Russian investigators believe passengers’ attempts to retrieve luggage during a fatal Aeroflot Superjet 100 fire probably slowed evacuation, and was a contributor to the severity of the outcome.
Forty passengers and one flight attendant did not survive the fire, which ignited as fuel spilled from ruptured fuel tanks during a hard bounced landing at Moscow Sheremetyevo on 5 May 2019.
Russia’s Interstate Aviation Committee says the rear half of the jet was consumed in the blaze, and all but one of the fatalities occurred in seat rows 11 and back.
“Considering that 14 seats in the passenger cabin were unoccupied, the results of the emergency evacuation were much worse than expected,” says the inquiry.
It says the captain was the last to leave the aircraft, 5min 26s after the evacuation began, which meant the time that some of the survivors remained on board “significantly exceeded” the standard evacuation time.
Certification requirements demand that the aircraft can be evacuated in 90s using only half the exits. When the Superjet was certified, the evacuation demonstration used the forward and aft right-hand exits.
The accident inquiry says passengers emerged from the forward right-hand exit just 15s after the aircraft came to rest, and from the forward left-hand exit 16s after that.
Analysis indicates that the flight attendant stationed at the aft pair of exits probably opened the rear left-hand door, but the presence of the fire made both aft exits unusable – forcing passengers to head to the front.
Neither cabin illumination nor passenger mobility complicated the evacuation. Although survivors testified that some bags fell from overhead bins during the hard landing, the inquiry says there is no evidence that they injured passengers or created obstructions.
But the inquiry says that some passengers observed others taking baggage, including backpacks and small suitcases, from the bins, leading to an “impassable blockage” in the aisle.
Several casualties of the accident, who had been sitting in the aft cabin, were found lying in the aisle between seat rows 6 and 10, indicating that that had been moving forward when they were overcome by toxic smoke.
“The difficulty in moving towards the exit, associated with the collection of hand luggage by a number of passengers, could have affected the severity of the consequences,” says the inquiry.
It points out that the flight attendant who opened the aft exit was among the fatalities, the only member of the crew not to survive.
Testimony from survivors shows that, after the hard landing, smoke began penetrating the cabin and caused “panic” among passengers.
“A strong crush formed in the aisle because many passengers, almost simultaneously, independently unfastened their seat belts and stood up,” says the inquiry. “The situation was aggravated by the heavy smoke and the fact that some passengers were trying to retrieve their hand luggage.”
Smoke caused breathing difficulties, prompting a number of passengers to bend and crawl along the aisle, slowing the movement to the exits.
There is also evidence, from passenger testimony, that the fire quickly penetrated the cabin, as early as 8s after the first forward exit was opened. The inquiry says this “most likely” occurred when smoke and flames simultaneously entered several window apertures.
This indicates that passengers in the rear cabin did not have the standard 90s interval in which to evacuate. The inquiry adds that a flashover – spontaneous ignition over a large area of the cabin as temperature rises – could account for injuries sustained.
It says the fire hazard was exacerbated by the aircraft’s engines, which were still running, and creating a “gas-burner effect” as spilling fuel flowed into the exhaust path.
“Conditions under which the evacuation took place were fundamentally different from those under which the [certification demonstration] took place,” the inquiry states. “They went beyond the expected operating conditions.”
