The humble cotton mop has been identified as the likely culprit behind the flooding of the business class cabin on a Qantas Airbus A380 in July, the Australian Transport Safety Bureau (ATSB) says.
Qantas flight QF94 headed for Melbourne was forced to turn back to Los Angeles after about 700 litres of water spilled out of a pipe in an upper deck galley shortly after takeoff on July 2. An initial engineering inspection conducted after the aircraft landed safely in Los Angeles found that the coupling that joined the water pipe at the floor level where the water supply entered the galley had become unlatched.
“There was evidence that the rope-style mops used by cleaners may have contributed to the coupling coming undone,” said the ATSB report, which was released on Wednesday.
“Fleet-wide inspection of the fittings found strands of cleaning mops tangled in the brackets, with evidence of couplings rotated in opposing directions.”
In response, Qantas conducted an inspection on all of its Airbus A380 fleet, inspecting, cleaning and refitting each clamp within 72 hours of the incident.
“As an interim measure and in consultation with Airbus, aluminium tape has been double wrapped around the couplings to avoid the likelihood of unintentional disturbance,” the ATSB said.
“The aircraft are to be cleaned under the galley bench areas using sponge style mops instead of cotton rope mops.”
After cabin crew turned off the water supply to the aircraft, passengers were unable to use the toilets for the duration of the flight. The in-flight entertainment systems and power to all controls in the seats were also switched off.
“The cabin crew determined that it was therefore untenable to continue the 14-hour flight,” the ATSB said.
“Leakage of that quantity of water had not occurred previously, and the eventual impact of the water on the aircraft was unknown.”
The flightcrew dumped fuel to reduce the landing weight to 445 tonnes, which the ATSB noted was above the landing weight of 391 tonnes. The aircraft landed safely.
“As the aircraft commenced descent, a cabin crew member advised the flightcrew that the leaked water was moving forwards in the aircraft,” the ATSB said.
“The flightcrew then conducted a slow speed descent to keep the water stabilised and prevent it flowing forwards.”