I would expect the risk to be understood in terms of flying hours, or whatever other scaling factor is relevant to the industry or field concerned, e.g. controlled flying hours for ATM. In the case of the MAA/MoD it then also chooses to 'normalise' this to risk to the individual per annum. All quite normal and allows comparison and measurement against HSE guidance and the MoD's legal obligations.
Thanks S-D, I understand that logic, but working backwards what does the risk of one death in 1000 per year mean in terms of flying hours? The HSE figure was arrived at for people in industry working a 40 hour week for, say 48 weeks a year. That equates to the risk of one death in 1,920,000 hours (1000 x 40 x 48), which is the boundary between Tolerable and Intolerable. Comparing like with like, that would mean the tolerable level for the Tornado risk was better than 1 in 1,920,000 flying hours, which I do not feel is being achieved. The figures, Class A misses and collisions per year, do not stack up to anything like that.
DV