My wife works as cabin crew for a major international airline. A few years ago she was grateful that they abolished the requirement that all crew (an A380 has around 30 crew) had to bring their manuals for every flight. The book was about 3kg and rather bulky so took up most of the room in her flight bag where she was also supposed to keep a jacket, jumper, pair of shoes (they switch from heels when boarding to flats during flight), hat, make up and various bits of documentation.