When it comes to air travel, it’s fair to say that we as passengers are pretty much at the mercy of the powers that be! From outrageously tiny airplane seats to odd banned foods to infuriating limitations on flying with children, airlines, the TSA, and airports around the world sure do know how to make us feel more than a little uncomfortable about the flying process.

We know, we know; we probably sound dramatic and pretty ungrateful with our rant. But you get it, right? If you’ve flown in the last 10 years, then we’re betting you do!

That being said, whenever we get too bent out of shape about the state of today’s air travel, we try to remember that most of the strict rules are imposed in order to keep us safe.

OK, rant over.

Or— rather, rant almost over because we just have one more nagging concern on our minds, and no, it surprisingly has nothing to do with the scant meals airlines are serving up these days. It actually has everything to do with the boarding process—just why in the heck are passengers always boarded on the left-hand side of the plane?

Why airlines make us “go left”

Interestingly, there’s not a whole lot of information out there on why or how this boarding tradition started, but we’ve heard a few pretty good theories that make sense to us.

Let’s take a look at one of the most popular ones—we’ll call this the “pilot theory” because it has to do with how boarding patterns can affect the pilot’s control over the air vessel.

The idea here is that the pilot’s seat in the cockpit is closer to the gate – when coming in on the left-hand-side, of course – a detail that makes it just that much easier to safely park the plane next to the jet bridge. Makes sense, right?

Another popular theory states that left-hand boarding helps speed up the boarding process as a whole. You see, when a plane pulls into a gate, the luggage and food for the flight need to be loaded on as quickly as possible—usually in under 40 minutes.

Since the loading areas for luggage and refreshments are traditionally on the right-side of the plane, workers are able to complete the mad dash faster than if they were made to wait for boarding passengers.

These sound reasonable, right? Well, it turns out they still might not provide the answer to our original question…

Sorry. Did that leave you even more confused than when we started? Watch the video below to learn the most likely answer for the left door boarding mystery. Spoiler alert: sometimes the simplest answer is the most powerful. Have any guesses on what it might be?

We’d love to hear your thoughts on this airline mystery! Why do you think passengers board on the left-hand side of the plane? Does the video’s main theory make sense to you? Are you someone who works in the airline industry who can put the rumors to rest once and for all?