Ninety seconds is all the time you have to get off a plane if there’s an emergency and everyone must evacuate. But research shows that an ageing society is increasing the time it takes to empty an air plane.
Evacuation times from planes increase with the age of passengers, an international research team wrote in the journal AIP Advances.
In practical terms, that means the internationally prescribed evacuation times are now hardly achievable when there is a high proportion of older passengers.
Under rules set by the United States aviation authority FAA and the European Union Aviation Safety Agency (EASA), an aircraft must be fully evacuated within 90 seconds in an emergency.
However, the new study shows that this target was not met under realistic conditions with seniors on board in any of 27 simulated scenarios.
Even in the most favourable case, passengers needed 141 seconds to leave the aircraft and reach the ground, almost a minute longer than the official requirement.
The scientists led by Chenyang Zhang of the University of Calgary in Canada examined the evacuation of an Airbus A320, one of the most commonly used aircraft types worldwide. The scenario was based on a fire in both engines. In such a case, the emergency exits directly above the wings are impassable, leaving only the four exits at the front and rear of the cabin.
For the study, the researchers used computer-based models and industry-standard simulation software to map human movement behaviour in the narrow cabin. They combined three different cabin layouts with three different shares of passengers aged over 60.
The results show that both the percentage of seniors and their exact seating distribution significantly influence evacuation time.
The delays are explained, the study said, by the physical and mental characteristics of older people. In the simulations, seniors were assumed to have a significantly slower walking speed.
Cognitive impairments in old age could also reduce situational awareness and slow decision-making in stressful situations. Declining fine motor skills can also make it harder to get out of seats.
The longest evacuation time was measured at 218.5 seconds in a densely seated cabin with 80% older passengers. To minimise the risks, the authors propose various measures.
Airlines could seat older passengers near exits or adapt cabin architecture with wider aisles and optimised handholds. Special safety briefings for seniors could also help shorten reaction times in an emergency.
The researchers acknowledged that children, toddlers and pregnant women could also lengthen evacuation times. They plan to investigate this in future. – dpa
