Implementation of rear facing passenger seats in commercial aircraft

- Legislation and regulation involved by EASA (European aviation safety agency) to incorporate this kind of modification to current and new aircraft. - The overall cost (Is it financially viable?) - Weight, (Can be linked with cost, since weight affects fuel efficiency). Rear facing seats might need the use of reinforcements to withstand the G-Forces upon impact in the event of a crash. - Human Factors involving the public's opinions (optional). - How different would the design of rear facing seats be compared to traditional forward facing seats.