The visualization displays a flight’s altitude and speed as two colored lines over time, using a dual-axis line chart. The left axis measures altitude, while the right axis tracks speed, with grid lines spanning both scales. It loads CSV data via `d3.csv` and renders SVG paths with `d3.line`, using `d3.scaleTime` and `d3.scaleLinear` for axes, and `d3.axisBottom` and `d3.axisLeft` for ticks.