What caused Air Asia flight's mid-air plunge?
The AirAsia flight that plunged 20,000 feet and was forced to land in Perth is believed to have been caused by a faulty valve.
On Sunday, the cabin crew started screaming on board Flight QZ535 to Bali and the pilot dropped to a height of 10,000 feet after the cabin depressurised 25 minutes into the journey.
Aviation experts believe a faulty valve depressurised the cabin and passengers could have been slowly running out of oxygen.
The pilot made the rapid descent to get oxygen to passengers in just eight minutes.
AirAsia flight to Bali makes emergency Perth landing after plunging 20,000 feet
Passengers slam 'screaming' AirAsia staff for 'hysterical' response to mid-air plunge
Although it is standard practice for pilots to drop to 10,000 feet in those circumstances, passengers said the crew looked shocked and tearful.
This prompted several passengers to say goodbye to each other.
"We looked to them (crew) for reassurance and we didn't get any," Clare Askew told reporters at Perth Airport.
"We were more worried because of how panicked they were."
AirAsia has apologised for the incident, which forced the pilot to turn around and bring the 145 passengers back to Perth.
The ATSB has categorised the incident as serious and estimates its investigation will be complete in May.
