Alaska Airlines Jettisons Paper Manuals

fullymodo writes: "Alaska Airlines has become the first major US airline to hop on board the paperless bandwagon. While it's not quite ready to ditch paper navigation charts just yet (though that is under consideration), the airline has announced that it will be replacing its traditional flight manuals with iPads, which will be loaded up with the GoodReader app and PDFs of 41 different manuals and other materials."
So explain why I have to shut off my non-wi-fi-capable ebook reader during take-off and landing?