A388 wake turbulence in cruise flight, any experience?

[radorabatin]

Hello guys,

I'm an area ATC,and today we had strange occurance, Airbus 330-200 at FL390,on opposite track A380-800 at FL380,no turbulence reported,after they cleared each other the flight A330-200 reported turbulence, suspended RVSM and requested descend ASAP,because of inability to maintain FL390,and loss of control,so Airbus 330 commerced descend.So I'd like to ask especialy you guys,the pilots,if you have any experience like this,with A388.

thanks,Rado

[tom775257]

So to confirm the A330 which had problems was above the A380? Wake descends not climbs. Perhaps some CAT?

[rudderrudderrat]

Hi Rado,

The only wake turbulence I've experienced has been when I was at or below the altitude of the other heavy.

[radorabatin]

The airbus 330 was above the 388, that's why I stated strange occurance, I'm fully aware of wake behavior,descending. But this happened shortly after crossing A388,the A330 first bumped more than 200ft up, and than reported problems described in my previous post.
Based on information about A388 wake,I know that it might extend to radius up to 600m (2000ft),but we never had such an occurance.

Sincerely Rado

[dontdoit]

You won't get any wake above any aircraft's level unless gravity has been suspended.

[Diesel Fitter]

But may be of interest -

Wake turbulence event Sydney Airport, NSW 3 November 2008 (http://agencysearch.australia.gov.au/search/click.cgi?rank=1&collection=agencies&component=0&docnum=882281&url=http%3A%2F%2Fwww.atsb.gov.au%2Fmedia%2F1356506%2Fao20080 77.pdf&search_referer=http%3A%2F%2Fwww.atsb.gov.au%2Fpublications%2 Fsafety-investigation-reports.aspx%3Fs%3D1%26sort%3DOccurrenceReleaseDate%26sortAs cending%3Ddescending)

[Digitalis]

You won't get any wake above any aircraft's level unless gravity has been suspended.

Wake turbulence extends behind any aircraft in a cone shape, which will indeed - at least for a while - go above the level of that aircraft. We tend to think of wake turbulence being like the wake of a ship, and extending only to the sides of the flight path and descending with time. Of course, an aircraft is flying through air, not on a surface, and so wake is a three-dimensional effect. Therefore it will always have a component which will extend above an aircraft's level, however briefly. I can quite imagine that the upper limit of an A380's wake could extend up to 1000' above its flight path for a period. Whether this has been researched in any detail, I don't know. I do know that its wake on the approach path was measured and found not to be as bad as first imagined.

[radorabatin]

Hello,

I fully agree with you,especially with todays winds aloft around 70kts, we had some experience at location,where it occurred today, with wave effect, so maybe the wake effect was affected by this wave,typical direction of winds aloft in our area is between 270 up to 330deg.,in combination with our mountains it could have created conditions helping wake to extend to level above, and result was as described at initial post.

thanks for contribution

Rado