[FoRK] Disruptions: Fliers Must Turn Off Devices, but It's Not Clear Why
sdw at lig.net
Tue Dec 6 01:13:23 PST 2011
Aircraft avionics are far different. And they are far away behind
metal bulkheads. Your speakers are totally unshielded with the
cheapest amp that would work. Good speaker systems (I've had a super
multi-input (including optical) Logitech for a few years) are totally
immune to this. Cheap speakers are essentially near-field receivers
that will amplify a certain range of frequencies.
If you can actually hear the words you are speaking over the speaker,
then either you are not hearing it from the traffic between the phone
and the tower, or you are using analog cellular which has been unlikely
for over 10 years. GSM phones have a characteristic repeating pattern
that is called "galloping horses". This is probably what you are
Aircraft avionics have to operate perfectly when there are AM aircraft
radios blasting transmissions at several watts, plus many other
electronic devices, plus engine ignition noise. Plus they have to
survive lightning hits to the aircraft, and very dry and therefore
A cell phone maxes out at 800mw. Bluetooth is a few mw: class 1 is
100mW, 2 is 2.5 mW, and 3 is 1mW. I've never found a class 1 device
outside of embedded industrial units. Wifi is limited to 1W but things
like laptops are 36mW max. Something like a Kindle, without radio
on, is micro watts or something similar. Static in people's sweaters
is probably a worse radio threat.
Any study of this shows there are no problem. Further, as soon as the
airline finds a way to make money on it, suddenly it isn't a safety
problem anymore. Nearly every cross-country flight, I now use Wifi
service which technically could transmit at power greater than modern
cell phones. And cell phones have been allowed on some flights. They
are only going to be disallowed because of social irritation.
There are only two types of radio that I'd be worried about: GPS
jamming and using an aviation radio to interfere with voice or VORTAC
transmissions. I'm sure with most aircraft, even if you had those
you'd have to rig them to transmit impossibly strongly to interfere
with an optimized skin antenna from inside a metal tube.
On Mon Dec 5 23:33:12 2011, Damien Morton wrote:
> My cellphone sits on my desk. Right near my other USB connections.
> keyboard, mouse, disk drive, etc. When my phone rings, I can hear the
> conversation between phone and tower on my speakers, and invariably,
> that conversation disables my usb connection such that I need to reboot it.
> Maybe aircraft are different and special when in comes to induced RF
> interference. I dont know really, but my basic position on this is "fuck
> all y'all ipads and shit"
> On Tue, Dec 6, 2011 at 2:38 AM, Stephen Williams<sdw at lig.net> wrote:
>> Fake security& false risk aversion, not to mention outright institutional
>> lying, bugs me.
>> Disruptions: Fliers Must Turn Off Devices, but It's Not Clear Why.<
More information about the FoRK