Runway edge lights, measured unit by unit

Frequently Asked Questions

What does a drone add over walking the row at night?

A walk tells you which units are lit. It cannot tell you that unit 14 is running at half the output of its neighbours, that unit 21 has drifted off its aiming, or that the red section over the last part of the runway has faded toward orange. The drone measures every unit from the same distances and angles, so each one has a figure that can be compared with its neighbours and with its own figure from the last visit. The result is a row you can rank for maintenance rather than a list of outages.

Is the runway closed for the inspection?

No. The passes are flown between aircraft movements in coordination with the tower, and the drone clears the strip when asked. Budget about an hour on site per runway for setup, the passes and a repeat if a movement interrupts one. The edge lights have to be on at the intensity steps being checked, which is a request to your lighting control room rather than to the tower. Processing and the protocol happen afterwards, off site.

Which passes do you fly?

Usually more than one, in a single sortie. A fly-over tracks directly above the row so each unit is seen down its own beam. A parallel sweep runs outboard of the row at a fixed standoff, which is how the beam shape across the horizontal sector is sampled. An observation arc sits out on the approach at the glide path height and looks back along the runway, which is the view a crew actually has. Every pass is generated from the surveyed unit positions, so the drone frames each unit rather than hunting for it.

How is intensity reported?

Both ways. In candela per unit, and as a ratio to the row and to the commanded dimming step, which is what the uniformity, dimming and section rows of the protocol ask for. A unit that reads well under its neighbours is named with both figures. The absolute one comes from the camera being characterised against a calibrated source before it flies, corrected for the measured range to each unit and for the atmospheric transmission on the day. The protocol prints that correction beside the value. That is a measurement in absolute units and not a certificate, so certified photometry of an individual fixture, which needs a calibrated instrument at the unit, stays outside this service.

Do you cover threshold, end and centre line lights too?

Threshold and runway end lights are part of the same passes and appear in the protocol with the edge lights, because the row is flown end to end and the bar at each end is in frame. Runway centre line and touchdown zone lights are covered where the runway has them, from the fly-over, and are scoped as a line item. Taxiway lighting is a different mission profile and is not included in this service.

What comes back if the layout was never surveyed?

The survey. Every unit's position comes from the passes with RTK positioning, so the first inspection produces the surveyed layout the next one is generated from. Spacing and alignment along the row are then checked against that layout, and a gap left by a missing unit is reported against the position it should occupy. If you already have a surveyed layout, we use it and report any unit that is not where it should be.

What happens if the inspection finds an outage?

A dark unit or a section of the row that is out is reported on the day of capture rather than held for the protocol, because it is a serviceability finding the aerodrome may want to act on at once. The protocol follows on the normal schedule and records the unit as unserviceable with its position. Whether the outage puts the runway lighting below the serviceability level your authority sets is a decision for the operator, made from the count and the positions the report gives.