The International Civil Aviation Organisation’s tough interim separation distances for the A380 could remain in place for another two years, despite Airbus’s earlier hopes that the limits would be relaxed by the end of 2007.

Following ICAO’s interim recommendations in October 2006 that the distance between the A380 and other aircraft should be greater than the standard for other large or “heavy” category aircraft, the airframer has been undertaking extensive back-to-back flight trials with other aircraft to prove the advice was too conservative.

Airbus had planned to submit its detailed wake vortex data to ICAO for analysis in September 2007, and was confidently predicting that revised distances similar to those required for the Boeing 747 would be issued before the end of 2007, but it says this has been delayed as testing has been “ongoing”.

Recent pictures of the A380 trailing smoke show it undertaking trials that were part of the original group of tests, which ran on longer than expected because of various issues, such as the availability of aircraft, says Airbus. “Testing was completed in early December,” it adds.

Airbus aims to pass the data to ICAO’s wake vortex steering group in January 2008 but is vague about when the revised distances will be issued, saying that “an update on new separation distances is expected in the coming months”.

However ICAO indicates that this could be optimistic, saying that its A380 wake vortex steering group is working “to present a proposal to amend the separation advice during the first half of 2008”.

But it warns that “any proposed new wake turbulence separation procedures will become applicable in November 2009” and that the A380’s  procedures “will remain until that time, unless they are amended with other temporary procedures through a State Letter, if required”.

It is important for the distances to be cut before the in-service fleet expands significantly because closely-timed A380 arrivals at a congested airport such as London Heathrow could have a negative impact on air traffic flow.

Source: FlightGlobal.com