Transport Canada Canadian Airports OGC WMS
OGC Web Map Service 1.3.0 endpoint for the same Canadian Airports with Air Navigation Services layer. GetCapabilities returns a conformant WMS_Capabilities document declaring GetMap, GetFeatureInfo and GetLegendGraphic. This is the one Transport Canada interface that is an actual open standard — any WMS client can consume it and any other WMS server could serve the same layer.