[7] However, after a number of accidents where smaller aircraft following closely behind a 757 crashed, tests were carried out showing the 757 generated stronger wake vortices than a Boeing 767.
[2] Wake turbulence groups enable distance-based separation minima for approach and departure as low as 3 nautical miles.
In 2012, the FAA authorized Memphis International Airport air traffic controllers to begin applying revised criteria for separation.
[12] This initially used six groups of aircraft, primarily based on weight: Super (A380), Heavy, B757, Large, Small+, and Small.
This allows efficiency gains over RECAT I because it takes the fleet mix – which aircraft fly most often – into account for each site, rather than doing a global optimization for the US national airspace system as a whole.
[13] RECAT Phase II went operational on August 3, 2016, at Southern California TRACON and associated towers.
[13] In Europe, the programme to increase runway throughput by introducing new wake turbulence groups was called RECAT-EU.
[20][21] RECAT-EU for arrivals and departures was successfully deployed by NATS at London Heathrow Airport in March 2018.
[22] In RECAT-2, the six categories were augmented by individual pair-wise separation, based on the characteristics of the lead and following aircraft types.
[23] In strong headwinds, reduced time based separation can be used because vortices are dispersed more quickly.