One issue I forgot to mention was re-flying a model damaged to some extentat an event. I think this is done fairly often and in lots of cases, it probably fractures rule 4, dependin on various interpritations of Rule 4. I may have done this myself, thinking back.

Small electric seaplane at a AMA float Fly. Knocked off motor frommount in a bad landing and splashed in pretty hard. Fixed motor mount, made a cursory check of the model repaired a couple of other minor cracksand all was well. I flew it again at the event.

Did I fracture Rule 4?