Without any disrespect to anyone, TS member or not, I think I would rather leave the assurance that new device usage will have no negative effects on all aircraft up to the FAA rather than my own, individual desires. One must remember that accepting transportation on a ship/aircraft/even a taxi requires accepting the rules and regulations of that apply to that vehicle and its 'driver.' No matter how much we might need to be somewhere at a specific time, we do not have the authority to force the driver to break any regulations in order to get us there at that time.
The authority of the Captain (and by delegation, the crew) derives from similar 'rules of the sea' applying to a Captain of a ship outside normal national waters. No matter how much we are inconvenienced by the temporary use of some device while traveling by air, we have agreed to abide by the regulations governing that mode of transportation. Failing to do so places us under the possibility of sanctions accorded by the court.
There is probably no problem with an iPad and even an iPhone with any modern aircraft. In fact, several airlines are using them in place of paper navigation charts. These uses are, however, being done in strictly controlled environments: specific types of aircraft with specific types of devices, loaded with specific apps and maintained to specific standards. I have no doubt there are also devices monitoring the performance of multiple aircraft systems during these uses. The most modern aircraft use fewer and fewer mechanical controls. They are becoming flying computers. The last thing anyone (terrorists excluded, of course) wants, is for those computers and their communications to be disrupted. These uses of an iPad are certainly encouraging and can even enhance safety.
Using an iPhone is also,
probably OK, also. It is not as useful, of course, with its rather small screen.
Regulations for air transportation are not decided by "
probably OK."
Nor do I think any of us would agree to fly with a pilot who is "
probably trained." Or on an aircraft that is "
probably safe." Or that it "
probably has enough fuel to reach the destination plus any required alternate(s) plus another 45 minutes."
There are thousands of devices, hundreds of aircraft of various ages with dozens of combinations of hardware. It is no small task to test and verify all those combinations. If the task(s) needing the use of these devices is so important that you are willing to endanger your own life (texting while driving, for example) that is one thing. Deciding to endanger the lives of others, is not. And that's not just my opinion, it is the law. If you don't agree with the law, you have at least two choices. Obey it or seek its change while either obeying it or by not participating in the areas where it is applicable. Taking the law into your own hands has not been an acceptable solution since we started electing/appointing/hiring policemen/soldiers.
The subtitle of this thread is somewhat missing the point; disregarding the lawful commands of the Commander of a ship or aircraft or her authorized crew, is not just "bad," it is against the law of the land/sea.