Initial four-dimensional (I-4D) flight operations - Flying a new dimension

On 10 February 2012, the Airbus A320 test aircraft flew from Toulouse to Copenhagen and Stockholm and then back to Toulouse testing initial four-dimensional (I-4D) flight operations.

I-4D operations consist in using airborne computed predictions in the ground systems in order to establish far in advance a sequence for all aircraft converging to a merging point in a congested area. In practice, after coordination between the ground systems and the aircraft, each aircraft is allocated a time constraint at a merging point, and in compensation is allowed to fly its optimum profile up to that point, meaning without any vectoring instruction from the controllers.

This flight trial is the very first live demonstration of an initial four-dimensional flight, and is a key element of the SESAR programme towards 4D trajectory management. It is the culmination of months of collaboration between several SESAR partners: aircraft, avionics and ground equipment manufacturers; and air navigation service providers Maastricht Upper Area Control Centre (MUAC) and NORACON, with the support of EUROCONTROL.


I-4D - Flying a new dimension