Spring strength
55%
The base centring force that pulls the stick back to centre. Every other force stacks on it. Too low and the stick feels limp in normal flight; too high and it fights your hand and masks the smaller cues layered above it.
▲ More: firmer centring that resists your hand at all times.
▼ Less: a limper stick that leans on aerodynamic load alone.
One constant spring at all speeds.
Spring deadband
4%
A small neutral zone around centre where the spring stays quiet, so tiny movements at rest don't chatter. Wider is calmer but looser; narrower is more precise but can twitch around centre.
▲ More: a calmer but looser centre with more free play.
▼ Less: a tighter centre that may chatter at rest.
The published breakout is 0.5 daN of 10 daN full — about 5% of travel.
Low-speed spring floor
50%
How much of the spring survives at a standstill, before airspeed can build any aerodynamic force. A high floor keeps the parked stick firm; a low floor gives the loose, cable-slack feel of a parked light aircraft.
▲ More: a firmer stick while parked and taxiing.
▼ Less: a floppier parked stick that only wakes up with airspeed.
Why here: The spring is the same parked and at 350 knots: half floor with almost nothing added above it, because airspeed never reaches an Airbus stick.
QSpring start knots 20 · QSpring full knots 60
Dynamic-pressure blend
off
Enables the low-speed spring engagement window (start/full knots above). Off, the spring is constant at all speeds.
Force never varies with speed: confirmed by the published tables.
Elevator load
100%
The sustained pitch load from elevator deflection and airspeed, balanced independently of roll. This is the main lever behind a type's pitch weight. It does not touch aileron, spring, trim, or buffet forces.
▲ More: heavier sustained pitch forces at speed.
▼ Less: a lighter elevator that takes less muscle to hold.
Why here: 100%, but scaled by the near-zero overall load below: axis balance is symmetric on a sidestick.
Aileron load
100%
The sustained roll load from aileron deflection and airspeed, balanced independently of pitch. Together with the elevator load it sets the control-harmony ratio reviewers talk about.
▲ More: heavier roll forces.
▼ Less: lighter, quicker-feeling ailerons.
Why here: 100%: identical to pitch. The sidestick is symmetric; there is no harmony story to model.
Overall aerodynamic load
4%
A master scale over both sustained axis loads, applied before their independent balance. Profiles normally leave this alone and tune the two axis loads instead.
▲ More: both axes load up harder.
▼ Less: both axes lighten together.
Why here: 4%: effectively zero aerodynamic load. This single number is the fly-by-wire story: the airflow does not touch your hand.
Cruise reference (kt)
280
The indicated airspeed where aerodynamic load reaches its designed full level. It anchors the whole load curve to the aircraft's real speed range: a 172 loads up by 110 knots, a jet much later.
▲ More: loads arrive later; the stick stays light up to a higher speed.
▼ Less: loads arrive earlier and cruise feels heavier.
Why here: 280 kt reference exists for the residual 4%; it is bookkeeping, not feel.
Airspeed curve
1.0
How sharply stick load builds with airspeed. 1.0 is linear; about 2.0 matches real aerodynamics, where dynamic pressure grows with the square of speed, so controls are much lighter slow and firm up fast. Felt when holding the stick off centre, not at rest.
▲ More: lighter at low speed with a steeper rise toward cruise.
▼ Less: a more linear build that loads up earlier.
Why here: 1.0: what little load exists grows linearly; a square law would imply aerodynamics the stick does not have.
Max output force
25%
A cap on each steady pitch or roll force before it reaches the device, guarding against slamming or saturating the hardware in strong maneuvers.
▲ More: stronger peak steady forces before clipping.
▼ Less: a gentler ceiling; hard maneuvers flatten out sooner.
Why here: 25%: the lowest cap in the fleet. A sidestick never fights you; protections mean never needing high forces.
Hydraulic load factor
60%
For hydraulically-boosted or fly-by-wire types: how much of the raw aerodynamic load actually reaches the pilot's hand. 1.0 is a fully manual control run; lower values model the artificial-feel systems that isolate the pilot from true surface loads.
▲ More: more raw aerodynamic load reaching your hand.
▼ Less: more isolation, closer to pure artificial feel.
Why here: Active for FBW: it scales the tiny residual load path down. With ForceGain at 4% its effect is academic.