Travelling ORD-LHR (AA, Bus CLass) then onward LHR-MUC (BA, Euro Trav Class). Travel very light (no checked luggage) with one standard-sized suitcase (overhead bin) and one handbag (beneath seat). I want to bring a small electric fan (220V) in carry-on. Will there be any problems with passenger security screening of carry-on luggage anywhere (Chicago, Heathrow, Munich on return, etc.) Note that the fan blade is all plastic and no sharper than the edge of a plastic soup spoon ....) Will screeners allow fan in carry-on? If not, what is likely reason in USA? In UK? In EU? tHANKS!