Infinite Flying (Important:Read Description) by char

step 1 

get elytra 

 put the first command in the chat wich is /scoreboard objectives add Flying stat.aviateOneCm

for the next command put a command block down and set it to ALWAYS ACTIVE and REPEAT, then type in this command

execute @e[score_Flying_min=1] ~ ~ ~ /summon Silverfish ~ ~ ~ {CustomName:"Fly",Size:0,Silent:1,ActiveEffects:[{Id:14,Amplifier:10,Duration:200000,ShowParticles:0b}]}

This command you set the command block to ALWAYS ACTIVE and CHAIN and put in the command

/scoreboard players set @a Flying 0                               make sure it is in a command block

command block is ALWAYS ACTIVE and CHAIN, command is                                          tp @e[type=Silverfish,name=Fly] ~ ~-1000 ~