ACAS II, the airborne collision avoidance system, is designed to reduce the risk of mid-air collision for carriages of fixed-wing aircrafts with a maximum takeoff mass exceeding 5,700kg, or those authorised to carry more than 19 passengers. However, it is important to consider whether safety benefits could be expected from extending the use of ACAS II to aircrafts belonging to the very light jet (VLJ) category, which have a maximum takeoff mass of 4,500kg, and to the light jet (LJ) category, with a maximum takeoff mass of between 4,500kg and 5,700kg. Indeed, the number of VLJ flights is anticipated to rapidly rise, particularly in the European core area, and to potentially impact traffic patterns in Europe.

For that purpose, a safety study has to quantify all the possible safety benefits resulting from equipping VLJs and LJs with ACAS II, and whether there would be, following this VLJ introduction in the European airspace, potential implications for the performance of the ACAS system as a whole. In particular, the implication on the ACAS safety benefits delivered to the commercial aircraft already equipped needs to be investigated.

In this perspective, Eurocontrol, the European Organisation for the Safety of Air Navigation, entrusted Egis Avia to perform a comprehensive study aiming at assessing the impact of VLJ and LJ operations on the safety benefits delivered by ACAS in the European environment, for example, the AVAL project.