Image copyright Reuters

Passengers who stopped to get their hand luggage put 300 lives at risk last week, after a fire broke out on an Emirates airliner in Dubai. Luckily, everyone escaped before the plane was consumed by flames - but it could have been different. What can be done to make people leave their bags behind?

"Passengers are told not to waste time getting luggage, but they just don't listen," says fire safety expert Prof Ed Galea of London's Greenwich University.

"This is not unusual, it happens in most cases. Often they don't appreciate the absolute urgency of their situation. They don't realise that every second can literally make the difference between life and death."

Two incidents in the last year have given a clear illustration of the problem. Before the Dubai fire video came pictures of passengers leaving a burning BA aircraft in Las Vegas, many wheeling bags across the tarmac.

But Galea suggested an answer to this problem more than 20 years ago - a central-locking system for overhead storage.

"On approach to land, the overhead bins should be locked by the flight deck," he says. "Passengers would obviously be informed that they are locked and cannot be opened until the plane is at the gate. I think it would make a huge difference."

It should not cause any inconvenience, Galea says. During the flight passengers would still have access to their bags, unless the "fasten seat-belt" light was switched on.

His ideas have fallen on stony ground, however.

Airlines think it would be unpopular with passengers, Galea says, and will not be "volunteering" to do it even now that the Dubai and Las Vegas incidents have underlined again the potential for loss of life.

Las Vegas 9 September 2015

Media playback is unsupported on your device Media caption One of the plane's engines caught fire during preparations for take off

Dubai 3 August 2016

Media playback is unsupported on your device Media caption A video shared on WhatsApp shows the panic on board the Emirates plane

While the video of the Dubai evacuation depicts a chaotic scene - some passengers screaming, a child pushing past adults to find her mother, men getting luggage from the overhead lockers and others people apparently trying to attach oxygen masks - passengers did not engage in a life-and-death struggle to reach the exits. But such struggles do take place.

In one account of the fire on a British Airtours jet at Manchester airport in 1985, in which 55 people died, an air stewardess describes people who, in their competition to get out, had become wedged into a gap near one of the exits so tightly that none of them could move.

In the aftermath of the disaster, Prof Helen Muir of Cranfield University attempted to simulate this panicked evacuation with volunteers. As it would have been unethical to make them fear for their lives she offered them money. All participants, many of them students, were paid £10 to take part in four evacuations over the course of a day, but there was an additional cash payment of £5 per evacuation to those in the first half of the group to leave the plane. This was sufficient to cause people to get wedged together in the over-wing exit on five occasions; on two other occasions the experiment had to be halted because a volunteer fell and could have been trampled underfoot. Aircraft exits were subsequently redesigned.

In such a scenario, where passengers are panicking - possibly in the dark, and choking on smoke - a wheeled bag could become a serious hazard.

Why bags are dangerous in an evacuation

They "slow people down and clog the aisles and exit points", as the pilot and author Patrick Smith puts it

On the evacuation slide, bags become "a deadly, high-speed projectile", he adds

In a mad rush for the exit, bags could trip passengers up

They could also puncture the evacuation slide and put it out of action

On the Professional Pilots Rumour Network (PPRuNe) last week there was some surprise that there had been no casualties in Dubai, as well as admiration for the Emirates cabin crew that got all the passengers out safely, and indignation that some passengers had recklessly risked their lives and those of others.

A handful of pilots commented that it was "time to introduce locking overhead bins".

However, a roughly equal number said that if the bins were locked, passengers would waste even more time trying to force them open.

An incident when a passenger tore off part of the ceiling of a Cathay Pacific Airbus in Hong Kong last month provides some support for this argument. Seated towards the rear of the plane, the man did not have an overhead locker above his seat, just a curved ceiling panel. Trying to "open" it, he pulled so hard that it came away.

Image copyright Facebook/@Tofu.Diary

Another expert who is sceptical about the idea of centrally locking overhead storage is Devin Liddell, principal brand strategist for Teague, a design and innovation consultancy that has designed the interiors of Boeing aircraft since 1946.

His solution is quite different: "To have far fewer bags in the cabin in the first place."

When Teague researchers recently studied the attitudes of passengers towards their luggage, they discovered that their main fear was finding no room for their bag in the overhead locker. That is why, Liddell notes, whenever any announcement is made about boarding - even if only to say that the first to board will be those with young children - everyone at the gate stands and starts inching forwards.

However, on probing further, the researchers discovered that passengers would be happy to part with their bags if there was no fee for putting them in the hold, and if they could be sure they would not get lost in transit.

Image copyright Alamy Image caption The overhead space on a Boeing 707 was often used for hats (as, perhaps, on this Qantas flight at Heathrow in 1959)

For many, their ideal model, Liddell says, was one used by short-haul commuter flights in the US, where bags are placed in a cart close to the aircraft door, and picked up again near the same door on the way out. He envisages a system where bags would carry a radio frequency ID tag, and passengers would receive a text message when their bag was loaded on to the plane, They would also be able to text a number to check where their bag was if they were concerned it was not on board.

Teague's studies also found that the additional time taken to board a plane and disembark when all passengers carry bags is usually greater than the amount of time spent retrieving luggage from a carousel - though Liddell also regards carousels as "dinosaurs", ripe for replacement by smarter systems.

For this reason, when the company unveiled a concept airline called Poppi last year, it provided no more space for hand luggage than there was on the Boeing 707, the aircraft that ushered in the age of jet travel half a century ago.

"When we looked at old photographs, the overhead space was occupied mainly by hats - hats, briefcases and jackets - so we nicknamed them 'fedora bins'," Liddell says.

Image copyright Teague Image caption Poppi's "fedora bins"

Image copyright Teague Image caption Poppi's aircraft would also have light coming through the fuselage roof

The original thinking behind the minimalist lockers was that getting rid of heavy carry-on bags would enhance passenger comfort, though Liddell says the safety argument is also a powerful one.

The response from passengers was "overwhelmingly positive", he adds. Whether airlines would ever warm to the idea, however, is uncertain. The fedora bins would be lighter and save on fuel, but airlines that charge for putting bags in the hold would lose a useful income stream if these fees were cancelled.

Airline pilot and author Patrick Smith who writes the AskThePilot blog is unconvinced both about centrally locked overhead bins, and the idea of radically restricting carry-on baggage.

"We are well past the point where the banning of hand luggage is a reasonable solution," he says. He does regard locked bins as "something to think about", though he notes that passengers might still grab any bags stored under the seat.

His preferred solution would be to re-focus pre-flight safety briefings - which so many passengers currently ignore - and to firmly emphasise just four or five bullet points, including the importance of leaving all bags behind during an evacuation.

While Devin Liddell does not see central locking of overhead bins as the best solution to the problem, he too does not rule it out. It would be a challenge getting across to passengers that there was no point trying to open the bins in an emergency, he says. On the other hand, he has a design idea that might help: "Redesign the bin so there is an LED light that glows fiery red when it's locked, and goes green when it's unlocked."

Prof Ed Galea thinks regulators may one day come round to his lockable lockers idea, but does not see it happening soon: "The difficulty with international regulators is they move at a snail's pace.

"Most international regulation is 'tombstone regulation' - lots of people have to be killed in an accident first."

But the passengers who stop to retrieve bags in an emergency are a "disaster waiting to happen," he insists. And one that will inevitably result in fatalities, sooner or later.

A debate on the Professional Pilots Rumour Network

asdf1234: Time to introduce locking overhead bins. Only accessible when the the seatbelt sign has been turned off.

Ranger One: Great idea - until someone's laptop lithium battery goes into runaway and the locking system fails in the "locked" mode.

etrang: Locking overhead bins would only make the situation worse as pax [passengers] try and figure out why they won't open. There is a simple solution however, don't let pax take any luggage into the cabin in the first place.

Fortissimo: Those with a brain leave their bags behind rather than risk their own and other people's lives while they delay the evac to collect things from the overheads, create trip hazards and hurl heavy bags down slides... Those with even larger brains keep items such as passports, phones and wallets about their person.

armchairpilot94116: We need to look at reducing the ability to carry on baggage. Having smaller bins, not bigger... Many airlines are charging for checking in bags. This should be reverse. There should instead be charges for hand carry.

DXBWannabe: Maybe instead of showing 4 different videos before T/O [takeoff] with info everyone already knows, the airlines should drill into people not to take their luggage with them during an evac.

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