system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why have no plane passenger parachutes been invented?
gpt
* Passenger airplanes are not designed such that 200 untrained passengers can jump out of them quickly and safely in an emergency.

* Parachutes are heavy. Carrying a parachute for every passenger of every flight would cost hundreds of billions of dollars in wasted fuel, while not really making anyone safer.