Looking for the Fabric version?
Using brass you are able to upgrade your copper backtank to a jetpack, using the pressurized air inside to propel yourself through the air.
Inspired by Simply Jetpacks, this jetpack also has a hover mode.
Like the copper backtank, the jetpack does also go in the chest slot, feeds air to items like the extendo-grip and can be enchanted with Capacity. Just like the backtank it is charged by placing it down and supplying it with rotational force.
When underwater while sprint-swimming, the jetpack boosts your swimming speed. Additionally, the hover-mode prevents you from floating downwards.
If a mod similar to Elytra Slot,
which enables equipping an elytra in addition to a chestplate,
the jetpack will instead give you firework-like boost while the player is pressing the UP-key.
Curios Support is possible by adding it via a datapack. Save to following to data/curios/tags/items/back.json:
{
"replace": false,
"values": [
"create_jetpack:jetpack"
]
}