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?


2 Answers 2


The FAA has categorized disturbances into four levels:

Level 1: Disruptive behavior - suspicious or threatening
Level 2: Physically abusive behavior
Level 3: Life-threatening behavior
Level 4: Attempted or actual breach of the flight deck

These are also ICAO standard classifications from the restricted Doc 9811, according to IATA. I'm not sure who came up with them first. That IATA document also provides sample things that might be considered to be each level.

  • 1
    $\begingroup$ So if I understand it correctly: Level 1 is an unruly or drunk passenger that is making a ruckus, level 2 is a passenger that's beyond a ruckus and has started to touch or beat passengers or crew, level 3 is a medical emergency, like a heart attack or a seizure, and level 4 is basically when someone tries to hijack the plane. Does that sound about right? I assume that each level is handled differently once the plane has made the emergency landing? $\endgroup$
    – Nzall
    Commented Jun 4, 2015 at 10:24
  • 1
    $\begingroup$ @NateKerkhofs: Passenger Disturbance Level 3 might cause a medical emergency, but most medical emergencies have other causes. $\endgroup$
    – MSalters
    Commented Jun 4, 2015 at 11:16
  • 7
    $\begingroup$ Level 3 seems more like someone pointing a gun at another person onboard. That also seems a reasonable curve-fit given the other levels listed, and IATA seems to agree; examples given are The threat, display or use of a weapon and Physical or sexual assault with intent to injure. $\endgroup$
    – user
    Commented Jun 4, 2015 at 13:51
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    $\begingroup$ @NateKerkhofs a medical emergency is not a passenger disturbance and is responded to by medics, not police. Level 3 passenger disturbance is physical violence capable of life threatening injury. $\endgroup$
    – casey
    Commented Jun 4, 2015 at 15:25

My guess is that it has something to do with FAR 121.580 which states

...No person may assault, threaten, intimidate, or interfere with a crewmember in the performance of the crewmember's duties aboard an aircraft being operated under this part.

The code may be assigned so that the terminal can send appropriate officials to the gate when the plane arrives.

This interesting article breaks it down into 3 "categories" (page 7 table 3) which may be what the pilot was referencing. Looks like this was written in 1997 and may have become law or influenced common standards since then but thats all I can find that seems to be similar to the situation you present.


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