My recent sojourn to Merida, Mexico for the ASTA Destination Expo allowed me to fly Aeromexico for the first time, and experience for the first time one of the rarely used methods of boarding – outside-in.

For those who aren’t familiar with the outside-in method, Aeromexico and United are the most prominent few who board by window seats first, then middle, then aisle.

It seemed fairly efficient – not perfect by any means, but somewhat efficient – although one of my seat-mates on the flight from JFK to Mexico City preferred to describe it as “more controlled chaos, less reckless abandon.”

Boarding can indeed be a chaotic process no matter how quickly the airlines try to turn a plane around. The carriers are fully aware that time on the ground costs money. There’s nothing they can do about de-planing, which is a tedious, torturous row-by-row madnessconsisting of standing in the aisle and impatiently waiting. And waiting. And waiting.

But there is something they can do about boarding the aircraft.

Virtually every airline boards its first class, business class and elite loyalty program members first, along with those traveling with children and those who are disabled and need help. After that, it’s pot-luck and there are different methods to the madness.

There is Random Seating, in which passengers board according to the time they checked in. American Airlines went to this method almost three years ago, with the carrier saying it eliminated gridlock in the main aisle.

Back-To-Front Seating has been the preferred way to do business by many airlines, with the boarding being just as the name suggests – the aircraft is loaded from the last row forward so as to avoid as much clogging of the main aisle as possible.

The By-Seat Method was use overseas by KLM for years, in which the airline announced seating by specific seat number.

On Aeromexico, the boarding area for a flight with three seats on each side of the aidle had three distinct, grouped lines for passengers who were not among first class, family or disabled – a line for those sitting in seats marked A and F (window), a line for those sitting in seats marked B and E (middle), and a line for those sitting in seats C and D (aisle).

Ostensibly, this is how it should look:

Aeromexico gave ample time between making “Now Boarding” announcements for the seat pairs, although there still was a backup in actually boarding the plane as passengers waited on fellow passengers to store their carry-ons.

Regardless of seating method, that will probably never change.

Nonetheless, the Outside-In method had its advantages and its drawbacks. The good? One third of the plane was seated by the time I got on with my aisle seat boarding pass in hand, and a good portion of the middle seats were filling up. The bad? Congestion, as some of the aisle seat passengers were still standing as they attempted to find space in the overhead bins.

It’s an inexact science, boarding the plane. Short of having two jetways for every flight where passengers can board and either go left or right, there probably is no “right” way to board a plane.