Spring strength
82%
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.
Why here: High for a light single: the 172's yoke centres positively behind its cable runs and big tail volume; 82% gives that solidity without masking the smaller cues.
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.
Why here: Wide enough to swallow the real yoke's cable slack and ramp jitter; much narrower would read as a pushrod aircraft, which this is not.
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: A parked 172 yoke is loose but not dead; cable tension keeps half the centring. The controls then come alive between 15 and 55 kt, so they are fully firm right at rotation speed.
QBlend enabled on · QSpring start knots 15 · QSpring full knots 55
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: Pitch is the reference axis at 100%. The heaviness the claims describe comes from the load curve and G-stiffening, and roll is set relative to this.
Aileron load
65%
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.
Pitch is the heaviest axis; the ailerons sit at roughly 0.65 of the elevator, the classical light-GA harmony.
Overall aerodynamic load
80%
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: Slightly under unity so the axis balance (elevator 100% / aileron 65%) lands in the device's comfortable range at the 110 kt reference.
Cruise reference (kt)
110
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: The 172S actually cruises around 110 KIAS, so loads reach their designed level exactly where the real aircraft spends its time.
Airspeed curve
2.0
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.
Direct cable controls feel the raw hinge moment, which scales with dynamic pressure (≈ V²). The force at the 110 kt cruise reference is unchanged — the exponent renormalizes there — while the sub-cruise band lightens, matching "comes alive at rotation, firm at cruise".
Centre firmness vs speed
15%
How much the centring itself stiffens with speed, on top of the deflection loads. Zero keeps centre feel constant; more makes the stick centre harder at cruise and looser in the pattern.
▲ More: a centre that hardens noticeably as you go faster.
▼ Less: constant centre feel at every speed.
The yoke keeps firming above 55 kt instead of going flat — about 1.45× the centering force at cruise versus rotation speed.
Spring airspeed stiffen cap 5
Max output force
55%
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: A trainer must not slam consumer hardware: 55% keeps the strongest steady pull near half device authority so buffet cues stay readable on top of it.
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: Inert here: only hydraulic and fly-by-wire control systems read this; the 172's manual run passes full loads regardless.