New Generation Handsets

Many of the new generation handsets, "Smart Phones" and "PDA's", have a PDA functionallity in them.

The new Nokia 6680 is one such phone I have in mind. It has an "off-line" function has disables the GSM Radio, this allows you to use the phone as a PDA or game console!

Recently, Saturday and again on Monday, I flew to Cape Town on Kulula airlines. On Saturday I had an agrument with the Air Hostess that if the phone was offline, it did not use the GSM radio and therefore it can not interfere with the aircarft's avionics; which I personally think is a lame excuse. I tested the GSM signal on takeoff and found that after about 800-1000m the phone lost signal, so how on earth can a GSM interfere at 10000m.

Anyway, I eventually gave in and switched on the phone, in the middle of my BackGammon game.

Never the lesss I am now determined to find out the following:
1. Does GSM signal interfere with aircraft avionics?
2. Has the Nokia phones like 6680 been approved by Civil Aviation and does it have to be?
3. What is the technial explaination of GSM "OFFLINE"?

Why do they allow iMate and IPAQ that have a GSM Radio to be used "OFFLINE" or "FLIGHT MODE" and yet not other hand sets?

Appreciate any comments.

lol, a colleage and i were discussing the "flight-mode" feature just this afternoon, and i was saying how i wonder if flight attendents would believe you if you tried to use the phone during a flight...

i always thought the "interference" came from the handset trying to find a signal, but i don't know if that is really the case

mm, i also think its the handset trying to find signal..

But there was some stuf a while ago about airbus(or boeing) testing with a GSM tower in the plane, and thus getting rid of those phones they stick into the arm rest thingies on overseas flights, now everyone would just use their cell phones, over some roaming agreement, going through the aeroplane's cell tower, and then getting routed via sattalite... There was something about a request to change the FCC rules to allow for this, but i havent seen anything in a while. Maybe it only effects older planes...

The thing that got to me(before i had my ipod) was the Air Hostess and the airline had some rule that no CD players were alloud during flight also kulula

If cell phones were dangerous on a plane - then they would make you hand them in like a gun for the flight. They would all be off and locked up in the cockpit.

Do you really believe that some people don't have their phones on during the flight? Have you ever heard them announce the cause of a crash or accident to be a cell phone?

The flight mode on all devices have to be approved by the CAA (Civil Aviation Authority) before you can use them on a flight. The Nokia phones have not been approved yet. So, its not the airlines that are being difficult, its the CAA... The US agency (FAA) have approved the Nokia "Offliine" mode already.
BTW - Interference affecting flight safety is only relevant on Fly by wire planes (the Airbus A320, A330 and A240, Boeing 777). Kulula use the Boeing MD80 series plane which uses Hydraulic flight controls. The danger comes in when your phone interferes with the radios and the pilot has the potential to miss important ATC instructions...