The Grigorovich M-7 (Russian: Григорович М-7) appears in different literary references with great contradictions, even denying their existence. Given that there is no documentary evidence to confirm which of the versions could be closer to reality, we will have to present them all referring to their main speakers.
Mijaíl Maslov, researcher and historian and author of innumerable works in relation to the M-7 writes:
The M-7, like the earlier M-6 appears to be an enlarged and unsuccessful version of the M-5 with a 150 hp Sunbeam engine. During the tests it failed to take off from the water. Modification attempts were of little help and eventually the aircraft was disassembled for spare parts.
VB Shavrov however alleges that the M-7 featured modified contours, higher tread and a wide angle keel. The takeoff was heavy but in the air the model behaved normally.
AO Alexandrov agrees with Maslov that the M-7 was originally unflyable, but tells of possible later tests in Baku.
According to Alexandrov, the M-7 was a three-seat development model of the M-7 created in the PRTV in a period between July and August 1915. A document dated September 24 is preserved where it is detailed that in a few days this three-seater model would be tested.
Apparently the decision to build the M-7 was generated as the company’s own initiative with the aim of presenting a model that would compete with the Curtiss K.
For unclear reasons, which could be due to the lack of the right engine or the terrible autumn conditions, the tests did not begin until November. On the 4th the prototype was sent to Revel, but the trip to that city took about two weeks.
SS Shchetinin considered it essential to participate personally in the development of the tests, since he had a great interest in their results. Unfortunately, her hopes were dashed when the M-7 flying boat refused to take off from the water at the end of November.
The company’s specialists kept hoping for an effective design and for this reason continued to work on the model. By mid-January 1916 the flying boat with a 150 hp Sunbeam linear V engine known as “Crusader”, was tested at the branch of the Petrograd Naval Pilot Officers School opened in Baku, on the shores of the Caspian Sea.
The results obtained with the new model M-9 led to the abandonment of attempts to continue working on the M-7. The subsequent fate is unknown.
M-7
Power plant: 1 Sunbeam 150 hp
Propeller: 3 m diameter / 2.25 m pitch
Accommodation: 3
Payload Capacity: 450kg
Calculated top speed: 95km/h
Calculated time to 2000 m: 30 min
Calculated endurance: 5 – 5.5 hours
All Aero 