The Piaggio P.IX, or Piaggio Stella P.IX, was an Italian nine-cylinder radial aircraft engine produced by Rinaldo Piaggio S.p.A. Based on the Gnome-Rhône 9K, the engine was rated at . Production was used to power a number of other aircraft developed in Italy. The main users were the

Savoia-Marchetti SM.81 The Savoia-Marchetti SM.81 ''Pipistrello'' (Italian: bat) was the first three-engine bomber/transport aircraft serving in the Italian ''Regia Aeronautica''.Angelucci and Matricardi 1978, p. 188. When it appeared in 1935, it represented a real s ...

transport and the IMAM Ro.37bis, the main reconnaissance aircraft in the

Regia Aeronautica The Italian Royal Air Force (''Regia Aeronautica Italiana'') 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. In 1946, the monarchy was abolis ...

during the

Second Italo-Ethiopian War The Second Italo-Ethiopian War, also referred to as the Second Italo-Abyssinian War, was a war of aggression which was fought between Italy and Ethiopia from October 1935 to February 1937. In Ethiopia it is often referred to simply as the Itali ...

Spanish Civil War The Spanish Civil War ( es, Guerra Civil Española)) or The Revolution ( es, La Revolución, link=no) among Nationalists, the Fourth Carlist War ( es, Cuarta Guerra Carlista, link=no) among Carlists, and The Rebellion ( es, La Rebelión, lin ...

and

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, but the engine was also used by other designs, including the prototype

Savoia-Marchetti SM.79 The Savoia-Marchetti SM.79 ''Sparviero'' (Italian for sparrowhawk) was a three-engined Italian medium bomber developed and manufactured by aviation company Savoia-Marchetti. It may be the best-known Italian aeroplane of the Second World War. Th ...

Design and development

Piaggio acquired a license from

Gnome et Rhône Gnome et Rhône was a major French aircraft engine manufacturer. Between 1914 and 1918 they produced 25,000 of their 9-cylinder Delta and Le Rhône 110 hp (81 kW) rotary designs, while another 75,000 were produced by various licen ...

in 1925 for their engines derived from the

Bristol Jupiter The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments turn ...

and, in 1933, brought out a developed version, created under the direction of engineer Renzo Spolti. The engine had nine cylinders and was therefore named P.IX. It was one of a range of Piaggio radial engines named Stella, or Star, all based on the same radial design. The engine had cylinders that had steel barrels and aluminium

heads A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...

. Aluminium alloy

piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...

s were connected to a split

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

via articulated

connecting rod A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksh ...

s. The valves were enclosed. Each cylinder retained the same bore and stroke as the Gnome-Rhône 9K, and respectively. However, it was more powerful and was rated at when fitted with a

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

. The engine was used to power aircraft that served during the

and

, including one hundred and forty

s, a

transport, and the majority of the production of the IMAM Ro.37bis reconnaissance aircraft. Most had retired by 1943.

Variants

;P.IX R.: Normally aspirated and geared. ;P.IX R.C.: Supercharged and geared. ;P.IX R.C.10: Supercharged and geared, rated at . ;P.IX R.C.40: Supercharged and geared, rated at .

Applications

* CANT Z.504 *

CANT Z.506 The CANT Z.506 ''Airone'' ( Italian: Heron) was a trimotor floatplane produced by CANT from 1935. It served as a transport and postal aircraft with the Italian airline "Ala Littoria". It established 10 world records in 1936 and another 10 in 19 ...

prototype * Caproni Ca.131 *

Caproni Ca.132 __NOTOC__ The Caproni Ca.132 was a prototype for a large aircraft built in Italy in 1934, intended for use as either a bomber or airliner. It was a conventional low-wing cantilever monoplane, powered by a radial engine The radial engine is ...

Caproni Ca.301 The Caproni Bergamaschi AP.1 was an Italian monoplane attack aircraft designed by Cesare Pallavicino, coming from the Breda firm. Design and development Developed from the Ca.301, a single-seat fighter version of a similar design that was not ...

Caproni Ca.305 The Caproni Bergamaschi AP.1 was an Italian monoplane attack aircraft designed by Cesare Pallavicino, coming from the Breda firm. Design and development Developed from the Ca.301, a single-seat fighter version of a similar design that was not ...

Caproni CH.1 The Caproni CH.1 was a single-seat biplane fighter, a single example of which was produced as a prototype in Italy in 1935. Design Antonio Chiodi began design work on a new single-seat fighter in 1934 as a private venture of the Caproni compa ...

* IMAM Ro.37bis *

IMAM Ro.43 The IMAM Ro.43 was an Italian reconnaissance single float seaplane, serving in the Regia Marina between 1935 and 1943. Design and development The Ro.43 was designed to meet a 1933 requirement by the ''Regia Marina'' (the Italian navy) for a c ...

prototype * Piaggio P.10bis *

Piaggio P.16 The Piaggio P.16 was an Italian heavy bomber designed and built by Piaggio for the ''Regia Aeronautica'' (Italian Royal Air Force). Design and development The P.16 was a three-engine shoulder-wing monoplane of mostly metal construction, with inv ...

Savoia-Marchetti S.73 The Savoia-Marchetti S.73 was an Italian three-engine airliner that flew in the 1930s and early 1940s. The aircraft entered service in March 1935 with a production run of 48 aircraft. Four were exported to Belgium for SABENA, while seven others ...

prototype *

Specifications (R.C.40)

References

Citations

Bibliography

* * * * * * * * * {{Piaggio aeroengines 1930s aircraft piston engines Air-cooled aircraft piston engines P.IX