You can use Fly once you have obtained the 3rd Badge from the Vermilion City Gym after defeating the gym leader Lt Surge. Fly can be used at anytime as long as your not inside a building or cave.
simply fly off or use the ferry.
Fly is an HM and therefore it can only be taught to Pokemon. No wild Pokemon will know Fly ahead of time.
Fly To island one and use surf
On route 16.
No, Butterfree cannot learn Fly.
chach a rear leaf Pokemon that fly
The HM's that are in leafgreen are: Cut, Fly, Surf, Strength, Flash, Rock Smash, Waterfall.
threre isn't one sry but you can get the fly tipes like zapidos and legendary Pokemon! >)
vermilion city. fly to pokecenter, then go south.
Use the pokeflute.
keep walking or fly to the second closest city to you.
You have to go through the game until you get fly.