THE PILOT OF THE ACCIDENT AIRPLANE COLLIDED WITH THE TOP OF A POWER TRANSMISSION WIRE ARRAY WHILE PERFORMING AERIAL APPLICATION MANEUVERS. HE STATED HIS CONCENTRATION WAS ON MAINTAINING CLEARANCE FROM THREE LARGE DIAMETER WIRES COMPRISING THE LOWER PORTION OF THE ARRAY. HE FAILED TO SEE THE SMALLER WIRES OF THE UPPER PORTION UNTIL THE 'LAST SPLIT SECOND' BEFORE THE COLLISION. THE WIRES REMAINED INTACT AND THE AIRPLANE REBOUNDED 300 FEET INTO A SMALL POND WHERE IT LANDED UPRIGHT.