way to charge premium rates from high above the Atlantic ocean, then the ads will talk about how they always put the customer first, no matter what.

Ultimately, however, it just isn’t worth the risk, Rory. So now you know and, as I was reliably informed throughout my childhood, knowing is half the battle.