Excellent analysis and gives serious food for thought. Given the number of attacks reported (and I have a strong suspicion there is actually significant underreporting) it would be helpful if the authorities issued some guidelines. PDR1's numbers suggest the risk decreases with height and above 10,000 feet on his numbers it looks low. But on final approach it could be significant. It appears you cannot reliably assess the power or exposure. But one option might be for a recommendation to get a medical check if targeted on final approach etc. Either way despite a little ill humour/stupidity that always seems to occur I think the wider discussion on this topic has been very helpful. Thanks to PDR1 and thumbs up to Scroggs.