It is the tower controller’s responsibility to determine what final approach spacing to use. Tower controllers should inform approach controllers of the spacing requirements needed unless there is already a set down procedure. If there is no set down procedure or coordination, then approach controllers will aim for 3nm spacing or vortex,whichever is greater. Any set down procedures can be found on our website.
Wake Turbulence spacing
High pressure air below a wing spills over to the low pressure air above the wing. This creates disturbances in the air, known as wake turbulence. Heavier aircraft require more lift thus creating greater disturbances. Lower speeds on approach require a high angle of attack - This also increases the turbulence intensity. The spacing between aircraft, determined either by time or distance, is to be applied so that aircraft of a lower weight category do not fly through the wake of an aircraft of a higher category within the area of maximum vortices.
|First Aircraft Vortex Category||Second Aircraft Vortex Category||Separation (NM)|
|Upper Medium||Upper Medium||3|
|Upper Medium||Lower Medium||4|