Been helping the local university aero engineers build entries for rc heavy lift competition. They have an aero engineer mentor who insists they use aluminum. He does not fly small scale, and all the expertise on small models advise these guys to give up on the aluminum. After several years and all failures to even fly, the group last year finally went to a combo or foam and aluminum. After every landing the rivets tore, structure buckled and something had to be replaced. This years it is back to all aluminum. The winners usually use foam and carbon fiber where appropriate. Aluminum is too weak when light enough to fly. Our local team's aluminum plane weighed in emtpy 12 pounds heavier than the foam and fiber plane that won. 12 pounds extra payload would have made our team contenders.