They can be. The cabin crew will communicate to the flight crew when the interior is ready, they won’t takeoff without it, and someone refusing to sit down or buckle up definitely counts as not ready.
If a passenger gets up and causes a disturbance later, that would also get communicated to the flight crew and, shot of the plane having started its takeoff roll, there’s a good chance everyone is going back to the gate to remove this person.
I’ve always seen the flight attendants stand and wait until whatever they request has been adjusted. But 90% of my flying experience is in Europe so maybe it’s different in the US.
Flights don’t get delayed because someone is standing or unbuckled.
They do if the captain is waiting for the final go ahead from the tower. They can’t go anywhere until everything is secure and ready to go.
They can be. The cabin crew will communicate to the flight crew when the interior is ready, they won’t takeoff without it, and someone refusing to sit down or buckle up definitely counts as not ready.
If a passenger gets up and causes a disturbance later, that would also get communicated to the flight crew and, shot of the plane having started its takeoff roll, there’s a good chance everyone is going back to the gate to remove this person.
They do: https://www.cbc.ca/news/canada/toronto/porter-airlines-flight-to-toronto-cancelled-child-standing-on-seat-9.7300786
I’ve always seen the flight attendants stand and wait until whatever they request has been adjusted. But 90% of my flying experience is in Europe so maybe it’s different in the US.