Sunday Incident Raises Eyebrows

Details remain sketchy at this point, and there's some information that's likely "lost in translation" -- but it appears an Airbus A320 narrowbody encountered some moderate to severe clear air turbulence this weekend, which may have been caused by the wake from an Emirates A380 overflying the smaller plane.

Armenian news reports state the Armavia Airlines A320 was over the former Soviet state of Georgia when the plane suddenly banked sharply to the right, triggering an automatic disconnect of the aircraft's autopilot system. The flight crew was able to quickly regain control, and the A320 continued on safely to its destination of Yerevan.

Armavia states that at the time of the incident, an Emirates superjumbo from Dubai to New York was 'flying in parallel' to the smaller plane, roughly 300 meters (approximately 984 feet) higher. The carrier believes the rough ride for its A320 was caused by wake vortices off the wingtips of the much larger Heavy.

An investigation has been launched... but at face value the A380 appears to have been in compliance with International Civil Aviation Organization standards for Reduced Vertical Separation Minima (RVSM) operations, which call for 1,000 foot vertical separation between conflicting traffic above FL290.

If Armavia's theory holds up, however, it may result in ICAO revisiting the minimum separation guidelines for traffic in trail of an A380.

As ANN reported in 2006, a three-year study determined wake vortices off an A380 in cruise flight were no greater than from any other Heavy aircraft (the A380 is officially designated as a "Super" Heavy), though stricter guidelines are in place when an A380 is landing or taking off.

FMI: www.armavia.am, www.emirates.com