Did you ever wonder why passengers always board airplanes from the left? (Read the previous sentence in your best Andy Rooney (60 Minutes) voice for those familiar with the American news magazine program😄.) Inside jokes aside, many reasons have been offered. Only one of them makes real sense in my view.

Deconfliction With Airport Operations

It could be that people board on the left because baggage loading, fueling and catering activities occur on the right side of the plane. It is good to keep these activities separate from passengers for safety and efficiency of operations. But that begs the question as to the reason for conducting these activities on the right side rather than the left. The reason these activities happen on the right seems to be to avoid the passengers on the left. That takes us back to square one.

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Iberia Airlines A340 at Adolfo Suarez MadridBarajas Airport (MAD) passengers on the left, ground crew on the right.

Also, sometimes ground crew work on left side when passengers board or disembark.

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Baggage loading and unloading on the left on this Bangkok Airways ATR-72 at Luang Prabang International Airport Laos

Is there anything special about the left side of the plane that could be the answer?

It Is Easier For The Pilots

In airliners, the captain sits in the left seat and the copilot sits in the right seat. A theory asserts that parking with the terminal on the left made it easier for the captain in the left seat to judge wing clearance from the terminal building and to put the aircraft door in the right spot relative to the terminal.

Two things undermine this explanation. First, captains often delegate parking the plane and leaving the gate to the copilot who sits on the right side of the aircraft.

Second and more importantly, ever sense at least the 1950s when I started hanging out at airports, pilots don’t rely on their eyeballs to park at or depart from the terminal. They follow the directions of air marshallers, ground crew who signal the pilots usually with handheld illuminated wands. We’ve all seen them at work.

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For good reason, pilots don’t approach the terminal until air marshallers wave them in and ensure the aircraft is properly lined up. Airlines insist on it. Most gates are tight and there is a lot of equipment on the ramp that pilots can’t see from the cockpit. Relying on pilot eyeballs to park in these congested spaces would lead to a lot of dinged up expensive aircraft and equipment.

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Planes have precise stopping points on the tarmac that the pilots can’t see. Cathay Pacific A350-900 at Singapore Changi Airport.

Making it easier for pilots doesn’t seem to be a good answer.

Nautical Tradition

The reason for boarding and disembarking on the left seems to be most closely related to the history of sailing vessels. The right and left side of ships is referred to as starboard and port, respectively. The port side was commonly used for docking and loading passengers and cargo.

That was because ships had a device called a “steerboard,” that was similar to a rudder, on the right side. With the steerboard on the right, loading and loading from a dock had to be carried out on the left on those vessels. Consequently, the left side became known as the “port” side and the right side became known as “starboard” a derivative of steerboard.

Aircraft also follow nautical tradition regarding navigation lights – the colored lights on the wing tips. A green light designates the starboard side. A red light identifies the port side just as on a ship. From a distance, nav lights identify which side of a craft you are looking at.

Exceptions

In the past, some aircraft had the ability to board through the tail. A Lockheed Constellation was the first plane I was a passenger on. It was a four-engine propeller driven passenger plane and the first to have a pressurized cabin. I remember boarding through the rear stairs at age three.

Rear stairs were also a feature of some later jet aircraft like the DC-9, MD-80 and 727 models. Those stairs served as emergency exits and were rarely used for boarding or disembarking.

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Northwest 727 with rear stairs deployed.

I think it is unfortunate that airlines generally fail to follow through with the nautical tradition of naming their craft. Many dinghies have names, but only a select few airlines have the decency to name the craft that cost them hundreds of millions of dollars.

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Kenya Airways 787-8 with name “Serengeti Plains” written on the fuselage below the cockpit.

Final Thoughts

Picking one side (left or right) for boarding and making it uniform worldwide is the best way to ensure smooth operations at every airport. Have you ever boarded or disembarked from the starboard side of an airliner or ship?