ANDREW HEASLEY AND ARI SHARPCosmic rays are being considered by air safety investigators as a possible cause of a Qantas plane plunging twice in quick succession on its way from Singapore to Perth in October last year.
Air safety investigators this morning brought down their second interim report into the flight QF72 incident, which left one flight attendant and 11 passengers with serious injuries, finding that an equipment glitch with one of three data collectors was a likely cause.
But the reason for the problems with the air data inertial reference unit, which gathers data from outside the plane and feeds it into the cockpit, remains unclear.
One explanation being considered for the October 7 incident is that cosmic or solar rays interfered with the system, noting that a single particle can cause problems with integrated circuits such as the one used in the data equipment.
"There is a constrant stream of high-energy galactic and solar radiation interacting with the Earth’s upper atmosphere," the report noted. "This interaction creates a cascade of secondary particles. Some of the secondary particles, in particular neutrons, can affect aircraft avionics systems."
The Airbus A330-303 was flying at 37,000 feet with 303 people on board when it plunged 650 feet before recovering to its original height and then plunging 400 feet.
The pilot declared a "mayday" an sought an emergency landing at Learmonth, Western Australia.
The data device experienced significant spikes in nine different categories of information, leading to the dramatic movements in the aircraft, which was using its autopilot system.
In releasing the report this morning, Australian Transport Safety Bureau safety investigator Ian Sangston said while the spikes could not yet be explained, changes to equipment had been taken to filter out extreme data.
"We don’t know the methodology of those spikes, however we understand the result of those spikes and how the upset occurred and there’s good safety action in place to ensure any spikes in future will not have that effect," he told reporters in Canberra. FULL STORY
