Chart assignment
Charts to read and discuss
Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.
Chart 1 of 1 · Air travel
What causes most flight delays?
The interactive chart needs JavaScript. The numbers are on the chart's page.
In the 12 months through August 2026, 39.8% of all minutes of delay came from a late-arriving aircraft: a plane that left its last airport late. The airline itself (crew, maintenance, cleaning, fueling) caused 32.9%, the air traffic system 21.1% and severe weather 6%. Weather also hides in the other causes: BTS counts ordinary weather that slows traffic under the air traffic system.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present) (Public domain (U.S. government work)) · Data as of Aug 31, 2026
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