Two very different systems on these aircraft...a Metro has a cross-FLOW system which simply lets fuel flow from one wing to the other....his requests for "360" turns seem to indicate an attempt to cause fuel to flow from one wing to the other..however in a co-ordinated turn this would not occur, a short time crossed controls in level flight would have done the trick.....the CV-580 has a cross-FEED system which allows an engine to be supplied fuel by the opposite wing...care has to be taken when performing this procedure...especisally if one opts to switch off the "tank valve" which the checklist calls for, but is entirely unnecessary....cant see how a huge fuel imbalance in either aircraft is worth dying over however...