Airspace4All has updated the previous (now 4 years old) analysis of mid-air collisions in the UK.

The 8 page report is available here: Mid-Air Collisions: An Evidence-Based Analysis of Risk – 1975 to 2018

The introduction from the report is reproduced below.


Mid-air collisions often have a high public profile but because they are relatively infrequent, occurrence statistics are not used directly for analysis of risk. Instead indicators such as airproxes, level busts, infringements and ACAS events are used to inform policy on the underlying risk of mid-air collision.

However, the CAA MOR database contains the record of every collision in the last 43 years providing a rich source of direct data. It enables us to analyse the nature and distribution of the risk itself to validate the indicators and inform airspace policy decisions. Unlike the indicators, it provides a direct framework of evidence against which to test potential safety policies such as electronic conspicuity options and airspace modernisation.

This paper assembles and analyses data on mid-air collisions within the UK FIR involving civil aircraft, including those operated by military personnel. The data was extracted from the CAA MORS and BGA accident databases and AAIB reports. Collisions solely between military registered aircraft are not included.

The analysis measures the distribution of collision risk by aircraft class, phase of flight and geographic position. It creates a mechanism to test safety policy options.