The distance over which a pilot can see runway markings or lights down the runway’s centerline, measured in meters or feet. RVR is a critical factor in determining whether a precision approach (CAT I/II/III) may legally be flown or continued to landing.
Key characteristics:
- Measurement: Determined by transmissometers or forward scatter meters positioned along the runway, typically reported for touchdown, midpoint, and rollout zones.
- Use in approach categories:
- CAT I: RVR ≥ 550–800 m (depending on regulation).
- CAT II: RVR ≥ 300 m.
- CAT IIIa: RVR ≥ 200 m.
- CAT IIIb: RVR ≥ 75 m.
- CAT IIIc: no minimum RVR (theoretical zero-zero).
- CAT I: RVR ≥ 550–800 m (depending on regulation).
- Operational impact: If actual RVR is below the required minimum for the intended approach category, the approach may not be attempted or must be abandoned.
- Dynamic: RVR values can change rapidly with fog, snow, or heavy precipitation, making it one of the most limiting factors in low-visibility operations.
Application in DCS World
- DCS allows weather settings (fog, visibility range, cloud base) that approximate low-RVR conditions, letting cadets practice approaches in restricted visibility.
- True RVR measurement and reporting systems are not modeled in DCS. ATC does not issue RVR values, and no automated transmissometer simulation exists. Pilots must estimate visibility by eye.
Cadets should simulate RVR conditions by flying approaches in low-visibility weather presets (e.g., fog with visibility <1 km). Practicing under progressively lower settings develops instrument discipline and decision-making under poor visibility.