This prototype (registration I-MAGO) was completed too late to enter the London-Melbourne race, but flew from Milan to Rome in just one hour and ten minutes, at a 410 km/h average speed. Soon after, on 2 August 1935, the prototype set a record by flying from Rome to Massaua in Eritrea in 12 flying hours (with a refuelling stop at Cairo). Adapting of the prototype as a bomber reconnaissance aircraft resulted in one of the most successful Italian bomber aircraft of World War II, with some 1,350 of all variants being built. Some were constructed by Aeronautica Umbra of Foligno, best known for the AUT.18.
The engines fitted to the main bomber version were three 582 kW (780 hp) Alfa Romeo 126 RC.34 radials, equipped with variable pitch, all-metal three-blade propellers. Speeds attained were around 430 km/h at 4,250 m, with a relatively low practical ceiling of 6,500 m. Cruise speed was 373 km/h at 5,000 m but the best cruise speed was 259 km/h (60% power). The landing was characterized by a 200 km/h final approach with the slats extended, slowing to 145 km/h with extension of flaps, and finally the run over the field with only 200 m needed to land (2,050 rpm, 644 Hg pressure). With full power available and flaps set for takeoff, the SM.79 could be airborne within 300 m then climb to:
The bomber version had ten fuel tanks (3,460 l).The endurance at full load averaging 360 km/h was 4 hr 30 min. The maximum ferry range, at best cruise speed was unconfirmed although in order to reach Addis Ababa with non-stop flights from Libya, aircraft specially modified to carry more fuel than usual were able to fly over 2,000 km. In every case, the range (not endurance) with 1,000 kg payload was around 800-900 km.
The aircraft crew complement was either five or six in the bomber version with cockpit accommodation for two pilots, sitting side-by-side. Instrumentation in the central panel included oil and fuel gauges, altimeter for low and high altitude (1,000 m and 8,000 m), clock, airspeed and vertical speed indicator, gyroscope, compass, artificial horizon, turn and bank indicator, rev counters and throttles for all three engines. Cockpit equipment also included the flight controls, fire extinguishers, and control mechanisms for the brakes and other systems.
No turrets were ever fitted to SM.79s, and there were limitations to each of the normal gun installations. Of all the weapons, the dorsal one was the most important for many reasons; such as the limited field of fire of the other guns, and the fact that, with the shift to low-level attacks (as a torpedo-bomber), the Sparviero was attacked almost exclusively from the rear and above. Attacks by enemy fighters from above were the main concern, with attacks made from below being less likely, especially in the early years owing to the speed of the Sparviero.
In addition, the cramped layout of the ventral gondola, with the bomb-aiming instruments located in front and the weapon in the rear, made it impossible to perform both bomb-aiming and rear defence simultaneously, so despite its field of fire being marginally better (70° horizontal, 0-70 vertical) its usefulness was compromised. Because of this, in the later versions which were used exclusively for torpedo-bombing tasks, the ventral weapon (and nacelle) was removed. The fixed forward Breda, aimed by the first pilot, was seldom used defensively, and often removed or replaced with a smaller calibre gun or mock-up, with an associated gain in speed and range due to the reduction in weight. It was more suited to offensive tasks: e.g. for when the aircraft would perform in the planned role of "heavy fighter", or when approaching ships (the Heinkel He 115 had a similar weapon, an MG 151 20 mm cannon specially developed for flak suppression during torpedo attacks).
All of these weapons were protected by aerodynamic shields (in the rear gondola and the rear hump position), opened in action. However, an incoming aircraft could attack the Sparviero unseen, so while in action, the defensive positions were usually left open even though this reduced the maximum effective speed.
The internal bomb bay was configured to carry bombs vertically, preventing larger bombs being accommodated internally. The aircraft could hold two x 500 kg, five x 250 kg, 12 x 100 kg or 50 kg bombs, or hundreds of bomblets. The bombardier, with an 85° forward field of view, had a "Jozza-2" aiming system and a series of bomb-release mechanisms. The machine gun to the rear of the gondola prevented the bombardier from lying in a prone position, and as a result, the bombardier was provided with gambali, retractable structures to support his legs while being seated. Torpedoes were carried externally, as were larger bombs. This was only standardized from 1939, when two hardpoints were fitted under the inner wing. Theoretically two torpedoes could be carried, but the performance and the manoeuvrability of the aircraft were so reduced that usually only one was used in action. In addition, the SM.79's overall payload of 3,800 kg prevented it carrying 1,600-1,860 kg of bombs without a noticeable reduction of the fuel load (approximately 2,400 kg, when full).
Despite the low overall power (ROF and energy of the projectile) of the SM.79's machine guns, it was heavily-armed by 1930s standards (for bombers, essentially three light machine guns), the armament being more than a match for the lightly-protected fighter aircraft of the time, not usually fitted with any armour. By the time of World War II however, the Sparviero's vulnerability to newer fighters was significant, and it lost its reputation of "invulnerability" gained over Spain.
Torpedoes could be carried on two hardpoints under the inner wings, but often only one was used at once to preserve agility and payload. This torpedo, a 1938 Whitehead design, had a weight of 876 kg, length of 5.46 m and a 170 kg HE warhead. It had a 3,000 m range at 40 knots, and could be launched from a wide range of speeds and altitudes: 40-120 m and up to 300 km/h maximum. It took over ten years to develop effective techniques, consequently there were few torpedo-bombers in late 1940. Since the failure of the Savoia-Marchetti SM.84 (its intended successor) and the lack of power of the Ca.314, only the SM.79 continued to serve as a torpedo-bomber until 1944, despite trials with many types of machines, including the Fiat G.55S.
To be effective, the launch needed to be made at between 500 and 1,000 m from the target. Under this distance, the torpedo could pass below the keel, failing to explode through not having a magnetic trigger mechanism. Above this range, the unguided weapon could be avoided as it would take almost a minute to reach the target. The lack of a homing system made the long range of the torpedo almost irrelevant, although British torpedo-bombers used a two km-range weapon to more effect in the Mediterranean. At close range, SM.79s often flew at low level above the ships before the torpedo was launched, and so were targeted by every weapon available, from the infantry's small arms to the heavy artillery. Theoretically, the forward Breda with its elevation over the flight line, was capable of targeting ships from around 2 km, but the aircraft needed to fly straight and level; a difficult and dangerous attack tactic.
The Sparviero had several advantages compared to British torpedo-bombers. Only the Bristol Beaufort could equal it in speed but did not afford the same protection to its crew in a ditching as the vulnerability of its glazed nose could be a danger should the aircraft crash at high speeds. The Vickers Wellington was slower and less agile, but had a very long range and could carry two torpedoes. A step forward in performance was provided by the Bristol Beaufighter, but no torpedo-bomber was more successful in the European theatre than the Fairey Swordfish. This biplane, being fabric-covered and having a fixed undercarriage, was old-fashioned compared to the Sparviero, even though they originated in the same year. It had one engine, was half as fast, and had half the SM.79's range, however, its agility, carrier compatibility and skill of the crews enabled it to sink 200,000 tons of shipping, more than that attributed to any other British aircraft. This was well in excess of that achieved by the Sparviero, even though there were only a few dozen Swordfish compared to hundreds of SM.79s used during World War II. Both aircraft had successors with similar, but enhanced engines. They were the SM.84 and the Fairey Albacore, but in both cases, the new engines proved to be less reliable, the heavier machines were less agile, and the operational results were so poor that they were replaced by their predecessors. Radar was an advantage for night attacks, but was only fitted to one experimental SM.79.
In addition to the barrage of defensive fire put up by target vessels (from large calibre guns at long range down to smaller ones at close range), the SM.79s fell prey to defending fighters. Neither the Blackburn Skua nor Gloster Gladiator presented a real threat for the Sparviero, being 90 and 10 km/h slower respectively. Soon however, the Sparviero faced the Hawker Hurricane, and the Fairey Fulmar which was faster but still quite slow relative to escort fighters. One attacked four SM.79s bombing British ships near Bardia, and shot down three of them on 3 September 1940. Beaufighters were fast and well-armed, and as well as being effective long-range day fighters, were successful night interceptors and late in the war often chased Sparvieros in night missions. Eventually, P-40s, P-38s and Spitfires made their début in the Mediterranean, preventing Sparvieros operating during the day. Additionally, Hurricanes, Martlets and Spitfires arrived on carriers improving the British defences against Axis air attacks.
The relative efficiency of torpedo-bombers compared to dive-bombers is debatable, particularly when dedicated torpedo-squadrons were equipped with heavy aircraft. Dive-bombers were less costly and more flexibles, using more economic and less specialized weapons, and had a less dangerous flight profile while diving almost vertically from high altitude. Additionally, they could be used against land targets with the same efficiency: Rudel used Stukas to score hits on ships as well as against tanks. Douglas Devastators, instead, were massacred at Midway without any success, while Dauntlesses managed to sink four carriers almost without losses. The only real advantage of using torpedoes was against battleships, being usually well-armoured against bombs, but less so against torpedoes.
Similar to the prototype, the "hump" was not fitted to some of the first production aircraft, being transformed into racing aircraft known as the SM.79CS. One of them, in 1937 set further records: with three Piaggio P.XI RC.40 engines (this allowed a total of 3,000 hp, like the much heavier S.M.84s) it averaged 423.618 km/h over 1,000 km with a 2,000 kg payload. This record then increased to 444.115 km/h, while another SM.79 achieved 428.296 km/h in the 2,000 km/ 2,000 kg category. Unofficially, a speed of 472 km/h was later reached in this same category, greater than the maximum speed of production bombers.
The five SM.79CSs went on to enter the Paris-Damascus-Istres race, where I-CUPA, I-FILU and I-BIMU took the first three positions, while the other two were placed sixth and seventh. The last was heavily damaged in Damascus. Two Fiat BR.20s also competed, but achieved only sixth (equal with one SM.79) and eighth places. Three of the SM.79CSs, which became famous as "i sorci verdi" (the green mice) due to their insignia, were modified to cross the Atlantic Ocean and reach Brazil. They took off on 24 January 1938 and landed in Dakar 11 hours later, then headed for Rio de Janeiro arriving at 22:45 local time on 25 January, however, one faulty aircraft landed at Natal. The aircraft remained in Brazil and were donated to the Força Aérea Brasileira.
The SM.79 saw action for the first time serving with the Aviazione Legionaria, an Italian unit sent to assist Franco's Nationalist forces during the Spanish Civil War. During the fighting over 100 SM.79s served as bombers attacking Republican targets, mainly in Catalonia.
Thanks to the experience gained in Spain, the SM.79-II, introduced in October 1939, formed the backbone of the Italian bomber force during World War II. Almost 600 SM.79-I and –II aircraft were in service when Italy entered World War II, and these aircraft were deployed in every theatre of war in which the Italians fought.
Favorable reports of its reliability and performance during the Spanish Civil War led Yugoslavia to order 45 aircraft generally similar to the SM.79-I variant in 1938, and these Yugoslavian versions were designated the SM.79K. They were delivered to Yugoslavia in 1939, but most were destroyed in the invasion by Germany in 1941. A few did survive, to be pressed into service with the pro-Axis forces of the NDH, apart from four which became AX702-705 of the RAF.
Attempts were also made to gain large-scale export orders, but only three countries finalized contracts, with twin-engined versions being supplied to Brazil (three with 694 kW/930 hp Alfa Romeo 128 RC.18 engines), Iraq (four with 746 kW/1,030 hp Fiat A.80 RC.14 engines), and Romania (24 with 746 kW/1,000 hp Gnome-Rhône Mistral Major 14K engines). Romania later acquired an additional 24 aircraft powered by Junkers Jumo 211Da engines, and these were designated the SM.79JR. They also built a further 16 JR variants under license.
The first recorded interception of an SM.79 formation took place on 11 October 1937 when three aircraft were attacked by 12 Polikarpov I-16s (known as the Rata (Rat) to the Spanish Nationalists). One of the SM.79s was damaged by repeated attacks made by the slightly faster Ratas, but its defences prevented the attackers from pressing close-in attacks. All the bombers returned to base, although one had been hit by 27 bullets, many hitting the fuel tanks. A few other examples of similar interceptions occurred in this conflict, without any SM.79s being lost.
Combat experiences revealed some deficiencies in the SM.79: the lack of oxygen at high altitudes, instability, vibrations experienced at speeds over 400 km/h and other problems were encountered and sometimes solved. Gen. Valle, in an attempt to answer some of the criticisms about the ability of the aircraft to operate at night (because its wingload and other characteristics were controversial) took off from Guidonia and bombed Barcelona, a journey of six hours and 15 minutes. On this occasion the aircraft proved it had a useful range (around 1,000 km with eight 100 kg bombs, for a total gross weight of around 1,000 kg). Normally SM.79s operated from the Balearic Islands and later from mainland Spain. Hundreds of missions were performed in a wide range of different roles against Republican targets. No Fiat CR.32s were needed to escort the SM.79s, partly because the biplane fighters were too slow.
After serving in the Spanish Civil War, the Sparviero came into use with 111° and 8° Wing. By the end of 1939, there were 388 Sparvieros in service, with 11 wings that were partially or totally made up of this aircraft. They also participated in the occupation of Albania in autumn 1939.
By the beginning of the war 612 aircraft had been delivered, making the Sparviero the most numerous aircraft in the whole of the Regia Aereonautica, assigned to a total of 14 wings (8, 9, 10, 11, 12, 14, 15, 30, 32, 33, 34, 36, 41 and 46). Not all of these wings had Gruppi (groups) entirely equipped with the SM.79, as some still used SM.81s, and every group had two Squadrons (Squadriglie). Every squadron had around nine to ten aircraft, but this included second line aircraft, so the force of each squadron consisted on average of around seven to eight bombers, and every wing had around 30 bombers. The Regia, at the beginning of the war had 25 bomber wings, 20 of them with modern aircraft. Since only eight wings performed fighter roles (even if with 50% more aircraft) the Regia was mainly an offensive force. Of the 20 wings partly or wholly equipped with modern aircraft, only four had BR.20s despite them having won a 1934 contest. The SM.79s were far more successful, though they had many shortcomings compared to the Fiat. Among these units; 8, 9, 11, 12, 30, 32, 36, 41 and 46 Stormi (Wings) were based in Italy, and participated in the fighting in France. They were equipped with a total of around 350 SM.79s, including those used in training squadrons, and over Malta, where they lost their reputation of being invulnerable following a loss sustained when encountering a Gloster Gladiator on 16 June. 34 Wing was involved in this campaign, together with 36 and 41 Wings.
In Abyssinia, Eastern Africa (now known as Ethiopia) there were a small number of SM.79s, that constituted a minor part of a force primarily made up of SM.81s and Ca.133s. The force of SM.79s was initially made up of 18 aircraft in 44 Gruppo. This bomber was the only type present that did not participate in the previous war with the Negus. These few aircraft were reinforced with several others, and modified to fly at an economical speed, over Sudan for the hazardous journey of over 2,000 kilometres. They could not, however, do much to save the Italian positions in Abyssinia, and they were forced to surrender in the spring of 1941. The same period saw the Sparvieros; the five Iraqi SM.79Bs and the 45 SM.79Ks in Yugoslavian service, unable to mount a successful defence in Yugoslavia or Iraq.
In the North Africa, around 100 SM.79s served in 10, 14, 15 and 30 Wings, bombing mainly non-strategic targets in the desert. On one of the first days of the war, following an attack made by Blenheim bombers on an airfield near Tobruk, an SM.79 arrived carrying Italo Balbo and at least eight other persons, among them the father of the Italian film director Folco Quilici. Anti-aircraft guns, possibly from the cruiser San Giorgio, downed the aircraft in flames and all were killed. The shoot-down was declared a tragic accident by the Italian government, though suspicions have lingered that Balbo's death may actually have been ordered by Mussolini. Balbo had already started to protest the continuous tactical missions asked of the Regia Aerenaoutica, which were reducing its effectiveness.
The offensive made by the British in December hit Italian aviation hard and many wings (a total of nine until May 1941) were phased out because of the losses. The tasks in which many aircraft were involved were in attacking British land forces, with bombing and strafing. The losses caused by Hurricanes and the ground fire increased, so at the beginning of 1941 only around 40 machines were still present in Libya and by the end of 1941, only one operational squadron remained. In the Battle of El-Alamein many Sparvieros were used for defensive tasks, such as countering SAS teams in the desert, as happened in 1940, and performing an anti-ship role.
From autumn 1940, SM.79s were used against Greece, then Yugoslavia. They continued to be hampered in their operations by the Royal Air Force, but also by poor weather conditions. Over the Mediterranean the Sparvieros were used in reconnaissance missions, and anti-ship attacks.
Known losses of SM.79s due to Royal Navy interceptors are as follows:
The total number of reconnaissance, bomber and torpedo bombers downed in these two years by naval fighters was, not counting aircraft heavy damaged and eventually lost, 24 aircraft, 2% of the total production. But even if this result may appear modest, the activity of the British naval fighters helped to discourage attacks by enemy aircraft. They also shot down 19 Z.506 and six Z.501 naval reconnaissance aircraft, in search of British forces, and prevented many others from locating and relaying the positions of Allied ships and convoys.
Over 2,300 bombs were used by SM.81s and SM.79s against British ships during the Battle of Punta Stilo alone, with few successes and nine losses (together with SM.81s). Despite the effort, this represented an overall failure to defeat the British Mediterranean Fleet. In fact the Sparvieros, were only effective when armed with torpedoes.
The Sparviero launched its career as torpedo-bomber on 25 July 1940 when a new unit was established after several years of experiments. The Special Aerotorpedoes Unit was led by Colonel Moioli. After having ordered the first 50 torpedoes at Whitehead Industries, on 10 August 1940 the first aircraft landed at T5 airfield, near Tobruk. Despite the lack of an aiming system and a specific doctrine for tactics, an attack on shipping in Alexandria was quickly organized. There were experiments for many years but still, no service, no gear (except hardpoints) and no tactics were developed for the new speciality. This was despite previous Italian experiments into the practice of aerial-torpedoing in 1914, 26 years before.
15 August 1940 saw the first action under way, with five SM.79s that were modified and prepared for the task of torpedoing enemy shipping, sent to El Adem airfield. Among these aircraft pilots were Buscaglia, Dequal and other pilots destined to became "aces." The journey was made at an altitude of 1,500 m and after two hours, at 21:30, they flew over Alexandria and began attacking the ships. This first attack was unsuccessful. The aircraft had only 1,000 m of runway for takeoff, so two of the fuel tanks were left empty to reduce weight. This gave an endurance of five hours, with a journey of 4.33 hours.
After this first action, only Buscaglia and Dequal, after over five hours, returned, both aircraft damaged by anti-aircraft fire. Buscaglia landed on only one wheel, with some other damage. The other three Savoias, attacking after the first two, were hindered by a fierce anti-aircraft defence and low clouds, so they returned to their base without releasing their torpedoes. However, all three ran out of fuel, were forced to jettison the torpedoes which exploded in the desert, and then force-landed, three hours after the attack.
Two crews were rescued later, but the third (Fusco) was still in Egypt when they force-landed. The crew set light to their aircraft the next morning, which alerted the British who then captured them. These troubles were experienced within a combat radius of only about 650 km, in clear contrast with the glamorous performances of the racer Sparvieros a few years before.
Many other missions followed, on 22-23 August (Alexandria), 26 August (against ships never found), and 27 August (Buscaglia against a cruiser). The special unit became known as the 278ima Squadriglia, and from September 1940 carried out many attacks on ships, including on 4 September (when Buscaglia had his aircraft damaged by fighters) and 10 September, when Robone claimed a merchant ship sunk. On 17 September, after an unsuccessful day attack, Buscaglia and Robone returned at night, attacking the British ships that shelled Bardia. One torpedo hit HMS Kent, damaging this heavy cruiser to the extent that the ship remained under repair until September 1941. After almost a month of attacks, this was the first success officially acknowledged and proven. After almost a month of further attacks, a newcomer, Erasi, flew with Robone on 14 October 1940 against a British formation and hit HMS Liverpool, a modern cruiser that lost her bow and needed 13 months of repair. After several months, and despite the losses and the first unfortunate mission, the core of the 278 ima was still operating the same four aircraft. The last success of this squadron was at Suda Bay Crete, when Buscaglia damaged another cruiser, HMS Glasgow, despite the anti-torpedo netting surrounding the ship. This powerful Royal Navy vessel was out of commission for nine months whilst repairs were made. The aircraft continued in service until a British bomb struck them, when the usual mounting of the torpedo under the belly led to a "chain reaction" which destroyed them all.
The year ended with a total of nine sunken and several damaged Allied ships. The Italians had lost 14 torpedo-bombers and sustained several damaged in action. This was the best year for the Italian torpedo-bombers and also the year when the SM.84, the SM.79's successor was introduced. Overall, these numbers meant little in the war, and almost no other results were recorded by the Italian bombers. Horizontal bombing proved to be a failure and only dive bombers and torpedo-bombers achieved some results. The damaging of the British cruisers was the most important result, but without German help, the Italians would have been unable to maintain a presence in the Mediterranean theatre. The 25 Italian bomber wings were unable to disturb the British forces, as the Battle of Punta Stilo demonstrated. Almost all of the major British ships lost were due to U-Boat attacks, with the damaging of HMS Warspite, and the sinking of HMS Barham and HMS Ark Royal. The British fleet was left without major ships in their Mediterranean fleet leaving the Axis better situated to control the sea.
The Allies aimed to provide Malta with vital re-supplies and fuel through major convoy operations at all costs. The first was the Harpoon convoy, and almost all the Axis air potential was used against the convoy. 14 June saw the second torpedoing of HMS Liverpool, by a 132° group Savoia, putting it out of action for another 13 months. Regardless of where the torpedo struck, (amidships in the case of the Liverpool, aft as for the HMS Kent, or forward as happened to HMS Glasgow) the cruisers remained highly vulnerable to torpedoes, but no Italian air attack managed to hit them with more than one torpedo at once. On this day the merchant ship Tanimbar was sunk by SM.79s of 132°, and finally the day after HMS Bedouin, a Tribal class destroyer, already damaged by two Italian cruisers, was sunk by pilot M. Aichner, also of the 132° Gruppo. For years this victory was contested by the Italian Navy, that claimed to have sunk the Bedouin with gunfire.
August, saw heavy attacks on the 14 merchant ships and 44 major warships of the Operation Pedestal convoy, the second Allied attempt to resupply Malta past Axis bombers, minefields and U-boats. Nine of the merchant ships and four of the warships were sunk, and others were damaged, but only the destroyer HMS Foresight and the merchant ship MV Deucalion were sunk by Italian torpedo-bombers. Although damaged, the tanker SS Ohio, a key part of the convey, was towed into Grand Harbour to deliver the vital fuel on 15 August 1942 to enable Malta to continue functioning as an important Allied base; a major Allied strategic victory.
By autumn 1942, in contrast to Operation Torch, 9 December was a successful day when four SM.79s sank a sloop and a merchant ship, with the loss of Angelucci's aircraft. Carlo Emanuele Buscaglia, another prominent member of the Italian torpedo-airforce who was credited with over 100,000 tons of enemy shipping sunk, was shot down the day after he said that they would probably all be dead before Christmas. The risks of attempting to overcome the effective defences of allied ships were too great to expect much chance of long-term survival, but he was later rescued from the water, badly wounded.
Despite the increased activity in 1942, the results were considerably poorer than those of the previous year. The efforts made by the bombers were heavily criticized as being insufficient. Many debated the possibilities of torpedo manufacturing defects or even sabotage. In the first 30 used, in 1940, the reliability was excellent, but a number of later torpedoes were found to be defective, especially those made at the Napoli factory. During Operation Harpoon, over 100 torpedoes were launched with only three hitting their targets.
General Ferdinando Raffaelli had come up with the idea packing an SM.79 with explosives and a radio control device. As the Pedestal Convoy was steaming off the Algerian coast on 12 August 1942, the SM.79 "Drone", a Z.1007bis guide plane and an escort of five FIAT G.50 fighters flew out to intercept the convoy. Once the pilot of the SM.79 had set his aircraft on a course toward the Allied ships, he bailed out leaving the Z.1007bis crew to guide the flying bomb the rest of the way by radio-or so it was hoped.
The radio, however, malfunctioned. With nothing to guide it,the SM.79-Drone cruised along until it ran out of fuel and crashed into Mount Klenchela on the Algerian mainland. Raffaelli later developed a simple, more expendable single-engine guided bomb, the Ambrosini A.R. ,which was tested in June 1943, but Italy surrendered before it could go into production.
Before the invasion, there was a large force of torpedo aircraft: 7 Gruppi (groups), 41, 89, 104, 108, 130, 131 and 132° equipped with dozens of aircraft, but this was nevertheless an underpowered force. Except 104°, based around the Aegean Sea, the other six Groups comprised just 61 aircraft, with only 22 serviceable. Almost all the available machines were sent to the Raggruppamento Aerosiluranti, that of almost all of the 44 aircraft, only a third were considered flight-worthy by 9 July 1943. Production of new SM.79s continued to fall behind, and at least until the end of July, only 37 SM.79s and 39 SM.84s were delivered. Despite the use of an improved engine, capable of a maximum speed of 475 km/h, these machines were unable to cope with the difficult task of resisting the invasion. The size of these aircraft was too large to allow them to evade detection by the enemy defences, and the need for large crews resulted in heavy human losses. In the first five days, SM.79s performed 57 missions, only at night, and failed to achieve any results, with the loss of seven aircraft. Another three aircraft were lost in the night in which the British aircraft carrier was damaged.
The Italians co-ordinated their attacks with the German forces, and succeeded in hitting an aircraft carrier for the first time, HMS Indomitable, on 16 July 1943, but this was more by accident than design.
SM.79s were not equipped with radar, so the attacks had to be performed visually, hopefully aided by the light of the Moon, while the enemy had ship-borne radar and interceptor aircraft.
The damaging of the Indomitable was due to an error of identification, because the incoming aircraft had been picked up on the ship's radar whilst still eight km away, and failed to be identified as a threat. The ship had seven dead, but the flooding was limited due to the 102 mm armoured belt, which was damaged so badly that it disintegrated at the impact point, but nevertheless prevented the ship from structural damages.
Despite their depleted state, the Regia Aeronautica attempted a strategic attack on Gibraltar on 19 July with ten SM.79GAs, but only two managed to reach their target, again without achieving any result.
Following the 1943 Armistice, the SM.79s based in southern Italy (34 altogether) were used by the Aeronautica Cobelligerante del Sud as transports in support of the Anglo-American military; those that remained in the North (36) fought with the German forces as part of the Aeronautica Nazionale Repubblicana, or were used by the Luftwaffe. A small number of SM.79s remained in service in the new Aeronautica Militare Italiana after the war. There they served as passenger transports into the early 1950s.
For this action 12 SM.79 bis models were used. They had enhanced engines, armoured shields for the lateral machine guns, an additional 1,000 litre fuel tank in the bomb bay, and had the bombardier's nacelle removed. Even these modifications could not provide sufficient range to achieve the necessary distance that the mission required, and so all the weapons except one were removed, one member of crew was left behind, and the fuel load was increased to 5,000 litres. To reach Gibraltar, it was necessary to take off from Istres, in Southern France, and then fly for a total of 2,700 km. Of the 12 aircraft that departed from Istres on 5 June 1944, a moonlit night, ten reached their target. The defenders were taken by surprise, and all the aircraft successfully launched their torpedoes, but three SM.79s ran out of fuel and were forced to land in Spain. Initial claims by the Italians were that four ships, totalling 30,000 tons, were sunk. British sources however stated that no ships were lost, due to an effective system of defence. Regardless, this was the largest enemy incursion over Gibraltar in four years of war.
The following data shows the changes in effectiveness of the SM.79 as a torpedo bomber:
One such incident befell the SM.79 MM.23881 of 278 ima, which took off at 17:25 on 21 April 1941, crewed by Oscar Cimolini, with the intention of searching for enemy shipping near Crete. The SM.79 carried out an attack at around 20:00, and then began the return to its base near Bengasi. The crew became disorientated and unable to locate their exact position, and missed Bengasi in bad weather conditions. Their radio was broken and they were unable to communicate. They were also unaware that they had reached the African coast. The fuel supply was exhausted at around 23:00, and the aircraft made a forced landing some 500 km away from its base. Most of the crew of six had suffered some injuries, but one crew member, Romanini was able to leave to search for help. He walked for over 90 km in the desert, and finally was overcome and died only a few kilometres from a road, but his remains were not found until 1960. Subsequent searches led to the discovery of the SM.79 and the remains of the rest of the crew. Its fate was similar to other aircraft, like the B-24 Lady be good, which crashed in the desert and were not discovered for many years.
Despite the low number of losses suffered by Sparvieros in Spain, the SM.79 MM.28-16 (with a total crew of 17) was destroyed in the air on 12 April 1938, when one of her bombs detonated in the bomb bay. MM.28-25 (again with a crew of 17), was lost when another SM.79, damaged by anti-aircraft guns collided with it on 23 March. A further SM.79, MM.28-16 was damaged by an anti-aircraft shell, and landed with dead and wounded on-board (4 January 1939).
9 Stormo was involved with the SM.79 almost since the beginning of its time in service. In 1937, six SM.79s were sent to Spain with XXI Gruppo, but the transition was slow and was only completed in 1938. On 30 June 1939 two of the aircraft, 13-6 and 13-7, both carrying a full fuel load, collided and crashed, with the entire crew of nine killed on impact. At the beginning of the war, one of the group's aircraft carried out a reconnaissance mission over Corsica on 12 June. The next day, six Sparvieros of 9° bombed Ghisonaccia airfield, but one was shot down by anti-aircraft guns and became the first Sparviero downed in World War II.
When it was sent to Africa to be used against the British forces, the 9° Stormo continued to suffer heavy losses. Initially used to harass light forces operating in the desert, the Sparvieros were subsequently sent against the British advanced columns in Operation Compass. On 16 December 1940, six Sparvieros were sent over Sollum to counter enemy armoured units, but before they could reach their target, three of the lead section were shot down with the loss of 16 men, including commander Mario Aramu. The wing was put out of action and the personnel were sent back to Italy aboard the RM Città di Messina, but on 14 January 1941 this ship was sunk by the submarine HMS Regent, with the loss of 432 men, including 53 members of 9°. The wing was later re-formed with Z.1007s.