DV, look at more of EdSett's comment, I would guarantee that no one will sign to say that the aicraft is
completely safe !
thus making the aircraft completely safe to fly and to conduct AAR
This may seem like splitting hairs, but people have to understand the reality of the situation, and the reality is that nothing is completely safe. The objective should be set in terms of an acceptable level of safety, and there are various ways of doing this if you look at different industries.
Regards
S_H