The Savoia-Marchetti SM.78 was an Italian

bomber A bomber is a military combat aircraft that utilizes air-to-ground weaponry to drop bombs, launch aerial torpedo, torpedoes, or deploy air-launched cruise missiles. There are two major classifications of bomber: strategic and tactical. Strateg ...

reconnaissance In military operations, military reconnaissance () or scouting is the exploration of an area by military forces to obtain information about enemy forces, the terrain, and civil activities in the area of operations. In military jargon, reconnai ...

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

flying boat A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy. Though ...

of the early 1930s.

Development

The SM.78 first flew at the end of 1932, designed for the role of

maritime reconnaissance Maritime patrol or maritime reconnaissance is the task of monitoring areas of water. Generally conducted by military and law enforcement agencies, maritime patrol is usually aimed at identifying human activities. Maritime patrol refers to active ...

-bomber. It was one of the many flying boats made by SIAI (

Savoia-Marchetti SIAI-Marchetti was an Italian aircraft manufacturer primarily active during the interwar period. History The original company was founded during 1915 as SIAI (''Società Idrovolanti Alta Italia'' – Seaplane Company of Upper Italy). As sugge ...

), that in 1915 had started building foreign aircraft under licence, followed two years later by the first of its own designs. The SM.78 was developed from the SM.62bis. The

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototype ...

, which carried the serial number ''MM222'', made its first flight late in 1932Donald 1997, p. 823. and then transferred the next year to Vigna di Valle for evaluation. The SM.78 was the last biplane flying boat, built or used in large numbers by Italy; 49 were completed in all (32 by Piaggio and 17 by SIAI).

Technical description

The SM.78 was a single-bay biplane. It had a long and slim aft

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

, with a tall welded steel fin and a wooden horizontal tail mounted centrally. The lower hull had two steps, to aid take-off from the sea. This aircraft evolved from the SM.62bis, retaining practically the same unmodified wings, tail and fuselage, but with a different model of

Handley Page Handley Page Limited was a British aerospace manufacturer. Founded by Frederick Handley Page (later Sir Frederick) in 1909, it was the United Kingdom's first publicly traded aircraft manufacturing company. It went into voluntary liquidation a ...

flap Flap may refer to: Arts, entertainment, and media * ''Flap'' (film), a 1970 American film * Flap, a boss character in the arcade game '' Gaiapolis'' * Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland'' Biology and h ...

s. The hull/fuselage had poplar frames, and

longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...

s made of

ash Ash is the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the ...

. The

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

-skinned hull had a double-layered bottom, with an external layer of

cedar Cedar may refer to: Trees and plants *''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae * Cedar (plant), a list of trees and plants known as cedar Places United States * Cedar, Arizona ...

, while the flanks were made from

orthogonal In mathematics, orthogonality (mathematics), orthogonality is the generalization of the geometric notion of ''perpendicularity''. Although many authors use the two terms ''perpendicular'' and ''orthogonal'' interchangeably, the term ''perpendic ...

ly arranged laminates of cedar. The fabric-covered wings had

spruce A spruce is a tree of the genus ''Picea'' ( ), a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Northern hemisphere. ''Picea'' ...

longerons and poplar ribs, utilising the low-weight and high-strength characteristics of these woods, and were painted to render them impermeable to water. Twin stabilising floats were mounted at mid-wing. While the pilot and co-pilot were seated side-by-side in an enclosed

cockpit A cockpit or flight deck is the area, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...

in the prototype, this was replaced by an open cockpit in the production model. A crew position mounting a 7.7 mm (0.303 in) Lewis Gun was situated in the nose, which also contained two cameras. This position was manned by the co-pilot when necessary, the aircraft having a three-man crew. A second, enclosed

turret Turret may refer to: * Turret (architecture), a small tower that projects above the wall of a building * Gun turret, a mechanism of a projectile-firing weapon * Optical microscope#Objective turret (revolver or revolving nose piece), Objective turre ...

was fitted in the dorsal position, also armed with a 7.7 mm (.303 in) Lewis gun, manned by the gunner/radio operator, who was also provided with an R.A.350 transmitter and an A.R.4 receiver. The aircraft was not fitted with an intercom, but the two pilots could communicate with the nose position using a "pneumatic message" system in which messages were passed through a tube. The forward machine gun had 564 rounds of ammunition in 12 magazines, while the aft machine gun had 470 in 10 magazines. Bombs were carried in a bomb bay within the lower wing, near to the fuselage. The weapon-load was 700 kg (1,540 lb) maximum. Typical combinations were: 2 × 250 kg (550 lb) and 2 × 100 kg (220 lb) bombs, 6 × 100 kg (220 lb) bombs, 4 × 70 kg (150 lb)

depth charge A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited ...

s, or 6 × 12 kg (26 lb) training bombs. Smoke generators could also be mounted on the inner hardpoints. A "''Jozza''"

bombsight A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose-designed bomber aircraft and then moved to fighter-bombers and modern tactica ...

was located on the right in the cockpit, behind a glazed window. The aircraft was powered by a single Isotta Fraschini Asso 750 W18 engine, generating 671 kW (900 hp) at takeoff, arranged in a steel structure mounted between the two wings, driving a four-bladed propeller with variable pitch that could be set before takeoff. This, and the much refined hull of this aircraft bestowed a good performance for the time. A CO₂

fire extinguisher A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which ha ...

was mounted by the engine. A total of 2,200 L (580 US gal) of fuel could be carried in six unarmoured

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' ...

fuselage

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; ...

s, two aft, two central and two forward.

Operational history

The SM.78 was built between 1932 and 1935, with only 16 by SIAI and 32 from

Piaggio Piaggio Group () is an Italian motor vehicle manufacturer, which produces a range of two-wheeled motor vehicles and compact commercial vehicles under five brands: Piaggio, Vespa, Aprilia, Moto Guzzi and Derbi. Its corporate headquarters are ...

. It equipped the 141° ''Squadriglia'', based at

La Spezia La Spezia (, or ; ; , in the local ) is the capital city of the province of La Spezia and is located at the head of the Gulf of La Spezia in the southern part of the Liguria region of Italy. La Spezia is the second-largest city in the Liguria ...

, the 144° based at

Livorno Livorno () is a port city on the Ligurian Sea on the western coast of the Tuscany region of Italy. It is the capital of the Province of Livorno, having a population of 152,916 residents as of 2025. It is traditionally known in English as Leghorn ...

, the 182° at

Nisida Nisida is a volcano, volcanic islet of the Flegrean Islands archipelago, in southern Italy. It lies at a very short distance from Cape Posillipo, just north of Naples; it is connected to the mainland by a camera-enforced 1km-long pedestrian zone. ...

and the 189° at

Syracuse Syracuse most commonly refers to: * Syracuse, Sicily, Italy; in the province of Syracuse * Syracuse, New York, USA; in the Syracuse metropolitan area Syracuse may also refer to: Places * Syracuse railway station (disambiguation) Italy * Provi ...

. It continued to serve until 1938, being replaced by the CANT Z.501, a

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

design with superior performance. Some aircraft remained in service during the early phase of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, performing in an air-sea-rescue capacity.

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

, which already operated SM.62s, tried unsuccessfully to acquire a licence to build the SM.78, leaving Italy as the only operator.

Operators

; *

Regia Aeronautica The Royal Italian Air Force (''Regia Aeronautica Italiana'') (RAI) was the air force of the Kingdom of Italy. It was established as a service independent of the Regio Esercito, Royal Italian Army from 1923 until 1946. In 1946, the monarchy was ...

Development

Technical description

Operational history

Operators

Specifications (SM.78)

See also

References

Further reading