I find this totally unacceptable.people can really get hurt when something like this happens.I hope this is an isolated case.I know people have bolted on 90's on this ARF.I guess after mounting your engine,one should pick it up by the motor and mount and put some stress and G's on it.pinning,dowling,screwing,tri angle stocking and regluing etc,are probably recomended on all ARF's