Huh, well whaddya know, lots of devices left on, and no plane crashes or mobile network crashes as a result!
While the US Federal Aviation Administration (FAA) debates whether airline passengers should be allowed to keep their portable electronic devices switched on during flights, the truth is that many of them already do, according to a new survey. The study, released jointly on Thursday by the Airline Passenger Experience …
"I once went on a flight and left my mobile on, and we didn't crash. Therefore mobiles don't cause plane crashes." - Flawed logic.
I work with aero-control systems as an electronic engineer, and to be honest, if I can't be certain that they *cannot* be interefered with by mobiles, then there is no way you can. Not forgetting that the vast majority of fleet aircraft are decades old, and mobile radio standards have changed several times in that timeframe.
If you've got a lot of radio and wireless communication that the plane needs in order to function safely, then having a shed load more transmission devices enabled on board which don't need to be there presents you with some risk.
I'm not saying its a big risk, but just like switching on your hoover made your TV channel go funny, or hearing the bip-beddy-bip-bip through a speaker when your mobile is too close to it and receiving a text message, if you're telling me that mobiles cannot interfere with flight systems then I'm going to disagree with you until it has been demonstrably proven otherwise. Aircraft are not necessarily hardened against this stuff - it's an incredibly expensive process to upgrade them, and airlines operate on the edge of profitability for the most part anyway, so they're not going to "just-in-case." Would you go an a flight that was 99.999% safe? because we in the industry would consider that completely unacceptable in terms of risk.
picture it: ATC reads a takeoff clearance. The pilot reads it back, but some fuckwit in the back receives a text message close to the pilots radio transmission antenna, and the clearance is read back wrongly, with a bip-beedy-bip-bip in it just in the right place that ATC doesn't cotton on. Pilot rolls out onto the runway just as another flight lands thinking he's cleared, killing every passenger in both aircraft.
Air accidents occur when errors are compounded, and everything happens *just* in the right sequence for it to end in disaster. The mobile not being turned off was only a contributing factor in the accident, but perhaps the accident *WOULD NOT* have occurred had the guy turned his phone off like he was told. So next time, turn your phone off - much as most passengers I've met don't want to believe it, there IS a reason you're told to do it.
You're oversimplifying the argument. It's not that ONE PERSON accidentally left their mobile on during a flight and the plane was fine, it's that, statistically, on every flight there are several mobile devices that have not been turned off. This has been going on for at least ten years. That's about 10 million flights during that time period with no cellphone-related crashes. In fact, the New York Times reports that air travel is the safest it has ever been, despite the proliferation of small transmitting devices and their inevitably being left on during flights.
IEEE Spectrum magazine ran a sensationalist piece of crap story where some industrial accident experts tried to extrapolate from data regarding mobiles being left on during flights that there was a 2 to 1 chance of a mobile causing an accident in the next 5 years. That was 10 years ago. The cover story they used regarding an "unsolved" plane crash had been definitively solved and available for all to see in the NTSB accident database for years before the article was published.
"Been on several flights recently, just carried on using my e-reader and DAP all the way up and down. Quite amazingly, two extremely low-power devices at the back of the plane didn't seem to cause any disruption. I'm astonished I survived, frankly."
Well, the truth is that the plane suffered a fault during take off, and crashed as a result, with some fatalities along with injuries varying from minor to life-threatening.
Yes, you did survive, but barely. You're actually in a coma dreaming away, merrily oblivious to what really happened.
I was on a flight a week ago - of the people in my row, only I powered down my device - pretty sure everyone else just put theirs in airplane mode...
How do I know? Well, on landing, the others were instantly using their iPhones - mine took about a minute to boot up....
I actually think that people believe that airplane mode is all that's required and don't actually know how to fully power off their devices. My guess is that only 30% of fliers actually power off their devices.
It wouldn't surprise me in the slightest if at least half those who claimed they had turned them off hadn't done so properly. Doing phone support for smartphone users the only way I can be certain they have really turned them off is to get them to remove the battery. Which is annoying when people have a Samsung iPhone.... (iPhone being a generic term for smart phone).
You didn't read the article, did you?
It's pretty much a given that someone has their cell phone turned on during takeoff and landing. On every single flight. Since around 2000.
In other words, the whole "your cell phone could cause the plane's sensitive navigational gear to give the pilot (or autopilot) all the wrong readings" is complete horseshit. Noone has actually done any actual research to actually determine if this would actually have *any* effect in real life, and they've always been saying "well... it *might*!" the entire time, and then rattled off the boilerplate so as to protect their own ass.
No, it doesn't have any effect. And if it did, then there's ways to fix the problem, and it would only require replacing small bits of avionics with better avionics.
So you can stop getting pissy with some poor slob who's just playing solitaire on their phone now.
 It's not that sensitive. Especially by today's standards. The Instrument Landing System is based on 1970's technology.
Turning the power off on my phone apparently prompts me before actually powering down, in the kerfuffle of boarding I thought I'd turned it off. Felt a bit of a Muppet when I got to arrivals and found the phone still asking me if I was sure I wanted to power down, but luckily didn't seem to kill 400 people, which is a plus.
Most aviation accidents happen during either take-off or landing, so they want you focused on the flight crew and what is going on rather than on your tablet and miss out on the "Please remain buckled in your seat and remain calm until the plane comes to a complete crash".
The concern about the electronics interfering with the craft's electronics started because they weren't sure (And devices back then caused orders of magnitude more RF noise than anything today). The warning was then kept as a scare tactic to keep you safe (Nothing convinces people to do something than telling them that fiery death will occur if they do not comply)
Really what they should be doing is telling people that they must remain alert and ready in case an emergency occurs without harping them on powering down their electronics.
BA lets you use the IFE system from the minute you sit down now, but during takeoff and landing you have to use their headphones, presumably to prove that you're plugged into the IFE and not your own iPod or other device. I assume that's so that you can hear any announcement over the PA which interrupts the IFE and broadcasts to the headsets too.
Which is another silly rule as most of their headphones (apart from the ones for J and F which tend to have odd connectors - audio and power so they can do noise cancelling) work just fine in non-BA issued gear, or at least they used to.
I had always assumed that putting my iPhone in airplane mode and pressing the power button to turn off the screen was enough to make them happy. I was really surprised on my latest trip when the stewardess asked me to hand her the phone and proceeded to shut it down completely by holding the two buttons for a few seconds.
Chances that I will remember to do that in the future are approximately zero.
I've noticed when flying that on a large proportion of flights I've taken from the US to the UK over the past decade, on approach to LHR I hear the distinctive Nokia feature phone SMS received tone, presumably their carrier welcoming them to a foreign country. I suspect with the demise of the feature phone I won't hear them as much now.
My parents were on a Virgin Atlantic 747 flight a few years back and related to me that the captain tried starting the engines, couldn't, and came over the PA saying for people to turn their phones off as it was causing interference. I highly doubt this, as the engine winding down noise was about the same time as the announcement, and there is no way the captain could have deduced the problem that quickly. I suspect that the cabin crew complained about people not turning devices off to the captain, and he started the air bleed from the APU to the engines to spin the first engine up but didn't turn the fuel on so the engine would never fire. Either that or he did that every flight to scare people.
American Airlines got permission from someone, I presume the FAA, to let passengers turn their phones on once they cleared the runway upon landing. Why AA can do that and other airlines can't I have no idea.
I always thought it was something to do with buggering the cell towers handoffs up, as the directional antennas arnt set up for overhead signals, which could blanket many towers from altitude and confuse the fuck out of em. Im probably wrong though.
A few other theories...
Not having passengers annoyed by constant ringtones.
not triggering bombs in the hold or contacting an outside party to do so.
As another poster said, stopping people getting distracted during safety drills.
My understanding is that the original concern was interference with the avionics in general, but that faded over time. What persisted as a concern I believe was the potential, however small, for interference with the highly accurate radio altimeters used in commercial aircraft for Cat III/autoland systems where you can't really afford to get it wrong. The system believing the runway is 15 feet lower than it actually is in zero visibility is probably going to have unpleasant and expensive consequences, so not really worth the risk.
ILS localizers operate at between 108.10 MHz and 111.95 MHz, while the marker beacons operate at 75 MHz. These frequencies are nowhere near the 800 MHz and above used by cell phones. For a cell phone to cause interference in such a specific way that the ILS avionics interpreted it as a valid signal but at 15 feet below the actual glideslope signal would be impossible. Your worst case is it would cause interference and the ILS would lose its lock on the glideslope leading to a missed approach.
> not triggering bombs in the hold or contacting an outside party to do so.
Surely if you were able to trigger a bomb on a plane remotely via a mobile you'd want to be safely on the ground when you did so??
Well the evidence is that terrorists these days are relatively indifferent to blowing themselves up. But even so, an interesting feat of logic by the OP, who believes that Al Twatada will obey any request to turn their mobiles off. Wouldn't want to hurt anybody, would they?
Honestly, the only reason I even bother switching to airplane mode is to save the battery, to keep ti from using full power whilst it hunts for a cell signal. I'm told the range is only about five miles on a good day and at six to eight miles up I'm almost certainly out of range anyway.
"...from using full power whilst it hunts for a cell signal..."
Hunting for a cell tower signal is a *receive* function. There's no inherent need for the phone to be transmitting full power into the void if it's not yet picked up a tower within range. Why would it do that? On what band or channel does it transmit if it doesn't know the details of the local tower?
Not intending to go all fanboi here, but simply provide the following comparison to perhaps make the world a better place.
My iPhone does exactly as I describe. It sits quietly, remaining cool and calm, not chewing up the battery in locations with no signal. When I move to a location where it can detect a signal, it reacts almost immediately. There's nothing imperfect at all with the details of the implementation. Kudos to Apple for getting this exactly optimum.
My colleagus Androud devices are daft. They do experience batteries being drained by poor cell coverage. They do take elaborate measures to work around this flawed implementation. They do switch to Airplane mode (...and drive home at the end of the day forgetting to turn off Airplane mode and catching hell for being out of touch). They do spend five minutes standing next to the office window begging for their phone to lock into the signal again.
It's all so unnecessary.
Hunting for a cell tower signal is a *receive* function ... There's nothing imperfect at all with the details of the implementation ... Androud devices ... take elaborate measures to work around this flawed implementation
Point 1: "The MS (ie, the phone) will send a Channel Request message to the BSS on the RACH."
Cell registration is an active process, requiring the cellphone to actively transmit. If you're looking for an excuse to bash Android devices, at least try to base it on facts: even if a phone can "hear" a base station, it still needs to transmit to register with it, regardless of whether you've got an Apple or Android or MS or Blackberry or whatever.
Nope. As well as the cell tower thing registration being an active function and the phone's radio power being a function of signal strength from the tower, iPhones are no different to any other - all four I've owned have all drained battery faster in low signal situations, such as my house's downstairs where I get 0/1/2 bars depending on exact location and phone orientation! As have all other phones I've had over the years, from fancy Nokia S80/S60 and RIMs to ye old Nokia/Moto/Sony-Ericsson dumbphones. It's how cell radio works, there's no way around it.
Locations with zero signal are somewhat different to low signal - I get that a lot too, as I do a lot of walking in the middle of nowhere with no reception. The iPhones all seem to handle that better than one-bar reception, and also better than my lass's Nexus 4 which drains as fast in no-bars as in a one-bar area. Given the spread of Android devices I'm not going to make any general statement about them from that one anecdote, though.
I figure that these devices have a similar electronic signature as a pacemaker (when in airplane mode). Should people with heart conditions turn them off?
I do agree that they need to be stowed during takeoff/landing. That's just to keep them from becoming projectiles in an emergency. But put them in airplane mode and hit the screen lock. It takes too long to power them up cold and restore them to the same place before you were forced to put them away (say, in the middle of a movie or while writing a document or playing a game).
I welcome the opportunity to listen to audio on short flights, and watch videos on longer flights. My choice of audio and video using high quality hardware; it's rare that their choice of movies appeals to me and their hardware sucks. Their seatback screen is barely good enough for the moving map.
Once upon a time while crossing the Pacific, I watched the entire 13-part Cosmos series (by Carl Sagan) on DVD with a 17-inch Laptop screen in one sitting with only a single interruption for a lovely meal. Heaven!
Record breaking duration flights are a pleasure, so long as the seat power outlet works.
"Once upon a time while crossing the Pacific,with only a single interruption for a lovely meal. Heaven!"
Speak for yourself. My experience of flying is a terrifying misery of being restrained in a noisy, smelly, uncomfortable aluminium tube, surrounded by hundreds of other frightened peasants in close proximity to two or more large devices spinning at around 70,000 rpm, themselves adjacent to thousands of gallons of jet fuel. The meals are diabolical parodies of food, and the prequel to this highly unpleasant transit is two hours of disrespectful incivility and dramatic pantomime performed by retards, intended to persuade me that my end is nigh at the hands of terrorists.
The real safety issue surely comes down to ensuring engineering tolerances are observed. A bunch of people having their devices (a tiny minority of which might be old and electromagnetically 'noisy' by modern standards, but most of which probably aren't) switched on will probably only cause very minor intermittent interruptions to communications. Digital systems will be error tolerant and self-correcting by design, so this won't matter at all for them. Maybe analog voice communications will be very slightly affected - perhaps once every so often someone will have to say "Say again?" during a radio transmission. 99.999% of the time it won't make any difference at all.
Except 99.999% of the time isn't good enough, because the problem is the Bastard Case that occurs <0.001% of the time. When a terrorist scare has suddenly and unexpectedly diverted your flight - and a whole bunch of others - to an obscure little airport on an island in the middle of nowhere in near-zero visibility with now insanely over-stretched staff who aren't strong English speakers and were never trained for this situation, a clearly transmitted but strongly accented analog voice saying "No! Not that fscking runway!" may be something you really, really don't want interrupted by interference from some random passenger's early 90's cellphone.
News Flash: This ACTUALLY HAPPENED. It's still listed as the most tragic airliner accident on record: the Tenerife disaster on the Canary Islands.
- Airport diversions due to terrorist attack, CHECK (Bombing at Las Palmas)
- Poor weather conditions, CHECK (Zero-V fog)
- Tricky landing conditions, CHECK (Airport is over 600m up and way too small)
- Poor English at the control tower, CHECK (ATCs not used to speaking English)
And note this occurred in 1977, BEFORE cell phones were the norm. As others have said, many planes have long duty cycles and therefore may not be well-hardened against internal radio transmissions. And note that frequency is not always at play--that's why even a modern GSM cell phone can still cause clicks when next to a radio, even though neither operate in the other's frequency ranges. I've PERSONALLY heard police radios (which operate around 800MHz) coming out of TV speakers which should have no tuning equipment to speak of. For the FCC, it's a case of "better safe than sorry".
If you leave you phone in online mode you will effect the electronics on the plane.
There have been several cases where a plane has rolled side to side. And there have also been aircraft crashes attributed to mobile phone interference (REF: http://en.wikipedia.org/wiki/Crossair_Flight_498 )
This is not so true of newer phones or newer planes. Newer planes have better shielding and newer phones transmit on a narrower band. Until you can be 100% sure the plane electronics can take it and that everyone has a newer phone, then this will be federal law and a jail able offence.
Any steward who does not actively ensure that your electronic device will lose their job. Let them do their job. Repeat violations by any airline will lose their flying license.
One day soon we will all be able to use what ever we want on a plane. We will laugh about what we had to do in "the old days" Until then don't do it. You are at the very least breaking a federal law. At the worst killing everybody on the plane.
"If you leave you phone in online mode you will effect the electronics on the plane."
If that was true, and if there was ANY risk at all, you wouldn't be allowed to take them on board.
After all they ban nail-clippers, so why allow something that supposedly could crash the plane...?
I'm a firm believer that one low-power rx/tx device (which all phones/tablets are) is not going to crash a plane.
However...would 10? 100? 500?
500 devices (not unrealistic) all pumping out 0.5w each = 250watts. That's a lot of RF noise, even if it is limited to a particular band.
On the upside, general RF noise from the electronic components will be tiny, especially by the time it reaches the flight electronics and sensors.
As ever people seem to be arguing about different things. I can believe a phone (or 100's of phones) sending & receiving signals is a potential danger but what I want to know is: do I need to turn my phone off or is aeroplane mode sufficient not to kill me & my fellow travellers?
I usually turn it all the way off but it takes ages, tends not to be in aeroplane mode when it powers on so while its booting it seems even more dangerous, gets confused about the time, ...
Surely airplane (US spelling to avoid those wiggly lines) mode is all that's needed? I don't turn off my watch or pacemaker.
And, why don't the airlines have detectors? Surely a wi-fi / phone / bluetooth signal can be detected? If we all had to sit there until the stewards figured out who was to blame & got them to turn it off the shaming should be enough to ensure we all turned them off to start with. And if the signal is too weak to detect what is it going to hurt?
Biting the hand that feeds IT © 1998–2019