The evacuation of a Qantas A330 aircraft at Sydney Airport highlights the importance of clear passenger information and commands, an Australian Transport Safety Bureau investigation details.
On the morning of 15 December 2019, the Perth-bound Airbus A330-200 carrying 2 flight crew, 8 cabin crew and 222 passengers returned to Sydney shortly after take-off, due to a hydraulic leak.
As the aircraft arrived back at the terminal under tow, a haze began to form in the cabin and flight deck, and passengers and crew experienced physical symptoms including irritation to the eyes and throat. The captain confirmed with the first officer and the cabin service manager the need to evacuate, and commanded the evacuation.
During the evacuation, 129 of the passengers disembarked via aerobridges, while the remaining 93 used one of the three deployed escape slides.
“A number of passengers used the escape slides in a manner that increased the risk of injury, and unfortunately six passengers were injured,” ATSB Chief Commissioner Angus Mitchell said.
One passenger who used an escape slide sustained serious injuries including tendon ruptures in both knees, while others sustained minor injuries including knee sprains, friction burns, and elbow cuts and abrasions.
“The ATSB found limitations and inconsistencies in how Qantas’s safety video and briefing card described emergency slide use and what to do with cabin baggage in an emergency,” Mr Mitchell said.
“For example, the pre-flight video showed a passenger sitting down and placing their bag next to them, just prior to sliding.
“The management of passengers in an emergency situation is the last line of defence to avoid injuries and fatalities, so it is important passengers are well informed through the provision of sufficient and accurate communication about what they may be required to do.”
Additionally, CCTV and other video showed at least 40 passengers exiting via aerobridges with carry-on luggage and some of these retrieved their baggage after the evacuation command, which likely slowed the evacuation process.
“Some passengers also brought cabin baggage to the top of the emergency slides, and while some complied with cabin crew and left them behind, others were shown on CCTV with their luggage in-hand, after using a slide,” Mr Mitchell continued
“Passengers should always leave their belongings behind during an evacuation.”
The ATSB found primary commands practiced by Qantas cabin crew to instruct passengers in an evacuation did not include phrases such as ‘leave everything behind’ and ‘jump and slide’.
Since the incident, Qantas has amended its passenger safety briefing video, and is looking to incorporate ‘leave everything behind’ into its primary evacuation commands.
Mr Mitchell noted the timing of the evacuation – as the aircraft arrived at the terminal and cabin crew had disarmed doors – presented a complex challenge, and the investigation found two cabin crew members did not rearm their doors prior to opening them during the evacuation.
“Crew members must remain prepared to react to an emergency at any time, until everyone has disembarked the aircraft,” he said.
Qantas has subsequently introduced periodic training that requires cabin crew members to physically demonstrate the procedures for an evacuation at a terminal.
The ATSB investigation found the hydraulic failure, which triggered the return to Sydney, occurred when a rudder servo hydraulic hose ruptured in flight.
After landing and stopping on a taxiway to await engineers and a tow, the flight crew started the aircraft’s auxiliary power unit (APU), and the APU bleed air was turned on to maintain air conditioning and power in the cabin.
Leaking hydraulic fluid was subsequently ingested into the APU air intake, and the atomised hydraulic fluid was then distributed into the cabin and flight deck via the air conditioning system as the aircraft was towed back to the terminal.
Some cabin crew members had detected unusual smells both before and after the aircraft had been towed back to the terminal, but did not pass this information on to the flight crew at the time.
This may have prompted the flight crew to turn the APU bleed air off, as part of the smoke/fumes procedure.
“Communication between the cabin crew and flight crew is essential in abnormal situations, and it is important for information to be relayed as soon as it becomes available,” Mr Mitchell said.
Finally, the ATSB report notes Qantas did not have a procedure for ‘rapid disembarkation’, which would enable faster than usual deplaning, but at a slower and more controlled pace than an emergency evacuation.
“Accidents around the world continue to show there is a significant risk of injury to passengers when escape slides are used,” Mr Mitchell said.
“This risk is acceptable in a life-threatening situation where the alternative may be catastrophic, but in cases such as a fumes event – particularly if the aerobridge is already attached – a rapid disembarkation procedure may be preferable.”
Qantas advised in May 2022 it was undertaking a review of its current non-routine disembarkation procedure, and looking to incorporate a relevant procedural framework.
“In this case, given the information available and the physical symptoms being experienced by crew and passengers, the captain’s decision to evacuate was a sound one,” Mr Mitchell concluded.