How We Source Our Flight Data

What we cover and why.ScoreFlights tracks the top U.S. airlines: the 8 that individually report on-time performance to the Department of Transportation, covering the large majority of domestic seat capacity. We don't include smaller airlines because the federal government doesn't publish the reliability data we'd need to score them fairly.

DOT Data

The U.S. Department of Transportation publishes an Air Travel Consumer Report every month. It includes complaints filed against each airline, denied boarding (bumping) rates, mishandled baggage rates, and on-time performance statistics. We use this data directly, updated monthly as new reports are released.

One quirk worth knowing: When two airlines merge under a single FAA operating certificate, the DOT reports their combined statistics under one carrier. Alaska Airlines and Hawaiian Airlines received a single operating certificate on October 29, 2025, so all of Hawaiian's complaint, denied boarding, and operational data is now reported under Alaska's totals. Hawaiian's own HA code was retired on April 22, 2026, and it came off our roster in September 2026 — more on that here. This is a structural change in how the data is reported, not a gap in our research.

Baggage and Change Policies

We source baggage fees, carry-on rules, change and cancellation policies, and basic economy restrictions directly from each airline's published tariff. Airlines file these with the DOT and publish them on their websites. We verify them manually and flag material changes (a carrier raising its checked bag fee, introducing dynamic pricing, or tightening its change policy) as they happen.

The basic economy section on each airline page covers what level of carry-on bag you're actually allowed in the lowest fare class, since this varies significantly by carrier.

Seat Specs and Fleet Data

Seat pitch, width, recline, and cabin amenities (WiFi, power, entertainment) come from fleet baseline data published by each airline and cross-referenced with manufacturer specifications. Actual configuration varies by specific aircraft tail number and retrofit status; the page shows the fleet-wide baseline.

Live Flight and Aircraft Data

Flight status, schedule times, and the specific aircraft assigned to your flight come from a real-time flight data provider that consolidates airline schedule feeds. This data reflects whatever the airline has published as of the moment you look up your flight. It is not a guarantee. Airlines reassign aircraft for maintenance, network recovery, and other operational reasons, sometimes as late as the day of departure, so a lookup made far in advance may show a provisional aircraft that later changes. See why airlines swap planes for how this works and what it means for your score.

Reliability and Delay Data

On-time performance, schedule padding, and delay cause breakdowns come from the Bureau of Transportation Statistics' On-Time Performance database. This is the same data the DOT uses for its monthly reports. We aggregate it across all of an airline's routes to show the carrier-level picture.

Update Cadence

Government data (DOT complaints, denied boarding, BTS on-time performance) is updated monthly as new reports are published. Airline policy data is reviewed on an ongoing basis and updated whenever a carrier publishes a material change. Our pages always show the last verified date for each data point.