There are no answers yet as to why QF 72 plunged suddenly but temporarily out of control over WA yesterday and made an emergency landing at Learmonth.

“We can’t rule anything in or out,” a spokesman for Qantas said this morning. He said that included the possibility of the Airbus A330 being “upset” by clear air turbulence, or a flight control systems failure, or any combination of any possible contributing factor.

But one thing is clear. This wasn’t like the serious incidents that affected QF 2 near Bangkok on 7 January, when leaking water from a galley triggered a series of electrical failures in a 747-400, nor like the oxygen bottle rupture that blew a hole in side of QF 30, another ageing 747-400 when it was fortuitously close to Manila on 25 July.

This was a comparatively new Airbus. In each emergency the pilots quickly put the flights on the ground, although in the case of QF 72, the passenger interviews and extent of passenger and crew injuries make the overworked word “plunge” seem liked the right word.

Weather satellite imagery (such as above) clearly shows the jet stream that is the prime suspect for containing cells of clear air turbulence that could have triggered the emergency.

No other flights using that area at around the same time reported anything but consistent moderate turbulence. But clear air turbulence comes in smallish nasty doses.

If QF 72 hit such a patch why did it end up in so much trouble? That’s the key question. And it doesn’t carry an adverse implication for the pilots either. It hit them, they dealt with it, and nobody died.

Any significant updates on the incident will posted on the Crikey blog, Plane Talking.