Learn how flight simulator crash detection, collision boxes, structural limits and visual damage work—and how to fix false crash events.
Across general-purpose flight simulators, crash detection compares the aircraft’s collision model, speed, attitude and structural limits with terrain, scenery and other objects. If a threshold is exceeded, the simulator may end the flight, record system or component failures, show visual damage, or simply reset—the exact behaviour depends on the simulator and realism settings.
What triggers a crash in a flight simulator?
A crash event is usually triggered when an aircraft contact point or simplified collision shape intersects something under conditions the simulator considers destructive. The visible aircraft model is not necessarily the shape used for collision calculations.
- Terrain or object collision: The aircraft intersects terrain, a building, vegetation, a vehicle or another aircraft with collisions enabled.
- Hard landing: Touchdown exceeds the permitted vertical speed, load or landing-gear limits. Aircraft mass, attitude and surface slope may affect the result.
- Structural overstress: Excessive G-loading, overspeed or violent control input exceeds an airframe limit.
- Aircraft-specific damage: A propeller strike, tail strike, gear collapse, engine abuse or unapproved water impact activates logic supplied by the aircraft itself.
Thresholds differ considerably. A basic aircraft may use one hard-landing value, while a sophisticated add-on calculates individual tyre, strut, wing, engine and control-surface loads. For Microsoft’s platform specifically, our explanation of MSFS collision, stress and landing-damage logic covers the platform’s limits and visual treatment.
Crash detection, damage modelling and visual effects are separate
Crash detection, physical damage and visible crash effects are separate layers, so one can work without the others.
| Layer | What it calculates | Typical result |
|---|---|---|
| Collision detection | Whether collision shapes or contact points intersect | Impact event, warning or ended flight |
| Damage model | Consequences for structures, engines and systems | Failed gear, reduced control, fuel leak or engine shutdown |
| Flight-model response | How damage changes forces and handling | Extra drag, loss of lift, vibration or asymmetric control |
| Visual effects | What the exterior model can display | Smoke, fire, detached parts or no visible change |
| Session handling | What happens after the event | Pause, reset, crash message or continued flight |
This separation explains why an aircraft can look untouched after a fatal impact, or show smoke while remaining controllable. Exterior models must be built with suitable damage states or detachable components; the simulator cannot automatically deform every aircraft accurately.
Why do damage effects vary between simulators?
Damage effects vary because each simulator is designed for a different purpose and exposes different systems to aircraft developers.
- Civil flight simulators usually emphasise procedural consequences such as structural failure, engine damage and an ended flight rather than detailed wreckage.
- Combat simulators are more likely to model localised hits, damaged control runs, fuel loss, weapon effects and aerodynamic changes.
- Procedural or training-focused software may freeze, reset or log an exceedance instead of displaying a dramatic crash.
- Complex aircraft add-ons may run their own damage and maintenance code independently of the simulator’s global crash setting.
In MSFS, X-Plane, FSX and Prepar3D, the platform’s collision response and an add-on aircraft’s internal failure logic may therefore produce different outcomes from the same impact. Visual spectacle is not a reliable measure of simulation depth; changes to lift, drag, control authority and system operation matter more.
Why does the simulator detect a crash when nothing was hit?
A false crash usually comes from an invisible collision box, incorrect terrain elevation, overlapping scenery or a faulty aircraft contact point.
- A building, tree or airport object has a collision shape larger than its visible model.
- Two scenery packages place surfaces or objects at different elevations.
- The aircraft spawns partly inside a jetway, hangar, platform or another aircraft.
- A custom aircraft has misplaced wheel, float, tail or fuselage contact points.
- Terrain or scenery loads late, leaving the aircraft below the corrected surface.
- High simulation rate, replay, slew or abrupt repositioning creates an unrealistic physics step.
The pattern often identifies the culprit. If every aircraft crashes at the same coordinate, suspect scenery or terrain. If only one aircraft does it, investigate that aircraft’s contact points or custom damage logic. These problems also affect older platforms; our guidance on legacy FS2004 collision-box and realism issues explains why apparently empty scenery can still trigger an impact.
How do I troubleshoot a false crash?
The quickest fix is to reproduce the event with default aircraft and scenery, then restore add-ons one at a time.
- Record the conditions. Note the aircraft, airport, exact location, speed, weather, simulation rate and whether the event occurs repeatedly.
- Establish a default baseline. Test a default aircraft at an unaffected default airport using normal simulation rate.
- Isolate the location. Try another aircraft at the original location. A location-specific result usually points to scenery or terrain.
- Disable relevant add-ons. Temporarily remove third-party airport, object and terrain packages affecting that area, including duplicated versions of the same airport.
- Check the aircraft. If the problem follows one aircraft, reset its saved state and inspect any documented damage, wear or maintenance options.
- Use collision-off mode as a diagnosis. If disabling collisions prevents the event, the cause is probably a collision volume rather than an engine or system failure.
- Restore content individually. Re-enable packages one at a time until the unwanted crash returns, then remove or replace the incompatible item.
Can crash detection be turned off without disabling failures?
In many consumer flight simulators, collision detection, structural stress and mechanical failures can be controlled separately, although the labels and available options vary.
Turning collisions off is sensible when testing scenery, using an airport with known invisible objects or operating around crowded multiplayer gates. Keep it enabled when practising touchdown limits, obstacle clearance or emergency landings. Be aware that aircraft with custom damage code may still record hard landings, engine abuse or overstress even when the simulator’s master crash option is disabled.
Is a crash to desktop the same as crash detection?
No. A crash to desktop, freeze or module fault is a software failure, not a simulated aircraft crash.
An impact can occasionally expose a bug in scenery or aircraft code, but the resulting application failure must still be diagnosed as a software problem. For one common platform-specific example, see our steps for troubleshooting an MSFS WASM crash to desktop.
Does aircraft damage carry over to the next flight?
Aircraft damage usually resets when the flight or aircraft is reloaded, but persistent maintenance systems can save wear separately.
Advanced aircraft or career add-ons may remember engine misuse, hard landings, tyre wear or overdue repairs after the simulator’s visible crash state has cleared. If damage remains after a reset, check the aircraft’s own maintenance or saved-state controls rather than the global collision setting.