Savoia-Marchetti SM.85
Encyclopedia
The Savoia-Marchetti SM.85 was an Italian
monoplane
dive bomber
and ground-attack aircraft that served in small numbers in the Regia Aeronautica
at the beginning of World War II
. They were soon replaced in service by the Junkers Ju 87
.
Billy Mitchell, which were enthusiastically adopted by Colonel Amedeo Mecozzi (who also developed the Breda Ba.64
and its derivatives) for attack aircraft.
The resulting aircraft, constructed of wood, had a wing set in an upper-middle configuration, a rectangular cross-section fuselage
, retractable undercarriage
and a fixed tailwheel, and was powered by two Piaggio P.VII C.35 engines. The wings, made totally of wood, had three longeron
s, with fabric covering. The aircraft was designed to give the pilot the best possible forward view, with a transparent panel built into the cockpit
floor.
The SM.85's useful payload was 1,150 kg (2,540 lb), including the possibility of fitting a 12.7 mm (0.5 in) machine gun with 300-500 rounds. The aircraft was capable of also using its flap
s as airbrake
s for diving attacks, a notable characteristic of this aircraft. The bombload was carried in a parallelogram-shaped section mounted under the fuselage. The SM.85 was capable of carrying a 500 kg/1,100 lb bomb (or an 800 kg/1,760 lb bomb, the heaviest weapon in the Italian aviation arsenal, but only on very short range missions).
At maximum payload, with a 4,000 kg (8,820 lb) takeoff weight, the climb rate was 20 min to 5,000 m (16,400 ft), but freshly started engines did not produce their theoretical maximum power and the aircraft was usually much slower than this. The takeoff needed 433 m (1,421 ft), and the landing 415 m (1,362 ft). Ceiling was 6,000-6,500 m (19,690-21,330 ft) and 756–827 km (470-514 mi) range. Maximum speed was 367 km/h ( mph) at 4,000 m (13,123 ft). The fuel capacity was 1,078 L (285 US gal), contained in four self-sealing fuel tank
s. At the maximum payload with a 500 kg (1,100 lb) bomb, it was incapable of taking off with a full fuel load (around 730 kg/1,610 lb), so this was used only on ferrying missions.
The first prototype was tested in December 1936, and in spite of its insufficient speed and the disappointing rates of climb, the Regia Aeronautica felt there was sufficient room for development and ordered the SM.85 into production. Despite some improvements, critical deficiencies continued to be experienced during test flights by the Reparto Sperimentale Volo a Tuffo. These revised aircraft were disappointing as dive bombers in almost every aspect, with the most serious problems encountered being frequent uncontrollable spins, extremely slow climb rate after a dive, and instability during the dive.
Production of the aircraft was halted, and the 34 produced up to that time were organised as 96° Gruppo Tuffatori (96th Independent Dive-Bomber Group).
, a small island off Sicily
, in anticipation of attacks on Malta
and the British Mediterranean fleet. The commander of the group, Maggiore Ercolano Ercolani, made it clear to the General Staff that in combat the performance of the aircraft was such that it would result in 100% losses. In order to prove his assertion, Ercolani volunteered to fly the aircraft himself.. These aircraft still didn't suffer any losses until the transfer to Pantelleria, when one of them crashed to a wall, killing the pilot. The others carried out a few missions over the Mediterranean until the end of July, but were never involved in real combat.
The aircraft was soon withdrawn from service and scrapped, and the Regia Aeronautica was obliged to acquire Junkers Ju 87s from Germany which were rapidly introduced into service by the end of summer 1940. The differences in speed and other characteristics between the two aircraft was not great, apart from the availability of a rear gunner, but the Ju 87 was much more effective as a combat aircraft.
SM.86
It was remarkably similar to the Henschel Hs 129
in appearance, weight, and performance; their roles were different, the SM.86 having neither heavy armour nor cannons for ground attack (there were some similarities to the de Havilland Mosquito
in that the SM.86 also utilized a small forward cockpit, inline engines, high mounted wing, and wooden construction).
The SM.86 was evaluated at Guidonia
in 1939, but in April 1940, an order for 97 of them was cancelled, despite the necessity to equip a wing with dive bombers. Although the SM.86 showed an overall improvement in performance, only one was eventually built. It was used over Malta and Greece
, because Savoia-Marchetti hoped to receive a contract for this new aircraft. Even though the test aircraft was downed (by a Ju 87), the aircraft project was continued despite the lack of any official interest until 1941, when it was terminated. A second prototype powered by 403 kW (540 hp) Isotta-Fraschini Gamma engines flew in August 1941. The development of the aircraft was abandoned soon after.
In any case, this new aircraft didn't compare well with the Ju 87's capabilities, even with a new set of airbrakes, flaps and other improvements (but also hampered by the addition of a new cockpit that provided poor rear and side vision for the pilot). The only marginal advantage compared to the Ju 87 was the twin-engine configuration, but the limited power of each engine was not enough to assure a return home if one of these was disabled. The air-cooled design allowed for the elimination of radiators and their vulnerability (with an improvement on aerodynamics, cost and weight), but at low speed and with a limited airflow, overheating was always an issue for this type of engine. The SM.86 was 32 km/h (20 mph) faster than the Junkers Ju-87B and even 2 km/h (1.2 mph) faster than the Ju 87D, but these differences, when compared to opposing fighter's speeds, were minimal. Without a good field of view all-around, and without the second crewmember in the cockpit armed with a defensive machine gun (nor a forward-firing weapon), the SM.86 was clearly more vulnerable to enemy fighters than the Junkers.
Although the SM.85 programme could be viewed as Savoia-Marchetti's worst mistake in wartime, this dive bomber was considered a threat by the British. They considered the possibility of suicide missions made with this aircraft against their ships, having mistaken the meaning of tuffatori.
The SM.85 was essentially made into a "training
dive-bomber" as it was never really suited to being an operational machine. Its engines were not powerful enough to achieve a satisfactory performance, and even when the SM.86 was developed, with much improved engines, it was too late. One SM.85 was, however, modified into a two-seat trainer version. This was developed within a programme that lead to the advanced SM.93, another interesting and unusual aircraft, with high-speed performance and a prone pilot position. Development began too late to be put into production, as with almost all other Savoia-Marchetti "series 90s" projects. In retrospect, the SM dive bombers were a failure.
Kingdom of Italy (Napoleonic)
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
dive bomber
Dive bomber
A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target reduces the distance the bomb has to fall, which is the primary factor in determining the accuracy of the drop...
and ground-attack aircraft that served in small numbers in the Regia Aeronautica
Regia Aeronautica
The Italian Royal Air Force was the name of the air force of the Kingdom of Italy. It was established as a service independent of the Royal Italian Army from 1923 until 1946...
at the beginning of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. They were soon replaced in service by the Junkers Ju 87
Junkers Ju 87
The Junkers Ju 87 or Stuka was a two-man German ground-attack aircraft...
.
Design and development
The SM.85 was part of a programme by the Regia Aeronautica to produce a twin-engine monoplane dive bomber based on the theories developed over the previous 20 years by the American GeneralGeneral
A general officer is an officer of high military rank, usually in the army, and in some nations, the air force. The term is widely used by many nations of the world, and when a country uses a different term, there is an equivalent title given....
Billy Mitchell, which were enthusiastically adopted by Colonel Amedeo Mecozzi (who also developed the Breda Ba.64
Breda Ba.64
|-See also:-References:* Mondey, David The Hamlyn Concise Guide to Axis Aircraft of World War II. New York: Bounty Books, 2006. ISBN 0-7537140-60-4....
and its derivatives) for attack aircraft.
The resulting aircraft, constructed of wood, had a wing set in an upper-middle configuration, a rectangular cross-section fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
, retractable undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
and a fixed tailwheel, and was powered by two Piaggio P.VII C.35 engines. The wings, made totally of wood, had three longeron
Longeron
In aircraft construction, a longeron or stringer or stiffener is a thin strip of wood, metal or carbon fiber, to which the skin of the aircraft is fastened. In the fuselage, longerons are attached to formers and run the longitudinal direction of the aircraft...
s, with fabric covering. The aircraft was designed to give the pilot the best possible forward view, with a transparent panel built into the cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
floor.
The SM.85's useful payload was 1,150 kg (2,540 lb), including the possibility of fitting a 12.7 mm (0.5 in) machine gun with 300-500 rounds. The aircraft was capable of also using its flap
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
s as airbrake
Air brake (aircraft)
In aeronautics, air brakes or speedbrakes are a type of flight control surface used on an aircraft to increase drag or increase the angle of approach during landing....
s for diving attacks, a notable characteristic of this aircraft. The bombload was carried in a parallelogram-shaped section mounted under the fuselage. The SM.85 was capable of carrying a 500 kg/1,100 lb bomb (or an 800 kg/1,760 lb bomb, the heaviest weapon in the Italian aviation arsenal, but only on very short range missions).
At maximum payload, with a 4,000 kg (8,820 lb) takeoff weight, the climb rate was 20 min to 5,000 m (16,400 ft), but freshly started engines did not produce their theoretical maximum power and the aircraft was usually much slower than this. The takeoff needed 433 m (1,421 ft), and the landing 415 m (1,362 ft). Ceiling was 6,000-6,500 m (19,690-21,330 ft) and 756–827 km (470-514 mi) range. Maximum speed was 367 km/h ( mph) at 4,000 m (13,123 ft). The fuel capacity was 1,078 L (285 US gal), contained in four self-sealing fuel tank
Self-sealing fuel tank
In aviation, self-sealing fuel tank is a fuel tank technology in wide use since World War II that prevents fuel tanks primarily on aircraft from leaking fuel and igniting after being damaged by enemy fire....
s. At the maximum payload with a 500 kg (1,100 lb) bomb, it was incapable of taking off with a full fuel load (around 730 kg/1,610 lb), so this was used only on ferrying missions.
The first prototype was tested in December 1936, and in spite of its insufficient speed and the disappointing rates of climb, the Regia Aeronautica felt there was sufficient room for development and ordered the SM.85 into production. Despite some improvements, critical deficiencies continued to be experienced during test flights by the Reparto Sperimentale Volo a Tuffo. These revised aircraft were disappointing as dive bombers in almost every aspect, with the most serious problems encountered being frequent uncontrollable spins, extremely slow climb rate after a dive, and instability during the dive.
Production of the aircraft was halted, and the 34 produced up to that time were organised as 96° Gruppo Tuffatori (96th Independent Dive-Bomber Group).
Operational history
In June 1940, 96° Gruppo Tuffatori was relocated to PantelleriaPantelleria
Pantelleria , the ancient Cossyra, is an Italian island in the Strait of Sicily in the Mediterranean Sea, southwest of Sicily and just east of the Tunisian coast. Administratively Pantelleria is a comune belonging to the Sicilian province of Trapani...
, a small island off Sicily
Sicily
Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...
, in anticipation of attacks on Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
and the British Mediterranean fleet. The commander of the group, Maggiore Ercolano Ercolani, made it clear to the General Staff that in combat the performance of the aircraft was such that it would result in 100% losses. In order to prove his assertion, Ercolani volunteered to fly the aircraft himself.. These aircraft still didn't suffer any losses until the transfer to Pantelleria, when one of them crashed to a wall, killing the pilot. The others carried out a few missions over the Mediterranean until the end of July, but were never involved in real combat.
The aircraft was soon withdrawn from service and scrapped, and the Regia Aeronautica was obliged to acquire Junkers Ju 87s from Germany which were rapidly introduced into service by the end of summer 1940. The differences in speed and other characteristics between the two aircraft was not great, apart from the availability of a rear gunner, but the Ju 87 was much more effective as a combat aircraft.
Variants
SM.85- 34 production aircraft (including prototypes). There were two prototypes, 10 of the B version (with smaller engine cowling rings) built in March 1939, and 22 model Cs, fitted with a "San Giorgio" reflector gunsightReflector sightA reflector or reflex sight is a generally non-magnifying optical device that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view...
and with provision for a 7.7 mm (0.303 in) or 12.7 mm (0.5 in) machine gun. They were built in July-December 1939 (MM 21689-21707 and 21847-21849). The limited production resulted in a curtailing of further type development.
SM.86
- Derived from the SM.85, it first flew on 8 April 1939 fitted with 447 kW (600 hp) Walter Sagitta inline engines of Czechoslovakian manufacture. This was a totally new aircraft, only marginally similar to the previous SM.85. The specifications included: wing area 30.8 m² (331.5 ft²), length 10.9 m (36 ft), height 3.35 m (11 ft), wingspan 14 m (46 ft), weight 3,300 kg (7,275 lb) empty, and payload of 1,720 kg (3,790 lb), which was around 50% higher than the SM.85 and enough to carry all the fuel and bombs together. The performances of the SM.86 included a speed of 412 km/h (256 mph) at 4,000 m (13,120 ft), 336 km/h (209 mph) cruise speed at 5,000 m (16,400 ft), climb to 4,000 m (13,120 ft) in 14 min 17 sec.
It was remarkably similar to the Henschel Hs 129
Henschel Hs 129
The Henschel Hs 129 was a World War II ground-attack aircraft fielded by the German Luftwaffe. Its nickname, the Panzerknacker , is a deliberate pun—in German, it also means "safe cracker"...
in appearance, weight, and performance; their roles were different, the SM.86 having neither heavy armour nor cannons for ground attack (there were some similarities to the de Havilland Mosquito
De Havilland Mosquito
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...
in that the SM.86 also utilized a small forward cockpit, inline engines, high mounted wing, and wooden construction).
The SM.86 was evaluated at Guidonia
Guidonia Montecelio
Guidonia Montecelio is a town and comune in the province of Rome, Lazio, central Italy.- Geography :The community of Guidonia Montecelio lies to the north-east of Rome, some kilometres from the Grande Raccordo Anulare - a ring-shaped motorway which forms a circle around the capital...
in 1939, but in April 1940, an order for 97 of them was cancelled, despite the necessity to equip a wing with dive bombers. Although the SM.86 showed an overall improvement in performance, only one was eventually built. It was used over Malta and Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, because Savoia-Marchetti hoped to receive a contract for this new aircraft. Even though the test aircraft was downed (by a Ju 87), the aircraft project was continued despite the lack of any official interest until 1941, when it was terminated. A second prototype powered by 403 kW (540 hp) Isotta-Fraschini Gamma engines flew in August 1941. The development of the aircraft was abandoned soon after.
In any case, this new aircraft didn't compare well with the Ju 87's capabilities, even with a new set of airbrakes, flaps and other improvements (but also hampered by the addition of a new cockpit that provided poor rear and side vision for the pilot). The only marginal advantage compared to the Ju 87 was the twin-engine configuration, but the limited power of each engine was not enough to assure a return home if one of these was disabled. The air-cooled design allowed for the elimination of radiators and their vulnerability (with an improvement on aerodynamics, cost and weight), but at low speed and with a limited airflow, overheating was always an issue for this type of engine. The SM.86 was 32 km/h (20 mph) faster than the Junkers Ju-87B and even 2 km/h (1.2 mph) faster than the Ju 87D, but these differences, when compared to opposing fighter's speeds, were minimal. Without a good field of view all-around, and without the second crewmember in the cockpit armed with a defensive machine gun (nor a forward-firing weapon), the SM.86 was clearly more vulnerable to enemy fighters than the Junkers.
Although the SM.85 programme could be viewed as Savoia-Marchetti's worst mistake in wartime, this dive bomber was considered a threat by the British. They considered the possibility of suicide missions made with this aircraft against their ships, having mistaken the meaning of tuffatori.
The SM.85 was essentially made into a "training
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...
dive-bomber" as it was never really suited to being an operational machine. Its engines were not powerful enough to achieve a satisfactory performance, and even when the SM.86 was developed, with much improved engines, it was too late. One SM.85 was, however, modified into a two-seat trainer version. This was developed within a programme that lead to the advanced SM.93, another interesting and unusual aircraft, with high-speed performance and a prone pilot position. Development began too late to be put into production, as with almost all other Savoia-Marchetti "series 90s" projects. In retrospect, the SM dive bombers were a failure.
Operators
Kingdom of Italy (Napoleonic)
- Regia AeronauticaRegia AeronauticaThe Italian Royal Air Force was the name of the air force of the Kingdom of Italy. It was established as a service independent of the Royal Italian Army from 1923 until 1946...
- 96° Gruppo Tuffatori