A few years ago, I was in court for my divorce. The clerk asked everyone to turn our cell phones off. I had just gotten a new blackberry, and assumed it was off. In reality, I only turned the display off and didn’t know that it was still on. Shortly thereafter, the clerk announced that someone’s phone was still on and asked all of us to check our phones again. I finally and embarrassingly figured out that it was mine.
But I’ve flown a couple of times with my phone on inadvertently. How come the airplane couldn’t detect this?
Are you sure there wasn’t some interference with the PA system in the courtroom? If certain types of cell phones are near a microphone, there will be a distinctive beeping/popping sort of noise. If one hears that noise, there’s no doubt there’s a cell phone on nearby.
This was a couple of years ago, but I believe that this was the source of the detection. I guess my point is that if cellphone use is potentially a safety hazard, airlines should have some sort of mechanism to check. I suspect that it’s probably not a significant hazard and that the time it would take to locate the offending cellphone(s) on the plane would be a cost that outweighs the safety benefit.
From what I understand, active cell phones are not actually a safety hazard onboard an airplane.
The problem is that when the aircraft is below about 10,000 feet, the cell phone towers are in contact with the active cell phones. The software in the tower is designed to handle transmit speeds that are consistent with highway speeds, not aircraft speeds. So, there is a potential for the tower’s operation to be compromised by the speedy cell phone when the signal is handed off to another tower.
I was in a plane a year or so ago in which a little after telling everyone to turn off their phones, the flight attendant made an announcement something like “There are 3 cell phones still on.” No idea whether she was lying or not, but perhaps they can detect them and just don’t care.
The court cares, because a ringing phone disrupts the proceedings. The airlines don’t give a shit, because it has no effect at all on their operations. The only people who care are the cell phone companies that own the cell towers you are flying over. Your altitude means your phone is in range of a large number of non-adjacent cell sites. This plays hob with the software that decides which cell site is going to handle your phone, in case you get a call. The cell companies have no way to force the airlines to care about that, though, so the airlines do nothing.
Mythbusters looked at this and it is possible for a cell phone to interfere with a plane. Not all cell phones will do it and not all planes are affected but it is easier to just tell everyone to turn off their phones.
I would bet you a dozen Krispey Kremes that the court clerk/recorder was only able to tell because of the interference thing with her/her electronic gadgets.
The gizmo that DCinDC linked to above uses the same principle. All it does is detect that there is a burst of activity on frequencies used by cellular companies. You don’t need this, if you know what to look for. Wireless carriers using a TDMA or GSM technology have a more distinctive interference tell-tale, and are more likely to get you busted (AT&T, T-Mobile, old school Nextel), while CDMA carriers (Sprint, Verizon) are much less likely to give you away.
Nextel was the worst, even before the phone rang, I knew it was going to because of the interference with my car’s stereo. I used to freak people riding with me out because I would hear the sound, turn off the stereo while saying 'My phones about to ring",. and then it would.
Still, no way they can narrow it down to you personally in the courtroom. Unless your guilty look gives you away.
The flight attendant was completely BSing. No way she knew there were three phones on, that was just a scare tactic.
It could be worse. This may be apocryphal, but I remember attorneys talking about a judge in N.D. Texas who demanded that the batteries be removed from all cell phones, pagers, etc… in his courtroom. If a cell phone went off anyway, it was an instant contempt of court finding, with a typical fine being $500, payable on the spot.
Not sure if it was true, or only happened to one person, but the essential message, “Don’t mess with a Federal Judge in their court,” was pretty clear.
Well, they probably could if they installed detection equipment. But that’s an expensive proposition. It’s not because the hardware would be expensive. It’s because any hardware would have to undergo government-approved testing to certify it as “flight worthy.” The testing is very expensive. And then there’s the installation costs.
It’s doutful an airline will install such a system unless there’s an FAA mandate.
Also the cost of training and a contingency plan for what to do when there’s a live cell phone on the plane. Do you ground the plane until that last person turns off their phone. Do you kick them off the plane if they refuse etc etc etc…and what if, after all that, it’s someone on the ground crew.
It’s just easier to ignore it.
My first thought is that they just said they could detect something to get the holdouts to finally turn the damn thing off. Get enough people in the room, chances are pretty likely someone’s left their on, making it look like they can tell.
Yet it’s obvious that simply telling people this is much less than 100% effective: some will ignore it, some will think their phone is off when in fact it’s on. So if there’s any meaningful chance of a meaningful problem due to interference, it would be extremely (nay, criminally) irresponsible to rely on voluntary compliance.
One plausible explanation that’s occasionally put forward says that airlines don’t want you distracted by a phone conversation during flight - you might not pay attention to the safety briefing, or be alert for instructions in case a problem happened.
Now pretty much obsolete - if and when your mobile phone is hitting too many towers, the cell system simply denies you service. (I’ve verified this on numerous occasions from a small plane.)
c) it is a “mandatory” Service Bulletin from the airframer or component supplier.
Neither the manufacturer or their suppliers have any enforcement power, but the risk of having an incident or accident related to an SB what wasn’t done would generate enough bad PR and press that they would lose money, and so most operators will comply with an SB. Depending on the severity of the risk being described, it may or may not need to become mandated by the FAA/Transport Canada/EASA/etc.
When I worked with Federal law enforcement (US), there was a tool (the name escapes me) that could impersonate a cell tower and enumerate all cell numbers for what I’ll just call "a reasonably wide radius). You could then pick your target number and use the tool as a directional detection device to track down the target’s whereabouts. This is going back a few years. But it was a neat toy. I ummmm… highly doubt the airlines or courts would use this though (at least divorce court - maybe for a high profile Dr. Evil case).