A very ‘close call’ involving a Qantas jet may have been caused by cosmic rays.

Two terrifying plunges by the Qantas Airbus A330-303 flying over the northwest region of Australia have been linked to malfunctions to an onboard computer by safety investigators.

Installed on about 900 aircrafts around the world, the computer was later found to be in a perfect working order once inspected by Qantas technicians.

The incident, which happened on October 8 last year, had caused serious injuries to one flight attendant and 11 passengers.

The Airbus A330-303 nose-dived violently twice in rapid succession, each time diving 650ft and 400ft respectively, tossing around both unsecured travellers and pieces of luggage in the cabin.

Cosmic rays have targeted as the very likely cause. This phenomenon happens when high-energy particles bombard the planet.

According to ATSB chief commissioner Martin Dolan, there was an abnormality sustained by the onboard computer as it was repeatedly sending the wrong data. He added that researchers where looking at various possibilities, including the likelihood of cosmic rays.

Mr Dolan, unable to give any explanation for the near-crash, claimed that measures introduced afterwards proved to be satisfying.

The onboard computers used to process data from airliner sensors will remain installed to the Airbus aircraft.

The fleet of Airbus A330 and A340 will eventually be retrofitted with new software in order to improve data processing.