Alitalia Flight 045 departed Rome (FCO) at 22:10 hours local time and climbed to a cruising altitude of FL70. At 22:32 the crew were cleared to descend to 5000 feet and further down to 4000 feet on its way to Naples (NAP). Last radio contact with the flight was at 22:37 when leaving the LD NDB for a direct visual approach. A wide turn on downwind leg caused the aircraft to enter a area of heavy showers. At 22:39 the aircraft flew into Monte Somma, at an altitude of 610 m (2000 feet) on a 90-degrees heading with a 20-deg left bank. PROBABLE CAUSE: “1) Delayed interruption of, or failure to interrupt, visual approach in the absence of minimum visibility conditions required for the type of manoeuvre involved. 2) Abnormally wide initiation of down wind leg which brought the aircraft considerably south of the circuit for visual descent to the airport and along an unsafe path in relation to the terrain in the area. 3) Inaccurate estimate of position of aircraft as a result of which the left turn manoeuvre was initiated too late for completion of the required manoeuvre.”