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Cellphones On Airplanes
Bonker writes "According to this USAToday article two companies, AirCell, and Verizon, are developing technology to let airline passengers safely use cellphones while in flight. The system would block frequencies normally used by cellphones and force cell customers to 'roam' on the new network. Saftey concerns aside, I thought that a plane cabin was the one place I would never have to deal with people who won't quit talking on the phone."
What about harmonics? Any length of wire or any metallic structure in the vehicle's chassis will act as a tuned antenna and pick up (or create) harmonics. This is the real risk. A benign use of a particular frequency can create unintentional interference on another.
This so-called "solution" looks like more of a money-making scheme than a safety system to me.
When on a cross-country flight this past december on JetBlue airlines, they specifically told us that we were permitted to use cell phones once we got above 10,000 ft.
People were using them during the whole flight. They would get constantly cut off and have to re-connect as we went over areas that didn't have service.
So, I don't get this whole thing. Every other airline specifically has said that cell phones need to be off once they close the cabin door. If it works for one, why not all the rest? What does the FAA or FCC have to say about all this?
Using your sig line to advertise for friends is lame.
This is all nonsense about mobile phones being dangerous to airplane communications. There have been lots of articles regarding this subject. One of many by John Dvorak who said "And I already mentioned the restrictions placed on cell phones in airplanes. There is no evidence that mobile phones interfere with communications. This just amplifies an atmosphere of utter stupidity and senseless rules that makes us all dumber. Logic, common sense, and science are shoved aside in favor of mysterious edicts derived from fear, lack of knowledge, New Age mumbo-jumbo, and superstition. Welcome to America, 2002."
Also, if they were so dangerous, they would collect the phones at security like guns and knives.. its just a big scam. There are many articles on the subject.
One of the John Dvorak articles is here.
There many more if you do a google search.
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So it's theoretically possible that your gameboy's signal could jam the frequency that the pilots need for communication with the ground, or with vital control operation (which is largely done via radio waves these days).
At 30,000 feet it's not a huge deal, since in the exceptionally unlikely event something went wrong, there's enough time to straighten it out before plane hit ground and go boom. At 30 feet during takeoff, however, there is no such recovery time, hence the ban.
However, the odds of it happening are darned near astronomical in any case, since the sideband radiation caused by the gameboy would have to be right on the right frequency and strong enough to override the "correct" signal...not terribly likely.
Cell phones, though, in that they are designed to transmit signals, have much more powerful transmissions (duh...) so it's more likely they could interfere.
Why the use of ANY electronic device is prohibited below a certain altitude, except when sitting still at the gate?
Because you can get away with just about any manouver in an airplane as long as you don't do it close to the ground. Continents have the right of way.
Takeoffs and landings require extreme precision, because going about a foot low means destroying the plane and possibly the cockpit crew and many in the cabin. There are a BUNCH of radio-based aids on a large number of frequencies and using a variety of methods - and if the one that's being used to guide the plane at a particular instant is suddenly interfered with, there may be no time to recognize that it's malfunctioning and switch to something else. So screwing up any one of them at a critical moment may result in a landing you don't walk away from, a mid-air collision, or some other mishap.
Similarly, the airport and the space immediately adjacent is a 3D traffic jam, coordinated by radio calls. Garbling even one radio message could result in a collision, in the air or on the ground. (As with highways they have a few even when they're NOT being interfered with. Now imagine highways with an occasional light going all-ways-green...)
Once the plane is AWAY from the space around the airport it has an ENORMOUS space to work in, and considerable time to work with. And there are "lanes" in airspace, as well as a rule that breaks it into stacks of altitude ranges where everything that isn't passing through in a well-known place is going in about the same direction. So if your laptop jams a navigational aid there's time to switch to another. (And if it somehow jams ALL of 'em the crew can run on internal nav and non-radio instruments and avoid other airplanes and mountains until the stew can get you to turn the bloody thing off.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
In the US, the ban is an FCC one, not from the FAA. The reason is because a cellphone signal can easily be picked up across a very wide area on land when it's a mile up, and so the phone has the capability of interfering with a large number of other devices. The notion of "cells" becomes problematic when your phone can be seen by tens of them, and when the nearest cell can, when flying over urban areas, change six times a minute (600mph, cells spaced a mile apart...)
As I understand it, the calls made from the hijacked planes were from in-plane back-of-the-seat phones, not from cellphones.
You are not alone. This is not normal. None of this is normal.
Penya asks: "Why the use of ANY electronic device is prohibited below a certain altitude, except when sitting still at the gate?"
The simple answer is "because the rules say so." To wit:
(14 CFR is the Federal Aviation Regulations, part 121 (and part 135, in some circumstances; 14 CFR 135.144 has identical stipulations) governs airlines)
So the rule is actually a Federal Regulation, not the airline acting unilaterally.
The reason for the rule is to prevent possible interference with not just aircraft avionics, but any systems in the aircraft. In addition to the avionics (comm radios, nav radios (typically just below the AM broadcast band and just above the FM broadcast band), marker beacons, and other devices), there are also sensors and equipment in the airplane that don't respond well to induced signals. I've seen a number of cases of electronics handling RF signals badly: monitors that shut down when I key a ham transmitter (2m (144 MHz), one watt, into a ducky at a distance of a couple of yards from the monitor), cars that activate the brakes when you key the transmitter (damn computer control!), and others. RADAR, in particular, responds badly to induced RF, and every airliner has it, for detecting weather. Some also have Stormscopes, lightning detectors that look for electrostatic discharge. The aircraft's electrical system itself is designed to run at 400Hz (not the usual 60), and inducing RF has the capacity to cause some problems. Introducing RF into the computerized engine controllers (remember, computer = clock = RF oscillator) is a really bad idea.
The reason they allow the use of some devices at cruise is that cruise is a less critical phase of flight. In the terminal area, things happen quickly, with frequent heading changes, altitude changes, and such. Pilots must be in constant communication with controllers, and their navigation must be very accurate, to avoid hitting things that might hurt (which, when you're travelling at 250 knots, is pretty much anything). Approach is a particularly critical phase: the navigation equipment in most airliners is designed to bring the airplane down at about 750-1000 feet per minute (vertical speed) at around 150 knots (average; bigger airplanes are faster), down to 100 feet above the ground (Category II ILS; Cat I is 200 feet, Cat III can go all the way to the surface, with zero forward visibility for IIIc). If the navigation equipment should become unreliable during the approach, the result is usually a Bad Thing. In cruise flight, however, the precision required is much less, communication with Center happens relatively rarely, and there's a lot more time to see and correct a problem before running into something.
The prohibition on the use of cell phones is actually twofold: the FAA prohibits the use of them, for the aforementioned reasons, and the FCC prohibits the use of them because sticking an antenna on a 35,000 foot tower is a great way to expand your signal coverage. Put a cell phone up there, which was specifically designed to have a small footprint, and one phone can simultaneously jam several dozen cells, preventing other people from using the network. It also requires rapid cell-swapping, which further overburdens the network (and eats batteries besides).
The reason some, but not all, devices are approved above a given altitude (usually around 10,000 feet) is because they're generally considered safe, by the fact that they're not designed to radiate RF signals. Computers, CD players, Game Boys, etc., all have an oscillator (clock), but they're designed to keep it internal, and rarely radiate anything. Fine at cruise, but nobody wants to take chances in the critical phases, because there's less margin for error. Radios (receivers) are verboten because they use an internal oscillator (modern designs, anyway; most are superheterodyne, which requires mixing the received signal with a local oscillator), and they have an antenna connected. Even though they're not designed to radiate, they usually do so, to some degree. Transmitters are obvious, particularly aviation-band transmitters. Even if you just listen, you're still running the LO, and handheld radios have a way of getting put in places in such a way as to key the mic, jamming the frequency, which, presumably, had somebody talking on it, or it wouldn't be very interesting. See also: Bad Things.
An interesting trend I have observed is the willingness of people to put themselves at risk, when they don't have the authority (as pilot-in-command) to do so. Passengers who insist on taking off into bad weather (against the advice of the pilot), or who ignore rules (such as portable electronics) because they want to. For example, Penya relates: "Not that I followed the rules because I wanted to take some nice pictures on a flight that barely went above that altitude for long (BGR to BOS)." You're playing dumb games here. No, you obviously didn't cause the airplane to crash, but unless you designed both the camera and the avionics, you didn't know what you were doing. Avionics are remarkably robust (they have to be before they can be certificated), but how do you know that the airplane didn't strike a small bird (I've personally hit two, on a single flight) that knocked loose some shielding or something? Ice, perhaps? Maybe there was a power surge that fried one of the filter capacitors. It has been my experience that the less educated the passenger on the possible dangers, the more willing he is to risk his (and everybody else's) life. Would you have argued if the flight attendant (or the captain) had asked you to turn it off, or would you have complied? (BTW, if you like aerial photography (I love it, as do a lot of pilots), there's a simple solution: a mechanical camera. A lot of them take better pictures than modern electronic ones anyway.
Incidentally, this isn't news: I read about this system a couple of years ago. At the time, AirCell had a model that could be installed in the aircraft, and used only their network, and another model that was portable, and used both conventional (terrestrial) cell networks and the AirCell network, switching automatically between the two.
And yes, I do know what I'm talking about. I'm a flight instructor/instrument flight instructor, and I regularly fly King Airs, among others.
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What is there to "deal" with about people talking on phones? Do you also have to "deal" with people talking to the person next to them?
The deal:
By some act of manufacturing or quirk of human nature, cell phones seem to have this inherent ability to turn otherwise friendly, considerate people into inconsiderate jerks.
On top of the obvious rudness of leaving your cell phone to ring in a movie - and then talking on it as you leave the theater - there's the more subtle rudeness of ignoring the people who are actually *present*.
Talking to Joe on your cell phone is isn't anything like a conversation with another passenger: It's the opposite. Conversations with other passengers are generally held at a respectful volume, and often other passengers are welcome to join in the discussion (a la slashdot).
On the other hand, having a long, loud conversation on a cell phone is disrespectful of other passengers. It says, "Not only are you not interesting enough to talk to, but you're so insignificant, I'm not going to feel any qualms about interrupting your ride by talking at the top of my voice."
Check out actual reports from PED-related (Personal Electronic Device) incidents.
You might also wish to read a discussion of the problems with PEDs on airplanes.
Finally, here's a list of how the ASRS connect electronic devices to airplane anomalies, according to various reports they've received:
Anomaly: NAV CDI needle swing (off course), Phase: CL, Possible Cause: tape players
Anomaly: CDI needle swings, Phase: ER, Possible Cause: chess player
Anomaly: erroneous nav signal of VOR station, Phase: ER, Possible Cause: dictaphone
Anomaly: loss of VOR capability, Phase: ER?, Possible Cause: cellphone
Anomaly: HSI's discsrepancies, Possible Cause: cellphone
Anomaly: NAV compass & CDI oscillation (off course), Possible Cause: PEDs
Anomaly: off VOR course, Phase: ER, Possible Cause: cellphone
Anomaly: off course, Possible Cause: tape player
Anomaly: music blocked VHF comm's, Possible Cause: FM radio
Anomaly: comm's blocked, Phase: GR/CL, Possible Cause: Nintendo, cellphone, notebooks
Anomaly: off course, Possible Cause: tape machine+Nintendo
Anomaly: off course, Phase: ER, Possible Cause: cellphone
Anomaly: both VORs lost, no VOR audio signal, Phase: ER, Possible Cause: cellphone
Anomaly: all directional gyros lost, Possible Cause: 25 radio's, 1 laptop
Anomaly: compass error; off course, Phase: ER, Possible Cause: laptop, comp.game
Anomaly: 2 missed approaches, Phase: FA, Possible Cause: PED suspected
Anomaly: loss of all autonav functions, Phase: CL, Possible Cause: 3 laptops, cdplayer/radio
Anomaly: loc receiver anomaly; missed app., Phase: FA, Possible Cause: PED suspected
Anomaly: compass precess 10deg, Phase: ER, Possible Cause: laptop
Anomaly: Omega NAV unreliable, Phase: ER, Possible Cause: tv set suspected
Anomaly: HSI errors, Phase: TA,CL,ER, Possible Cause: cellphone
Anomaly: nav compass sys error; off course, Phase: CL, Possible Cause: cellphone
Anomaly: temp loss of com freq., Possible Cause: cd player
Anomaly: INS nav errors, Possible Cause: electronic games
Anomaly: off course, Possible Cause: cellphone
Anomaly: eng fuel ctlr + vhf radio interference, Possible Cause: cellphone
Anomaly: off course, Possible Cause: laptop
Anomaly: EMI interference & radio alt flag, Phase: ER, Possible Cause: cd-players (2)
Anomaly: erratic cdi indications, Phase: ER, Possible Cause: 2 gameboys
Anomaly: autopilot erratic, Phase: AP, Possible Cause: cellphone suspected
Anomaly: off course, Possible Cause: gameboy
Anomaly: nav radio interference; off ILS course, Phase: AP, Possible Cause: computer game
Anomaly: EMI interference causes a split between the compass system in flight ER laptop both LOC and GS 'OFF' flags showed just prior to the Outer Marker
Phase: AP, Possible Cause: PED suspected
Anomaly: significant LOC rate of deflection, Phase: AP, Possible Cause: PED possible
Anomaly: loss of Captain EFIS display, Phase: AP, Possible Cause: 8 laptops
Anomaly: electronic compass erratic, Possible Cause: cd player
Anomaly: interfering transmitter, Phase: AP, Possible Cause: cellphone
Anomaly: NAV and COM radio problems, Phase: PED, Possible Cause: suspected
Anomaly: off approach path, Phase: AP, Possible Cause: PED suspected
Anomaly: off course due to drifting, Phase: FM, Possible Cause: PED suspected
Anomaly: HSI discrepencies, Possible Cause: PED suspected
Anomaly: EICAS interference, airspeed discrep., Phase: ER, DC, Possible Cause: PED
Anomaly: loss of COM frequency, Possible Cause: cellphone
Anomaly: ILS, radio altimeter, and primary flight display went out, Possible Cause: 20 cellphones
Beware: In C++, your friends can see your privates!
AFAIK, the FCC only bans radios and other "transmission" devices during flight. Other devices are at the discretion of the airline. For example, I was once on a flight where walkmans were allowed, but discmans weren't, because they could "interfere" with the electronics. This is a standard excuse given to everyone. If you actually get into the details, you'll find that the flight attendants know jack shit about electronics (not that they need to). It's probably just a CYA move for the airlines. Admittedly, much avionics hasn't changed much since the '60s, and it's likely it'd be far more susceptible to interference than modern stuff, but there's not much we can do about that. Laptop computers will be the next to be banned, because the flight attendants can't tell what has 802.11b and what doesn't. The simple solution is, of course, not to fly.
Now, if you're talking about the restriction on electronic devices during takeoff and landing, that's because they don't want you playing Super Mario Brothers while you're supposed to be listening to the stewardess tell you how to get off the plane in an emergency. Of course, you could read a book and not pay attention, but I guess they assume that people who are reading a book and probably read the safety information card.
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