How important are they?
No passenger aircraft is permitted to fly without a minimum crew of two pilots in the cockpit. That is the law laid down by aviation authorities worldwide. It is the responsibility of the captain to ensure the safety of a flight. All of the necessary information comes together in the cockpit, which is ultimately where all decisions are made – especially in an emergency. No passenger aircraft exists that can take off, fly or land without a cockpit crew.
Couldn’t the airplane’s autopilot take it up and land it again without human assistance?
The autopilot consists of several interconnected computer units, it is programmed and monitored by the pilots before and during the flight. Landing in extremely poor weather conditions is one situation that calls for assistance from the auto flight system, but using it requires far more effort and is a greater burden on the pilots than if they were landing manually in good weather. The autopilot can only be used in certain landing situations as an aid to the pilots, but not to replace them. An autopilot cannot take off.
Can we expect planes to fly without pilots in the future?
Work is underway to develop the pilot-free cockpit, but for what? To make air traffic safer or to cut labor costs? I don’t know. But as long as there are passengers on board, there will be pilots, too. From a technical point of view, it may already be possible for an airplane to fly fully automatically across the North Atlantic. The question is, would you board it?