A software update by CrowdStrike caused a massive IT outage, affecting millions of Windows machines, including those used by airlines, resulting in widespread flight cancellations and disruptions. The outage had a significant impact on Delta Air Lines, which was hardest hit, with a 46% reduction in flights. The article analyzes the effects of the outage on US aviation, using data from ADS-B Exchange to track aircraft takeoffs. The author also explores the reasons behind Delta's slower recovery compared to other airlines.