No, not all commercial flights have two pilots. The number of pilots required on a commercial flight depends on various factors, including the type of aircraft, the regulations of the country in which the flight operates, and the policies of the airline.

Most commercial flights, especially long-haul or larger aircraft, have a minimum of two pilots: a captain (also known as the pilot-in-command) and a first officer (also known as the co-pilot). This is commonly referred to as a two-pilot crew or a cockpit crew.

Having two pilots in the cockpit provides several safety benefits. These include:

1. Crew coordination and workload sharing: With two pilots, tasks and responsibilities can be divided between them, allowing for effective coordination and workload sharing. This helps to reduce fatigue and enhances the ability to handle critical situations during the flight.
2. Redundancy and backup: Having two pilots provides a backup system in case one pilot becomes incapacitated or unable to perform their duties. The second pilot can take over control of the aircraft and manage the situation.
3. Monitoring and cross-checking: Two pilots can cross-check each other’s actions and decisions, helping to mitigate human errors and improve situational awareness. They can monitor various flight parameters, instruments, and systems to ensure a safe and efficient flight.

However, there are certain situations where a commercial flight may have only one pilot in the cockpit. This can occur during certain phases of flight when the workload is relatively low, such as during cruising when the autopilot is engaged. However, it’s important to note that having a single pilot in the cockpit does raise safety concerns due to the absence of immediate backup in case of an emergency or pilot incapacitation.

Aviation authorities and airlines have strict guidelines and procedures in place to ensure the safety of flights with a single pilot. These procedures may include enhanced monitoring by air traffic control, specific training and qualification requirements for single-pilot operations, and the use of advanced technology and automation systems to assist the pilot.

Ultimately, the decision to have one or two pilots on a commercial flight is determined by regulatory requirements, operational considerations, and the airline’s safety policies.