Rotorcraft Flight Model (RFM) is a physics framework that allows accurate representation of the physical flight characteristics of real-world helicopters.
This is a public TEST build. It flies, but there will be bugs, and I'm one person, so I can't find them all on my own. That's what this release is for. If something breaks, please report it (see the bottom).
Instead of vanilla's scripted handling, RFM flies off the forces the aircraft actually makes. Every rotor blade is simulated as it turns, the engines and gearbox actually drive the rotor, and the weight and balance change as you load up, burn fuel and fire.
AIRCRAFT
RFM versions sit next to the vanilla helicopters in Game Master and the Conflict vehicle lists. Vanilla helicopters aren't changed.
- UH-1H: transport, armed, HE/HEDP gunships, shark-nose gunships, civilian
- Mi-8MT: transport, armed, HE/HEDP gunships, civilian (red/blue)
WHAT'S SIMULATED
- Rotor blades: lift, drag, stall and flapping on every blade. Teetering rotor on the UH-1, articulated rotor with lead-lag on the Mi-8.
- Tail rotor torque, translational lift, ground effect and retreating-blade stall.
- Engines, gearbox and governor: real start-ups, rotor RPM that can droop and overspeed, autorotation, single-engine flight on the Mi-8, and a rotor brake on the Mi-8.
- Weight and balance: fuel, crew, passengers, cargo, supplies and weapons all change the weight and CG live.
- Skids and wheels with suspension, and nose-wheel steering on the Mi-8.
- Damage uses the vanilla hit zones: engines, gearbox, drive shafts and rotors fail on their own, and repairs carry over.
- Rotor strikes on trees, buildings, terrain and water, and they hit back into the airframe.
- Mi-8 AP-34B autopilot (attitude, heading and altitude hold).
CONTROLS
- Uses the vanilla helicopter keybinds (Settings > Controls > Helicopter).
- Joystick/HOTAS, keyboard, keyboard + mouse and gamepad. Pick one in Settings > RFM (Auto by default).
- Keyboard is rate-based: hold a key to move a control, let go and it stays there.
- Pedal helper: handles the anti-torque pedal for you if you don't have rudder pedals.
- Bind "Force Trim Release" (Settings > Controls > RFM) before you fly. It sets where the cyclic rests and currently engages the Mi-8 autopilot.
SETTINGS (Settings > RFM)
Control device, pedal helper, input tuning (sensitivity, key speeds, deadzone, response curves), camera shake, an RFM HUD that only shows inside the aircraft, and speed units (knots, km/h, m/s).
MULTIPLAYER
Works on dedicated servers. The pilot's machine flies the aircraft and everyone else sees it smoothly. Multiplayer is the part I've been able to test the least, so server reports help a lot.
KNOWN LIMITATIONS
- Some Mi-8 data (blade airfoil, a few masses and dampers) are engineering estimates.
- I haven't confirmed Conflict refuel/repair or server save/restore work with RFM aircraft yet.
- The Mi-8 autopilot on/off is a stopgap for now (trim button: release to engage, double-press to turn it off).
REPORTING BUGS
Tell me which aircraft, what you were doing and what happened, and attach your log:
Documents/My Games/ArmaReforger/logs/<date>/console.log
If it happened on a dedicated server, the server's console log helps too.
LICENSE
Rotorcraft Flight Model (RFM) is released under the Arma Public License – No Derivatives (APL-ND).
Allowed:
- Using RFM in your missions, scenarios and servers.
- Making your own mods that list RFM as a Workshop dependency. That includes new aircraft built with RFM's components and variants of RFM's aircraft (liveries, loadouts, stations). Those mods can be open or closed.
Not allowed:
- Modifying RFM, or re-uploading or repacking it, in whole or in part.
- Copying RFM's scripts, prefabs, configs or other files into another mod. Use it as a dependency instead.
- Any commercial use (also forbidden by the Bohemia Interactive EULA).
Credit isn't required, but I'd appreciate it. If your mod uses RFM, please mention it on your Workshop page, since it changes how helicopters fly.
Full license text: https://www.bohemia.net/community/licenses/arma-public-license-nd
