Morane-Saulnier Ms.225/226/226bis/227

The Morane-Saulnier Ms.225 family was a French fighter aircraft of the early-to-mid 1930s. It was a parasol monoplane with a fixed landing gear and powered by a single Gnome-Rhône 9Krsd nine-cylinder air-cooled radial engine which yielded 493hp of power and drove a two-bladed propeller. It was armed with two fixed forward-firing 0.303in (7,7mm) Vickers Mk.I mounted on the fuselage.
Just by having a circular fuselage, it was already more robust than its inmediate predecessor, Morane-Saulnier Ms.224.
Initially it was conceived as an interim, before more advanced aircraft types were available. The Ms.225 flew for the first in model form at the Paris Air Show in 1932 and, after the prototype flew successfully, series production started at once.
It was classified in the C.1 (single-seat fighter) category by the Armée de l'Air (French Air Force) and only a total of 75 exemplars were manufactured by Aeroplane Morane-Saulnier, in Puteaux, France. The first ones rolled out of the factory in November 1933 with 53 of them being delivered to the Armée de l'Air and the Aéronavale (French Navy's Naval Arm) received 16 of them in February 1934. Three of them were sold to China in an attempt to export the type. They were delivered to a Chinese warlord and, when defeated, the three fighters were also destroyed to prevent them to be captured.
The Morane-Saulnier Ms.225 were assigned to the 7e Escadre de Chasse (7th Fighter Wing) based in Dijon and to two escadrilles (squadrons) of the 42e Escadre (42nd Wing) based in Reims. In the Aéronavale they served in the Escadrille 3C1 which was based in Marignane. This formation would be transfered to the Air Force in early 1936, forming the Groupe de Chasse II/8.
The Armée de l'Air's acrobatic squadron used modified Ms.225s with larger vertical stabilizers and the last unit to be equipped with the Ms.225 was the Flying school of Salon-de-Provence.
When the World War 2 started, only 20 Ms.225 were still in flying condition and most of them were scrapped in mid-1940.
The Morane-Saulnier Ms.226 and Ms.226bis were two regular Ms.225 fitted with an arrestor gear so it could perform carrier operations (namely, the Béarn) and powered by a Gnome-Rhône 9Kdr engine, which was an improved version of the regular 9Krsd. The Ms.226bis was a variant of the Ms.226 equipped with foldable wings, so they could be fitted into the Béarn. Two prototypes were made with fixed wings and arrestor hook and a third one with arrestor hook and foldable wings was made. However, as the Ms.226 was heavier and slower than the Ms.225 the Aéronavale considered it as obsolete and they weren't ordered into production.
The Morane-Saulnier Ms.227 was a variant powered by a different engine. It was equipped with a single Hispano-Suiza 12Xcrs inline engine which yielded 690hp of power and drove a four-bladed propeller. This new engine allowed the installation of a 20mm cannon to be fired between the cylinder banks. Just one of them was produced and it was used as test bench for the engine and for testing the cannon-engine configuration which would later be used in the Morane-Saulnier Ms.406.

Sources:
1. https://en.wikipedia.org/wiki/Morane-Saulnier_M.S.225
2. https://forum.valka.cz/topic/view/12977
3. http://www.historyofwar.org/articles/weapons_morane_saulnier_MS225.html
4. http://www.historyofwar.org/articles/weapons_morane_saulnier_MS226.html
5. http://www.historyofwar.org/articles/weapons_morane_saulnier_MS227.html
6. Salamander Books - The Complete Book of Fighters