August 6, 1925 at the Leningrad airplane factory GAZ №3 under the leadership of one of the directors of the Board Aviatresta IK Hamburg meeting was held on the activities of the design bureau Grigorovich and implement a three-year plan for the construction of prototype. We considered the following types of aircraft:
1. I-7 (I-2) — 1 series.
2. MRL-1 — 1 series.
3. Aircraft Ukrvozduhput (SUVP).
4. I-7 (I-2) — 2nd series, 10 copies.
5. Marine fighter base with motor «Napier» (min-1).
6. Naval destroyer (MM).
7. Scout seas (POM).
8. Deck (ship) fighter (PI-1).
9. catapult reconnaissance (C-P).
10. Alteration of training boats of M-5.
From this extensive list of planned activities to the practical implementation has not reached half the vehicles. Ship engine fighter with «Liberty», several options naval intelligence with folding wings, metal floats to the I-2bis — all of these projects have remained unfinished. However, doubts about the reliable implementation of planned already expressed almost immediately, including on the above meeting. It was said in particular that numerous types of aircraft required the command of the sea, do not match the capabilities of the design bureau, primarily — the presence of educated and trained professionals.
In November 1925, the leadership of the Air Force acknowledged that the situation of naval aviation in the USSR heavy, «it is now unfit for combat» because of the lack of modern seaplanes.
With regard Grigorovich (report of 10 November 1925 in the number of PBC 3601 cc) stated: «From domestic designers only engineer Grigorovich has experience in building gidrolodok, but two of his last gidrokonstruktsii proved unsatisfactory, because without a thorough laboratory testing now Good design can be given. «
Meanwhile, at the initiative of Grigorovich in November 1925, at the GAS №3 already started the design and construction of the second instance scout SCLC. The guide
Aviatresta while outraged amateur designer, however, included in this new plan boat industry for years 1925-26. under the designation MRL-2 (improved MRL-1). Initially, the plane is also assumed by the engine «Liberty», but later used the engine «Lauren Dietrich,» with which it was completed on 18 June and manufacturer brought to the test in September 1926, overall dimensions are slightly larger than MRL- 7. The plane had much less of overweight in the siding, riveted aluminum rivets. «
Flying boats SCLC-2, for which the designation has been used as the MR-2, examined the Commission in the following composition: from UWS II Mashkevich, EK Stoman from plant №3 DP Grigorovich, VL Corwin. Members of the Commission recorded that the first instance of the aircraft is different form the wings, improved contours of the boat, the engine is well closed streamlined hood moved back back Rifle installation.
The first flight of the MR-2 lasting 15 to 17 minutes, took place September 22, 1926 Ahead sat Grigorovich, piloted Mel’nitskii next to him on the right seat located Corwin. On the same day the second flight, AS Mel’nitskii, and again with the passengers: a mechanic and engineer Funtikov Wiegand. The third flight performed representative PLA pilot VN Philip, who noted the long run is on the rise, unstable regime in level flight and planning. However, the overall assessment stated that handling and lateral stability MR-2 is better than the MP-1, and longitudinal stability worse. This longitudinal instability of the MR-2 was the cause of the accident pilot FS Rastyagaeva, which occurred October 19, 1926
Rastyagaev was a naval aviator, and previously flew the flying boats, but it was invited to Moscow for the first phase of state testing.
October 18, he made a training flight with a pilot factory Zhukov on the flying boat MOORE (M-5 engine with «Ron» 120 hp), and then left alone.
In his opinion, nothing special maritime piloting the aircraft did not have «no problems and no difference.» October 19 Rastyagaev took off, circled over the bay, and then made a steep planning (or so it has turned out), and then followed by another plan, noted by observers on the ground. Next MR-2 went into a dive, I rolled over and fell into the water at the shallow depth of half a meter to the seaward wall of the western Kronshpitsa (at the output port of the ridges at the Vasilyevsky Island). Rastyagaeva recovered from the wreckage of the aircraft with multiple wounds. On the night of his injuries he died. Emergency Committee under the chairmanship of NM Tulupova initially concluded that the accident occurred due to the lack of familiarity with the test pilot marine engines. According to the official protocol prepared by a commission to study the catastrophe MR-2 on November 27, 1926 followed by: «… MR-2 is unstable in the longitudinal relation. For small enough angles of flight control surfaces. When the pilot
Rastyagaev went to plan, then he gave the pilot land manners handle sharply away, the plane began to tighten into a dive. When you try to secondary rudder was not enough, and he moved to a negative peak. » Then began a thorough clarification of the causes of the disaster, was quickly made a model airplane and made her research in the wind tunnel TsAGI. Blow picture showed catastrophic longitudinal instability of the MR-2 flight alignment was 48% MAC and the stabilizer was set at a positive angle. Continue the work the Commission noted that if the aerodynamic research done in a timely manner, the accident could have been avoided. It should be noted that the history of the MR-2 is very polikarpovskogo recalled the history of the IL-400, crashed in the first flight, also due to excessive rear alignment. The cause of these troubles is seen not only in the lack of theoretical studies, self-confidence and the desire for independence of the two designers — Grigorovich and Polikarpov.
Correct to speak of complete isolation in the years of the practice of science that actually really led to failure of all other designers seeking to implement their designs. In any case, after the crash of MP-2 definition alignment for flying boats it was one of the most important elements of the calculation, and the wind blowing patterns became a mandatory part of the preparation of the working draft.
SDM-1, MPD-2, M U -2
By 1924 the few M-5 and M-20, which is used to train naval pilots, much worn and dilapidated. Attempts to build them in a small amount to make up for the existing fleet of training vehicles have seemed unproductive. Using float biplane MU-1 is also not completely solve the problem of learning, so June 26, 1925 in the name of Grigorovich was sent a proposal to create a new training aircraft that can replace the old «coppers» and «twenty». This training unit assumed under the engine «Ron» (M-2) 120 hp, so was designated SDM-1 (Naval Training with Ron engine — the first). In fact, the new aircraft wings has become replaced by the next modification of the single-shelf M-5, a lesser scale. The wing and tail section using a thicker profile, further strengthened the tail part of the hull to reduce its rolling on bends.
In tests MOORE-1 showed a higher flight speed — 120 km / h, but on other indicators turned out to be worse than the M-5. His normal alignment was approximately 50% of the MAR, so to ensure safety in the bow of the boat had to fix one or two pound dumbbells. It is clear that with such «improvements» MUR-1 could not be considered as training aircraft. However, the first prototype was flight tested and delivered in September 1926 and in October of the same year pilot TS Zhukov brought it in pilot training flight Rastyagaeva.
Then built a new hull, which is characterized by increased up to 14 ° lateral deadrise near Redan. The plane with the new boat was named
MUR-2, but further development and has not received it. It is only known that Moore-2 was operated for several years. In particular, it between 1929- 1931’s. We conducted experiments to measure the water pressure at the bottom of the boat at different modes — taxi, gliding and landing.
Trying to improve the M-5 has confirmed that for really satisfying results requires no retrofitting of old samples, and a fundamentally new design. Since job training flying boat remained in force, Grigorovich started to design a new system — now under the domestic M-11 engine with 100 hp This aircraft was designated the MU-2, it features an all-metal hull boats with simplistic lines and contours overlaid redanom, which meant cheaper its production startup in the series. Cross-set boat fuselage MU-2 consisted of 27 frames, five of them were equipped with watertight bulkheads. Control of the aircraft helmsman, dual pedals pilots swing, with a horizontal axis of rotation. Racks for fixing the central pyramid engine metal, wooden racks mezhkrylevye, empennage duralumin. Wings dvuhlonzheronnoe with a profile in the section «Hey, Fel-367.» The main fuel tank capacity of 105 liters placed behind the cockpit, and the extra supply tank capacity of 11 liters — in the front of the engine cowling M-11. Pumping fuel from the ground to the supply tank carried a pump driven by chickenpox or manual pump.
Construction of the MU-2 began in 1927 and ended in the absence of Grigorovich. The test aircraft began August 29, 1929 at gidrobaze aircraft factory №31 in Taganrog. September 6, 1929 decided the fate of the aircraft at a meeting of the technical council Aviatresta. Present Polikarpov, Richard, Artamonov, Zhuravchenko, Samsonov, Chetverikov. It was reported that the MU-2 is located in Taganrog, where the pilot Rybalchuk performed on its first flight. He noted that the cockpit close, while the cockpit is very large cut-out (which demonstrate the presented photos). The flight of the aircraft Rybalchuk assessed as low.
He argued that there is no guarantee spin recovery. In addition, the boat had run long and hard to take off. Climb, too, was modest — on the ceiling of 3500 meters climbed training boat for 85 minutes. At the same time it pointed out that the alignment of MU-2 is the same as the Italian flying boat Savoie C-16 — 38% MAC. It was further proposed to make the aerodynamic model in TsAGI purge, and then continue to refine the aircraft. In practice, the improvement of training boats MU-2 is not engaged. A little later, on the basis of its aircraft factory №23 Designer A.S. Moskalev has prepared a draft training flying boat (with wooden fuselage), which received the designation MU-3. It was built at the beginning of 1931, and then quite successfully tested. However, in the series I went to a completely different plane with engine M-11 — a multipurpose amphibious VB Shavrova LU-2, which is widely used also for training of marine pilots.
MM-1 (MM I)
The advent of high interest to the large sea planes in the Soviet Air Force rightly be linked to the active work of the special organization
— Ostekhbyuro headed by VI Bekauri. One of the main activities were listed Ostekhbyuro work «military secret character», including mines and torpedoes delivery to the intended purpose with the help of aircraft. Already in 1924 Ostekhbyuro offered to build a special plane, in one embodiment defined as aconite (Air Cruiser Special Purpose).
Part of the problem was solved in 1925 by creating a twin-engine bomber land TSAGI ANT-4. At the same time work in the fall Ostekhbyuro
1925 Air Force leadership has intensified interest in the creation of large marine aircraft, able to perform tasks of marine bombers and destroyers.
December 17, 1925 at the Leningrad airplane factory №3 «Red Pilot» held a meeting on the problems of experimental aircraft.
One of the main bore the discussion of the draft Maritime destroyer MM and so-called scout seas (POM). Indeed, the destroyer project, designed to deliver a 450-mm torpedoes and designated MM-1, was completed in January 1926. In its original form the MM-1 is a floatplane increased in size, in which boat-floats were «covered» elliptical wing to provide additional stiffness provided with support braces. Machine gun turret, allowing to provide a nearly circular firing front and rear hemispheres, located in the fore and aft parts of the boat floats. Fastened to the wings of two flat beams passing in dual vertical tail. The cockpit was located in the center of the wing. Two engines «Lauren Dietrich» power of 450 hp designers placed one after the other, they were installed above the wing on a particular farm is almost over the cockpit.
In the present form of the aircraft, which could also be defined as a catamaran, it has not caused the unanimous approval, so in 1926 the project has been transformed into a classic biplane Double-MM-2. This unit is also powered by «Lauren Dietrich,» I had a very simple lines: wings and tail rectangular fuselage — box section. Defensive armament consisted of a bow and medium machine-gun turrets, shooting down the back and there was more shooting setting. The torpedo was placed under the fuselage.
The next project appeared MM-3, later renamed the Marine torpedo MT-1
(MT1-2LD450). It was a biplane flying boat with engines between the wings. The only torpedo was suspended under the lower wing near the fuselage.
However, none of the aforesaid projects are not implemented in practice, and focuses on the spy plane ROM.