When you board a plane, you probably think about whether or not you want a window or aisle seat that is either close to the bathroom, or far away.  But new research published in the journal AIP Advances concludes that when it comes to safety, who is sitting around you matters more than where you sit on a plane.

There’s a global aviation safety standard rule you’ve probably never heard of: every passenger must be able to evacuate a plane in 90 seconds.

But here’s the catch: it's based on controlled tests, under perfect conditions, involving calm people and ideal scenarios.

I've never been in a plane emergency, but I imagine people panic, aisles clog and not all passengers will move at the same speed. 
 
The new research asked a simple question - what actually happens during a realistic evacuation and does the passenger type and seating location affect survival?

The researchers built a full digital model of an Airbus A320 cabin and simulated emergency evacuations under one of the worst-case scenarios: a dual-engine fire. This scenario prevents the use of wing exits, forcing everyone to escape only through the front and back doors 
 
They ran 27 different scenarios with different passenger mixes and seating arrangements. 
 
Surprisingly they found that the fastest evacuation didn’t happen with the strongest, fastest passengers but instead when only 20 percent of passengers were elderly and evenly distributed near exits.

That scenario took 141 seconds. It still didn't meet the 90 seconds target, but it was the fastest of all of the scenarios and much better than the worst evacuation, which took over 218 seconds.

At first glance, the findings seem obvious. Older passengers move more slowly, which slows down evacuation, but the real insight is not just how many slower passengers you have, it’s where they are

Here’s what the study found: 

• Older passengers may move more slowly, take longer to react, need assistance and struggle in stressful, unfamiliar situations.
• Clustering slower passengers in one area creates bottlenecks
• Random placement causes unpredictable surges and congestion
• Even distribution smooths the flow and reduces jams
• When exits are limited (like in a fire scenario), small delays ripple outward and slow everyone down. 
   

This research is important because the world is aging, meaning that in the near future, more flights will include a higher proportion of older passengers.
 
The researchers suggest that airlines should strategically distribute slower-moving passengers evenly to improve safety, so maybe in the future your seating choice might be made by your age, not whether or not you like the window seat. 

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