This guide explains how to build and tune Arma 3 PlaneX/basic flight model config values with the RKSL Flight Model Graph Tool.

The tool is designed for addon makers who need to see how envelope[], thrustCoef[], control authority arrays, drag coefficients, altitude limits, and landing values work together before exporting a config snippet.

• Step by step workflow
• Finding the source data
• Field reference
• Formulas and estimates
• In-game tuning checklist

• Imports an aircraft config snippet or starts from a BIS aircraft preset.
• Draws the main PlaneX graph arrays as editable speed curves.
• Lets the user drag graph points vertically to rewrite the matching array values.
• Shows derived stall, thrust, drag, climb, and control authority views.
• Exports a clean config snippet for the tuned class.

The tool is a tuning assistant. It does not replace in-game testing, resolved inheritance checks, Geometry LOD mass checks, or final config validation.

Keep these three things separate while tuning:

• Extracted game config values.
• Tool-only estimates and graph overlays.
• In-game calibration changes made after flight testing.

• Bohemia Interactive - Arma 3 Plane class config reference
• Bohemia Interactive - CfgVehicles config reference

Follow this process for each aircraft type. Do not tune duplicate editor variants separately unless they use genuinely different physics values.

Open the tool and choose one of the BIS aircraft presets that most closely matches the aircraft role, mass, speed range, and engine type.

Good starting comparisons:

Use the preset as a known-good baseline, not as the final answer.

Find the aircraft class you are tuning in CfgVehicles.

Record:

• Class name.
• Parent class.
• Display name.
• Source file path.
• Any inherited parent class where the flight model values are actually declared.

If the aircraft inherits from another class, resolve inheritance before changing values. Many editor-facing variants reuse the same physics class.

Enter these values before editing curves:

mass kg, base thrust N, and the structural limits are tool calculation inputs. They are not exported as PlaneX config fields by the current tool.

Paste the existing config values into the matching fields:

• envelope[]
• thrustCoef[]
• aileronCoef[]
• elevatorCoef[]
• rudderCoef[]

The tool resamples editable curves to 14 points. Before resampling a real config array, keep the original values in the source note or version control.

Each numbered point is a speed station.

• envelope[] covers 0% to 125% of maxSpeed.
• thrustCoef[], aileronCoef[], elevatorCoef[], and rudderCoef[] cover 0% to 150% of maxSpeed.

Drag points vertically to change the value at that speed. Use the point table to see the exact speed and coefficient being edited.

Use the Lift Envelope view.

• Set the 1 g crossing near the clean stall target.
• Raise the mid-speed region until sustained turns feel credible.
• Keep the peak near the desired maneuvering range.
• Taper high-speed lift so the aircraft cannot pull unrealistic turns at maximum speed.

If stallSpeedForced is 0, the tool estimates clean stall from the envelope[] 1 g crossing.

Use the Thrust, Drag, and Climb Estimate views.

• Shape thrustCoef[] so low-speed acceleration, cruise acceleration, and high-speed falloff are plausible.
• Use airFrictionCoefs2[] for most high-speed drag tuning.
• Use airFrictionCoefs1[] for broader speed-range drag adjustment.
• Keep altNoForce higher than altFullForce.

The goal is for available thrust and drag to balance close to the intended level-flight top speed, then degrade plausibly with altitude.

Use the Control Authority view.

• aileronCoef[] controls roll authority by speed.
• elevatorCoef[] controls pitch authority by speed.
• rudderCoef[] controls yaw authority by speed.
• aileronSensitivity, elevatorSensitivity, and rudderInfluence are broad scalars.

Use the arrays for speed-specific behaviour and the scalar fields for whole-aircraft heaviness.

Use the Stall / Landing view and test with flaps, gear, and airbrake options.

• Raise flapsFrictionCoef until approach and descent behaviour are useful without becoming a brake parachute.
• Tune gearsUpFrictionCoef against gear-down speed loss and approach drag.
• Tune airBrakeFrictionCoef against dive recovery and combat-speed deceleration.
• Keep landingSpeed above the landing-configuration stall speed with a practical margin.

Use Copy snippet or Download config.

Paste the exported values into the aircraft class or into a controlled child test class. Test in-game before replacing production values.

After each meaningful change, record:

• Date.
• Source class.
• Changed fields.
• Test conditions.
• Result.
• Next change.

Use the best available source for each value. Prefer extracted config and measured model data over guesswork, then use real-world data where the game needs a credible target.

The bundled presets were extracted from a local Q:\a3 config tree. If your Arma 3 source tree is mounted elsewhere, search the equivalent unpacked PBO folders.

Check these files first:

• config.cpp
• config.hpp
• Included vehicle config files.
• Any generated config output used before packing.

Find the final aircraft class, then follow parent classes until the flight model fields are declared.

Record whether each value is:

• Directly declared on the aircraft class.
• Inherited from a parent.
• Estimated by the tool.
• Calibrated after in-game testing.

If you only have PBOs, unpack the relevant Arma 3 PBO and convert config.bin to readable config text with your normal Arma tooling.

Common source areas:

• Arma 3\Addons\air_f*.pbo
• Arma 3\Addons\drones_f*.pbo
• Any DLC aircraft PBOs used by the inherited class.

Do not edit extracted BIS files. Copy the values into your own addon class or test class.

Use Object Builder or your modelling workflow to inspect:

• Geometry LOD mass.
• Main dimensions.
• Wing span and wing area if available.
• Centre of mass position.
• Gear/contact point layout for takeoff and landing testing.

The tool uses mass kg for estimates. The final in-game aircraft behaviour still depends on the model and config together.

Useful real-world or design-target values:

• Maximum level speed.
• Stall speed clean.
• Stall speed with landing configuration.
• Landing approach speed.
• Maximum takeoff mass and empty mass.
• Engine static thrust or shaft power.
• Climb rate.
• Service ceiling.
• Positive and negative G limits.
• Roll rate and pitch response if available.

Use real data as a target, then adapt it to Arma gameplay and AI behaviour.

Build a small test mission with clear weather, no wind, repeatable fuel/loadout, and a known starting altitude.

Record:

• Aircraft class.
• Fuel and payload.
• Altitude.
• Speed.
• Flaps, gear, and airbrake state.
• Throttle setting.
• Test result.

Run the same test after each change. If the test method changes, do not compare the numbers as if they came from the same run.

This page maps the tool fields to Arma 3 config values and explains how to source or calculate each value.

The current editor uses 14 draggable points for each graph array. Imported arrays with a different count are resampled for editing.

The tool exports:

• displayName
• simulation
• maxSpeed
• landingSpeed
• stallSpeedForced when above 0
• envelope[]
• thrustCoef[]
• airFrictionCoefs0[]
• airFrictionCoefs1[]
• airFrictionCoefs2[]
• aileronCoef[]
• elevatorCoef[]
• rudderCoef[]
• aileronSensitivity
• elevatorSensitivity
• rudderInfluence
• flapsFrictionCoef
• gearsUpFrictionCoef
• airBrakeFrictionCoef
• altFullForce
• altNoForce

These formulas explain how the tool places graph points and how to calculate useful starting values.

For a graph array with N editable points and zero-based point index i:

station_speed_kmh = maxSpeed_kmh * range * i / (N - 1)

The current tool uses N = 14.

Example for maxSpeed = 800 and envelope[] point 6:

station_speed_kmh = 800 * 1.25 * 6 / 13
station_speed_kmh = 461.5

When stallSpeedForced is 0, use the speed where envelope[] crosses 1 g as the clean stall estimate.

If two adjacent points surround 1 g, interpolate between them:

t = (1 - lower_g) / (upper_g - lower_g)
stall_speed = lower_speed + t * (upper_speed - lower_speed)

If no two points cross 1 g, the curve does not provide a useful clean stall estimate.

Use landing-configuration stall speed if known:

landingSpeed = landing_stall_speed * 1.20 to 1.35

Use the lower end for light aircraft with forgiving handling and the upper end for heavy, fast, or AI-sensitive aircraft.

A practical initial shape:

• Below stall: below 1 g.
• Around stall: crosses 1 g.
• Maneuvering region: rises toward the desired positive G target.
• High speed: tapers so the aircraft cannot sustain unrealistic maximum-speed turns.

Use this relationship as a rough check:

approx_maneuver_speed = stall_speed * sqrt(positive_limit_g)

This is only a tuning guide; Arma behaviour still needs in-game validation.

Bohemia documents PlaneX air friction as a per-axis model-space calculation using airFrictionCoefs2[], airFrictionCoefs1[], and airFrictionCoefs0[].

In simplified form for each axis:

friction_force = v * abs(v) * coef2 + v * coef1 + sign(v) * coef0

The arrays contain three values:

airFrictionCoefs0[] = { X, Y, Z };
airFrictionCoefs1[] = { X, Y, Z };
airFrictionCoefs2[] = { X, Y, Z };

Use the same axis ordering as the source config. Preserve signs and decimal precision when copying values.

base thrust N is a tool-side graph input, not an exported PlaneX config value.

If static thrust is known:

baseThrustN = known_static_thrust_N

If engine power is known instead:

baseThrustN = power_W / target_speed_mps

For prop aircraft, choose a low to medium target speed near best climb or cruise. For jets, start with known static thrust if possible.

If no thrust or power data exists, copy a similar BIS preset and calibrate until the Thrust and Drag views balance near the intended top speed.

The tool estimates climb from excess power:

excess_thrust_N = thrust_N - drag_N
excess_power_W = excess_thrust_N * speed_mps
climb_mps = excess_power_W / (mass_kg * 9.80665)

Use this only for comparison between tuning passes. Final climb rate must be checked in game because Arma control response, AI behaviour, payload, altitude, and model setup all affect the result.

A useful tuning assumption:

• Below altFullForce, thrust remains fully available.
• Between altFullForce and altNoForce, thrust progressively reduces.
• At or above altNoForce, thrust influence reaches zero.

Keep altNoForce higher than altFullForce. If the values are too close, aircraft performance can collapse abruptly with altitude.

Use this checklist after every meaningful curve or drag change.

• Build a temporary test class or keep the tuned class isolated in a test addon.
• Use a fixed fuel and payload state.
• Use clear weather and no wind.
• Test at known altitude bands.
• Record the config version or commit.
• Record which preset or aircraft class was used as the baseline.

Run level flight tests at:

• Sea level or low altitude.
• Typical combat altitude.
• Near altFullForce.
• Above altFullForce but below altNoForce.

Record:

If top speed is too high, increase high-speed drag or reduce high-speed thrustCoef[]. If acceleration is too weak but top speed is right, raise low/mid-speed thrustCoef[] and compensate high-speed drag if needed.

Test clean, flaps, and landing configuration.

If the clean stall is too fast, raise low-speed envelope[] around the 1 g crossing. If it is too slow, lower the same region.

Record:

• Rotation speed.
• Lift-off speed.
• Runway distance.
• Pitch authority at rotation.
• Gear-up acceleration.

If the aircraft will not rotate, adjust low-speed elevatorCoef[] or elevatorSensitivity. If it rotates but will not lift, adjust low-speed envelope[].

Record:

• Stable approach speed.
• Sink rate.
• Flare authority.
• Touchdown speed.
• Runway stopping distance.
• AI approach behaviour if AI use matters.

If approach is too fast, check landingSpeed, flap drag, and low-speed lift. If the aircraft floats excessively, reduce low-speed lift or flap effect.

Use arrays for speed-specific problems. Use scalar fields when the whole aircraft feels too light or too heavy.

Tune one device at a time. Do not change flap, gear, and airbrake drag together unless you are deliberately doing a broad reset.

A tuning pass is ready to move forward when:

• The exported config loads without errors.
• The aircraft can take off, climb, cruise, land, and recover from stalls.
• The aircraft reaches a plausible level-flight maximum speed.
• Altitude performance degrades smoothly.
• Controls are useful at low speed and not excessive at high speed.
• AI behaviour is acceptable for the intended role.
• Source notes identify which values are extracted, estimated, or calibrated.