Military Airworthiness is what it suggests, ie it is separate from, and different in many ways to, its Civilian cousin. The reason that you need a fully integrated failure warning in a Military IFF fit could not be made more clear than with this avoidable Fatal Air Accident. We have been told that it was so fitted on the F3 variant. Rather than look for Fairies on Pin Heads to count, let us just agree that the lack of it here meant that this variant was that bit more vulnerable if the slices of Swiss Cheese started their dreaded shuffling. You might well label this as Fitness For Purpose, it really makes no difference to the outcome. Never mind the lessons that the USA should learn, that is for them to get on with, the obvious lesson for us is to make sure that our combat aircraft are in future made fully airworthy militarily, which includes being fit for purpose. The only way to get to that far off place is to have a fully independent MAA and MAAIB ASAP, separated from each other and from the MOD. Anything less and the same sorry avoidable accidents will continue to be unavoided.