greenery

Do you see many people sneak a Cell Phone conversation while the flight is Airborne? I read about all the people who used their Cell Phones on the flights on Sept 11th but I was always under the impression that Cell Phones do not work above 2000 feet on a plane.

I checked my phone as I was flying right over Philly at 25,000 feet and had no service. I know it is illegal but at what elevation does the Cell Phone stop working even though you are directly over a City?

UKtoUSA

I was once told that they do work on planes and that because the phone companies cannot pinpoint your location (as your moving into different areas so quickly) that your calls are free??

FlyingToFly

I'm confused about this as well. There have been times where I honestly forgot to turn off my phone, remembered in-flight, and reached into my pocket to turn it off. It has never displayed service.

rufflesinc

since the hijackers were aiming for buildings, they were probably flying much lower than the planned flight level so cell phones could get a signal.

owflyer

Blackberrys will often sync up when near major cities at altitude.

AAaLot

I once noticed that GSM service literally did not begin until about 20 feet over the runway.

PhlyingRPh

Cellphones, GPS device, Digital Camera, iPOD, Noise Canceling Headphones - ALL ON! I no longer have any respect for american aviation laws so I don't bother turning any of my devices off any more.

dd992emo

And when someone asks you to do something you don't want to do, do you hold your breath until they acquiesce?

VideoPaul

I spent a very boring flight staring at the signal indicator on my cell phone and several times I got one or two bars but they did not last long enough to sync up or be useful. The reason these devices typically don't work in the air is that the antennas are mounted on their towers or builings with a significant amount of "beam tilt" downward, sometimes as much as 7 degrees. This focuses the signal to the ground where the cell phones are and limits interference site to site. In a very tall building, if the building has not installed indoor cell repeaters, you will have a hard itm getting relibale signal at the top floors. The Hankock center here in Chicago is a very good example.

Typicaly on landing you will start to see synchronization inside the inner ILS marker and you will get the phone synced up and things like voicemail alerts and such synchronized by the time you are over the numbers. I did hear a cell phone ring once in the middle of the flight, that certainly raised some eyebrows.

Ther are some services, I had this happen with Nextel, that proactively prevent you from using your phone at a certain altitude. I was up in my Piper at around 3,000 feet and the display had tons of signal and was time and services synchronized, but said "service unavailable" if I tried to make a call. With Verizon I have found that if I loiter in the air witin half a mile of a cell tower I can get phone calls made.

Not that I'd ever do that while flying...

--PP

sany2

I once recieved a phone call while in flight. I don't remember where in flight.. what altitude, etc, but I remember forgetting to turn my cell phone off and it vibrating in my pocket saying incoming call. For obvious reasons, I didn't answer it.

greenery

So all the talk about the many Cell Phone calls from Passengers flying over rural PA on September 11th were all hype?

marsel

flying NBO-AMS and having forgotten to switch off the mobile i then found two 'welcome to the network' messages - obviously from networks of two of the countries we were flying over. ofcourse no idea how high was the flight at that moment but one message i remember was from a Tunisian network (so not even close to NBO to get it at departure)

I'mOffOne

You have to be pretty low. I don't talk on the phone much when I'm flying GA, but when I lost my radio a year ago in a light aircraft I used it to call the tower to get my landing clearance. I had a hard time getting a connection above 2,000', and the call wasn't clear until I was below 1,000'. When flying at work, I usually don't hear the interference from someone who left their phone on until final approach below 2,000'.

I believe the 9/11 aircraft were being flown low. They may not have had a strong or steady signal, but enough of one to make a cell call.

brosnan6

Agreed. I get reception very close to landing, maybe a few hundred feet above ground?

dimramon

Since no one has done it yet, here goes:
Great question by the OP!^