Some interesting comments in this thread! All aeronautical navigation uses DR as the primary method of navigation, both VFR and IFR. DR is supported by navaids and/or map reading. The CASR Part 61 MOS (vol 2) lists radio navigation as a required competency for both the PPL and CPL, there is a legal requirement to be trained to a defined level of competency before being authorised to conduct solo navex's. The approval to use PEDs as EFBs is limited to satisfy the requirement to carry charts and manuals, not as a means of navigation. It concerns me when I see aircraft fitted with multiple PEDs mounted on control columns, stuck on instrument panels and hanging off window mounts. Surely one is enough, these devices will (if they haven't already) lead to accidents as the result of distractions, like mobile phones in cars are.