Date: 201809
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Anomaly: Deviation / Discrepancy - Procedural Security; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Detector: Person Flight Attendant; Person Gate Agent / CSR
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: Prior to boarding; agent advised crew of a passenger who had shown signs of disruptive behavior in waiting area. Agent said 'He is a very big guy; who had outbursts in the waiting area. He was told to sit down and wait quietly. This passenger is traveling with his family; (mother; grandmother and another female) he may have some mental disabilities and we gave him the last row of seats 33D;E;F. He should be fine to fly.' He also stated that he had not interacted with the passenger and was relaying the message from boarding agent.Crew asked to speak with boarding Agent that had interacted with [the passenger]. Boarding Agent stated that while in the airport lobby [passenger] was pacing and projected to his mother 'Mom do I need to take my medication.' Captain advised the agents to contact Medlink regarding medication concerns as well as the stability and suitability for safe travel. Agent returned with a printed medical release stating passenger was on schizophrenia medication from personal doctor and Medlink said he was cleared for travel.C FA (Flight Attendant); takes out flex cuffs and leaves out for flight in aft galley; A FA does the same in forward galley. (prior to taking off).When passenger boarded the A FA was asked by [passenger] where his seat was. A FA escorted passenger toward last row. This was at the end of boarding so the overhead bins near row 33 were full leaving [passenger] to stow his bags at 25ABC. [Passenger] could not understand why his bag needed to be stowed away from his seat and would not take direction from A FA. [Passenger] yelled to his mother seated at 32D to move several times. After explaining multiple time that there wasn't room he finally placed bags in overhead.B FA; Briefs 2 ABPs (Able Bodied Passengers) to assist if needed. (Prior to take off).[There were] multiple outbursts and incidences throughout the flight left Captain mapping closest airports and peeping for threat levels. [Doctor on board] Believed that [passenger] was in a manic state of his Schizophrenia. Doctor offered to sit with [passenger] if needed. [Passenger] had multiple outbursts during the flight including storming up the aisle yelling at a passenger seated around row 22-24. Yelling at people who were waiting to use the bathroom. Yelling for people to put on seatbelts. Stating that he didn't like blondes. Stating he didn't want D FA to come near him. Became more aggravated if his family talked to him *This is just to name a few*.As a crew we defused many potential situations during the flight which could have escalated quickly. I honestly don't think we could have put flex cuffs on [passenger] without being seriously injured. The fact is; we took out Flex-cuff restraints and prepared ABPs before we even left the ground because of Medlink's clearing an unstable passenger to fly.  [Passenger] is currently an unstable passenger who should not fly without an advocate able to defuse potential escalation of his diagnosis and can restrain him if needed.Our crew handled a situation that didn't need to exists. [Passenger] needs more assistance than family traveling with him for future travel.Cockpit interaction as follows:We were brought into the matter prior to boarding when the A FA said we needed to hear what they had just learned about a passenger. There was little to go on at first until we were able to talk directly to the agent that had witnessed the behavior. As soon as I heard that the passenger was on medications I asked the agent to contact Medlink to make an assessment.  The agent returned with a photocopy of a letter from a Doctor authorizing the passenger to travel and a report that Medlink cleared the passenger to travel. None of the crew had seen the passenger yet and we were informed that the passenger was traveling with his family but that he 'didn't like them'. We had a crew brief regarding the situation and came to a consensus that we were ok with the passenger travelingbut that we were going to take precautions. I asked the crew to be vigilant and to think in terms of Threat Levels. I also encouraged them to call us at anytime there was a problem including below 10;000 feet.  Upon boarding the passenger; the A FA got my attention to see him. He was in his 20's to 30's perhaps but well over 6 feet tall and of medium build. Another brief with the crew for selecting ABP's.As can be seen in the previous narrative; there were several incidents that generated calls to the cockpit. While each of them was diffused; the atmosphere for all of us was that of a ticking bomb. It wasn't 'if' but 'when' for the 6 hour flight. While the crew was handling the various events in the back; [First Officer] and I briefed likely Threat scenarios and divert locations. As we approached [destination]; I sent a message to Dispatch advising of passenger situation and the need to have Supervisor meet the plane. Upon radio contact with [destination] I confirmed they had been informed by Dispatch and that a show of force was not a good idea due to passenger's size and seating location in the rear of the jet. No further incidents after landing. Crew debriefed with Supervisor and Agent.The post flight debrief gave us the opportunity to review what we did and what we would do in the future. Crew worked well together but came to the conclusion that we would not put ourselves in that situation again. Had it not been for Medlink clearing passenger to fly; he would have been left at the gate.




Synopsis: Air carrier Captain reported that a passenger who was approved to fly displayed disruptive behavior before and during the flight.