"A vertical separation of 1,000 feet must be maintained between two aircraft. An International Civil Aviation Organization study showed that wind turbulence of an A-380 can travel up to 300 metres, which is 985 feet. The initial reports we are getting is the SIA aircraft came in the reciprocal wake turbulence caused by another A-380 going in the opposite direction," said a source. The regulator will also check if there was a breach of minimum separation between the two planes, causing more problems for the one at lower level as vortices (air flow from wing tip as a result of producing lift) travel downward. The fact that an A-380 — it is kept airborne by four extremely powerful engines - can shake up another big bird of its size has surprised some. Smaller planes are known to suffer this impact very often — an A-380 caused the same problem to an Indian carrier's aircraft 10 days ago.
21/10/14 Saurabh Sinha/Times of India