What is the point behind requiring airline passengers to turn off all electronic devices?

Question

I think I can understand wireless phones, pagers, satellite radio, etc. But why every electronic device, no matter what it is?

Answer 1

Control.

Answer 2

This is all about EMI ( electro-magnetic interference ). All electonic and elctromechanical devices radiate energy away from the device when they operate.

While manufacturers of the devices test for EMI emissions and certify compliance with the compliane labs such as UL and CE the FAA still has concerns that the emissions will trigger signals in aircraft systems which are unintended or block intended signals resulting in undesired control inputs or blocking of desired control inputs. There is also a smaller concern about interference with communications.The aircarft systems are shielded from RFI and EMI by the manufacturers. The FAA is simply being conservative.

This unintended input is most dangerous when the aircraft is close to the ground as the time to correct the matter before impact with the ground is short...the closer to the ground you are the shorter the time to correct.

Hope that helps a bit.

Answer 3

First of all, t/o and landing are the most dangerous times of a flight. Second of all, a cell phone or other device could interrupt the planes electronics due to the electrical signals the device is zinging around inside of it. Now, do you want to be 50 feet off of the ground in a jumbo jet going 200 miles per hour when the pilot suddenly loses response to the aircraft?

Answer 4

Take an example of a mobile ringing in close proximity of a TV, radio or even computer monitor, one can observe the interference caused. Taking mobile as an example lets discuss the following:
Aircraft communication normally works from HF to UHF, since our mobiles operate in nearly GHz range and the intensity is quite high, there is high probability of interference with aircraft communication/navigation system. The extent of interference depends on the number of transceivers working (mobiles in our case) in the various frequency range with varing power densities.
The consequences can be well thought of if the aircraft reads incorrect attitude information or the communication is lost with the ground. Thus, as a safe measure it is advised to switch off all electronic instruments which can transmit or receive EM waves.

Answer 5

ALL electronic devices emit electromagnetic radiation (EM waves). EM waves can induce currents and such in wiring and cause interference with other waves (like communication).

The frequencies should be different enough that there is no problem. But instead of taking the risk, turn everything off.

Answer 6

Triggys answer is right, but just wanted to add, the reasoning is T.O. and landing are the most critical phases of flight, when the A/C is close to the ground.
Also, the rule says no cell phone useage when operating under IFR, but for commercial flights this means all the time. Private flights may be flown under IFR or VFR.

Answer 7

radio devices may interfer with the sensitive aircraft equipment. aircraft radio equipment are EXTREMELY SENSITIVE. more sensitive than the normal radio equipment... normal electronic devices do so too, though may not be so significant...

every electronic device? due to security. any electronic device is a possible terrorist equipment. with the increase in the number of air-hijacks over the year, they wanna make sure no terrorist try anything on them :)

Answer 8

To see if you're an obedient sheep.

And because all electronic devices emit an electro-magnetic pattern that may, under truly bizarre circumstances, interfere with navigational and communication equipment onboard.

Answer 9

Anything that uses energy (in most cases in an airplane, a battery) gives off electromagnetic waves which can interfere with radio waves from tower to plane or plane to tower. So they wait until you have broken through 10,000 feet so these waves can disapate to some extent before reaching whoever they may be talking to. And they also wait until this altitude because they don't transmit as many messages so there is less to interfere with!

Answer 10

All electronics give off different wave lengths and for safety
reasons, it should all be turned off. Its probably one in a
million percent chance the electronics will effect the aircraft's
sensistive electronic system but nevertheless, nobody would
take that chance and quite rightly so I believe.