This example visualizes airline performance data for October 2003, plotting the total number of flights against the number of on-time flights for major U.S. airports. Each circle represents an airport, with its size encoding the count of delayed flights, and airport codes label each point. The visualization uses d3.csv to load the data, d3.scaleLinear for positioning and sizing, and d3.axisBottom and d3.axisLeft to render the axes. A legend in the right margin shows the mapping between circle radius and delay count, while the filtered dataset focuses on a single month from the airlines.csv file.