Originally Posted by Distant Voice
The "Top Event", main risk or incident, is "Airprox". (Obtained from MAA Bowtie data).
The bowties are used to explore and catalogue the causes of incidents, and to enable probabilistic analysis. So, you have seen the bowtie which explores the causes of airproxes, which has 'airprox' as its Top Event. The analysis resulting from this bowtie would be a component of the predicted occurrence rate for Mid-air Collision, which is the actual risk logged in the Duty Holders' risk registers. Airprox is not, itself, the risk under treatment; it is a proxy from which the potential causes of mid-air collisions can be broken out and then individually treated. Plenty of airproxes result in no degradation of safety whatsoever.
Originally Posted by Distant Voice
The collision risk associated with Tornado GR4 aircraft is neither Tolerable, nor ALARP
On what basis do you say that? The fact that there has been a collision in which 3 people were killed, and X number of Cat A airproxes, does not automatically make the risk intolerable. Your statement is, however, a neat demonstration of societal risk. I haven't seen the latest numbers on the mid-air collision risk, but it wouldn't surprise me to find that societal issues helped to push CWS over the funding threshold.