Wake turbulence?

[INLAK]

Last week, while routing WAL -> MID at FL250, talking to London 131.12 (I think!) we experienced an uncommanded roll of c. 35 degrees to the left and pitched c. 5 degrees down. TCAS was showing an aircraft about 7 miles directly in front and +2000ft. I think it was Speedbird 268, which declared a PAN call soon afterward owing to a medical emergency on board.

Can anybody confirm what type of aircraft was BA268?

Is it possible that it was wake from this aircraft that caused the situation? Is there any recommended spacing for aircraft while on an airway, due wake?

[Bern Oulli]

I'm just a humble approach bloke, and no doubt the en-route magicians will correct me if I'm wrong. If memory serves me the vortex wake separation required is 5nm if crossing behind, or in trail, at the same level, otherwise minimum of 1,000' below (assuming the other a/c is a "Heavy".

Having said that there are a number of well documented cases of vortex wake affecting aircraft up to 2,500 ft below. It all depends on the ambient air conditions I'm told. Scant comfort when your aeroplane rolls over and hits you!

[AlanM]

BAW268 is a B747-436 operating to LAX.

Happy Christmas Bern!