Why do we have to turn mobile phones off on an aeroplane????

Question

What is the actual reason...what does it disrupt, and what would happen if we took a call on a plane????

Answer 1

Apparently, there is no reason whatsoever.
On some planes [well Virgin Atlantic anyway] they have phones in the arm of every seat, and they use the same signals are normal mobiles, and they have no realised the signals to not interfere at all, it's just left as a law due to the fact it's common courtasy to other passengers. how crap would a red eye be with someone jabbering on the phone next to you.

:)

Answer 2

2

Answer 3

One and for all here is why you should not use cell phones on aircraft to all the unwise.

Signal turbulence: As wireless gadgets multiply, so does the likelihood of interference with aviation systems
Monday, April 21, 2003

By Byron Spice, Post-Gazette Science Editor

Something odd was happening as the Boeing 737 made its approach to Chicago's Midway Airport. A cockpit instrument called the course deviation indicator, or CDI, showed the plane was on course, but the pilots, peering through the night sky at the lights below, thought they were too far south. An air traffic controller radioed the same concern.

Then the CDI's vertical needle suddenly swung to the left, showing the plane north of its course. After the captain made a scheduled turn to align the plane with the runway, the CDI needle again indicated the plane was on course. But then the needle swung again, showing the plane too far south.
By this time, the runway was in view and the pilots could see they were too high and too far north to land.

The apparent cause of these electronic gremlins was discovered as the plane circled around for another approach and the captain asked the passengers to make sure they had turned off all electronic devices.

The flight attendants reported that a woman passenger had been talking on her cell phone. When she turned it off, the instruments immediately settled down and the plane landed safely.

This incident, which the captain reported last year to NASA's Aviation Safety Reporting System, is just one example of how portable electronic devices everything from cell phones to Game Boys can interfere with the electronic navigation and communication systems aboard a modern airliner.
No one has yet blamed an aircraft accident on a malfunctioning laptop computer or an overactive pager, but the profusion of cell phones, laptops, CD/DVD players, game systems and personal digital assistants, or PDAs, that passengers now carry onboard is raising concern about electronic interference with avionic equipment.

Cell phone use already is prohibited aboard planes and the FAA recommends that use of all portable electronic devices be limited below altitudes of 10,000 feet. But technological changes are making it more difficult to enforce those rules.
Some people seem particularly skeptical about the in-flight ban on cell phone use, suggesting it's an airline effort to force passengers to use extra-cost phones located in the seatbacks.

In fact, the prohibition is a Federal Communications Commission rule. An activated cell phone, even when not being used for conversation, sends signals to the nearest base station. High in the air, a cell phone can "light up" base stations in a wide swath beneath the airplane's path and cause headaches for the cell network.

Answer 4

Just in case. Just being cautios.

In the instances where they think a cell phone has interuped avionic or navigational equpitment. Nobody's been able to reproduce it. They'er like witches 300 years ago. Any unexplained event has to be caused by a cell phone, we can't prove it but what else can it be?

If cell phones could disrupt a flight, do you really think they would let you have them on a plane?

There MAY be some truth to this. I was in the flightdeck of 747-200 and when I used my old anolog Motorola 2 way radio the out flow valves would open. If this happened at altitude it woud depressurize the plane.

Answer 5

Here is what is known: Neither the federal government nor the airlines are currently considering a modification of their rules. Phoning from a plane is still a no-no unless you're using one of the approved seatback handsets. We know that flight attendants are trying to be more vigilant than ever about security-there have been reports of some crewmembers refusing to fly because of worries about safety-so cellular scofflaws could face severe punishment if they're caught.

We also know that wireless communications networks weren't designed for ground-to-air communication. Cellular experts privately admit that they're surprised the calls were able to be placed from the hijacked planes, and that they lasted as long as they did. They speculate that the only reason that the calls went through in the first place is that the aircraft were flying so close to the ground.

Answer 6

Popeye has a good answer. In reality in a modern aircraft a single phone even making a call would have little effect. However if all the phones were on, as the aircraft moved away from the first base station all the phones would be transmitting simultaneously as they dropped the first station and logged on to the next. That might generate 200 watts of RF energy in the cabin, which might well interfere with the GPS system or worse

Answer 7

There is a possibility that the signals can disrupt aircraft instruments and communications.
It is small but still there.
That being the case, they also require people to pay attention in case of emergency. Many people get so preoccupied with conversations they will not pay attention to the trouble at hand.
That is why they make you sit up straight and listen as the attendant tells the emergency procedures every flight.
People just do not pay enough attention in times of crisis.
If people were infallible they would not even need the written instructions.

Answer 8

The problem primarily stems from older phones. There were not as many transceiver base stations in the past, so mobiles tended to transmit at much higher RF power levels. Nowadays they do not need to transmit as much power due to the number of base stations, the increased sensitivity of the phones and the base stations and the use of improved Forward Error Correction. Phones use a number of frequency bands that are part of a GSM system, and these cover a very wide range of frequency bands. These frequencies and harmonics (a 1GHz signal will also send 2GHz, 3GHz etc) of these frequencies are used (coincidentally) by internal aircraft systems and for ground based landing beacons (Instrument Landing Radar). Phones do contain filters to reduce the harmonics and other spurious transmissions, but these filters reduce the levels of these, they do not eliminate them. Aircraft have been designed with better RF shielding (referred to as EMC protection) on critical systems for many years, just like cars have, and the techniques are constantly improving. So the improved shielding combined with the reduced power of the phones has resulted in aircraft systems being unlikely to be affected by phone transmissions. The aircraft manufacturers are thoroughly testing this now and the results so far look promising. Aircraft remain in service for many years so it will be a long time before you can use a phone on every aircraft that is being used.

Answer 9

You have to turn it off because you are told to!

Aeroplanes are not the place for you to start ****ing about, especially if I am a passenger on it.

Safety is taken very seriously on aeroplanes. Mobile telephones when switched on imediately start transmitting and scanning for a base station to connect to. There is an outside chance all that radio activity could interfere with any one of a number of systems on the aircraft thus putting the aircraft at risk in some way.

Answer 10

The U.S. Federal Communications Commission prohibits the use of mobile telephones aboard any aircraft in flight. The reason given is that mobile phone systems depend on channel reuse, and operating a phone at altitude may violate the fundamental assumptions that allow channel reuse to work
Another NASA publication[2] details the fifty most recent reports regarding "avionics problems that may result from the influence of passenger electronic devices." Although some of the reports merely have to do with passenger interactions with flight crews, a number of them document cases of anomalous instrument readings and other problems, apparently associated with passengers' use of mobile phones as well as other devices.
The data support a conclusion that continued use of portable RF-emitting devices such as cellphones will, in all likelihood, someday cause an accident by interfering with critical cockpit instruments such as GPS receivers.