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Comment by Craiggybear | Hacker News Reader

I think its because that if there were an accident involving the spill of aviation fuel (even in an aborted takeoff situation, I can see that happening) then the danger of ignition would be that much greater if everyone's phones, tablets, laptops, etc were all in a powered-on or RF transmit mode.

It makes good sense to minimise that risk.

I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now.

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"I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now."

Some woman started yelling at me in a gas station forecourt last year (2010) because I was talking on the phone while sitting in my car with the door open. "You're going to blow us all up!" she yelled at me (twice), then sped off far too quickly to have been a safe speed for leaving a gas station parking lot. :/

FACT: the risk of my mobile phone igniting vapourised fuel in a gas station forecourt is almost exactly equivalent to the probability that my ipod nano will tangle with an airplane's cockpit electronics.

It's all myth and fud spread by a) people with ulterior motives (see above) b) people who are too uneducated or too stupid to make their own judgement. Like air hostesses, petrol attendants.

Inside your iPod nano, or any other device with a computer chip is a radio transmitter. Inside the cockpit are many radio receivers, some of which are pretty critical to the proper flight of the airplane. Your radio transmitter, and radio transmitters being run by other passengers, mix and mingle their signals, producing an unpredictable effect on these key cockpit receivers.

The probability that this happens is not zero or low, but very high.

The probability that this happens is not zero or low, but very high.

No, it isn't. If it were, we wouldn't be depending on the honor system.

1. Not all devices with a computer chip have radios, my TI-84 calculator has a Z-80 processor but there is no radio in it 2. Aircraft radios operate on a very different frequency then consumer electronics, and I'm pretty sure the FCC wouldn't allow consumer electronics to operate on the same frequency as the radios in a cockpit regardless

Technically, yes, there is a "radio" in your TI-84. The Z-80 is clocked by a crystal oscillator, which runs at a few MHz. Some of that energy will escape in the form of electromagnetic radiation. Sensitive instruments (including an ordinary AM radio) can pick up this radiation from distances ranging from a few inches to several yards. This is true of essentially all modern electronics, although the frequencies have obviously gone higher and higher over time.

If it were true that the RF energy levels emitted by FCC Part 15-covered consumer electronics could interfere with aircraft systems, it would be utterly unthinkable to permit them on board in the first place, whether "powered off" or not. The TSA would be confiscating Game Boys, not bottles of water. Since that isn't happening, it's difficult to avoid the conclusion that the prohibition is just one more exercise in bureaucratic security theatre.

If all electronic devices were dangerous, airlines would be asking passengers to remove the batteries from their wristwatches for the duration of the flight.

http://www.snopes.com/autos/hazards/gasvapor.asp

It makes good sense to minimise that risk.

Not really. To the extent a risk exists, the only response that would make any sense whatsoever would be to redesign the fueling and/or avionics systems to make them compatible with common consumer electronics. The fact that this isn't happening suggests that the warnings are all just so much hot air.

No one seems to remember or bother about that now.

Perhaps because there isn't a single documented case of a fire or explosion at a gas station being caused by RF energy at levels around one watt.

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