Flight Report

This dataset covers two days of ADS-B traffic at Seattle-Tacoma International Airport (KSEA) from December 20-21, 2025, capturing 1,587,698 position points across 2,107 total flight operations. Arrivals and departures were nearly balanced at 1,037 and 1,033 respectively, with 37 touch-and-go operations also recorded. Traffic involved 641 unique aircraft registered across 17 countries, with US-registered aircraft accounting for 573 of them. Canada contributed 12 aircraft, followed by several countries with smaller counts including China, Germany, Japan, South Korea, and the United Kingdom with 4 each. The peak hour fell at 14:00 PST with 145 flights, driven heavily by departures (101 versus 43 arrivals that hour). The 08:00 hour was the busiest for combined balanced traffic, with 64 arrivals and 64 departures. Overnight hours between 02:00 and 04:00 saw the lowest activity, though the airport recorded operations across all 24 hours. Los Angeles was the top route pairing with 65 total movements, followed by Phoenix (59), Portland (56), Spokane (54), and Boise (53). Anchorage and Vancouver were also in the top ten, reflecting both domestic and transborder traffic. Approach and departure headings were concentrated to the east and south-southeast, with E and SSE topping both direction charts. Altitude data shows a strong concentration of position reports between 34,000 and 36,000 feet, the most densely sampled cruise band in the dataset. The average altitude across all recorded points was 17,378 feet, and the maximum logged was 45,500 feet, reached by tail number N544FX on a departure to Oakland. The shortest logged flight ran just 9.8 nautical miles and 19 minutes between KSEA and Boeing Field. The longest was a departure to Fort Lauderdale covering 2,731 nautical miles over 508 minutes. Average leg distance across all operations was 799 nautical miles.