Nowadays, passengers on commercial aeroplanes don’t interact much with the pilots outside of voice announcements every now and then. However, most people know that there are usually two pilots aboard a commercial plane. But why is that? Why is one pilot (usually) not enough? Here are the reasons and how it works.

Why two pilots are important
Firstly, not everyone actually agrees about whether or not it is important to have two pilots in a plane. While it is mandatory in the US, for example, there are places such as the European Union or Canada where it is not required, and the importance of it is debated.
Europe and Canada used to have a “rule of two” stating two pilots were necessary, but the rule was relaxed in recent years. In the case of Germany, the government even cited that having two pilots could present a safety issue following the Germanwings crash of 2015, which was caused by an argument between the two pilots.
But most of the time, everyone still agrees that two pilots are necessary in order to ensure the passengers’ safety. The first reason is workload management. As flights are getting longer and longer, it means that pilots are working long hours and need breaks in order to avoid fatigue. Indeed, the majority of plane crashes are caused by pilot error, and fatigue is usually the cause of them. Having two pilots allows one to replace the other while they take a break.
Another reason is related to health. If one of the pilots becomes unable to do their job, be it because they fall ill or are otherwise incapacitated, the other needs to be able to replace them, especially for landing. In a famous case in 2017, an Etihad Airways pilot was able to safely land the plane after the other pilot died of illness on board. Pilot incapacitation is rare – one in 34,000 flights, according to a study by the Australian Transport Safety Board – but it does happen, the most common causes being a gastrointestinal disease and vision impairment caused by laser pointers.
With technology progressing, a single pilot is theoretically capable of piloting a plane, and single-pilot planes are actually becoming more common. Nowadays, auto-pilot is able to perform most of the pilot’s duties, and computers are the ones guiding planes during the flight. However, pilots are still required for take-off and landing, as these are the most dangerous parts of the journey and require precise manoeuvres that auto-pilots are not yet advanced enough to perform.

How it works: pilot flying vs pilot monitoring
Usually, one of the two pilots is the Captain or aircraft commander and occupies the left seat, while the other is the First Officer or co-pilot and occupies the right seat. The Captain is the First Officer’s superior and is the one who assigns the duties of ‘pilot flying (PF) and ‘pilot monitoring (PM).
The pilot flying is the one who is actually flying the plane: they are responsible for handling the controls, programming the autopilot, and steering the plane. Meanwhile, the pilot monitoring is responsible for communicating with air traffic control, monitoring the engines and other parameters, and completing the checklists. They are also responsible for cross-checking the PF’s actions, which is another reason why having two pilots is important for safety.
Most of the time, the two pilots alternate between the roles of PF and PM during the course of a flight. Some operators also require the roles to be switched between takeoff and landing in order to improve operational safety.
The two roles’ duties are well defined in order to share the workload. The Captain is ultimately responsible for the plane’s safety, but both pilots are trained to manage emergencies equally.
In short, having two pilots is required for safety reasons so that they can relay each other, and one pilot is responsible for flying the plane while the other is tasked with monitoring. Did you learn something new? Let us know down below!