Originally Posted By: chaosmagnet
I'm no expert on Android but in Airplane Mode the radios are supposed to be turned completely off for FAA regulatory compliance.

That's a good point about airplane mode and I don't know if this "feature" applies when airplane mode is turned on, but if wifi is turned off, it's actually still secretly on by default unless you go in and change a sub-setting. I believe these guys were the first to report on this behavior of version 4.3 here.