The Jetpack is an equippable tool that allows the player to fly for as long as the fuel in the Jetpack lasts. Flying is performed by holding down the jump key. It also has a Hover Mode, which can be toggled by pressing the M key. In Hover Mode, holding the jump key will make the player descend at about one quarter speed, while releasing it will make the player fall at about half speed.
The Jetpack is limited to a maximum flying height of ~245 meters (blocks) above the bedrock layer. For comparison, the Electric Jetpack is limited to ~185 meters above bedrock.
There is also a mostly superior, electric, version of this tool, the Electric Jetpack.
See: Crafting Guide
A fully fueled Jetpack can properly fly for about 60 seconds, followed by about 8 seconds of low power mode (which can only slow the player's descent, instead of fly).
The Jetpack can be refueled by placing it in the bottom of a Canning Machine, and placing 6 fuel cells (i.e. Coalfuel Cells or Biofuel Cells) in the top of the Canning Machine. 6 CoalFuel Cells will give about 95% fuel, and 6 Biofuel Cells will give about 30% fuel. As such, there is no way fully fuel an empty Jetpack without wasting some fuel.
As of 2.x, the Jetpack needs to be refueled in a different way. Since the biofuel and coalfuel cells no longer exist, the Jetpack is now fueled with Biogas(Fluid). The jetpack is refueled by placing it in a Canning Machine, or inside a Bottling Plant. Biofuel is made inside the Fermenter.
We present you the intimidating, delicate and surely amazing movement device of the future:
The Jetpack, HAYO!
Everyone knows, owning a Jetpack is the dream of every miner. Actually it's everyone's dream.
Thus, we decided to make another dream come true and invented this sweet Jetpack.
The Jetpack Move-It-Tiki-Style 999 has everything you need to conquer the air:
Thrusters, advanced tin straps, forwards thrusters and even a fuel tank! And don't forget the full automatic Chicken Launcher and the integrated Mr. Cappuccino for flight breaks.
We are not responsibly for starvation caused by not filling up the containers of the food supply equipment. In the current version of the Jetpack Move-It-Tiki-Style, said containers do not exist.
Just equip it like a casual chest armor, though it's being strapped on the back, and hold SPACE to fly around... until your Fuel runs out that is...