What is sign commissioning?
The final checks on each airfield sign before it goes into service — proving it shows the right message, in the right place, with sound electrics, even light and a working control.
Sign commissioning is the last check on each airfield sign before it enters service. It is not enough that the sign lights: the legend must match the signage plan, the sign must stand in the right place, facing the right way, and its electrics, light and control must all work.
A sign with the wrong message or the wrong orientation can misdirect pilots and vehicle drivers, even if it lights perfectly. The electrical tests are made with the circuit isolated, then the sign is energised for the light and control checks, and every result is recorded. A defect is isolated, fixed and re-tested. When the checks pass, the sign is ready for acceptance.
- Legend. Compare the message, colours and arrows with the signage plan, and confirm the correct face is shown.
- Position. Confirm the sign is at the plan location, faces the right way, stands upright and is clear of obstructions. Check its height, its distance from the pavement edge and that the frangible mounting is correctly fitted, as the signage plan and standard require.
- Electrical. With the circuit isolated and proved dead, check wiring and connectors, insulation to earth and the earth bond.
- Light. Energise, then check the sign lights evenly with no dark segment, at every brightness step, in the right colour and legible. Where the specification calls for measured luminance, record it against the required values.
- Control. Switch the circuit and step the brightness from the control point, and check any status indication.
- Record. Log each result; isolate, fix and re-test any defect.
Frequently Asked Questions
Q1What is sign commissioning in airfield ground lighting?
The final set of checks on each airfield sign before it goes into service. It proves the sign shows the right message, stands in the right place facing the right way, is electrically sound, lights evenly at every brightness step and responds to its control. Each result is recorded.
Q2What is normally checked?
The legend, colours and arrows against the signage plan; the sign’s position, orientation, height, frangible mounting and clearance; continuity, insulation to earth and the earth bond; even lighting, every brightness step, colour, luminance where specified and legibility; and the circuit control and any status indication.
Q3Why check the legend and position, not just that the sign lights?
A sign that lights perfectly but shows the wrong message, or faces the wrong way, can misdirect pilots and vehicle drivers. Lighting alone proves nothing about whether the sign is correct, so the legend and position are checked against the design before service.
Q4How is sign commissioning different from sign testing?
Sign testing is the set of checks used throughout a sign’s life: at commissioning, after a repair and on the routine programme. Sign commissioning is the one-off acceptance of each new sign into service, bringing together the legend, position, electrical, light and control results in a single record.
Q5Are the electrical tests done live?
No. Continuity, insulation resistance and the earth bond are measured with the circuit isolated, locked out and proved dead. Only when those pass is the circuit energised for the light and control checks, which follow the site permit-to-work procedure.
Q6What happens if a sign fails a check?
The defect is recorded, the sign or circuit is isolated, the cause is found and corrected, and the affected checks are repeated. The record shows the failure, the correction and the passing re-test.
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