I thought this article from yesterday's
Singapore Straitstimes would be of interest to this thread ....
US airlines allowing use of PDAs that can connect to Net
By Ng Hui Hui
THE use of personal digital assistants (PDAs) that enable wireless connection to the Internet is allowed if you travel on an American airline.
The Federal Aviation Administration (FAA), which regulates aviation safety in the United States, does not ban the use of a PDA - even one that can connect to the Internet through a cellular network, a spokesman for the FAA told USA Today recently.
But most of the major airlines operating in the Asia-Pacific region told The Sunday Times they do not allow the use of PDAs.
USA Today cited two examples where passengers had used their PDAs to receive e-mail messages.
When contacted, United Airlines spokesman Sophia Mah said the use of PDAs is allowed, as long as they do not transmit radio waves, which are known to interfere with an aircraft's navigation system.
But experts say it is premature to dismiss PDAs with communication functions as harmless.
'A PDA may use less bandwidth to check e-mail, but you are using the same frequency as a cellular phone, and in much the same way,' Mr Terry Wiseman, an expert on in-flight communication systems and editor of Airfax.com, told USA Today.
While this remains a grey area for American airlines, other major airlines in Asia-Pacific have definite guidelines - PDAs with communication capabilities will be treated like mobile phones, which are banned.
The five airlines are Singapore Airlines (SIA), Cathay Pacific, Japan Airlines, Qantas and British Airways.
'While there is no risk of some PDAs interfering with the plane's navigation equipment because they have relatively basic functions, others have more advanced functions that may cause some interference,' said SIA spokesman Karen Liaw.
However, if the communication functions on the PDAs can be disabled, passengers are allowed to use them for other purposes such as text editing, so long as it is not done during take-off and landing.
All electronic equipment have to be switched off during take-off and landing.
According to USA Today, Mr Wiseman suggested that the FAA's policy on PDAs may be outdated, given the convergence of phones and computing devices.
For example, he asked, should the Nokia Communicator 9110, which allows users to send e-mail messages and has other note-keeping functions, be considered a PDA and its use be allowed on aircraft?
Or, should the BlackBerry 5810, which has a built-in phone, be considered a cellular phone and be banned from use?
There are also sceptics who asked airlines to prove that mobile phones interfere with flight navigation systems.
'Make them prove it. I am an electrical engineer, and I cannot see how a mobile phone is going to mess up with aircraft navigation systems,' frequent flyer John Turner told USA Today.