Using Bellingcat’s New Open Source Tool to Explore Historical and Spatial Flight Data

**Executive summary:** Bellingcat’s Turnstone is a web and open-source tool that aggregates ADS-B flight-tracking data to help researchers visualise historical aircraft movement patterns and identify anomalies; the report demonstrates practical use cases (spikes in US tanker traffic prior to strikes, identifying deportation flights to Guantanamo Bay, and mapping CBP aircraft and MQ-9 drone activity), describes filtering and upload features (region, aircraft type, time/distance windows, hex lists), and emphasises limitations of the underlying data (MLAT positional errors, incomplete ownership/registration records, and possible LLM misclassification), advising independent verification and providing links for access and contribution.