After leaving SS Schetinin and creating his new experimental factory, DP Grigorovich managed to obtain a contract for the construction of 40 training flying boats with Le Rhône engines of 110 and 125 hp. In general, they were Grigorovich/Schetinin M-5 hydros with minor changes in their construction, which is why the contract originally called the airplanes M-5, but when production began they would begin to be delivered as M-20s (Russian: Григорович М-20), to differentiate them from the copies built at the Schetinin factory.

The M-20 was generally similar to the M-5 flying boat, itself a development of earlier models with better hull hydrodynamics and modifications to the tail section for greater efficiency.

From the constructive point of view, the M-20 presented a typical design. The structure was made of ash covered with 3 mm plywood on the edges and 5 – 6 mm on the bottom. 10 mm plywood was used in the recess area. The internal structure was made up of frames with diagonal reinforcement supports in certain areas. Joints in the hull skin were reinforced by plywood plates fixed with copper rivets from the inside. In the lower outer area of the hull, the joints were covered with 0.3 mm copper sheets and soldered together with tin. On the outside the wood coating was covered with varnish and on the inside with pitch.

The construction of the wings, the stabilizer and the keel of the vertical empennage was made of pine wood. The elevators and rudders were built from a light structure of thin-walled steel tubes (30×28 and 20×18 mm) with some wooden ribs and fabric covering. The M-20 simplified the number of guy wires between the supports and the upper flange.

The wing featured a double spar structure, built from I-profile pine pieces with holes to save weight. The wing ribs were made from 20 x 5 x 5 mm pieces of plywood, also lightened by perforations. Its wing profile was extremely thin (4% chord bristle). The interplane supports were made of wood and the cross tensors were made of 5-8 mm cables.

Behind the cabin, the hull became little more than a trapezoidal section stringer with the narrowest face upwards, on which the characteristic drift and rudder assembly was located. The horizontal plane of the tail was raised to distance it from the effect of the water by means of a pyramidal structure of steel tubes and tension cables.

As a power plant, the M-20 used Le Rhône engines of 110 and 125 hp, which were installed in a steel tube structure fixed to the central supports of the wing box. The main fuel tank was located in the hull, behind the cockpit.

Pilot and student were accommodated side by side in an open cabin, located immediately in front of the wings.

In the middle of 1917 the tests of the first copy equipped with a 125 hp engine were carried out and the results obtained resulted in the confirmation of the original production contract. On March 31, 1918, the Grigorovich factory was nationalized and destined for the production of agricultural aggregates, so the engineer went to Sevastopol and only in 1920 would he return to Moscow to renew his work as an aeronautical constructor.

The production of the model went 1917 to 1920, ending with close to 80 copies at the 1917 price of 16,000 rubles.

In October 1919 a special commission chaired by NN Polikarpov studied the possibility of transferring the production of the M-20 flying boats to the Tverskoi Wagon Factory and later to the Duks factory in Moscow. The lack of experience in shipbuilding did not allow to develop this idea

Most of the M-20 units participated in the Civil War on the side of the reds. These flying boats flew in the Baltic, Caspian Sea, Volga, Dnieper and North Dvina rivers. As armament some copies carried a machine gun located on a tripod in front of the cabin on the right and bombs of up to 32 kg. Some survived until the mid-1920s.

М-20
Powerplant: One 120 hp Le Rhône
Upper plane wingspan: 13.62 m
Wing area: 37.96 m²
Length: 8.22m
Empty weight: 660kg
Flying weight: 960kg
Fuel and oil weight: 124 kg
Maximum load capacity: 300kg
Wing loading: 25.3 kg/m²
Power Load: 7.1kg/hp
Speed at sea level: 115km/h
Ceiling: 3500m
Time to 1000m: 9min
Time to 2000m: 22min
Endurance: 4 hr
Accommodation: 2

With the beginning of the First World War in Russia, the Army and the Fleet were forced to develop their own research and development units where the prototypes were designed, the production documentation was developed and the experimental units were manufactured, which would later be presented to the national industry in search of a candidate for production. With this objective, it was proposed to create in 1918 the Kherson centers for the Army and the Grebni port center for the Navy. Both institutions would be developed from state funds and rapid results were expected from them.

DP Grigorovich soon understood the situation and decided to offer his services to the Navy, proposing the creation of a specialized construction bureau and an experimental factory for the development of flying boats. The request for support from an experienced engineer was welcomed by the military and soon Grigorovich, who was already 33 years old at the time, was able to count on the necessary material resources to become independent and be able to carry out his ideas independently. SS Schetinin for his part, freed himself from the development. The Navy also gained from the real possibility of presenting real results in the short term and somehow demonstrating to the authorities that the decision to provide it with its own engineering facilities had not been simply another waste of money.

On June 1, 1917 Grigorovich ended his working relationship with SS Schetinin. Grigorovich received bank loans with low interest rates that allowed him to lease some facilities to organize an experimental factory and an empty building belonging to the Ismailovski regiment, at 12 Rota, Building 26. As an aid to be able to make the loan payment, the new facility received an order for the construction of 40 M-5 flying boats (later M-20), which was signed on July 28, 1917 with deliveries scheduled for the period between September 1, 1917 and January 1, 1918. The price of each unit was set at 16,000 rubles. In parallel Grigorovich received requests for the development of several experimental models.

Dmitri Pavlovich designed the flying boat that received the 17th consecutive in the series of naval models (Russian: Григорович М-17), obtained as a development of the M-11 fighter with a 130 hp Clerget engine. The second prototype, slightly modified, would receive the designation M-17bis.

For different objective reasons, the two M-17 copies would only be finished in 1918. The tests of the model began on September 26, 1918 and showed the same problems of the basic model M-11 among which the negative influence of the rotary engine and poor seaworthiness stood out. Despite not successfully testing as a fighter, both the M-17 and M-17bis entered service with the Baltic Sea Fleet, where they remained for some time.

According to VB Shavrov, the M-17 was equipped with the 150 hp Hispano-Suiza engine and several copies were built that served with the Baltic Fleet and between 1921 and 1922 even in the Black Sea. In November 1917 the M-17bis with a 130 hp Clerget engine would appear.

M-17
Power plant: Clerget, 130 hp
Wingspan: 8.80m
Length: 7.60m
Empty weight: 680kg
Normal takeoff weight: 940 kg
Top speed: 155km/h
Cruising speed: 135km/h
Accommodation: 1

Pilot Nagurski’s flights in a Maurice Farman MF.11 model to the Arctic in 1914 showed that floats could serve not only to land on water, but also on ice and snow. With the M-11 Grigorovich had shown the possibility of installing skis on flying boats, but the performance was affected in such a way that the need soon arose to create a model capable of operating during the time when the waters froze in the north ocean seas.

Dmitri Grigorovich began work on the M-16 model between August and September 1916 (it could be a little earlier). Naval pilots needed a “winter” model, capable of operating on the frozen and snow-covered surfaces of the Baltic Sea.

With the war, the Navy was involved in multiple tasks, generally operational, so they could pay very little attention to channelling the interests. The Department of Aeronautics of the Naval General Staff (MGSh) could do little burdened with bureaucratic tasks. Under these conditions, the builders of the aeronautical factories began to define what type of naval aircraft to project, assuming that they would cover the needs of the military. The owners of these factories, on multiple occasions, worked on account and at risk. Military experience and engineering thought were divorced, but this procedure would constitute the seed for the development of an experimental aviation program.

On September 20, 1916 at a meeting attended by representatives of naval aviation, the aeronautical departments of the MGSh and GUK and representatives of factories (BP Dudorov, AA Tuchkov, IN Dmitriev, DP Grigorovich, Yu. A. Brezhniev and AN Tupolev) future requests for naval models were discussed. Those present defined the technical task for the projection of the winter model. This airplane had to have the ability to land on water, ice and snow with a landing speed of no more than 75 km/h. The maximum speed was to exceed 100 km/h.

Schetinin promised to have such a plane ready by mid-October. This model was the Grigorovich M-16 (Russian: Григорович М-16), although it is also known as Sch M-16 or Schetinin M-16, being one of the last works of Grigorovich before becoming independent to his own factory.

The M-16 was a single-engine biplane with a short crew gondola supported between the planes by a system of struts.

The wing, similar in construction to that of the M-9 model, was characterized by having a large area. The wing featured an unequal span and three sections supported and braced by tension cables.

Two flat-bottomed floats without grooves with a large support surface, necessary to operate on snow, were attached to the lower plane. Each float weighed about 77 kg, to which must be added a third very wide unit located under the tail region and weighing 8 kg.

The tail unit featured a single yoke and rudder assembly; Although similar in general configuration to that of the M-15 flying boat, the new aircraft’s rudder extended behind the horizontal planes, and the stabilizers were supported by four spars from the wings.

The central gondola, Farman type, accommodated the crew located in tandem, the instrumentation, the machine gun and the fuel. Aft of the gondola was a 150 hp Salmson liquid-cooled radial engine driving a two-blade propeller, with radiators located on the sides of the gondola.

Defensive armament consisted of a Lewis, Maxim, or Vickers machine gun located forward on a movable mount and operated by the spotter. The M-16 could carry up to 100 kg of small bombs.

On November 6, a naval commission participated in the factory tests of the M-15 and M-16 prototypes (with factory number 1080). The M-16 with a payload of 350 kg was capable of reaching 500 meters in 6.5 minutes, which was considered enough for a firm request for the construction of 40 examples to be made a couple of weeks later.

At the beginning of December, the first M-16 (it could be the prototype) was delivered to the Third Naval Station in Revel and received the registration ZS-1. On the 13th, piloted by Prokofiev-Severski, he managed to survive an accident about which the captain of the first rank BP Dudorov has left us evidence in a communication issued to the MGSh:
“Today during a race on the water after ditching, the M-16 winter aircraft broke the gondola stringers at the engine mounting site, which ended up falling off. Fortunately, everything ended without consequences. I request to stop all construction work on the “winter” apparatus and urgently send engineer Grigorovich to Revel to investigate the causes of this accident.”

Only two days later, Dudorov would recall his request again, since the situation had become extremely complicated due to the impossibility of flying the flying boats due to the winter frost.

On December 16 and with the presence of Grigorovich, the commission of naval aviators reviewed the plane and came to the conclusion that it would be necessary to raise the engine installation by lengthening the float supports and reinforcing the rear amortization system. of both units. It was also proposed to reinforce the entire engine installation system. For this, the rear supports had to be reinforced, adding new steel parts.

Everything seems to indicate that these recommendations were heeded and brought positive results, since in subsequent tests there were no problems with fixing the motors.

Another interesting detail is that on December 30 Military pilot Captain Grigorov, who at that time was studying at the Nikolayevsk Military-Aeronautical Academy, proposed to the Navy to test a self-designed fuel tank protection system on the M-16. Shortly before the war this officer had designed a protection system by coating the tanks with a layer of rubber that was considered cheap and effective and the M-16 greatly needed this system because the fuel tank was located in the nacelle, in front of the engine, so that in the event of a small fuel leak, the proximity to the hot engine could turn into a fire. It is not clear if this system was actually used on the plane, but there is evidence that protections of this type were prepared in the Russian-American Society “Triugolnik” based in Petrograd.

Based on the results of the first month of operation of the M-16, in January 1917 a list of requests for improvements in the construction of the model was delivered to the factory. In addition to the increase in the rear of the floats, the military requested to locate a transparent hatch in the floor of the gondola and the installation of steps that would allow the crew to occupy their positions, to locate a windshield in front of the pilot and to install on the left side a bombardment collimator designed by Senior Lieutenant SA Lishin. It was also requested to move the compass position and install an artificial horizon, as well as the installation of removable supports for bombs to be placed under the gondola and the wings.

The pilots highlighted a strange behaviour of the model from the elevators. When pulling the stick rearward, the plane initially did not react, but when the stick reached a certain position the plane “jumped” upwards. The same thing happened during the descent. It was pointed out that with a full tank and without a passenger, the model behaved quite well, but when the tank emptied a little or was carrying the weight of another person, there was a tendency for the plane to lower its nose, forcing the pilot to maintain constant pressure on the nose.

The initial production contract included a request for 40 complete examples, 10 without motors to be used as spare parts and an unspecified number of float sets. Production started from the end of 1916. In general, the Schetinin factory produced 36-40 examples.

Contract date: November 24, 1916
Number of copies: 40+10 spare without motor
Serial numbers: 1201-1232, 1242-1245
18,000 rubles per unit with a 150-hp Salmson engine and 17,700 for spare ones. 3150 rubles for each additional set of floats. Expected deliveries from December 10, 1916 to February 1, 1917.

Contract date: January 30, 1917
Number of copies: 1
Serial numbers: 1080
Contract for the purchase of the prototype

Between November 6, 1916 and July 1917 the Baltic Sea Fleet received at least 36 examples of the M-16. These planes were used primarily as scouts and patrol planes. The model became known to the military as ZS (Zimni s Salmsonom or Invernal con Salmson) and military registrations featured these letters and a consecutive number (ZS-1, ZS-2, etc).

At least one example was severely damaged during a fire on the night of January 6-7, 1917, and another was totally destroyed. The numbers of these were 1205 and 1206. By mid-1917, according to reports in the Baltic Sea Fleet, 15 were registered.

The Black Sea aviation did not need the “winter” models due to the climatic conditions in the area of operations.

Six M-16s fell into Finnish hands during the Russian Civil War. After the abandonment of Revel by the Russian troops, six M-16 in perfect condition went to Finland, where they were exploited for several years until being decommissioned around 1923.

The first Finnish parachute jump was done on June 17, 1922 from a M-16 by a parachuter named E. Erho. The aircraft were flown until 1923.

By May the Baltic winter campaign was over. The mechanics replaced the alcoholic coolant in the engines with a normal type and on the 22nd of that month, officer G. Ya, Erdeli received the order to prepare six M-16 units with wheels, but there is no evidence that this was done, nor does any evidence support VB Shavrov ‘s assertion that during winter operations some M-16s replaced their floats with skis.

In the summer of 1917 the head of the 6th Baltic Sea Air Division, Lieutenant AI Makarevich, modified one of the M-16s in order to improve its performance. The changes were made at the base of the division’s 2nd Brigade based at Abo and as a result the officer hoped to achieve a normal wheelset. Unfortunately this officer would never get to see his finished design. The winds of revolution reached Abo, discipline cracked and Makarevich’s authority degraded to such an extent that the Naval Aviation Command decided to reform the unit. The order came on July 18, but its execution was delayed and by the 30th the sailors, gathered between the hangars, assassinated Makarevich.

By mid-November, however, it was finished in the local workshops and prepared for testing. Apparently, the results were positive, since by the beginning of December at least three M-16 copies had been modified. Foreign intervention and the Civil War that followed erased practically all the evidence and for this reason no data on this project was preserved. Presumably without the heavy floats and their bracing structure the modified M-16 performed better.

With the arrival of the winter of 1917-1918 military activity in the Baltic area practically disappeared, the M-16 was used mainly in reconnaissance and liaison missions. For the summer campaign the model was totally obsolete, being able to be used only as a bomber.

Operators:
Estonian Air Force
Finnish Air Force
Imperial Russian Navy
Soviet Naval Aviation

Specifications:
M-16
Engine: 1 × Salmson, 150 hp
Wingspan: 18.0 m
Wing area: 61.8 sq.m
Length: 8.60 m
Empty weight: 1,100 kg
Max. takeoff weight: 1,450 kg
Full load capacity: 350kg
Fuel and oil capacity: 185 kg
Wing loading: 23.5 kg/ m²
Power Load: 9.7kg/hp
Maximum speed: 130 km/h
Speed at sea level: 110km/h
Cruising speed: 92km/h
Service ceiling: 3,500 m
Time to1000m: 15min
Time to2000m: 40min
Endurance: 4 hr
Crew: 2
Armament: 1x MG
Bombload: 100 kg