It's up to the GM and the situation. What are the consequences in relation to the story you are trying to tell? For example if you are using parkour on a chase scene, you can probably skip falling damange because the real consequence is not being able to chase or escape. Alternatively you can allow failed rolls to cause stress, turing the chase into semi combat where the characters are trying to pull off manuevers that will cause the other to fall or be taken out. In another situation, falling might be the start of an adventure. How many stories have you read where a character has fallen down a chasm, blacked out, then woken in some mysterious place and they now have to find their way back home? Same with drowning. The only consequence might be waking up on a desert island. You could probably do a similar thing with being ejected into space. I'd try to use falling as the lead in to an adventure or obstacle to overcome in most cases. If falling is the result of a player decision, for example jumping from a moving train, I'd say it's reasonable to just assign a consequence or have a stress value that the player rolls against to reduce. If the fall is likely to kill the player, you could just have them wake up in a new morph without even assigning consequences. A clever player would probably pay a fate point to add some detail to the world to prevent damage. Something to either grab onto or something to break their fall when they land.