Operational history of the Savoia-Marchetti SM.81
| Company type | Military aircraft |
|---|---|
| Industry | Aviation |
| Founded | 1930s |
Area served | Italy, Ethiopia, Spain, North Africa |
| Products | Bomber, transport, reconnaissance aircraft |
The Savoia-Marchetti SM.81 made its combat debut in the Second Italo-Abyssinian War, demonstrating remarkable adaptability by fulfilling roles as a bomber, transport, and reconnaissance aircraft. During the Spanish Civil War, SM.81s were deployed by the Aviazione Legionaria, becoming some of the earliest aircraft dispatched by the fascist regimes to support Francisco Franco.
Despite being outdated by the outbreak of the Second World War, nearly 300 SM.81s remained active within the Regia Aeronautica. Their limited speed and susceptibility to attacks from fighter aircraft relegated them primarily to secondary daytime missions, with a greater emphasis on transport duties. However, during nighttime operations, the SM.81 proved to be an effective bomber, particularly in campaigns across North Africa.
By the time of the Italian armistice in 1943, most SM.81s had been withdrawn from frontline service, though a number continued to operate under both the Italian Social Republic and the Italian Co-Belligerent Air Force.
A handful of these aircraft survived postwar and were incorporated into the Aeronautica Militare Italiana, but all were retired by 1950.
Early history
The initial batch of 100 aircraft was assigned to Wings 7, 9, 13, and 15, with early deployments focusing on Ethiopia where their performance was notably effective. The SM.81 quickly adapted to multiple tasks including bombing runs, strafing, close air support, and reconnaissance missions. This conflict was marked by Italy’s renewed aggression against its longstanding rival, which had previously defeated Italian forces at Adwa in 1896. Despite international laws, both sides committed numerous war crimes; notably, SM.81s were used to deploy chemical agents such as Phosgene and Yperite against enemy forces. Throughout the Ethiopian campaign, a total of 170 bombers — combining both Caproni Ca.133s and SM.81s — operated within two groups of 9 Wing, with one group ("bis") serving as a duplicate unit while the original remained stationed in Italy.
Following the capture of Addis Ababa in 1936, Italian forces encountered continued resistance for several months. Stability was only achieved in 1937 due to Italian air dominance and ground support, which proved crucial against a determined adversary in challenging terrain. A contingent of 36 SM.81s stayed behind in Ethiopia to support occupying troops through transport missions and supply airlifts. Although low-altitude flights exposed them to small arms fire, damage rarely forced these unarmored planes down since they were equipped with self-sealing fuel tanks.
Initially, SM.81s also served with Wings 8 (Bologna), 10 (Bresso), 11 (Ferrara), 12 (Guidonia), 14 and 16 (Vicenza), as well as Wings 30, 32, and 33 based in (Napoli). Additionally, they operated within Wing 15 in Libya where they were outfitted with Gnome-Rhône 14K engines complemented by anti-sand filters for desert conditions.
Spanish Civil War
The SM.81’s primary operational phase commenced on 28 July 1936. During a mission aimed at aiding General Francisco Franco and his "alzamiento" (uprising) against the Republican regime at the outbreak of the Spanish Civil War, a group of 12 SM.81s, disguised as Spanish civilian aircraft, departed from Elmas, near Cagliari, bound for Morocco. They transported 63 troops without uniforms under the leadership of Colonel Ivanoe Bonomi. The planned ferry distance was approximately 1,135 km (705 mi), but multiple issues arose during the flight.
The flight was expected to take less than four and a half hours at speeds between 260 and 270 km/h (160-170 mph). However, upon encountering strong headwinds at an altitude of 1,000 m (3,280 ft), the crews ascended to 3,500 m (11,480 ft), which was the optimal cruising level for the Alfa Romeo 125 engines. After five hours airborne, they were still roughly an hour away from their destination at Melilla in Morocco. Maintaining close formation through cloud cover proved fuel-intensive and erratic in flight path. Ultimately, only nine aircraft successfully landed in Melilla: one crashed into the sea, another made a rough landing, and a third performed an emergency landing unharmed in Algeria. The remaining planes arrived with an average fuel reserve of just 130 L (34 US gal), with the highest being 200 L (53 US gal). This latter aircraft was dispatched to search for missing comrades. Given that this amount represented merely 3% of total fuel capacity, it allowed only limited additional flight time and indicated that even slightly stronger headwinds could have led to all aircraft being lost or forced to land in Algeria. These surviving planes proved vital assets and were promptly employed as troop carriers and bombers.
The troops of Franco's Spanish Army of Africa played a crucial role in turning the tide of the alzamiento, which had previously suffered defeats against Republican forces. On 6 August 1936, African soldiers were ferried to Spain aboard four merchant vessels. The presence and bombing capability of the SM.81s, later supported by the Italian vessel RM Morandini, effectively deterred the predominantly Republican Spanish navy from interrupting Francoist convoys—otherwise capable of blocking these maritime transports. On 9 August, under the command of Ettore Muti, SM.81s targeted and destroyed nearby fuel and ammunition depots belonging to the Spanish Navy, compelling fleet operations to shift to northern ports and further securing sea routes for Hispano-Moroccan troop movements.
Following these initial actions, reinforcements arrived for the SM.81 units from four additional squadrons—213, 214, 215, and 216—organized into two Groups (XXXIV and XXXV), as well as squadrons 251 and 252 within the XXV ("Pipistrelli") Group. Throughout the conflict, SM.81s fulfilled roles as attack planes alongside transport and bombing duties. Although some sorties were protected by Fiat CR.32 fighter escorts, unescorted daytime missions relied on tight formation flying for mutual machine gun defense and on instrument flying capabilities while navigating clouds. After Polikarpov I-15 and I-16 fighters arrived in Spain, operations increasingly shifted to nighttime sorties. By that stage, only seven of the original nine aircraft remained operational, having delivered approximately 210 tonnes (230 tons) of ordnance and contributed—with Junkers Ju 52 transports—to a total of 868 flights ferrying troops from Morocco.
After accumulating thousands of flight hours across a fleet numbering between 90 and 100 aircraft, at least 64 SM.81s remained in Spain within the G-12 Group by late 1938. One example was lost near the war’s conclusion in 1939 along with numerous senior officers. The exact number of SM.81 losses during combat or due to operational incidents throughout the war remains undetermined.
Further developments
Although the aircraft was employed across numerous roles and by various units, the limited speed of the S.81 quickly resulted in its replacement by the SM.79 for many functions. A later variant of the SM.81 was equipped with two Isotta Fraschini Asso inline liquid-cooled engines, each producing 626 kW (840 hp). However, its overall performance was underwhelming, achieving a maximum velocity of only 330 km/h (210 mph), rendering these modifications largely ineffective.
Another iteration served as a tanker aircraft, designated for fuel transportation rather than aerial refueling.
A command version was also created, featuring enhanced radio communication equipment.
The VIP variant saw moderate use; notably, Mussolini personally piloted one such aircraft, nicknamed the 'Turtle' due to its slow pace. The SM.81 was also colloquially known as "Lumache" (snail). Despite its sluggishness, its spacious fuselage offered greater comfort compared to faster bombers like the Sparviero. A pioneering element was the Caproni-Lanciani turret, armed with a 12.7 mm (.5 in) heavy machine gun, considered superior to dual 7.7 mm (0.303 in) guns, though the Scotti machine gun installed proved unreliable.
An experimental variant named Saturno was developed to counter magnetic mines; it featured a large electrified steel ring designed to detonate such mines. Initially, the weight of this apparatus was excessive, prompting a replacement with an aluminum ring.
The SM.81 was also trialed as a torpedo bomber in 1936, testing configurations carrying up to two torpedoes. However, even when equipped with a single torpedo, its speed remained insufficient for this role, which was better fulfilled by the SM.79.
Primarily, the aircraft functioned as a transport platform. The SM.81T model emerged in 1941 with Caproni-Lanciani turrets and AR 126 engines. Production continued into 1942 despite the introduction of the larger SM.82. The S.81's speed approached that of the C-47, boasting defensive armament and comparable range and payload capacity, albeit with slightly lower power and velocity.
The late 1930s and World War II
During the latter half of the 1930s, the SM.81 stood out as one of the most widely utilized multi-engine aircraft within the Regia Aeronautica. It was regarded as a reliable and pleasant aircraft to operate, despite being slower and less agile than the SM.79. In pre-war exercises, it performed well flying in three-aircraft formations executing complex maneuvers; however, regardless of regime propaganda, the Regia lagged behind in pilot training and tactical development except for a small cadre of highly skilled aircrew.
Following Italy’s occupation of Albania, the SM.81 was deployed by 37 and 39 Wings as transport aircraft across the Adriatic Sea, swiftly ferrying troops to Albania in a widely publicized operation highlighting Italian military efficiency. In Libya during 1938, an entire parachute battalion was airlifted when King Victor Emmanuel III visited Italo Balbo’s colony.
By this period, production numbers were: SIAI – 237 units; Piaggio – 60; Macchi – 76; CRDA – 36; Breda – 36; CMSA – 58; AerUmbra – 20; and Caproni – eight; totaling 530 aircraft plus one twin-engine prototype built by SIAI.
At the outbreak of World War II, approximately 300 SM.81s remained operational within the Regia, distributed among units such as 37 Wing at Lecce, 40 Group of 38 Wing, and 39 Wing stationed in Albania. The Egeum Aeronautic, a semi-autonomous RA entity, operated with 39 Wing; Libya hosted 14 and 15 Wings; while five Groups based in Ethiopia maintained strength with these aircraft.
Initially deployed in anti-ship strikes and sorties over Alexandria, squadrons including 37th, 38th, and 39th Wings engaged at Punta Stilo and achieved limited success at Capo Spada. The first attack on Alexandria occurred on July 7 with eleven aircraft participating. These long-range missions recurred on July 16 and 25; August 26; September 8 and 21; and October 5 but yielded only modest results against naval targets.
During autumn operations against Greece, units from the 37th Wing at Valona and the 39th Wing at Lecce took part.
In East Africa, around fifty-nine SM.81s were distributed roughly as squadrons within each group. Despite availability of more advanced SM.79s, the SM.81 remained Italy’s principal bomber there. The first Italian combat sorties in East Africa featured two SM.81s: one bombing Port Sudan on June 11, 1940; another performing reconnaissance over the Red Sea. That night three bombers launched against Aden, but one aborted mission while another crashed near Massawa during landing attempts.
With opposition from Gloster Gladiators and Hawker Hurricanes intensifying, SM.81 usage declined sharply. Only forty-three out of fifty-nine were initially operational for several night bombing raids without losses but sustaining considerable damage overall. On June 13 four bombers attacked Aden—two were shot down—while over thirty days nine were lost in combat or destroyed on ground with no replacements available. By February only ten remained serviceable; this number dwindled further to three by March.
In spring of 1941 an SM.81 equipped with A.130/AR.8 long-range radio systems landed at Kirkuk, serving as command aircraft for Italian-German efforts supporting Iraq's uprising that year—though British forces had already suppressed it by then causing mission failure. Out of twelve Fiat CR.42 fighters forming "Squadriglia Irak", only seven returned.
Throughout North Africa and Italy after war onset’s first year, SM.81s increasingly fulfilled night bombing roles rather than anti-ship or daylight attack missions. By January end of that year, Group 145 had transported some eleven thousand personnel and over one thousand tons (approximately one thousand two hundred sixty tons) of supplies during three thousand two hundred flight hours.
For Operation Herkules, planned invasion of Malta, SM.81s from the eighteenth Wing were assigned to move an assault division but ultimately transported the Folgore division instead to El Alamein. Post-battle operations saw these aircraft supplying reinforcements and materiel across North Africa and evacuating Tunisia—with eighteen Wing alone moving twenty-eight thousand troops. On islands like Pantelleria and Lampedusa where runways were short, SM.81s were often Italy’s sole air cargo option.
After their first year in combat roles diminished significantly to secondary duties such as troop transport or cargo carriage—many marked with red crosses for medical evacuation purposes—nearly all front-line squadrons retained at least one SM.81 or equivalent for support tasks within their ranks due to its sturdy fixed undercarriage enabling operations from varied terrain unlike slat-lacking SM.79s.
Numerous SM.81s alongside SM.73s participated on Eastern Front during Battle of Stalingrad, attempting relief missions for encircled Axis forces but all were lost during this engagement.
By September 1943 many remained active across Italy; several southern units operated bomber and transport groups conducting sorties over Balkan regions until spare parts shortages halted further operations entirely—about sixty aircraft remained in northern Italy with thirty-six still airworthy.
The Transport Group Terracciano, led by Maggiore Egidio Pellizzari formed at Bergamo before relocating to Goslar, Lower Saxony in January 1944 where forty-four SM.81s awaited Italian crews.[1] Though initially in poor condition they were restored to flying status by their pilots before being administratively placed under ANR control but operationally subordinated to the Luftwaffe as "Transport Gruppe Italien 10".[2]
On April 8th the first squadron equipped with twelve SM.81s deployed to Šiauliai, Lithuania followed by additional Savoia-Marchetti squadrons from second and third units operating across Baltic States, Russia and Finland conducting troop transport and medical evacuation.[3] By June sixteen nineteen aircraft arrived at Imola bringing technical personnel from Estonia supporting German fighter reinforcements under Gefechtsverband Kuhlmey.[4]
When Soviet forces advanced toward Jelgava, Latvia in July 1944 "Transport Gruppe Italien 10" still maintained thirty-two operable 'Pipistrelli' but fuel shortages coupled with decreased German interest led to gradual withdrawal after six months heavy service.[5] None survived postwar as final four were destroyed upon conflict cessation.
References
- Notes
- Bibliography
- 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.
- Neulen, Hans Werner. In the Skies of Europe - Air Forces Allied to the Luftwaffe 1939–1945. Ramsbury, Marlborough, THE CROWOOD PRESS, 2000. ISBN 1-86126-799-1
- Passingham, Malcolm. "Savoia-Marchetti SM81". Aircraft Illustrated, May 1977, Vol 10 No 5. pp. 182–187.
- Sutherland, Jon & Diane Canwell: Air War East Africa 1940-41, The RAF versus the Italian Air Force. Barnsley (South Yorkshire) Pen and Sword Aviation, 2009. ISBN 978-1-84415-816-4.