Aeronautical ground lighting (AGL) systems are single-phase series circuits where constant current regulators supply transformers and luminaires. These systems provide visual reference to aircraft during airport operations. There is a lack of AGL system models and measurements in the literature to study AGL system behaviour and predict their response to electrical events and future technological changes. The study contributes to AGL system modelling with an equivalent circuit useful to study AGL system concerns by Matlab/Simulink simulations. It also presents field measurements taken at Reus airport (Catalonia, Spain) for the validation of the proposed model and understanding of AGL system behaviour in the event of luminaire failure.