WiFi systems on airplanes disable themselves when the cabin door is closed, and only turn back on when the plane is above 10,000 feet. Also, WiFi use on a plane is not going to have as much RF power as a cell phone trying to transmit to a tower a few miles below the plane.

There are several planes out there now equipped with picocells to allow cell phone use. The idea here is the cell phones inside the plane transmit to antennas in the cabin, and the picocell takes care of retransmitting the signal via either satellite, or down to the ground with antennas on the outside of the plane. This way, cell phones will only use minimal RF power to transmit.


The danger isn't in a device causing the plane to fall from the sky, it's usually either interfering with navigational equipment, or the radio transmissions between the control tower and pilots. If electronics did pose a risk to anything really vital, better steps would be taken to ensure the marketing guy in row 5 did actually turn off his Blackberry. As for an iPod shuffle, it's more a distraction reducing issue. If a passenger has headphones on and music blaring, they may miss vital information if something does go wrong during takeoff or landing (the highest risk part of a flight). It's also far easier to say "turn off everything" instead of "turn off A, B, C and D, but E, F, G and H are ok".