The continuing growth of aviation increases demands on airspace capacity, therefore, emphasizing the need for optimum utilization of available airspace. Improved operational efficiency derives from the application of different Wake Turbulence Separation techniques, as a direct factor influencing the decrease of delay.
There are two Wake Turbulence Separation minima, one is based on four Wake Turbulence Categories (Super, Heavy, Medium, Light). This is the legacy Wake Turbulence Separation with its legacy Wake Turbulence Separation minima. The second set of applicable provisions is based on wake turbulence groups (A, B, C, D, E, F, G), taking into account on wake generation and resistance characteristics of the aircraft. These depend primarily on maximum certificated take-off mass, wing characteristics, and speeds and is called “enhanced Wake Turbulence Separation” (eWTS).

Purpose and scope

Legacy Wake Turbulence Separation is based on 4 aircraft categories, with 7 different separation minima applicable between leaders & followers.
Enhanced Wake Turbulence Separation is based on 7 aircraft groups, with 18 different separation minima, as an alternative mean to separation of aircraft during arrival or departure phase of flight. Increasing the number of aircraft groups in eWTS enables safe reductions in separations for wake turbulence between certain aircraft and enables increased airport capacity. This generates higher complexity for Air Traffic Controllers that needs to be managed.

Safety Assessment and Monitoring

For the States and appropriate ATS authorities who will transition to ATC operations or trials using enhanced Wake Turbulence Separation minima, local specific safety monitoring activities may be conducted in relation to the deployment safety assessment, within particular a review and evaluation of the local wake encounter reports for an initial period of operations.
The monitoring of wake turbulence risk should cover the two aspects of the risk: the evolution of the frequency of wake turbulence encounter occurrence and their related severity.
Based on the collected wake turbulence reports shared by States, appropriate ATS authorities, or Operators, the ICAO will also proceed with a global review and analysis of related to the operational use of the new enhanced wake minima.