This document discusses electronic flight bags (EFB), which provide pilots with digital alternatives to paper charts, manuals, and documents. It outlines three classes of EFB based on how integrated they are with the aircraft, from portable commercial devices not connected to aircraft systems (Class 1) to fully integrated systems requiring airworthiness certification (Class 3). The main problems reported with EFBs are issues with electronic displays, hardware reliability, human performance impacts, and improper placement, mounting or stowage of the devices in the cockpit.