50 kg (110 lb) or 160 kg (352 lb) with a maximum payload of 640kg. By the end of 1942, there were 199 aircraft in service, 88 of which were operational. Maritime reconnaissance had at that time 290 aircraft in total. By September 1943, there were still 240 aircraft assigned to maritime reconnaissance: only 84 were Z.501s, in three squadrons, and another 11 (mixed), out of 20 in total. Only around 40 aircraft were operational. Total production, 218 by CANT and 236 by Aeronautica Sicula, but 12 incomplete aircraft were captured after the invasion of Sicily. Later, Aeronautica Sicula repaired many of the ICAF aircraft. Some modifications were adopted during production, such as the removal of the nose machine gun and replacing it with an enclosed fairing. Some Z.501s were supplied to Romania and to the Nationalists during the Spanish Civil War. Following Italy's surrender in 1943, a few of these flying boats continued to operate with both the Axis Aeronautica Nazionale Repubblicana and the Allied Italian Co-Belligerent Air Force. After the armistice, several flew to southern Italy, including the nine aircraft of 149 Sqn with 80 persons aboard. In October, there were 16 aircraft operational in southern Italy, which dropped to 10 by May 1945. The squadrons involved were Nos 141, 147, and 183. After the war 183 Sqn. was based at Elmas with four Z.501s, and these were scrapped in 1950. Romanian service In 1941, twelve Z.501s were exported to Romania. One of these 12 flying boats was lost during the war, shot down in the autumn of 1943 by Soviet ace Grigoriy Rechkalov. The Gabbianos performed well in the Black Sea, a single unit managing to sink two Soviet submarines in August 1941. Combat performance Generally, the Z.501 had a mixed reputation. It was pleasant to fly, having low wing loading and good performance (when it was first introduced). It was quite reliable despite having only one liquid-cooled engine. However, there were problems with the durability of the wooden fuselage, particularly the aircraft built during the war. Its seafaring qualities were poor and the aircraft was susceptible to bad weather conditions. The fuselage would often break up in rough seas. Another problem was the engine nacelle: if the aircraft landed heavily the propeller could crash down into the cockpit. The aircraft was used in the reconnaissance role thanks to its long endurance, but it was very vulnerable