With the introduction of the Airbus A380 one of the main challenges for ATM was to develop associated wake turbulence separations before it entered service. The issue was the lack of a proven methodology available so, in July 2003 a European led A380 Steering Group was established with representatives from EUROCONTROL, JAA (EASA), AIRBUS, FAA, NASA and ICAO.
The tasks of the group were to:
- Select methodologies for evaluation of A380 wake turbulence;
- Assess A380 wake turbulence in comparison to other aircraft in the Heavy category;
- Establish recommendation for A380 wake turbulence separation to ICAO.
An initial but conservative approach resulted in an interim ICAO State Letter requiring a 10NM separation minimum for all aircraft following the A380.
A second State Letter, this time based on a Safety Case and Safety Assessment Report produced by the Working Group in accordance to EUROCONTROL Safety Regulatory Requirement 4 (ESARR 4), was issued by ICAO in October 2006 with reduced interim separations; a third State Letter was then issued July 2008 with further reduced separations enabled by additional data.
Work was then extended with the analysis of Airbus flight test data to determine if further separation reductions were possible. At this stage it was agreed with EASA and Airbus that the A380 work be incorporated into the wider wake turbulence re-categorisation for Europe (known as RECAT-EU).