Savoia-Marchetti SM.82

The SM.82 was developed from the earlier SM.75 Marsupiale civil transport as a heavy bomber and military transport. Although having the same configuration of the SM.75, the SM.82 was larger. The aircraft was quickly developed and the prototype first flew in 1939. Although underpowered and slow, it was capable of carrying heavy loads, including the L3 light tank and a complete disassembled CR.42 fighter (these loads demanded special modifications). It had both cargo and troop transport capability, with room for up to 40 men and their equipment. Deliveries to the Regia Aeronautica began in 1940. However, production rates were slow, with only 100 aircraft delivered in 1940, and another 100 in 1941, so that there were never enough of these aircraft in service. By 1942 production doubled to 200 a year, while in 1944 almost 300 were produced, by which time the factory was under the control of the Germans. In 1939 it set a world's closed circuit distance record when it covered 10,000 km at an average speed of 239.67 km/h, remaining in the air for 56.5 hours. The aircraft saw extensive service throughout all the various African campaigns. ==Design==

The SM.82's fuselage was of mixed-construction, with welded-steel tube framework, with 22 frames and four longerons, skinned with metal forward, and plywood and fabric elsewhere. The wings were constructed almost entirely of wood, having three T-section spars, and 42 ribs in each. The flaps were made from a single piece of wood, while the ribs were of light and flexible poplar. The skin was of fabric-covered plywood, doped to be water-resistant. The ailerons (+13/-28°) occupied about half of the wing's trailing edge while Handley Page slats occupied the leading-edge. The tail had a conventional spruce structure and a plywood skin, while the rudder and elevators were a fabric-covered metal framework. Inside, there were two levels. The upper level held seats for 32. The lower level was used for freight or to carry bombs when used in the bombing role, with two large duralumin bomb bay doors. The floor was made of wood, with nine detachable panels, that helped with the accommodation (through the bomb bay doors) of heavy loads. The cockpit held four: two pilots, with the first (on the left) with an armoured seat, a mechanic and an engineer/gunner. Internal equipment comprised a radio-transmitter (AR8 and AR350), a fire extinguisher system, and an electrical generator. The instruments included altimeters, thermometers, compass, clock, and a Telefunken P63N radio goniometer. The SM.82 was fitted with three 641 kW (860 hp) Alfa Romeo 128 RC.18 radial engines with aluminium and steel three-blade constant speed propellers 3.6 m (11 ft 9 in) in diameter. These engines were the ultimate evolution of the license-built Bristol Pegasus. The aircraft had six self-sealing fuel tanks in each wing, three between the second and third spar, with a total of 1,276 L (337 US gal). Between the first and second spar there were another three fuel tanks with 653 L (173 US gal). Another tank in the nose, with 167 L (44 US gal) of 100 octane fuel (rather than 87) for the electric generator. The total weight of fuel amounted to 4,403 kg (9,707 lb), plus 136 L (36 US gal) of oil. The SM.82 had both defensive and offensive armament. For offensive purposes it could carry a very wide range of ordnance, up to 4,000 kg (8,820 lb). • 4 × 800 kg (1,760 lb) • 8 × 500 kg (1,100 lb) • 8 × 250 kg (550 lb) • 27 × 50 kg (110 lb) or 100 kg (220 lb) bombs • 25 × 100 kg (220 lb) cluster bombs, each containing 56 bomblets, though these were rarely used. Control over bomb release was in the retractable ventral bombardier's gondola, equipped with a Jozza bombsight and also fitted with a rear-facing 7.7 mm (.303 in) Breda machine gun. Accommodation for the bombardier was far from ideal, being cramped, unheated, unpressurized, and not connected to the oxygen system. The 1 mm steel structure was also highly vulnerable to enemy fire. For protection, only the first pilot's seat was armoured, while the self-sealing fuel tanks were proofed, theoretically, against 12.7 mm (.50 in) rounds, but did not have Carbon dioxide pressurization to prevent explosions if they were hit by tracer, incendiary or explosive rounds. No other armour was fitted. All this made it extremely vulnerable to enemy fire. The main defensive weapon was a Caproni-Lanciani rotating dorsal turret, armed with a Scotti 12.7 mm (.50 in) machine gun with 350 rounds. This weapon was theoretically more powerful and lighter than the Breda-SAFAT, but reliability was a concern, and projectile dispersion was so wide as to reduce the theoretical range of 400 m (1,310 ft) to around 200 m (660 ft) in practice. Additional 7.7 mm (.303 in) Breda-SAFAT machine guns were mounted in each side and in the bombardier's gondola, with four 215-round magazines each. The gondola's machine gun was of little use given the cramped accommodation, and was often not fitted, even in the SM.82 equipped for the bombing role. German machine-guns were used in the Luftwaffe versions, with the 13 mm (.51 in) MG 131 in the turret. 7.92 mm (.312 in) MG 17s were used in some aircraft. The SM.82's performance was modest, with a cruising speed only 250 km/h (160 mph) at 3,000 m (9,840 ft), even without the bombardier's gondola under the nose (which added more drag) it was slow, while its silhouette was large and easy to spot. The ceiling was seldom over 5,000 m (16,400 ft). This left the SM.82 well inside the operational altitude of most fighters of the time, as well as the effective range of heavy and medium anti-aircraft guns. In comparison, the B-17 had a typical ceiling of 6,000–8,000 m (19,690–26,260 ft),(note that the B-17 and B-24 Liberator both had unusually high operating ceilings for the time, as compared to other bomber and transport aircraft). In operation, when faced with a fighter opposition, the SM.82 suffered a devastating loss rate. On 24 November 1942, three Beaufighters downed seven SM.82s, a 100% loss. Later on 10 April 1943, 10 out of 20 in formation were downed by a single pass of a P-38 Lightning squadron. At altitude, the SM.82 was almost a fixed target for both flak and fighter opposition. ==Operational history==

Early missions The first missions were to transport Italian troops to Libya, together with their heavy equipment, but the first two squadrons had only three SM.82s each. The first flights were made the beginning of June 1940, transporting 360 men of 61° Infantry Regiment. Initially, the aircraft were organized in 149° Gruppo, with a SM.73 and SM.75. On the 17 June 1940 the first mission for all five aircraft of the Gruppo, transported ten anti-tank guns and 17 radio-communication units. By 24 June, there were 11 aircraft employed in transporting men and equipment to Africa. Within a few weeks a further 25 were delivered. On 24 June, the first SM.82 was lost during a resupply mission in the desert. In July 1940, a series of bombing missions to Gibraltar was organized, with 1,000 kg (2,200 lb) of bombs in each aircraft. The first bombing mission was on 17 July 1940 with three SM.82s taking off from Guidonia at 1940, and flying 1,600 km (995 mi) to arrive over Gibraltar eight hours later at 0340. Another mission was launched from Sardinia to shorten the journey, then another on 20 August, this time by 32° Wing. However one of the two aircraft, carrying a 1,000 kg (2,210 lb) bombload, was shot down. The other two aircraft in 32° Wing were reassigned to transport squadrons. In mid-1940, 41° Group was sent to Rhodes with three SM.82s, and other four in October, for the special mission to the British-controlled oil refineries at Manama in the Persian Gulf. This meant a flight of 4,200 km (2,610 mi), lasting 15 hours at 270 km/h (170 mph), that was for the time arguably a record for a bombing mission. Four SM.82s took off from Rhodes, under the command of Ettore Muti. Each aircraft carried a load of 1,500 kg (3,310 lb). After the war, about 30 SM.82s continued in service with the Aeronautica Militare until the early 1960s. Civil transport Even with the outbreak of the war long-range civilian routes did not end. The civil aircraft had 14 seats, 1,306 L (345 US gal) of additional fuel, and 350 kg (770 lb) of military equipment removed. They flew to Brazil via Spain and West Africa. Between 11 September 1940 and the entry of Brazil into the war in 1941, 68 flights were made. Two aircraft, I-BAIA and I-BRAZ, were lost in December 1940. Some S.82s were used in militarized service, with Special Air Services and the task of personnel transport, including the civilian evacuations in 1941. ==Variants==

Although the basic design of the SM.82 remained the same there were many configurations and modifications in the 10 series manufactured from 1940 to 1945. ;SM.82: This was the standard version, a transport aircraft with 32 seats, or room for up to 50 men, produced in the following series: • I, 50 aircraft (MM.60260-60319) (December 1939 – December 1940) • II, 20 aircraft (MM.60320-60339) (December 1940 – February 1941) • III, 30 aircraft (MM.60483-60512) (March 1941 – June 1941) • IV, 50 aircraft (MM.60586-60635) ( July 1941 – December 1941) • V, 62 aircraft (MM.60721-60782) (January 1942 – August 1942) • VI, 102 aircraft (MM.60783-60884) (July 1942 – December 1942) • VII, 102 aircraft (MM.61175-61276) (March 1942 – July 1943) • VIII, 10 aircraft (MM.61314-61323) (July 1943 – December 1943) • VIII, 80 aircraft (MM.61398-61477) (July 1943 – November 1943) • IX, 120 aircraft (MM.61513-61632) ( November 1943 – April 1944) • X, 100 aircraft ordered, but only 87 built (MM.61782-61881) (April 1944 – September 1944) ==Operators==

; • Luftwaffe ; • Zrakoplovstvo Nezavisne Države Hrvatske operated two aircraft as transports. ; • Regia Aeronautica • Italian Co-Belligerent Air Force ; operated some surviving aircraft during a period in which Italy was forbidden from owning bomber aircraft post-WW2. They returned the planes in the early 1950s ; • Aeronautica Nazionale Repubblicana ; • Italian Air Force operated some surviving aircraft until 1960 ==Specifications (SM.82)==