Jetpack

/summon FallingSand ~ ~1 ~ {Block:repeating_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,Command:"/testfor @a {Inventory:[{Slot:100b}]}"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:repeating_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,conditionMet:1b,Command:"/effect @a[score_jetpack=0] levitation 0"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:chain_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,Command:"/effect @a[score_jetpack_min=1] levitation 1 15"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:chain_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,Command:"/scoreboard players set @a[score_jetpack_min=1] jetpack 0"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:chain_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,Command:"/execute @a[score_jetpack_min=1] ~ ~ ~ /particle lava ~ ~-1 ~ 0.1 0.5 0.02 0.01 15"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:chain_command_block,Data:1,TileEntityData:{auto:1b,powered:1b,Command:"/execute @a[score_croupir_min=1] ~ ~ ~ playsound random.fizz @a[score_croupir_min=1] ~ ~ ~ 0.75 2"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:command_block,Data:0,TileEntityData:{Command:"/scoreboard objectives add jetpack stat.sneakTime"},Time:1,DropItem:0,Passengers:[{id:"FallingSand",Block:heavy_weighted_pressure_plate,Data:1,Time:1,DropItem:0}]}]}]}]}]}]}]}