I was listening to RealATC for a United Flight UAL1074 which declared an emergency needing to return to Washington Reagan National Airport. During the ATC recording, the flight declares an emergency due to a passenger disruption.
ATC asks for something called the Passenger Disturbance Level. The Copilot replies with a Disturbance Level of 2. As I had never heard this asked for before, I was curious as to what the levels are for and what they each mean?