The horizontal distance currently required between lighter and heavier aircraft to avoid wake turbulence might have to be doubled for smaller aircraft flying behind the new Airbus A380, according to preliminary findings of the International Civil Aviation Organization (ICAO). Final recommendations are not expected to be made before early next year, but in a letter sent last month to its member states, ICAO said current data analysis indicates that A380 wake vortices will descend farther and be “significantly stronger” than those for other heavy aircraft. The organization is calling for minimum spacing of 10 nm behind an A380 during landing and 15 nm en route.