Low Visibility Procedure (LVP) is a set of enhanced airport operating rules activated when visibility or cloud ceiling drops below the minimums required for standard instrument approaches.
How It Works#
Airports activate LVPs when conditions fall below specific thresholds. Typically, this means a runway visual range (RVR) below 550 meters or a cloud ceiling below 200 feet. RVR is a measured value, reported in meters or feet, that describes how far a pilot can see along the runway surface.
Once LVPs are active, air traffic control (ATC) applies stricter separation between aircraft. More space is kept between landing and departing traffic. This protects the sensitive ground-based equipment, called the Instrument Landing System (ILS), from interference caused by other aircraft taxiing or holding near the runway.
Ground movement also comes under tighter control. Vehicles and aircraft on the airfield must follow specific routes and receive explicit clearance before entering any protected area. Controllers manage traffic more carefully because both pilots and ground crews have severely reduced visual reference.
Only aircraft and crews certified for the relevant approach category may operate under LVPs. In practice, this means Category II (CAT II) or Category III (CAT III) ILS approaches, which allow landings in conditions far below standard IFR minimums.
Example in Aviation#
A wide-body airliner approaches an airport in dense fog. The tower reports an RVR of 300 meters and a ceiling of 100 feet. The airport has declared LVPs active. ATC increases spacing behind the preceding aircraft and holds all ground traffic clear of the ILS critical area. The flight crew, certified for CAT IIIb operations, flies the approach using the aircraft's autopilot and autothrottle all the way to touchdown. The crew never sees the runway until they are already on it.
Why It Matters#
LVPs exist because low-visibility conditions compress the margin for error to nearly zero. A missed approach or a go-around in fog is a complex, high-workload event. The procedures layer in extra protection by controlling traffic, protecting equipment, and ensuring only qualified crews attempt these operations.
For student pilots and aviation enthusiasts, understanding LVPs explains why some airports continue operating in weather that seems impossible to fly in. The system works because the procedures, the equipment, and the crew certification all meet a defined standard at the same time.
Key Takeaways#
- LVPs activate when RVR or ceiling drops below standard approach minimums.
- ATC applies increased aircraft separation to protect ILS ground equipment.
- Ground vehicle and aircraft movement is strictly controlled during LVPs.
- Only CAT II or CAT III certified crews and aircraft may operate under LVPs.
- LVPs allow airports to remain open in conditions that would otherwise halt operations.