'Violent' employee sues United Airlines over poor staff training

A former security officer who dragged a 69-year old man off an aeroplane last April is suing his former employer for not training him on how to use force correctly.

Security guards pulled David Dao from his seat from an overbooked flight in Chicago, and apparently knocked him unconscious in the shocking video of the incident. Dao suffered concussion, a broken nose, and lost two teeth.

The violent removal was widely shared, causing outrage and a backlash against United Airlines.

James Long, a security guard who was sacked after the incident, alleges that he was not trained in how to use force in his role.