CHART: There Was A Stunning Spike In Turbulence Incidents Over Australia Last Year

Australia’s aviation safety authority recorded a stunning – and so far unexplained – surge in the number of recorded turbulence incidents at the end of last year.

While turbulence does tend to see seasonal increases in the warmer months, the chart below shows the extraordinary nature of the increase between October and December last year, when turbulence events were 64.5% higher than the same period the previous year.

The number of turbulence related injuries is also up with 20 injuries recorded between October and December, well above the five year average of 6.45. Here’s the chart, provided to Business Insider by the Australian Transport Safety Bureau:

Turbulence affects flights when air masses moving at different speeds and temperatures collide – typically involving warm air rising from the ground and cold air descending from above. Last summer was warmer than average for Australia but not the hottest on record, which was 2012-13. The ATSB says it doesn’t have any theory on what’s behind the increase but will continue to monitor it closely.

According to ATSB data for the five-year period between 2009 and 2013, there were 677 turbulence occurrences on flights in, to or from Australia.

During the same period 197 minor injuries and two serious injuries to passengers and cabin crew were reported.

Severe turbulence injuries reported in October 2013 included four passengers on a flight bound for New Zealand reported a head injury, a fractured neck vertebra, and a sprained hand.

In another turbulence event the ATSB reported a Qantas 767 flight in November last year between Sydney and Melbourne experienced two minutes of serious turbulence, several passengers were struck in the head and injured by a laptop.

The United States Federal Aviation Administration estimates that the cost to the worldwide aviation industry of turbulence injuries is over $US100 million annually.

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