When it comes to road transport, drivers of motor vehicles sit on either the left or right-hand side, depending on the country they’ve been produced to drive in. However, air travel is a far more internationally-focused domain. As such, is a greater degree of uniformity regarding where the captain sits, as they always find themselves on the left-hand side of the cockpit. But why is this the case?
The fact that the left-hand seat of a two-person cockpit is reserved for the aircraft’s captain dates back to the decades before the advent of jet-powered engines. According to Ask Captain Lim, this tendency came about due to the nature of early rotary-driven aircraft, such as fighter aircraft from the First World War.
It was easier for these aircraft to turn left as this allowed them to follow the torque of their engines. Their left-turning torque functioned in this way because most aircraft propellers at the time span clockwise. Contrastingly, right turns required early pilots to counteract this force, demanding stronger control and rudder inputs.
World War I era fighter aircraft, such as this Bristol F.2, found it easier to turn left. Photo: Kogo via Wikimedia Commons
Subsequent operational tendencies
The relative ease in turning left for these aircraft led to several operational tendencies that cemented the left-hand side as the captain’s seat. For example, many airports began to favor traffic patterns consisting of easier left turns. With such patterns being predominantly left-handed, it became the norm for an aircraft’s captain to sit on this side, where they would be on the inside of the turn.
This subsequently allowed them to benefit from greater visibility when making such maneuvers, which typically happened more commonly than right-hand turns. This is a tendency that has continued to prevail over the years. Of course, the advent of newer engine technology in the following years removed the unbalanced turning tendencies that led to left-hand turns being favored in the first place.
Modern airliners can be flown equally well from either side of the cockpit. Photo: Jake Hardiman | Simple Flying
However, the tradition remains today, with the captain still seated on this side. Of course, it is worth noting that the right seat has the same controls today. As such, first officers are in an equally viable position to control the plane.
Different for helicopters
Interestingly, the tradition of seating captains on the left-hand side does not apply to helicopters. According to Smithsonian Magazine, sitting on the right-hand side is common (but not universal) practice as it allows the pilot in command to keep their right hand on the aircraft’s sensitive cyclic control stick.
According to the American Psychological Association, around 90% of people favor the use of their right hand, hence this tendency. Meanwhile, this leaves their left hand free to operate the helicopter’s less sensitive ‘collective control.’
Boarding aircraft from the left is also partly down to the captain sitting there. Photo: Jake Hardiman | Simple Flying
Impact on boarding procedures
The fact that airline captains have historically always sat on the left-hand side of their aircraft has also impacted the way in which passengers board the aircraft. As Simple Flying explored in an article last year, this also typically takes place from the left, with this operational quirk resulting from a combination of factors.
One of these was the fact that aircraft used to park parallel to airport terminals for boarding, rather than head-on, as is the case nowadays. This required the captain to sit on the side closest to the building in order to complete such maneuvers in the most precise manner possible. As such, with their seats being on the left-hand side of the aircraft, this was the side that pulled up at the terminal.
Were you aware of why captains sit on the left-hand side? Perhaps you’ve been lucky enough to visit a flight deck and take a seat there yourself? Let us know your thoughts and experiences in the comments!
Sources: American Psychological Association, Ask Captain Lim, Smithsonian Magazine