Lockheed SR-71
Lockheed SR-71: Artificial feel motivates a fixed supported stick response.
Aircraft and simulator scope
- Lockheed SR-71 · X-Plane 11 · family starting point
- Lockheed SR-71 · X-Plane 12 · family starting point
Lockheed SR-71 · The retained pages display XR-71-TB Testbed for X-Plane 12 despite the SR-71 URL. This is a simulator identity and scope mismatch requiring explicit distinction.
The simulator model and controls
Lockheed developed the SR-71 for strategic reconnaissance at very high altitude and sustained supersonic speed. Long chines blend into the fuselage and wing; two large nacelles house the engines and carry inward-canted fins. The airframe reflects the thermal and aerodynamic demands of that mission.
This starting point selects Lockheed SR-71. Its aircraft-level settings do not select a particular developer’s custom systems.
How this profile feels
Artificial feel motivates a fixed supported stick response. Spring resistance builds with the selected airspeed response. A separate aerodynamic term adds speed-dependent control load.
Downstream trim actuators change surfaces without moving stick neutral. Valid trim provides the configured pressure relief. Autopilot following is off.
Controls and trim
The SR-71’s irreversible hydraulic controls use artificial feel. Its pitch/roll trim actuators are downstream of the feel springs and do not displace the stick. The high-speed reconnaissance configuration therefore separates surface trim from inceptor centering.
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 pages display XR-71-TB Testbed for X-Plane 12 despite the SR-71 URL. This is a simulator identity and scope mismatch requiring explicit distinction.
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.
Aircraft and variant
ReviewedThis starting point selects Lockheed SR-71. Its aircraft-level settings do not select a particular developer’s custom systems.
Flight controls
Not yet reviewedThe SR-71’s irreversible hydraulic controls use artificial feel. Its pitch/roll trim actuators are downstream of the feel springs and do not displace the stick. The high-speed reconnaissance configuration therefore separates surface trim from inceptor centering.
Trim
Not yet reviewedDownstream trim actuators change surfaces without moving stick neutral. Pitch authority 0.3 relieves permitted loading; hydraulic centre movement is off. Roll authority is 0.09.
Autopilot and stability
Not yet reviewedAutopilot following is off; the configured spring and load retain the hardware feel.
Equipment
Not yet reviewedGear, flap and ground cues follow the selected settings and available simulator-reported states.
Speeds and limits
Not yet reviewedThe indicated-speed references set the profile response scale; they are separate from aircraft operating limits.
Simulator integration
Not yet reviewedThe profile targets xplane11, xplane12. Add-on-specific controls use only the supported references configured by this profile.
Force-feedback settings
Not yet reviewedThe settings define the profile’s effect balance. Device output limits affect physical hand force.
Starting settings and their rationale
These configured values are starting estimates. The explanations describe what each setting controls; physical validation appears separately below.
| Setting | Starting value | What it controls and why |
|---|---|---|
| Spring strength | Starting value0.8 | What it controls and whyArtificial feel motivates a fixed supported stick response. The baseline spring is 0.8. Its low-speed blend reaches baseline strength at 90 KIAS. |
| Master force gain | Starting value0.85 | What it controls and whyScales overall profile strength while preserving effect balance, subject to device and output limits. |
| Profile force gain | Starting value0.25 | What it controls and whyThe aerodynamic-load gain is 0.25 with an indicated-speed reference of 300 KIAS. The hydraulic-load factor of 0.35 scales that modeled term; it is a selected artificial-feel approximation. |
| Force tuning speed/reference | Starting value300.0 kt | What 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 speed | Starting value90 kt | What it controls and whySets the IAS where the low-speed blend reaches baseline strength; high-speed stiffening also uses it. |
| Aileron force scale | Starting value0.65 | What it controls and whyRoll and pitch aerodynamic scales are 0.65 and 0.65, respectively. They set the aerodynamic axis balance. No custom spring-travel curve is enabled. |
| Elevator force scale | Starting value0.65 | What it controls and whyScales pitch aerodynamic loading; pitch spring travel and trim responses are separate settings. |
| Trim feel | Starting valueEnabled | What it controls and whyRetained for compatibility and group membership. Trim relief, rather than this flag, controls centre movement. |
| Trim relief | Starting valueEnabled | What it controls and whyAllows trim relief with supported control law and valid telemetry. Axis authorities set its amount. |
| Autopilot follow | Starting valueDisabled | What it controls and whyAutopilot following is off; the configured spring and load retain the hardware feel. |
| Autopilot neutral hold | Starting valueDisabled | What it controls and whyPermits centering hold during a supported AP state, separate from following a moving target. |
| Output force limit | Starting 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.
| Setting | Starting value | What it controls and why |
|---|---|---|
| Spring strength | Starting value0.8 | What it controls and whyArtificial feel motivates a fixed supported stick response. The baseline spring is 0.8. Its low-speed blend reaches baseline strength at 90 KIAS. |
| Spring deadband | Starting value0.035 | What it controls and whySets travel around the centre before the baseline spring resists. Smaller values engage it sooner. |
| Profile force gain | Starting value0.25 | What it controls and whyThe aerodynamic-load gain is 0.25 with an indicated-speed reference of 300 KIAS. The hydraulic-load factor of 0.35 scales that modeled term; it is a selected artificial-feel approximation. |
| Master force gain | Starting value0.85 | What it controls and whyScales overall profile strength while preserving effect balance, subject to device and output limits. |
| QBlend Enabled | Starting valueEnabled | What it controls and whyAllows baseline spring strength to rise with indicated airspeed where the control law permits it. |
| QSpring Minimum Factor | Starting value0.55 | What it controls and whySets low-speed spring strength as a fraction of baseline when blending is enabled. One keeps full strength. |
| QSpring Start Knots | Starting value20 kt | What 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 speed | Starting value90 kt | What it controls and whySets the IAS where the low-speed blend reaches baseline strength; high-speed stiffening also uses it. |
| Force tuning speed/reference | Starting value300.0 kt | What 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 gain | Starting value0 | What it controls and whyThe high-speed spring-stiffening gain is 0. No additional speed-driven stiffening is added; this does not disable independent aerodynamic loading. |
| Airspeed spring stiffening limit | Starting 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 scale | Starting value0.65 | What it controls and whyRoll and pitch aerodynamic scales are 0.65 and 0.65, respectively. They set the aerodynamic axis balance. No custom spring-travel curve is enabled. |
| Elevator force scale | Starting value0.65 | What it controls and whyScales pitch aerodynamic loading; pitch spring travel and trim responses are separate settings. |
| Output force limit | Starting value0.55 | What it controls and whyCaps directed-force output. Native spring effects and device limits remain separate. |
| Trim feel | Starting valueEnabled | What it controls and whyRetained for compatibility and group membership. Trim relief, rather than this flag, controls centre movement. |
| Trim relief | Starting valueEnabled | What it controls and whyAllows trim relief with supported control law and valid telemetry. Axis authorities set its amount. |
| Elevator Authority | Starting value0.3 | What it controls and whyDownstream trim actuators change surfaces without moving stick neutral. Pitch authority 0.3 relieves permitted loading; hydraulic centre movement is off. Roll authority is 0.09. |
| Aileron Authority | Starting value0.09 | What it controls and whyScales supported roll-trim relief and permitted centre movement. Zero removes roll response. |
| Force Trim Enabled | Starting valueDisabled | What it controls and whyEnables local force trim, separate from aircraft-owned trim and add-on integration qualification. |
| GLoad Enabled | Starting valueEnabled | What it controls and whyAllows load-factor changes to modify permitted spring laws. Passive fly-by-wire feel can suppress it. |
| Rate Damping Enabled | Starting valueEnabled | What it controls and whyEnables rate damping with the configured coefficients and control law. |
| Autopilot follow | Starting valueDisabled | What it controls and whyAutopilot following is off; the configured spring and load retain the hardware feel. |
| Autopilot follow authority | Starting 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 hold | Starting valueDisabled | What it controls and whyPermits centering hold during a supported AP state, separate from following a moving target. |
| Autopilot neutral hold strength | Starting value0.6 | What it controls and whySets admitted AP neutral-hold strength; inactive while neutral hold is disabled. |
| Enabled | Starting valueEnabled | What it controls and whyEnables aerodynamic cues; each still needs nonzero strength and its simulator conditions. |
| Gain | Starting value0.3 | What it controls and whySets stall-buffet strength. Zero removes the cue without changing simulator stalls or warnings. |
| Gain | Starting value0 | What it controls and whySets high-Mach buffet strength; onset and full-strength thresholds are separate. |
| Gain | Starting value0 | What it controls and whySets flap buffet at the configured position and speed gates. Flap movement texture is separate. |
| Maximum flap index | Starting value1 | What it controls and whySets the final flap index for detent normalization. UP plus three detents uses maximum index3. |
| Minimum flap index | Starting value1 | What it controls and whySets the first flap detent that admits buffet; this is a handle index, not degrees. |
| Gain | Starting value0.1 | What it controls and whySets gear aerodynamic buffet; movement and ground-contact cues are separate. |
| Shaker Enabled | Starting valueEnabled | What it controls and whyPermits shaker at supported warning conditions; the switch does not establish aircraft equipment. |
| Stick shaker amplitude | Starting value0.9 | What it controls and whySets triggered shaker strength; inactive while the shaker feature is disabled. |
| Enabled | Starting valueEnabled | What it controls and whyEnables ground effects; each still needs its own strength and contact or motion telemetry. |
| Gain | Starting value0.4 | What it controls and whySets rolling texture strength, modified by speed, surface and undercarriage configuration. |
| Gain | Starting value0.32 | What it controls and whySets gear-bump texture during ground motion, separate from touchdown impact. |
| Gain | Starting value0.9 | What it controls and whySets landing-impact strength; landing telemetry and response shape determine the pulse. |
| Gain | Starting value0.5 | What it controls and whySets reverse-thrust vibration with valid reverser and engine conditions. Zero removes the cue. |
| Enabled | Starting valueEnabled | What it controls and whyEnables engine cues with nonzero settings and valid running-engine telemetry. |
| Gain | Starting value0.06 | What it controls and whySets estimated engine vibration using configured telemetry and response, not measured cockpit vibration. |
| Enabled | Starting valueEnabled | What it controls and whyEnables accessory cues with configured strengths and observed accessory movement. |
| Gain | Starting value0 | What it controls and whySets texture from observed flap movement; a command without movement does not establish the cue. |
| Gain | Starting value0.12 | What it controls and whySets texture from observed gear movement, separate from aerodynamic and touchdown effects. |
Limits and open questions
- The pages do not describe primary hydraulic boost, artificial feel or control gearing.
- Trim mechanisms are not documented.
- Automatic-flight installation is not established.
- Mach-3 simulation and refueling audio do not establish the selected SR-71 gear, flap or engine implementation.
- Mach-3 branding is not an applicable indicated-speed schedule or a basis for the retained 300-knot reference.
- Links to a knowledge center do not define an external control or status contract in the retained text.
- Contributor experience and immersion claims do not measure stick forces, inlet-unstart cues or vibration amplitude.
- Lockheed SR-71 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.