In my opinion, three hours is the maximum amount of time that planes should be allowed to stay on the tarmac before taking off or returning to a gate, whether the flight is domestic or international. Two or two and a half hours would be better. It’s true that if you end up back at the gate after a long spell on the tarmac, you will probably find yourself in a long line waiting to be rebooked. But at least you won’t be stuck in a cramped metal tube that might not have air conditioning, water, or working bathrooms. And speaking of bathrooms, I suggest that there should be a regulation requiring a plane to have at least a certain number of functioning lavatories before it can take off and to divert to the nearest usable airport if all its toilets go out of order during the flight and there is more than a certain amount of scheduled time (45 minutes, maybe?) left in the flight.
In my opinion, three hours is the maximum amount of time that planes should be allowed to stay on the tarmac before taking off or returning to a gate, whether the flight is domestic or international. Two or two and a half hours would be better. It’s true that if you end up back at the gate after a long spell on the tarmac, you will probably find yourself in a long line waiting to be rebooked. But at least you won’t be stuck in a cramped metal tube that might not have air conditioning, water, or working bathrooms. And speaking of bathrooms, I suggest that there should be a regulation requiring a plane to have at least a certain number of functioning lavatories before it can take off and to divert to the nearest usable airport if all its toilets go out of order during the flight and there is more than a certain amount of scheduled time (45 minutes, maybe?) left in the flight.