When was EASA first involved in aircraftwake turbulence separation? While the Airbus A380 aircraft was being developed, the issue ofwake turbulence for such a heavy and large aircraft was raised. An international group, initially involving the International CivilAviation Organization (ICAO), the US Federal AviationAdministration (FAA), the former Joint Aviation Authorities (JAA)and EUROCONTROL, was formed to assess potential additionalseparation minima. In 2006, ICAO published the initial guidancematerial for A380 wake turbulence separation.

Following the completion of the A380’s airworthinesscertification, EASA took over the role of the JAA in theinternational group. The technical activities started with theorganisation of subsequent flight tests and the consolidation ofthe overall safety case. EASA’s test pilots encountered more than100 instances of wake vortices during the test flights.

48 VIEWPOINT

EASA’s role in waketurbulenceseparation standards

www.eurocontrol.int Autumn/Winter 2015 Skyway

Emmanuel Isambert,  Strategy & SafetyManagement Directorate

Alain Leroy, Head of Department, Certification Directorate

Andrea Boiardi, Chief Expert, Certification Directorate

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VIEWPOINT 49

The European Aviation Safety Agency (EASA) is the European Unionregulatory authority for aviation safety. In the context of RECAT-EU, itsrole is to assess the proposed changes to the ICAO standard for aircraftwake turbulence separation as proposed by EUROCONTROL and itsstakeholders for pan-European adoption.

In parallel, EASA joined ICAO’s WakeTurbulence Study Group (WTSG), whichwas in charge of preparing newinternational standards in this field. In 2011,EASA took part in the review of the firstproposal made by the FAA andEUROCONTROL for the revision of the ICAOwake turbulence categories and separationminima (which had not evolved since the1970s).

As no consensus in both the A380 groupand the ICAO WTSG could be reached,several European members – representingsafety authorities, service providers, aircraftmanufacturers and research organisations –undertook the development of a revisedaircraft categorisation and its associatedminima. They took the results of extensiveresearch activities conducted in Europe,combined with the latest results from A380flight tests, into account.

The proposed new wake turbulenceseparation scheme for application atEuropean airports is known as RECAT-EU. InOctober 2014, EASA satisfactorily concludedits independent safety review of RECAT-EUand informed its Member States accordingly.

What is the role of EASA in this domain?The application of aircraft wake

turbulence separation is the responsibility ofAir Navigation Service Providers (ANSPs); theiroperational procedures are based on ICAO’sATM standards and approved by theirrespective safety authorities.

The determination of safe waketurbulence separation minima follows theassessment of the manufacturer’s data foraircraft design and performance (both with

the aircraft as a wake generator and as trailingaircraft), wake vortex characteristics, air trafficsafety and operational data.

Having as its main mission thedevelopment and maintenance of pan-European aviation safety standards, EASA’srole here is to oversee this risk assessment foraircraft wake turbulence categorisation andseparation minima.

For new Heavy aircraft, such anassessment can be carried out either in thedevelopment or certification phase. Recently,for the Airbus A350, EASA supervised thework of a joint team of EU experts involvingthe manufacturer, EUROCONTROL andresearch organisations, for the assessment ofthe aircraft categorisation in both the ICAOand RECAT-EU separation schemes.

Following the experience gained withnew heavy aircraft and RECAT-EU, our focus isnow on developing common technical andsafety standards for the determination ofminima, their implementation in ATCprocedures and systems and the continuoussafety monitoring of operations.

Our regular exchanges with Europeanstakeholders, such as National AviationAuthorities (NAAs) and Air Navigation ServiceProviders, are of prime importance and areused to establish common EU positions onthe changes needed for ICAO’s internationalATM standards in this domain.

Furthermore, we foster the developmentof cooperation with non-EU organisations,such as the FAA, in order to harmonisebilateral work processes between aviationauthorities.

In addition, EASA is also monitoringseveral research initiatives addressing aircraft

wake turbulence, e.g. the SESAR programme,with the aim of drawing on the latestscientific developments in order to supportits decision-making processes and to adviseresearch teams on the development of newstandards.

What are the next steps, following theacceptance of RECAT-EU categories andminima?

Following the notification of EASA’sacceptance for RECAT-EU, a dedicatedimplementation project is being run at ParisCharles de Gaulle (CDG) airport; it is being ledby the French DGAC. The completion of thisimplementation will be an important step inprogressing European standards in this field.

EASA recently concluded a workingarrangement with the Civil Aviation Authorityof Singapore (CAAS) for evaluating theimplementation of RECAT-EU at Changiairport. A similar technical cooperation willalso begin with the UAE General Civil AviationAuthority (GCAA).

The development of a new revised ICAOstandard, called RECAT-2 and planned foradoption in 2018, is being actively pursuedthrough cooperation between the SESAR andUS NextGen programmes. EASA is taking partin this development with the aim of ensuringthe smooth transition from RECAT-EUstandard and for preparing the associatedsafety management system for such newstandard.

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