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Electronics In Flight — Danger Or Distraction?
another similar writes "IEEE Spectrum has a blog post revisiting the debate on whether electronic devices pose a risk to flight avionics spurred by a NY Post article about Arianna Huffington's refusal to power down her Blackberry during takeoff. The post points out the EU's removal of their own ban on cell phone use in 2007 and the likelihood of significant non-compliance daily in the US — and curiously, planes haven't been falling from the sky at a similar rate. While the potential exists for there to be a problem, it would appear the risk is low. Ever bent the rules? Is an app for landing commercial jets somewhere in our future?"
Don't confuse this. Electronics are banned on take off and landing for different reasons, not just for interference. Electronics are banned for radio interference, because that is the easy explanation, but one of the multiple reasons is passenger attention. Take off and landing are, statistically, the most dangerous times, where all passengers are required to be attentive to what goes on. When you take off at night and they dim the cabin lights, some people say that it is for electrical considerations, but it also gets your eyes used to the outside light in case you need to evacuate. Airplanes and procedures are carefully planned so that you can evacuate quickly in case of an emergency, and people being distracted form electronics isn't really a good idea.
The urgent is done, the impossible is on the way, for miracles expect a small delay.
That has been long gone out the window...
I dread the day when cell phones are allowed in use on the plane. Can you immigine a 2 hour flight with some person yacking away the entire time getting loud and annoying... I still don't like to listen to other people phone conversations at a restaurant. You know the type...
IIRC, aircraft, at least the reasonably high altitude ones, have to be designed to cope with the possibility of lightning strike(not really as bad as it sounds, even badass voltages are relatively harmless when you are inside an aluminum tube). Lighting, of course, is basically the biggest, meanest spark-gap in the entire terrestrial context(compared to, say, Jovian lightning, it isn't much at all, but that isn't really relevant to any aircraft except Xenu's space-DC9s...).
Spark gaps tend to put out some seriously gross, broad band, RF noise. A spark gap with the energy of a lighting bolt should be quite the RF emitter.
Unless the designers depend exclusively on the aircraft's outer skin for RF protection(which seems unlikely, given the systems that need to communicate and/or scan the outside world, which obviously can't be faraday-caged inside the outer skin...) they have presumably had to deal with RF of the sort that would make your weedy little powered-by-batteries-and-FCC-regulated widget wet itself.
Also one would sincerely hope, given what the higher level of cosmic ray exposure can(with low but nonzero frequency) do in terms of flipping bits in any circuitry that isn't rad-hard, critical systems would be redundant, watchdogged and quick to reboot, or both.
Your car is touching the ground. Shielding is easy when you have a solid ground. How, exactly, do you get an effective ground when you're in the air?
I'm an airline pilot, and a colleague of mine (on a Boeing 737/300) once saw his fuel quantity indicators suddenly jump to zero. He asked a cabin attendant to check if anyone was using electronic equipment in the cabin. One passenger, sitting next to the wing, was using a portable CD player. He was asked to turn it off, and fuel quantity indication returned to normal. Switched it back on again... indications went back to zero. The cause of the interference was later determined to be the motor of the CD player, which is rapidly switched on and off to keep a variable speed necessary for reading data at different distances from the center.
Personally, while flying in the cockpit myself, I have forgotten to turn off my cell phone many times. This usually just resulted in a drained battery but no ill effects on the airplane. On a few occasions, it even started ringing during final approach. I never saw any fluctuations in the instrument indications. However, I have heard the typical noise on the radio "trrrrrrrr tkt tkt tkt tkt", which I'm sure pretty much anyone has already heard when a phone was about to ring and it was close to a radio. The instrument landing system receives signals on frequencies pretty close to those of ordinary radio, so I can imagine it being affected in the same way. But I haven't actually seen the needles jump as a result.
In any case, this interference is VERY unlikely to affect the flight controls. Most landings are done manually, so interference should not actually be able to bring down an airplane. However, in foggy weather, the plane is landed automatically and in this case, it's probably safest to just keep all electronics off just in case the autopilot suddenly behaves in some weird way. Planes have crashed because of relatively minor errors in input, for example the radio altimeter reading an altitude that is much too low, and the plane thinking it's above the runway and bringing the power back to idle while in fact it's still at a few hundred feet. That sort of thing. Yes, it can happen, and planes have crashed as a result.
great home experiment:
you will need 1 GSM phone, another phone to call it, a USB 2 external hard drive, your computer, and a large file.
After attaching the USB-2 cable between your HD and computer, place the GSM phone on or near the cable. I have had success within one or two feet, but for the purposes of your first run, placing the phone on the cable itself is the most likely way to see results.
begin the transfer of the large file.
call the GSM phone.
if the GSM phone receives the call while the file is transferring, the drive should crash. i've encountered blue screens from this experiment in the past.
>pilots do not wait until the aircraft is 300 feet off
Actually your REQUIRED TO perform full autolands every 90 days in each aircraft in order to keep it certified to perform such landings when you 'really' need its help.
(work for airline, wrote the system that keeps track of the compliance)
Also have been in aircraft cockpit several times during autolands and even performed one myself in the full SIM. It's pretty amazing.
-- Given enough time and money, Microsoft will eventualy invent UNIX.
I don't think anything would interfere with engine or other instrumentation, as most of that is hard-wired. The problems lie in potential interference with nav radios (primarily VOR and ILS).
As much as I hate to bring Mythbusters into any serious discussion, they brought several electronic devices, aircraft instruments, and a ramp test box (which simulates the aforementioned navigation aids) into a faraday cage to see what they could see.
As I remember, nothing had any effect, except for an attempted cell phone call on a specific frequency that significantly deflected either the VOR or ILS (don't remember which now). Since ILS is what the pilots use to find the runway when they can't see, that would concern me.
Given that the cabin crew can't tell what a given device might be doing, "all off during takeoff/landing, and no cell phones in the air" seems like a totally reasonable policy.