Savoia-Marchetti SM.81 operational history

Infobox Aircraft
name=Savoia-Marchetti SM.81


caption=Savoia Marchetti SM.81 in action (escorted by Fiat CR.32 fighters)
type=Bomber and transport aircraft
manufacturer=Savoia-Marchetti
designer=
first flight=1934
introduced=1935
retired=1950
status=
primary user=Regia Aeronautica
more users=Spanish Air Force
Aeronautica Militare Italiana
produced=
number built=534
unit cost=
developed from=Savoia-Marchetti S.73
variants with their own articles=The Savoia-Marchetti SM.81 first saw combat during the Second Italo-Abyssinian War, where it showed itself to be versatile serving as a bomber, transport and reconnaissance aircraft. SM.81s also fought in the Spanish Civil War with the "Aviazione Legionaria" and were among the first aircraft sent by the fascist powers to aid Francisco Franco.

Despite their obsolescence, by 1940, when Italy became involved in the Second World War, more than 300 (290-304 depending on source) SM.81s were in service with the "Regia Aeronautica". Its low speed and vulnerability to fighter aircraft meant that during daytime, it was restricted to second line duties, finding use as a transport. At night the SM.81 was an effective bomber, particularly in the North African theatre.

Most SM.81s were withdrawn by the time of the Italian armistice of 1943, though some remained in service for both the Italian Social Republic and the Italian Co-Belligerent Air Force.

Several examples survived the war and went on to serve the "Aeronautica Militare Italiana", but by 1950 these had all been retired.

Early history

The first 100 aircraft were delivered to 7, 9, 13 and 15 Wings, serving initially in Ethiopia where they proved to be well suited, and quickly adapted to the roles of bombing, strafing, air support and reconnaissance. This was an aggressive war against Italy's old adversary that in 1896 had defeated the Italian expedition corps at Adwa, and despite international conventions, both the Italians and Abyssinians committed many war crimes unopposed, including the use of chemical weapons, with SM.81s deploying Phosgene and Yprite against enemy troops. A total of 170 bombers — Caproni Ca.133s and SM.81s — operated in the Ethiopian war in two groups of 9 Wing, which was a cloned unit ("bis") of the original 9° that remained in Italy.

After entering Addis Ababa in 1936 having "officially" beaten the Negus, the Italians continued to face fierce opposition for many months. There was a regime of cruel repression throughout the country, and Mrsc. Graziani was badly wounded in an attack by local inhabitants. The situation only became stable in 1937 by virtue of the Italian air-supremacy and support, which was decisive against an extremely dangerous enemy in this difficult and wild terrain, with 36 SM.81s remaining to perform "police duties" and provide support to Italian troops, including air supplies and transport. Small arms fire was a danger in such missions, usually flown at low-level, but the damage was normally insufficient to bring down the aircraft, even though they had no protective armour apart from having self-sealing fuel tanks.

SM.81s also initially operated with 8 Wing (Bologna), 10 (Bresso), 11 (Ferrara), 12 (Guidonia), 14 and 16 (Vicenza), 30, 32 and 33 Wings (Napoli); and equipped 15° in Libya, fitted with Gnome-Rhône 14K engines and anti-sand filters.

pain

The main career of the SM.81 started on 28 July, 1936. On a mission dedicated to support General Francisco Franco and his "alzamiento" against the Republican government at the start of the Spanish Civil War; 12 SM.81s under the guise of Spanish civilian ownership took off from Elmas, near Cagliari, to fly to Morocco carrying 63 non-uniformed troops led by Colonel Ivanoe Bonomi. The anticipated ferry flight was around 1,135 km but several problems occurred en-route.

The journey should have been flown in less than four and a half hours at 260-270 km/h, but on encountering strong headwinds at 1,000 m they climbed to 3,500 m; the best cruise altitude for the Alfa Romeo 125 engines, but after five hours they were still an hour from the final destination of Melilla, Morocco. Trying to maintain tight formation despite the clouds was also fuel-costly, with non-linear flight, and only nine aircraft managed to land at Melilla. One ditched in the sea, while another crash-landed and a third force-landed without damage, both in Algeria. The remaining aircraft arrived with an average of only 130 litres of fuel remaining in the tanks, the most being the 200 litres left in the aircraft sent to search for the missing SM.81s. Being only 3% of the total fuel capacity, this was enough for just a few minutes of flight and meant that, with only a slightly stronger headwind, all the Savoias would have been lost or forced to land in Algeria. Some sources state that the aircraft were fitted with one 100 kg bomb, helping to explain why aircraft capable of at least 1,800 km ferry range were unable to complete this mission. The Savoias were valuable assets and soon put to use as troop-transports, and bombers.

Franco's Spanish Army of Africa troops were fundamental in raising the fortunes of the "alzamiento" which had hitherto been mainly beaten by the Republican loyalists, and on 6 August, 1936, African troops were transported to Spain aboard four merchant ships. The threat of the Savoias and their bombs, once reinforced by the Italian ship RM "Morandini", were sufficient to keep the mainly Republican Spanish fleet at bay, which otherwise would have been able to prevent any Franchist convoy reaching Spain. On 9 August, SM.81s under the command of Ettore Muti, one of the most important protagonists of the fascist regime, destroyed the Spanish Navy's fuel and ammunition reserves in the vicinity, forcing the fleet to use northern bases, and further preventing interference with the sea-transport of Hispano-Moroccan forces.

After these exploits, the initial SM.81s were reinforced by four squadrons: 213, 214, 215, and 216 in two Groups (XXXIV and XXXV), and by 251 and 252 squadrons for XXV ("Pipistrelli") Group. Throughout the war, SM.81s were even used as attack aircraft as well as transport and bombers. Though some missions were flown with Fiat CR.32 fighter escorts; unescorted day missions were made possible by flying in tight formation with mutual machine gun protection, and by the aircraft's ability to fly on instruments while in cloud cover. Sorties were increasingly flown by night after the arrival of Polikarpov I-15 and 16s in Spain, by which point only seven of the original nine aircraft were still serviceable, having released 210 tonnes of bombs and contributed (together with Junkers Ju-52s) to 868 flights transporting Morocco's troops. After thousands of hours flown, at least 64 surviving SM.81s were left in Spain in the G-12 Group at the end of 1938. One example was lost near the end of the war along with the lives of many senior officers, but the precise total number of SM.81 losses is not known.

Further developments

Even if this aircraft were used in many tasks and by many units, soon the modest speed of the S.81s suggested to leave them by first line and replaced them with S.79s. The flight with S.81 was easy: it was a docile and stable aircraft, with low wingload and not trascurable power available. One of the model developed was a two engine version, with 2 Isotta Fraschini Asso, an inline, liquid cooled engine with 840 hp. But the performances, theoretically interesting given the reduced drag and the almost as powerful propulsion system, were quite disappointing, including 330 km/h maximum speed, so the modifications had no success.

Another version was a tanker aircraft (for fuel transport, not air refuelling), made in few examples.

A command version was made with a powerful radio equipment, used as well in few examples.

The VIP version was used in some numbers. Mussolini had one, that piloted this aircraft personally. It was called 'Turtle', meaning the slow speed it was capable. Another nickname of the S.81s was 'Lumache', also telling about the slowness of this aircraft. But the wide fuselage was more comfortable than the 'fast bombers' like Sparviero. An innovative feature was the new Caproni-Lanciani turret, armed with a 12,7 mm heavy machine-gun. This was considered better than two 7.7 mm but the Scotti machine gun proved unreliable.

Another example was experimented as anti-magnetic mines aircraft: it was called Saturno, because it had an immense steel ring with high voltage, to set the trigger of magnetic mines, the most dangerous of all the mines. The weight of the gear was too high and so it had not success at the beginning. But it was modified with an aluminium alloy ring, much lighter and the results were acceptable. But only this aircraft was made and used in La Spezia port. It was used as the Vickers Wellington in one of its many versions.

Another task for the S.81 was as a torpedo-bomber. In 1936 there were experiments with up to two torpedoes. But even with one the aircraft was slow and so not ideal to the task, also because there was S.79 available. In every chase, Handley-Page Hampden, Mitsubishi G3Ms and Wellingtons had not so better performances to display, and still were used as torpedo as well. Some S.81 had the torpedo racks under the wings, but this option was never seriously considered.

But the main task for this aircraft was as a transport, as this machine after all, was meant in its original design. Designed S.81T they were ordered in 1941, when their first line employ, as first line bomber, was almost ended. They were fitted with Caproni-Lanciani turret and AR 126 engines. From 1942 they were delivered from 28 November 1942, when they were quite obsolete at any level. It's strange that, despite the presence of the bigger S.82, still many S.81 were ordered, because they had almost nothing to offer except a less big target for the enemy and a more economical construction, but not much because they were made in non-strategical materials as structure and had the same engines as the bigger Marsupiales, that can hold the twice of payload. Even so, S.81 were almost as fast as C-47, and had a defensive weapon set, while the range and payload was almost equal, with only a slight inferiority on installed power and speed.

The late 1930s and World War II

SM.81s began the most diffused multi-engine aircraft of Regia Aereonautica in the second half of '30s. It was a pleasant and reliable aircraft to fly, even if obviously it was too slow with flight commands to be a manoeuvrable aircraft as the SM.79. It gave a good impression, also, in the pre-war exercises, with these big aircraft aligned on the ground or flying in three-aircraft formations. Several complex manoeuvres were performed, but the reality, apart the propaganda's regime, was that Regia lagged behind in training and tactics, except for a bunch of very experienced flyers, that were much superior than the average, often with air raids or world records.

With Albania's occupation the SM.81s were used (37 and 39 Wing) as transport aircraft over the Adriatic sea, sending quickly soldiers over Albania, in a much publicized operation that showed the 'efficiency' of Italian armed forces. In Libya, already in 1938 a whole parachutist battalion was launched when the King went on an official visit to Italo Balbo's colony.

The production was: SIAI, 237; Piaggio, 60; Macchi, 76; CRDA, 36; Breda, 36; CMSA, 58; AerUmbra, 20; and Caproni, eight. Total, 530 and the twin-engine example (SIAI). This production program was so involving almost all the Italian aeronautic industry, but still, it produced less than the half of SM.79s and even less than SM.82.

When World War II broke, Regia had still 293-304 machines on charge, with 37 Wing (Lecce) and 40 Group of 38 Wing. The other 38 Wing group, the 39°, was in Albania. The Egeum aereonautic, a small and almost independent military entity of RA, had 39 Wing, Libya had 14 and 15 Wing and finally five Groups in Ethiopia were present with this aircraft in strength. (at those time, there were apparently 14 wings with S.79, at least one of these groups, four with Fiat BR.20s and two Cant Z.1007 in a total of 25 Wings).

SM.81s fought initially in first line, with anti-ship attacks and missions over Alexandria. 37, 38 and 39 Wings fought at Punta Stilo, and others fought at battle of Capo Spada, still with modest success. Alexandria was attacked for the first time 7 July, with 11 machines. This long range missions were repeated 16, 25 July, 26 August, 8 and 21 September and finally, 5 October. All these missions, especially those against ships were only modestly successful.

Greece was attacked in the fall, also with the use of 37 (Valona) and 39 (Lecce) Wings, that were involved also in air reforgements and air attacks. When faced with the RAF, the SM.81s suffered in according.

In Eastern Africa, SM.81s were 59, so every group had around a squadron of aircraft. Despite the presence of the most modern SM.79s in this war the Pipistrello was the main Italian bomber. When Gloster Gladiators and Hawker Hurricanes made the things difficult, the SM.81s were used less and less. Initially of the 59 aircraft there were 43 ready to use. They were involved in several bombing, generally made by night. The SM.81s were used also to bomb a big British convoy, without losses but many aircraft were damaged. Already in 13 June, four bomber were sent in Aden, the main British base, and two of them were shot down. In 30 days, without replacements, nine aircraft were shot down, 10 were destroyed on the ground, and 18 were heavily damaged, two-thirds of the total. On February 10, there were only 10 serviceable aircraft, and only three in March. These are small numbers, but the decline of SM.81s force was very important for the battles there fought.

Another SM.81 was sent in the area: an SM.81 with A.130/AR.8 long-range radio, that landed at Kirkuk in the spring 1941. It was the command aircraft for the expedition made, too late, by Italian forces (together with Germans) to help the Iraqi 1941 rising. But Iraqis were already defeated by British, despite their equipment was quite powerful, and the Axis mission failed. So, of the 12 Fiat CR.42s of the 'Squadriglia Irak', only seven returned claiming two Gladiators.

In the meanwhile, SM.81s in North Africa and Italy where used more and more as night bombers, quickly leaving the anti-ship and day bombings but not before the first year of war. 145 Group delivered until the end of January 1941, 11,600 men and 1,140 tonnes of various materials, in 3,200 flying hours, and this happened in a very critical period for Italy's North Africa troops.

For Operation C3, Malta invasion, SM.81s of 18 Wing would have transported to Malta an assault division, but finally they were used to transport Folgore division at El Alamein. After that battle, SM.81s were used to reinforce with men and supplies the north-African troops, but also to evacuate Tunisia, with 18 Wing alone transporting 28,000 men. The SM.81s were vulnerable, but in fact the most usually preys were SM.82s and Ju-52s. In Pantelleria and Lampedusa the SM.81s were the only Italian air cargo aircraft capable of operating in the short airfields. The SM.81s, after the first year of war were used only for second line tasks like troops and materials transport, with very few modifications. Many had the white and the red cross to evacuate wounded without any armament or military equipment.

As second line tasks, almost all the first-line Groups had SM.81s or other aircraft in their squadrons, used as support aircraft (for transport), with one SM.81 often present in every squadron. SM.81s with their fixed and robust undercarriage were able to operate from every terrain, despite the lack of slats, unlike SM.79s.

In Russia were used other aircraft, from 12 August there were 245 squadriglia (Squadron) on two, later 10 SM.81s, then 246 on other 18, and finally 247 on SM.73 militarized. With the terrible Russian winter there was an heavy employ, with ice and cold all around. These aircraft tried to help the trapped troops when soviets started the Stalingrad offensive, and all these machines were lost in that battle.

On September 1943 there were still many SM.81s in Italy. With many of them was constituted in the South the bomber and transport group, with SM.81 used for aviolaunches and even landing in balkan territories. But after 14 months the lack of spare parts stopped the SM.81 operations. In North Italy there were more aircraft: at least 60, 36 of which were serviceable. They were used in Terraciano Group, Italian manned but operating with Luftwaffe in eastern front. After six months of heavy employment in Finland, Russia, Poland, and other countries, the surviving aircraft were so badly reduced, with their wood and fabric structures, they were phased-out. No SM.81 survived the war, since the last four were soon demolished when the hostilities were ended.

References

*Mondey, David. "The Hamlyn Concise Guide to Axis Aircraft of World War II". Chancellor Press, 2002.
*Lembo, Daniele, "SIAI 81 Pipistrello", Aerei nella Storia, n.33.