What is the LVP lighting configuration?
How the approach, runway, stop-bar and taxiway lights are set up when Low-Visibility Procedures are in force — and why the stop bars and taxiway centreline are interlocked.
Low-Visibility Procedures (LVP) are the rules an aerodrome applies when visibility or cloud base is below set limits, to protect CAT II/III approaches and low-visibility take-offs. The LVP lighting configuration is the defined set of airfield lights, intensity steps and interlocks that must be on, healthy and monitored while those procedures are in force.
On the ground, the stop bar and the taxiway centreline work as a pair. A lit stop bar means stop, so the green lights beyond it go out, and ATC extinguishes the bar only to let the aircraft go. The lights also follow the RVR step table, and critical items sit on a secondary supply with a very short switch-over.
The aerodrome's approved LVP document sets the triggers, the light list and the minima. It decides what this schematic shows for your runway, so the values here are an example of the usual arrangement, not a requirement.
| Light group | Normal operations | LVP in force |
|---|---|---|
| Approach lights | Per runway category; CAT II/III-only elements may be off or at a low step in good visibility | Full CAT II/III pattern lit and healthy, at the RVR step |
| Threshold, edge, end | On at the step for the visibility; edge lights yellow in the caution zone | On, step set from the RVR step table; edge caution zone stays yellow |
| Touchdown zone and centreline | May be off or low on runways not in CAT II/III use | On at the step for the RVR, with the required spacing |
| Stop bars | Used as ATC needs them | Selected on at every runway holding position in use; extinguished only to clear a movement |
| Taxiway centreline | Normally on | Switched by route segment; lights beyond a lit stop bar are off |
| Runway guard lights | Where provided, normally on at night | On where required by the RVR and traffic rules in Annex 14 |
| Power and monitoring | Standard monitoring | Standby supply and CCRs ready; status of lamps, circuits and interlocks shown to ATC and maintenance |
Frequently Asked Questions
Q1What are Low-Visibility Procedures (LVP)?
LVP are the procedures an aerodrome puts in force when visibility or cloud base falls below set limits, to protect aircraft making CAT II/III approaches and low-visibility take-offs and to control vehicles and aircraft on the manoeuvring area. They combine ATC rules, protected critical areas, reduced ground movement and a defined airfield lighting configuration. The lighting part is what this entry covers.
Q2When are LVP started and cancelled?
The aerodrome sets its own triggers in its approved LVP document, commonly an RVR of around 550 to 600 m or below, or a low cloud base, and ATC declares the phases. Cancellation normally uses a clear margin and a time delay, in the same way as the RVR step table, so that LVP do not switch on and off with every reading. Follow the values in your aerodrome manual and authority approval.
Q3What changes in the lighting configuration when LVP are in force?
The full CAT II/III pattern is lit and monitored: approach lights, threshold, edge, touchdown zone and centreline lights at the step set by RVR. Stop bars are switched on at runway holding positions in use, taxiway centreline lights are switched in route segments, and runway guard lights are used where required. The exact list depends on the runway category, the take-off minima and the aerodrome's approved configuration.
Q4Why are stop bars and taxiway centreline lights interlocked?
A lit stop bar means stop. If the green centreline beyond it stayed lit, the pilot would get a contradictory signal. In an interlocked design the centreline lights beyond a lit stop bar go out, and the stop bar is switched off only when ATC clears the aircraft to proceed. The pair works as a controlled gate, and a failure of the interlock should be alarmed.
Q5What power and monitoring are needed?
Critical lights need a secondary power supply with a very short switch-over time, generally about 1 second for the critical items on a CAT II/III runway and 15 seconds for others, as set out in the secondary power table in ICAO Annex 14 Chapter 8. The control and monitoring system should show lamp, circuit and interlock status to ATC and maintenance, and standby CCRs and generators should be ready before LVP start.
Q6What if lights fail while LVP are in force?
Each light group has a minimum serviceability level, and the rule that no two adjacent lamps may be out (barrettes and crossbars are the usual exception). If the level is not met, the operational category or minima must be reduced and ATC informed, which usually means a notice to airmen. Keep the serviceability criteria for your category close by and use the serviceability entries in this encyclopedia as the starting point.
Q7Is it safe to work on the lights during LVP?
Not without permission. Work on critical circuits, CCRs, the stop-bar or interlock logic, or the RVR link can change what the pilot sees in the worst conditions, so it needs a permit-to-work, ATC agreement and a documented return-to-service test. Where possible, plan maintenance outside LVP periods and finish pre-LVP inspections before the phase starts.
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