Latécoère · Seaplane

Latécoère 631

A six-engine flying boat created for long-distance passenger travel over water.

Meet the aircraft

The French Latécoère 631 was a six-engine flying boat intended for transatlantic passenger service. Its long hull, high wing and radial engines date from the final era of large civil flying boats. The Second World War disrupted development and service.

Land-based airliners later displaced this approach to long-distance transport. The aircraft's numerous engines and large crew stations reflect the systems and navigation demands of its period.

Read the full aircraft reference →

Catalogue programme-20261011-v3

FFB-BRIDGE BUILT-IN PROFILE

Latécoère 631

Free and ProRevision 1Partial review

Latécoère 631: The profile supplies selected large-transport resistance.

Aircraft and simulator scope

  • Latécoère 631 · MSFS 2024 · family starting point
  • Latécoère 631 · MSFS 2020 · family starting point

Latécoère 631 · The retained manual and official announcement identify the Local Legend Latécoère 631 simulator.

The simulator model and controls

The French Latécoère 631 was a six-engine flying boat intended for transatlantic passenger service. Its long hull, high wing and radial engines date from the final era of large civil flying boats. The Second World War disrupted development and service.

This starting point selects Latécoère 631. Its aircraft-level settings do not select a particular developer’s custom systems.

How this profile feels

The profile supplies selected large-transport resistance. Spring resistance builds with the selected airspeed response. A separate aerodynamic term adds speed-dependent control load.

Pitch relief is separate from multi-engine management and hull contact. Valid trim provides the configured pressure relief. Autopilot following is enabled for supported control references.

Controls and trim

The Latécoère 631 combined six radial engines and a large flying-boat hull for transatlantic transport. Its expansive crew stations and engine-management work belong to the final large civil flying-boat generation.

About the values

The gains are normalized profile settings. They describe the chosen effect balance; hand force depends on the device and its output limits. IAS references are tuning values rather than operating limits. Physical acceptance of this revision remains pending.

What the documentation establishes

The retained manual and official announcement identify the Local Legend Latécoère 631 simulator.

Elevator, aileron and rudder trim wheels and indicators are documented; the underlying actuators and hand-force effects are not explained.

The gyropilot and master controls provide heading and altitude holding. This substantiates installed simulator assistance, without verifying external control movement.

Six R-2600 radial engines, movable wing floats and flaps from 0 to 17 degrees are documented. Float retraction is not evidence of retractable wheel gear.

Headline cruise is 173 mph, while takeoff and landing values use km/h at specified weights. The retained 150-knot IAS loading reference is an estimate.

Documentary review and sources

These decisions describe the documentary basis and remaining gaps for this revision. Aircraft documentation and a starting setting describe different kinds of evidence.

Starting settings and their rationale

These configured values are starting estimates. The explanations describe what each setting controls; physical validation appears separately below.

Estimated starting settings · revision 1
SettingStarting valueWhat it controls and why
Spring strengthStarting value0.74 What it controls and whyThe profile supplies selected large-transport resistance. The baseline spring is 0.74. Its low-speed blend reaches baseline strength at 75 KIAS.
Master force gainStarting value0.85 What it controls and whyScales overall profile strength while preserving effect balance, subject to device and output limits.
Profile force gainStarting value0.8 What it controls and whyThe aerodynamic-load gain is 0.8 with an indicated-speed reference of 150 KIAS. This supplies speed-dependent loading alongside the spring.
Force tuning speed/referenceStarting value150.0 ktWhat it controls and whySets the IAS reference for aerodynamic loading. It is an estimate, not published cruise TAS or a flight limit.
Spring response reference speedStarting value75.0 ktWhat it controls and whySets the IAS where the low-speed blend reaches baseline strength; high-speed stiffening also uses it.
Aileron force scaleStarting value0.72 What it controls and whyRoll and pitch aerodynamic scales are 0.72 and 1, respectively. They set the aerodynamic axis balance. No custom spring-travel curve is enabled.
Elevator force scaleStarting value1.0 What it controls and whyScales pitch aerodynamic loading; pitch spring travel and trim responses are separate settings.
Trim feelStarting valueEnabled What it controls and whyRetained for compatibility and group membership. Trim relief, rather than this flag, controls centre movement.
Trim reliefStarting valueEnabled What it controls and whyAllows trim relief with supported control law and valid telemetry. Axis authorities set its amount.
Autopilot followStarting valueEnabled What it controls and whyFollowing is on at 0.1 authority when a supported, valid autopilot control reference is available.
Autopilot neutral holdStarting valueDisabled What it controls and whyPermits centering hold during a supported AP state, separate from following a moving target.
Output force limitStarting value0.55 What it controls and whyCaps directed-force output. Native spring effects and device limits remain separate.
All 44 starting settings and their rationale

The settings define the profile’s effect balance. Device output limits affect physical hand force.

Estimated starting settings · revision 1
SettingStarting valueWhat it controls and why
Spring strengthStarting value0.74 What it controls and whyThe profile supplies selected large-transport resistance. The baseline spring is 0.74. Its low-speed blend reaches baseline strength at 75 KIAS.
Spring deadbandStarting value0.045 What it controls and whySets travel around the centre before the baseline spring resists. Smaller values engage it sooner.
Profile force gainStarting value0.8 What it controls and whyThe aerodynamic-load gain is 0.8 with an indicated-speed reference of 150 KIAS. This supplies speed-dependent loading alongside the spring.
Master force gainStarting value0.85 What it controls and whyScales overall profile strength while preserving effect balance, subject to device and output limits.
QBlend EnabledStarting valueEnabled What it controls and whyAllows baseline spring strength to rise with indicated airspeed where the control law permits it.
QSpring Minimum FactorStarting value0.5 What it controls and whySets low-speed spring strength as a fraction of baseline when blending is enabled. One keeps full strength.
QSpring Start KnotsStarting value20 ktWhat it controls and whySets the IAS where the low-speed spring blend starts rising. This is a feel threshold, not a flight limit.
Spring response reference speedStarting value75.0 ktWhat it controls and whySets the IAS where the low-speed blend reaches baseline strength; high-speed stiffening also uses it.
Force tuning speed/referenceStarting value150.0 ktWhat it controls and whySets the IAS reference for aerodynamic loading. It is an estimate, not published cruise TAS or a flight limit.
Airspeed spring stiffening gainStarting value0.15 What it controls and whyThe high-speed spring-stiffening gain is 0.15. It strengthens the permitted spring response above 75 KIAS, with the squared-speed ratio capped at 5.
Airspeed spring stiffening limitStarting value5 What it controls and whyLimits the squared airspeed ratio used for high-speed spring stiffening; it is not a device-force cap.
Aileron force scaleStarting value0.72 What it controls and whyRoll and pitch aerodynamic scales are 0.72 and 1, respectively. They set the aerodynamic axis balance. No custom spring-travel curve is enabled.
Elevator force scaleStarting value1.0 What it controls and whyScales pitch aerodynamic loading; pitch spring travel and trim responses are separate settings.
Output force limitStarting value0.55 What it controls and whyCaps directed-force output. Native spring effects and device limits remain separate.
Trim feelStarting valueEnabled What it controls and whyRetained for compatibility and group membership. Trim relief, rather than this flag, controls centre movement.
Trim reliefStarting valueEnabled What it controls and whyAllows trim relief with supported control law and valid telemetry. Axis authorities set its amount.
Elevator AuthorityStarting value0.3 What it controls and whyPitch relief is separate from multi-engine management and hull contact. Pitch authority 0.3 provides load relief and permitted centre movement; roll authority is 0.
Aileron AuthorityStarting value0 What it controls and whyScales supported roll-trim relief and permitted centre movement. Zero removes roll response.
Force Trim EnabledStarting valueDisabled What it controls and whyEnables local force trim, separate from aircraft-owned trim and add-on integration qualification.
GLoad EnabledStarting valueEnabled What it controls and whyAllows load-factor changes to modify permitted spring laws. Passive fly-by-wire feel can suppress it.
Rate Damping EnabledStarting valueEnabled What it controls and whyEnables rate damping with the configured coefficients and control law.
Autopilot followStarting valueEnabled What it controls and whyFollowing is on at 0.1 authority when a supported, valid autopilot control reference is available.
Autopilot follow authorityStarting value0.1 What it controls and whySets admitted AP-follow gain, not a percentage of travel. Runtime ownership and input limits still apply.
Autopilot neutral holdStarting valueDisabled What it controls and whyPermits centering hold during a supported AP state, separate from following a moving target.
Autopilot neutral hold strengthStarting value0.6 What it controls and whySets admitted AP neutral-hold strength; inactive while neutral hold is disabled.
EnabledStarting valueEnabled What it controls and whyEnables aerodynamic cues; each still needs nonzero strength and its simulator conditions.
GainStarting value0.35 What it controls and whySets stall-buffet strength. Zero removes the cue without changing simulator stalls or warnings.
GainStarting value0 What it controls and whySets high-Mach buffet strength; onset and full-strength thresholds are separate.
GainStarting value0.14 What it controls and whySets flap buffet at the configured position and speed gates. Flap movement texture is separate.
Maximum flap indexStarting value3 What it controls and whySets the final flap index for detent normalization. UP plus three detents uses maximum index3.
Minimum flap indexStarting value2 What it controls and whySets the first flap detent that admits buffet; this is a handle index, not degrees.
GainStarting value0 What it controls and whySets gear aerodynamic buffet; movement and ground-contact cues are separate.
Shaker EnabledStarting valueDisabled What it controls and whyPermits shaker at supported warning conditions; the switch does not establish aircraft equipment.
Stick shaker amplitudeStarting value0.5 What it controls and whySets triggered shaker strength; inactive while the shaker feature is disabled.
EnabledStarting valueEnabled What it controls and whyEnables ground effects; each still needs its own strength and contact or motion telemetry.
GainStarting value0.4 What it controls and whySets rolling texture strength, modified by speed, surface and undercarriage configuration.
GainStarting value0.25 What it controls and whySets gear-bump texture during ground motion, separate from touchdown impact.
GainStarting value0.65 What it controls and whySets landing-impact strength; landing telemetry and response shape determine the pulse.
GainStarting value0 What it controls and whySets reverse-thrust vibration with valid reverser and engine conditions. Zero removes the cue.
EnabledStarting valueEnabled What it controls and whyEnables engine cues with nonzero settings and valid running-engine telemetry.
GainStarting value0.12 What it controls and whySets estimated engine vibration using configured telemetry and response, not measured cockpit vibration.
EnabledStarting valueEnabled What it controls and whyEnables accessory cues with configured strengths and observed accessory movement.
GainStarting value0.12 What it controls and whySets texture from observed flap movement; a command without movement does not establish the cue.
GainStarting value0 What it controls and whySets texture from observed gear movement, separate from aerodynamic and touchdown effects.
Limits and open questions
  • Control surfaces and cockpit controls are listed without explaining the primary linkage or aerodynamic gearing.
  • The guide gives cockpit functions without external float, trim or autopilot status definitions.
  • Surface areas and six-engine performance do not establish control-force gradients or hull-contact vibration levels.
  • Latécoère 631 documentary evidence does not establish force-feedback hardware acceptance.

Physical validation

No physical force validation is recorded in this public catalogue for this revision. Documentary review and software checks do not establish how a particular device feels.

FFB-Bridge maintains this profile’s revisions and tuning discussion.

Revision 1 and download availability in FFB-Bridge ↗
Exact profile identity
Profile
airframe-latecoere-631
Artifact SHA-256
774ae739627c91f45729dae3171ae8f8991d34e22d71fef0cbaa47f340fc0a63
Bytes
12684
Spring strength
Forces.SpringStrength
Spring deadband
Forces.SpringDeadband
Profile force gain
Forces.ForceGain
Master force gain
Forces.MasterGain
QBlend Enabled
Forces.QBlendEnabled
QSpring Minimum Factor
Forces.QSpringMinimumFactor
QSpring Start Knots
Forces.QSpringStartKnots
Spring response reference speed
Forces.QSpringFullKnots
Force tuning speed/reference
Forces.CruiseSpeedRefKnots
Airspeed spring stiffening gain
Forces.SpringAirspeedStiffenGain
Airspeed spring stiffening limit
Forces.SpringAirspeedStiffenCap
Aileron force scale
Forces.AileronForceScale
Elevator force scale
Forces.ElevatorForceScale
Output force limit
Forces.MaxOutputForce
Trim feel
StickFeel.TrimFeelEnabled
Trim relief
StickFeel.TrimReliefEnabled
Elevator Authority
StickFeel.TrimRelief.ElevatorAuthority
Aileron Authority
StickFeel.TrimRelief.AileronAuthority
Force Trim Enabled
StickFeel.ForceTrimEnabled
GLoad Enabled
StickFeel.GLoadEnabled
Rate Damping Enabled
StickFeel.RateDampingEnabled
Autopilot follow
Autopilot.FollowEnabled
Autopilot follow authority
Autopilot.FollowAuthority
Autopilot neutral hold
Autopilot.NeutralHoldEnabled
Autopilot neutral hold strength
Autopilot.NeutralHoldStrength
Enabled
Aero.Enabled
Gain
Aero.Stall.Gain
Gain
Aero.Mach.Gain
Gain
Aero.Flap.Gain
Maximum flap index
Aero.Flap.MaxFlapIndex
Minimum flap index
Aero.Flap.MinFlapIndex
Gain
Aero.Gear.Gain
Shaker Enabled
Aero.ShakerEnabled
Stick shaker amplitude
Aero.Shaker.Amplitude
Enabled
Ground.Enabled
Gain
Ground.Rumble.Gain
Gain
Ground.Bumps.Gain
Gain
Ground.Thump.Gain
Gain
Ground.Reverse.Gain
Enabled
Engine.Enabled
Gain
Engine.Rumble.Gain
Enabled
Mechanical.Enabled
Gain
Mechanical.FlapMotion.Gain
Gain
Mechanical.GearMotion.Gain