FiveM Fly Hack Detection Explained

Fly hacks and levitation cheats let a player float, hover, or ascend at will, bypassing gravity entirely. They are among the most visually obvious cheats on any FiveM server, yet detecting them reliably is harder than it looks. The challenge is not spotting a player rising through the air. The challenge is distinguishing that player from a legitimate pilot in a helicopter, a parachutist losing altitude at the wrong rate, or a passenger riding on top of an object. Get the heuristic wrong and your anticheat bans innocent players. Get it right and fly hackers are flagged within seconds of lifting off.

What a Fly Hack Actually Does

In GTA V’s underlying physics engine, a pedestrian entity is subject to gravity at all times when not in a vehicle. A fly hack overrides this by either injecting a continuous upward velocity component into the position report the client sends to the server, or by toggling a flag that marks the ped as non-physics-controlled. Both techniques produce the same observable anomaly from the server’s perspective: a player entity with a pedestrian model that maintains or increases altitude without any registered vehicle, parachute, or scripted ragdoll state.

Levitation cheats are a subset. Rather than ascending rapidly, the player simply holds a fixed altitude, drifting horizontally as if walking on invisible ground. These are subtler than a full fly hack because the vertical delta per tick is zero or near-zero. A naive detector looking only for rapid altitude gain will miss them entirely. The correct signal is sustained non-zero altitude above the nearest terrain or surface for a duration that exceeds any plausible jump or fall arc.

The Core Detection Problem: Aircraft & Parachutes

The reason fly hack detection is treated as a difficult problem is the abundance of legitimate vertical movement in GTA V. Helicopters, planes, gyrocopters, jets, and air vehicles of all kinds produce exactly the same altitude-increasing signature as a fly hack. A player exiting a helicopter mid-flight, equipping a parachute, and drifting down also produces altitude readings that could look suspicious if the detector lacks context.

Any detection module that fires purely on "altitude increased while on foot" will have an unacceptably high false-positive rate on servers with active aviation. The solution is entity-state validation: before classifying vertical movement as anomalous, the server checks whether the player has a legitimate vehicle assignment, a parachute item in the correct slot, or an active ragdoll state consistent with falling. This is exactly the kind of server-side context that a client-side check cannot easily replicate, since the client can lie about its own state. A server-authoritative check, by contrast, cross-references the entity model, the registered seat, and the physics state reported over the network simultaneously.

This is closely related to the problem discussed in the behavioral detection explainer: a single position reading tells you almost nothing. A sequence of readings, cross-referenced against entity state changes, tells you everything.

How Vertical-Movement Analysis Works

Effective fly hack detection builds a movement profile from several inputs sampled every server tick:

• 1. Altitude delta over time. The vertical distance covered per second is compared against the maximum value physically achievable for a pedestrian entity. Any sustained positive delta that exceeds the jump-force cap without a registered vehicle is a hard signal.
• 2. Ground clearance duration. GTA physics guarantees that an airborne pedestrian will return to the ground within a bounded time window determined by jump height and gravity. A pedestrian who remains airborne beyond that window is either in a vehicle, on a parachute, or cheating.
• 3. Entity model validation. The server confirms the player entity model is not classified as a vehicle or aircraft before applying pedestrian physics rules. A player seated in a helicopter with the correct vehicle hash will never trigger the pedestrian altitude rule.
• 4. Horizontal-to-vertical velocity ratio. Fly hacks often produce movement vectors that are physically impossible for a running, jumping, or falling ped. A player ascending at 12 m/s vertically while moving laterally at 2 m/s matches no known animation or physics state for a pedestrian.
• 5. Parachute and fall-state cross-check. If a player is flagged as falling or parachuting by the server script layer, the vertical detector is suspended for the duration of that state, preventing false positives during legitimate skydiving or BASE jumping.

The combination of these signals produces a confidence score rather than a binary flag. A single tick of unexpected altitude gain scores low. Ten consecutive ticks of sustained hover with no vehicle, no parachute, and a velocity vector that maps to no known physics state scores very high. Actions such as a kick, a screenshot capture, or a ban are triggered only above a threshold that balances sensitivity against false-positive rate.

Fly Hacks vs. Noclip: Different Signatures, Different Detectors

It is worth drawing the distinction clearly. A noclip cheat moves the player through solid geometry in any direction, ignoring collision meshes entirely. The horizontal position delta can skip through walls, interiors, and terrain. Fly hacks, by contrast, typically preserve horizontal collision. The player still walks around walls; they simply do not fall. The detection logic differs because the signal differs.

Noclip detection focuses on position continuity against the map’s collision mesh, the same domain covered in depth in the noclip detection breakdown. Fly hack detection focuses on vertical physics validity for pedestrian entities. Running both modules independently, rather than combining them into a single movement check, reduces the risk that a false negative in one category creates a blind spot in the other.

Speed hacks add a third dimension to movement abuse: a player may move at legal altitude but at an illegal horizontal rate. Fly hacks and speed hacks are sometimes combined in multi-cheat menus, so a player flagged for vertical anomalies is also re-evaluated against the horizontal speed caps described in speed hack detection. A compound flag, where both modules agree, produces a much higher-confidence action than either module acting alone.

How Fiveuxe Handles This

Fiveuxe is a fully server-side anticheat. There is no kernel driver and no ring-0 access. The movement analysis runs entirely within the resource on your server, receiving position data over the standard FiveM network layer and applying the entity-state cross-checks described above on every relevant tick.

The fly hack check is part of the Movement & Combat detection family, one of 27 modules across six detection families including Event Security, Economy Forensics, Entity Protection, Screen & Snapshot Intelligence, and the SENTINEL AI security co-pilot. SENTINEL correlates low-confidence signals from multiple modules, so a player who triggers a marginal fly-hack score alongside a marginal speed anomaly is escalated for review rather than ignored because neither module crossed its individual threshold.

When a player is confirmed, the Hive-Mind global ban network propagates the ban to 100+ member servers in approximately 0.3 seconds. Shadow-Link identity enforcement across HWID, Discord IDs, IP address, and 12 additional identifiers ensures that a ban survives a new account or a hardware spoof. Fly hackers who think a fresh account restores access are stopped at the join screen.

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