Infrared image of passengers carrying bags after exiting an A320

Bag retrieval during aircraft evacuations begs test criteria changes

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A meaningful number of airline passengers continue to waste precious seconds during time-critical evacuations by prioritizing the retrieval of their carry-on bags over quickly exiting the aircraft. This persistent and growing trend gives credence to the argument that current test criteria used to satisfy 90-second emergency evacuations should include more realistic simulations of passenger behavior. And indeed, the European Union Aviation Safety Agency (EASA) is now under the gun to do just that.

This human factors issue was highlighted once again by an accident report published by the UK’s Air Accidents Investigation Branch (AAIB), which examined the 1 March 2019 evacuation of a Laudamotion Airbus A320 at London Stansted Airport after a minor contained engine failure and subsequent rejected takeoff. In all, there were seven crew and 169 passengers on board the flight. The senior flight attendant moved to evacuate the aircraft, though the pilots later said they had not ordered an evacuation.

The report categorizes the evacuation as proceeding “swiftly, without significant panic or delay”, but the AAIB raised particular concerns that flight attendants had to take back luggage that passengers were attempting to carry through the exits, potentially blocking the process.

The AAIB explained:

At the supervised doors, the FAs removed baggage from them. At the unsupervised overwing exits, passengers with bags could exit unchallenged. Baggage brought to the exits created difficulty for the FAs who then needed to remove it and store it somewhere which could have created an obstruction.

The carried baggage probably slowed the evacuation and had the potential to damage the escape slides or injure other passengers on the slides.

It was not possible to determine how long the evacuation took compared to the [EASA cabin safety] CS-25 requirement of 90 seconds.

The image at top, which shows the Laudamotion passengers carrying their bags, was taken by an infrared CCTV security camera and included in the AAIB report. These types of images have become commonplace. Clearly, the methods used today to raise passenger awareness of the risks associated with grabbing bags during an evacuation – such as passenger briefings and printed instructions – have proven ineffective.

For many years aviation authorities have required that emergency evacuation requirements for new-design aircraft be demonstrated by real-life demonstrations. Some regulators have, however, accepted computer simulation test data to re-certify aircraft to carry more seats.

The challenge of real-life demos has always been that there is a significant element of risk in conducting these studies and participant behavior is also unpredictable. In the AAIB’s view, another challenge is that the demos “do not include a realistic simulation” of passengers grabbing bags, slowing down the evacuation and increasing the risk of injury.

Given its findings in the Laudamotion incident, the AAIB now recommends that EASA commission research to determine how to prevent passengers from obstructing aircraft evacuations by retrieving carry-on baggage.

Crucially, it also recommends that EASA consider including “a more realistic simulation of passenger behavior” in regard to carry-on baggage in the test criteria and procedures for the emergency demonstration outlined in CS-25.

Rotation
EASA, the US National Transportation Safety Board (NTSB), Canada’s Transportation Safety Board, and the Royal Aeronautical Society (RAeS) have in fact already been studying this vexing phenomenon.

In an ‘Emergency Evacuation of Commercial Passenger Aeroplanes’ study published in June, RAeS highlighted how evacuation demonstrations are not representative of real life scenarios.

“Cabin baggage, pillows and blankets are placed in the aisles, but the baggage is very lightweight [and] usually contains only light density materials,” noted RAeS. “Again this is not representative of many emergency evacuations where passengers have taken heavier items such as ‘baggage with wheels’ with them to emergency exits and down evacuation slides.”

RAeS recommends that aviation authorities consider the feasibility of certifying a remote locking mechanism for overhead bins from the flight deck during taxi, takeoff and landing — the phases of flight when aircraft accident risks are highest.

But there are other opportunities to improve safety. Digital modeling could be informed by the large stores of data gathered from 50 years of practical simulations, suggested RAeS. And data modeling variables could include data gathered from real accident reports over the years.

An “airEXODUS” computer-based mathematical model has been under development since 1989 with support from the UK CAA and the aviation industry. The video below shows how it can provide insight into the evacuation process.

 

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