Jetpack

alaindustrial:jetpack

ItemsLVImplementeditemenergyjetpackflightequipment

Summary

The Jetpack is a worn EU/FE flight device: it occupies the chest slot (instead of armor) and carries a 30,000 EU/FE buffer (jetpackBuffer). Hold jump in the air and the engine thrusts you upward, burning 50 EU/FE/tick (jetpackEuPerTick): a full charge is ~30 seconds of continuous flight. Release jump — a normal fall. Out of charge mid-flight (or above the altitude ceiling jetpackMaxY) the same held jump turns into a free powerless glide: the sink rate is damped and the landing deals no damage. The glide is THIS flight's safety net: it engages only if the engine actually fired during the current flight — a jetpack that started empty falls like plain clothing, no "levitation". The buffer always burns to a clean zero: the last thrust tick takes whatever remainder is left below the per-tick cost. The safety is the engine, not the garment: letting go of jump mid-air and dropping still hurts. This is tier 1 (LV): a modest climb rate, one thrust mode, no hovering. It charges wherever the mod's whole powered family does — the Battery Box charge slot — and from an Energy Pack, though only while the jetpack sits in the inventory: the worn pack occupies the same chest slot, so the two are never worn together. Like the Energy Pack the jetpack is not vanilla armor: no durability, no enchantments, no repair; it grants 5 armor points (one under an iron chestplate's 6) through an attribute modifier — the price of the occupied slot, and protection in flight.

Energy

Its own EU/FE buffer, off the grid. Charged in the Battery Box slot, by an Energy Pack (while carried) and by other mods' chargers; spends charge only on ticks of actual thrust.

The draw is taken server-side only (in 26.2 inventoryTick is called only on a ServerLevel); the server sees the held jump through the vanilla input sync (getLastClientInput), so the jetpack ships no custom packet. A creative/spectating owner pays nothing (the shared ItemEnergy.spend rule, the flight and the safety still work.

Inventory

Not applicable — an item (stacks to 1) holding only its EU/FE charge.

Block properties

Not applicable (item).

Recipes

Crafted on a workbench (a full 3×3 grid — the priciest powered item in the mod): an iron shell, an Energy Pack at the centre (the tank and the heart of the jetpack), two batteries at its sides (the engine starters), an Electronic Circuit on top (the thrust controller), and two tin nozzles around a Copper Coil (the turbine) at the bottom.

IEI
BPB
TCT

Craft: — shaped 3×3, category: equipment: top row: iron (minecraft:iron_ingot) — Electronic Circuit — iron; middle row: battery — Energy Pack — battery; bottom row: tin — Copper Coil — tin. Repair — not applicable: the jetpack has no durability; "repair" is recharging EU/FE (see "Energy").

Behaviour

Thrust: the engine runs while the player is airborne and holds jump — on the ground a held jump stays a vanilla jump, the thrust picks up on the next tick. Each thrust tick: the client (player motion is client-authoritative in 26.2) adds a vertical acceleration of +0.15 b/tick² saturating at a 0.5 b/tick climb; the server, gating on the same three conditions, burns 50 EU/FE, zeroes the fall distance and draws the exhaust (smoke + sparks) with a soft hiss every 8 ticks. Drains to zero: the engine thrusts while even 1 EU/FE remains; the last tick takes the sub-cost remainder (the spend clamps) — there is never a dead 15–20 EU/FE tail showing an unusable 1%. Glide (this flight's safety net): at 0 EU/FE (or above jetpackMaxY) there is no thrust, but if the engine already fired during the current flight, the held jump caps the sink rate at 0.3 b/tick (~6 m/s) and keeps zeroing the fall distance — the landing is soft, free and silent (the client resets its own fall distance too, so no hard-landing thud plays). A jetpack that never fired this flight does not glide at all — the fall is exactly as without it. The flight session resets on touching the ground. Releasing jump is a normal, damaging fall: the distance accumulates from the point of release. "Flight never kills by accident" = keep holding jump all the way down. Altitude ceiling: above jetpackMaxY (default 320 — the overworld build limit) the engine refuses to thrust — glide only. A knob for server owners. Flight glow: while the engine thrusts, a torch-like light follows the flyer (jetpackFlightLightLevel = 10, a bit under a torch; 0 disables it) — visible at night and in caves. It is a moving minecraft:light block (26.2 has no per-entity lighting): placed at the player's cell each thrust tick and removed the moment the flight ends. Cleanup is leak-free — a once-per-server-tick sweep clears any light block not refreshed that tick, so no orphan light is left behind even on logout, death or unequip mid-flight. The light is only ever placed into air or water (waterlogged), never over a real block. Creative/spectator: no EU/FE is spent (the powered family's shared rule); vanilla creative flight has priority — with ability-flight on, the jetpack stays out of the way. Indication: the charge bar under the icon (gold, the LV colour); the tooltip carries the charge X / Y EU/FE and the two control lines; the chest-slot charge HUD panel in the top-left corner (shared with the Energy Pack, key H). A worn charged jetpack shows the lit model on the back, a drained one the dead model (the single visual switch point is ItemEnergy.set, like the pack's). Drop/death/relog: the charge lives in the item and persists.

Progression

The mod's first vertical-mobility item: available after the Battery Box and the Energy Pack — without LV infrastructure it can be neither crafted nor charged. Pricier than the rest of the powered family (the craft consumes a whole Energy Pack): flight is a serious convenience step. Future tiers (MV/HV: faster climb, a hover mode, a bigger buffer) are separate tasks.

Compatibility

Viewers: JEI, REI, EMI (as a plain item). Charges from other energy mods: the loader's item energy capability (Team Reborn Energy on Fabric, FE on NeoForge), insert-only, 1 EU/FE = 1 FE. Elytra: a slot conflict — the jetpack and the elytra are never worn together; compatibility is an honest either-or. Enchantments: not enchantable (no ENCHANTABLE component) — unbreaking/mending do not apply, there is no durability. Known limitations (accepted for tier 1): no hover mode — altitude is held with short jump taps; the client thrust does not apply while a screen is open (the jump key is not read) — the engine is silent on the server too at that moment (no input arrives), so there is no desync; the server does not validate altitude/speed beyond vanilla's anti-cheat thresholds — the jetpack rides the stock client-authoritative player movement model.

Balance

30,000 EU/FE at 50 EU/FE/tick is ~30 seconds of flight on a full charge; charging at the LV ceiling (32 EU/FE/tick) takes ~938 ticks (~47 s). Flight is noticeably pricier than mining (the Electric Drill's 50 EU/FE buys a whole block), as befits a premium convenience.

Related

Energy Pack — a crafting component and the jetpack's in-inventory charger; the chest-slot neighbour. Battery Box — charging the jetpack (the charge slot). Electric Drill — the price anchor: 50 EU/FE = one mined block = one tick of flight. Electronic Circuit — a crafting component.

Crafting

Shaped Crafting

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Jetpack