In 1922 and after a break of 5 years DP Grigorovich returned to aircraft construction with the development of more powerful versions of the successful Grigorovich/Schetinin M-9. Grigorovich considered that for a more powerful engine it would be necessary to increase the structural rigidity, which would entail a reinforcement of the fuselage and the need to modify the lines of the hull, but despite this he decided to continue the development of the already recognized model with the main objective to be able to interest new customers and quickly secure a new position in the aeronautical industry.
At that time, Grigorovich had not yet been able to put together a work team and lacked the facilities to develop it, so the design work began in his apartment in Moscow. He would soon invite old collaborators to his side, among them the engineers MM Shishmariov, Ye. I. Mayoranov and V. L. Korvin-Kerber.
The M-23 (Russian: Григорович М-23) was an interim development of the M-9 line with a new power plant. The initial model project was completed by mid-1923 but was soon abandoned in favour of a modified version designated M-23bis.
The M-23bis was built at the GAZ No.3 “Krasni Liotchik” in Petrograd in the middle of the summer of 1923. During the tests the model refused to take off from the water. The analyses showed that it was a design error of the bow and contour lines of the hull, so the flying boat was stored pending the necessary modifications, but at the end of the year it was destroyed during a flood that occurred in the hangars on Krestovsky Island.
M-23bis
Power plant: 1 Fiat, 280 hp
Wingspan: 12.5m
Wing area: 45.8 m²
Empty weight: 1165 kg
Takeoff weight: 1615 kg
Total load capacity: 450 kg
Wing loading: 35.0 kg/m²
Power Load: 5.8kg/hp
Accommodation: 2
All Aero 