Savoia-Marchetti SM.62

The Savoia-Marchetti SM.62 was an Italian single-engine maritime patrol flying boat produced from 1926. It served with the Regia Aeronautica and with a number of foreign users, and was produced in Spain and the Soviet Union. Some of the Spanish aircraft were still in service during the Spanish Civil War.

Design and development
The SM.62 flying boat was one of the main successes of Savoia-Marchetti, evolved from the SM.59 which first flew in 1925.

The single-engine, single-spar wing, wooden biplane aircraft was powered by a single Isotta Fraschini Asso 500 R.I., 373 kW engine mounted between the upper and the lower wings, and drove a pusher propeller. It had a wingspan of 15.5 m, a maximum takeoff weight of 3,000 kg including fuel, bombs and four crew, and entered production in 1926.

Apart from the two machine guns in the aft and forward fuselage, both mounted in uncovered positions, the possibility of fitting an Oerlikon 20 mm cannon was explored, but never put into service.

The progress of the project was almost continuous, and the following year saw the SM.62bis development that had a more powerful engine. This aircraft, with a 16 m wingspan, formed the basis of the future SM.78. The new 559 kW Isotta Fraschini Asso 750 engine produced 50% more power, which allowed a maximum take-off weight of 4000 kg with a maximum speed of 220 km/h, while the range was 1200 km. For those times, these were respectable performance figures for a single-engine aircraft.

The SM.62 was one of the first Italian racing- and world-record attempting aircraft, competing in the 1926 New-York to Buenos Aires air race and the 10000 km air race in northern Europe, in addition to setting the speed records of 190.537 km/h averaged over 500 km in 1926 – later augmented to 194.237 km/h – and the world records flying 500 km while carrying 500 kg, and finally 100 km (60 mi) and 500 km with 1000 kg.

This was the most successful Italian flying boat outside Italy, with at least one being acquired by Japan for its naval aviation service, several by Romania, and 40 by Spain, some of which were license-built. The USSR acquired the license to construct the SM.62bis in Taganrog plants as the MBR-4, with many examples built.

Romania also acquired the license to construct the SM.62bis, at the IAR factory in Brașov. Five such flying boats were produced in 1936.

Despite their obsolescence, several Spanish examples fought in the Spanish Civil War. Since the aircraft of those times were not capable of great speeds, several were used at the Desenzano "high-speed flying school" in Italy, as well as continued to serve as reconnaissance bombers. The next derivative, the SM.78, with over a ton more weight and 20% more power; could carry a greater fuel load, effectively doubling the range; and was slightly faster than the SM.62bis.

Variants

 * SM.62:1926
 * SM.62P:Civil version.
 * SM.62bis:1927, powered by a 559 kW Isotta Fraschini Asso 750 W-18 engine.
 * SM.62ter:
 * MBR-4: Soviet production of the SM.62bis at Taganrog

Operators

 * Kingdom of Italy
 * Regia Aeronautica
 * Imperial Japanese Navy Air Service
 * Royal Romanian Naval Aviation (11 units)
 * 🇪🇸 Spain
 * Spanish Republican Air Force
 * Spanish Air Force – Post civil war.
 * Soviet Naval Aviation
 * Spanish Air Force – Post civil war.
 * Soviet Naval Aviation
 * Soviet Naval Aviation
 * Soviet Naval Aviation