What if? Suchoj-Chizhevskiy SuCh-1 a.k.a. Suchoj I-2M107 (Whif/Scratched)

[dizzyfugu]

Durchaus großes Tennis - was tun, wenn man ein Modell von einem Projekt bauen will, dass es bestenfalls auf dem papier gab, und das einige... Eigenheiten hat? Da hilft nur die Säge, viel Spachtel und Berge an Spendermaterial!

Hintergrund ist ein reales Projekt des OKB Suchoj, das 1943 auf dem Papier stand (habe ich in einem Buch gefunden) und unter dem Namen "Suchoj I-2M107" ("Jäger mit zwei M107-Motoren") lief. Die Idee war einen schweren Jäger zu bauen, der die Leistung einer 2-Mot-Maschine brachte, ohne deren aerodynamische Nachteile. Daher baute man die beiden Motoren hintereinander in den Rumpf, versetzte sie zueinander und kam man auf dieses asymmetrische Layout:



Hat was, oder? Das Ding wurde nie wirklich gebaut, und Anfang des Jahres habe ich mich dann dazu durchgerungen, diese Flugzeug in 1:72 aufzubauen, zumindest näherunsgweise.

Wer will kann raten, was da alles drin verschwunden ist . Tja, und dies ist nach drei Wochen daraus geworden:

Some background:
The mighty Suchoj SuCh-1 started its life in early March 1943, when the Sukhoi OKB finished work on the design of a high-speed fighter with a unique powerplant arrangement. The aircraft was an all-metal low-wing mono­plane with conventional tail surfaces. The three-section wings had constant dihedral and basically trapezoidal planform; the sta­bilizers had zero dihedral.








Two Klimov M-107 water-cooled Vee-12 engines, each with a. take-off power of 1 ,600 hp (1,193 kW) and a maximum design power of 1,500 hp (1,119 kW) at 5,500 m (18,045 ft), were mounted in the center fuse­lage in a staggered-tandem arrangement: the front engine was offset to starboard and of the rear one to port. Thus, the total power was increased but the drag was the same as for a single-engined aircraft, which was expected to increase fight speed consider­ably. Consequently, the project was internally designated 'I-2M107', literally "Article powered by two M107 engines".

Furthermore, the left cylinder bank of the front engine and the right cylinder bank of the rear engine were disposed vertically, so that each engine had one set of exhaust stubs on top of the fuselage and one on the fuselage side. Both engines drove a single three ­blade tractor propeller of 4.0 m (13 tt 2 in) diameter via parallel extension shafts and a common reduction gearbox. Both water radiators were located side by side in a chin housing, while the oil coolers were buried in the wings. The total fuel capacity of the four tanks arranged in the center fuselage was 1,113 litres (244.86 Imp. gal).






Because of the power plant arrangement and the large ground angle (necessary to give adequate ground clearance for the large propeller) the cockpit was offset to port and placed ahead of the wing leading edge to provide better forward visibility on take-off and landing. The cockpit was protected by a bulletproof windscreen, a front armor plate and an armored backrest; the armor weight totaled 70kg (154Ib).

The main landing gear units with 800 x 280 mm (31.5x11 in) wheels retracted inwards into the wing roots and the 400 x 150 mm (15.7 x 5.9 in) tail wheel retracted aft. The fighter's armament consisted of two wing-mounted 12.7-mm Berezin UBS machine-guns firing outside the propeller disc and a single 20-mm ShVAK cannon fir­ing through the propeller hub*.








A full-scale mock-up was inspected in December 1943, and with German long range bombers threatening the Western front line as well as the lack of a fast and powerful fighters to intercept them (the earlier MiG-5 had turned out to be a disappointment, and Mikoyan's I-211/221 family if high altitude fighters also suffered from serious technical problems at that time), OKB Suchoj received an immediate go-ahead for further development of the SuCh-1, how the I-2M107 was now officially called, since Vladimir A. Chizhevskiy took lead of the project.

In the course of 1944 three prototypes went through a fast development program. While the aircraft itself was easy to handle, overheating problems and trouble with the gearbox for the two engines could only partly be rectified - esp. the power transmission should remain the SuCh-1s Achilles Heel.








Anyway, the SuCh-1 was ready for service introduction towards late 1944, and the powerful type was exclusively to be used as an interceptor. Several improvements had been made, compared to the prototypes: now two slightly more powerful Klimov VK-107A engines were used, which were better suited for high altitude operations, and the chin-mounted water cooler was considerably enlarged. The oil coolers had been re-designed and they were now placed under the wing roots.




The wing span had been extended by 6' and a bigger (now 4.3m diameter!), four-bladed propeller was added in order to improve performance at high altitude. No pressurized cabin was installed, but the cockpit received an extended glazing for better all-round field of vision.

Armament had also been augmented: now a Nudelman N-23 23mm cannon was firing through the propeller hub, and the number of UBS machine-guns in the wings was increased to four.

As initial duty experience was gathered, it became quickly clear that the firepower had to be augmented, so that the propeller-hub-mounted 23mm cannon was quickly replaced by a  Nudelman-Richter NR-37 37mm cannon, and the four wing-mounted UBS machine guns were replaced by two 20-mm ShVAK cannons or even two Nudelman N-23 23mm cannons - the latter became the production standard from March 1945 on, even though the type's designation did not change.








Experience also showed that the overheating problem had been cured, but the complicated gear box tended to malfunction, esp. when full power was called for in aerial combat: high G forces took their toll and damaged the bearings, even warping the extension shafts and structural parts, so that some SuCh-1 were literally torn apart in mid-air.

The high torque powers of the large propeller also took their toll on handling: starting and landing was described as "hazardous", esp. when the fuel tanks were empty or in cross winds.
Consequently, SuCh-1 pilots were warned to engage into any dogfight or enter close combat with single-engined enemy fighters, and just focus on large enemy aircraft.








On the other side, the SuCh-1's powerful cannon armament made it a deadly foe: a single hit with the NR-37 cannon could down an aircraft, and its top speed of roundabout 700 km/h (435 mph) was more than enough for the Luftwaffe's heavy bomber types like the He 177.

Several engine and armament experiments were undertaken. For instance, at least one SuCh-1 was outfitted with a Nudelman-Sooranov NS-45 45mm cannon firing through the propeller hub, even a 57mm cannon was envisaged. Furthermore, one airframe was prepared to carry two Charomskiy M-30V 12 cylinder diesel engines, in order to produce a heavy long-range escort fighter (internally called I-2M30V).
In order to minimize the torque problems a contraprop arrangement with two three-bladed propellers and a diameter of only 3.6m was under development.






All in all only 120 of these powerful machines were built until the end of hostilities, as the feared mass attacks of German long range bombers did not materialize. as the Su-7 was complicated to operate and jet engines promised a far more efficient way of propulsion for high speeds, the type was already retired in 1947 and replaced by 1st generation jet fighters like the Yak-15 and MiG-9, which carried a similar armament, attained a better performance (except for the range) but weighed only half of the large and heavy SuCh-1.


General characteristics
Crew: One
Length: 11.75 m (38 ft 5 3/4 in)
Wingspan: 13.85 m (45 ft 3 1/4 in)
Height: 5.30 m (17 ft 4 in)
Empty weight: 5.250 kg (11.565 lb)
Max. take-off weight: 8.100 kg (17.840 lb)

Powerplant:
2× Klimov VK-107A liquid-cooled V12 engines with an output of 1.650 hp (1.210 kW) each at sea level and 900 hp (650 kW) at 8.300m (27.220 ft)

Performance:
Maximum speed: 720 km/h (447 mph) at height, clean configuration
Range: 750 km (465 mi)
Service ceiling: 11.700 m (38.400 ft)
Rate of climb: 876 m/mim (2.850 ft/min)

Armament:
1× Nudelman-Richter NR-37 37mm cannon with 60 RPG, firing through the propeller hub
2× Nudelman N-23 23mm cannons with 120 RPG in the wings
Many different cannon and machine gun arrangements coulod be found, though.

*Information about the conceptual Suchoj I-2M107 was primarily gathered from the book 'OKB Suchoj', written by Yefim Gordon & Dmitriy Komissarov; Hersham (UK), 2010.









Die Grundlage bilden:
● Rumpf und Flügelwurzeln einer NOVO Supermarine Attacker (ein gruseliger Bausatz aus den 60ern!)
● Flügel einer Italeri Fw 190 D-9
● Die Nase mit Kühler ist ein Resin-Merlin-Treibwerk von OzMods, aus einem Umrüstsatz für eine RAAF-Avro Lincoln









Das Cockpit wurde dann aus den Vollen gefräst, und mit einer antiken Haube einer P-39 (muss 30 Jahre alt sein!) aufgebaut:








Die Auspuffanlage besteht aus einzeln, in gefräste Schächte eingeklebte HO-Dachfirst-Ziegeln...




Die Lackierung orientiert sich an späten sovietischen Jägern, freies Vorbild ist eine Yak-9.








Muahahaha!