Phones Off?

[FlyingStone]

Originally Posted by Fly.Buy

Obviously the phone must send out and receive signals when in flight mode to provide live navigational data.

GPS receivers don't need to send out data during their operation, hence they work in flight/airplane mode.

[Uplinker]

Originally Posted by Ian W

I would think that in any aircraft with 100+ pax, there will be at least one cell phone left operating for the entire flight...……………. I think that this is one of those rules like the ban that used to be applied on cell phone use at gas stations where nobody wants to be the first to say it is not necessary.

At the same time as the flight attendants are attempting to enforce a rule that has no safety impact, they are not asking for window blinds to be opened for taxi/takeoff and landing that doeshave a safety impact should an incident require a decision on what side NOT to evacuate from for example.

(My bold). Both those phenomena are unlikely but still real and potentially dangerous. I would not want anybody to be engulfed in a ball of burning gas when the petrol fumes surrounding them as they refuelled their car were ignited by a small spark jumping between metal caused by a cell-phone transmission.

Neither would I want to see an aircraft arriving at 22 feet, or lower, at decision alt, in very low visibility but 100m to one side of the centre-line, owing to a rogue cell-phone's transmissions.

100% enforcement is unlikely too, but worth trying our best, I feel?

[Uplinker]

Originally Posted by FlyingStone

GPS receivers don't need to send out data during their operation, hence they work in flight/airplane mode.

But some receivers can unintentionally "leak" certain frequencies - even when only receiving. They shouldn't do if the circuit design is proper, but some might, or they might be damaged. Hence, for really critical situations, it might be requested to switch the whole device off.

[tdracer]

Originally Posted by Uplinker

But some receivers can unintentionally "leak" certain frequencies - even when only receiving. They shouldn't do if the circuit design is proper, but some might, or they might be damaged. Hence, for really critical situations, it might be requested to switch the whole device off.

Automotive radar detectors have been notorious for this - and it doesn't take damage, just cheap design/construction. Basically, some receivers - looking for a particular incoming frequency (e.g. radar detectors) - create a reference frequency that they compare to the incoming signal. If not well shielded, that reference signal gets transmitted out and can corrupt other receivers. Some cheap auto radar detectors would set off other detectors as much as a quarter mile away.
One of the reports I saw of suspected PED related interference was blamed on a Gameboy - pretty sure they don't have a designed transmit mode...