Delta Flight 2809 had just arrived when, according to passengers, a group of federal agents suddenly boarded the plane and stormed the cockpit.

Hawker Hunter Aviation (HHA) operates a fleet of retired Hawker Hunters. HHA provides the jets to RAF and other NATO partners for purposes like air combat training, Joint Tactical Air Controller (JTAC) training and trials. These contracted Hunters are often upgraded with modern avionics.

The Southwest Airlines jet was in the same airspace as a Hawker Hunter owned by a British defense contracting company, according to AP.