This bubble chart visualizes airline performance by plotting total passengers on the x-axis, fleet size on the y-axis, and using bubble radius to encode on-time performance percentage. The chart uses a categorical color scale to distinguish airlines, with an SVG legend positioned to the right. Interactive tooltips appear on hover using a custom HTML overlay that follows the mouse. Built with D3 v7, the visualization reads CSV data and configures axes, scales, and event handlers through the D3 API.