Planet Models Bolokhvitinov S-1 <Not Quite> COMPLETE

[Pin]

I did not plan to build this model, I got the kit accidentally and all of a sudden found myself building it

 

The plane was conceived as a fast light bomber and reconnaissance plane. To obtain high speed and good aerodynamics, it was powered by two M-103 inline engines in tandem in a fuselage nose, driving two contra-rotating coaxial three-blade propellers. The design had quite unusual look, with long fuselage nose and a crew cab moved rearwards, towards double tailfin. Wings had a fighter-like form and their span was rather short. The VVIA under Bolkhovitinov was enlarged to tackle the expected problems in the design of the Bolkhovitnov S. The rear engine was geared to two high-speed shafts which passed either side of the forward engine to drive the rear propeller gearbox, whilst the forward engine and gearbox drove the forward propeller via shaft through the middle of the rear propeller gearbox. The structure of the S was predominantly light alloy stressed skin, the wing having two spars with heavy flush-rivetted upper and lower skins, and the fuselage built up from pre-formed upper, lower, and side panels attached to four longerons to give a strong but relatively simple structure to build. A total of 29 electrical actuators drove the Fowler Flaps, undercarriage, (rotating 90deg to lie flat in the wing), exit flap of the large common radiator duct, and many other services. The tail unit consisted of twin fins with rudders attached to the tips of the tailplane, variable geared elevators and separate servo and trim tabs on elevators, and rudders. Detail design of the aircraft began in 1937 and construction in July 1938. The first prototype S-1 was built in 1939, but it was made in order to evaluate an airframe only and therefore was powered by only one engine M-103. It was unarmed and fitted with a fixed skid landing gear. It first flew on January 29, 1940, with B.N. Kudrin at the controls.^[1] A maximum speed was 400 km/h. The second prototype S-2 was powered by two engines and was armed with a single machinegun and bombs.^[1] Four 100 kg bombs were carried vertically in a bay between pilot and a rear gunner-navigator, under a common canopy. Its state testing started from March 20, 1940, and lasted until July 1940.^[1] A maximum speed reached was 570 km/h (354 mph). The plane had good handling, except for take-off and landing, which were difficult due to high wing loading.^[1] Its range and speed were also lower than estimated. As a result, it was decided to improve the plane further. However, the plane was not developed in a favour of next Bolkhovitinov designs.^[1]

It was first planned to build also an attack plane with 2 Ultra-ShKAS machineguns with a high rate of fire, in a rear part of fuselge, firing downwards and manned by a second crew member. Also an interceptor aircraft was proposed, armed with 37 mm recoilless rifle, firing upwards at an angle and manned by two crewmen.^[1]

The plane had no official designation given. It was mostly known as S - sparka (otherwise explained as spartak, skorost (speed) or Stalin), also known as BBS - blizhniy bombardovshchik skorostnoi (close-range fast bomber), BB - bombardovshchik Bolkhovitinova, LB-S - legkiy bombardovshchik sparka (light bomber paired), SSS - svyerkhskorostnoi samolet (very fast aircraft).^[1]

 

 

 

More about the prototype, 

[TonyTiger66]

On 20/03/2017 at 0:37 AM, Pin said:

 

I did not plan to build this model, I got the kit accidentally and all of a sudden found myself building it

 

 

This applies so often to me Pin, but unfortunately I seldom get to the 'suddenly finding myself building it' stage

 

In this case, I'm very glad that you have . It's a fascinating subject.

 

Reading the information you provided above, what a design! There was a lot of complex engineering in this. The arrangement of gearboxes and drive shafts for the two engined aircraft is quite something to read. 

 

It really also was was very fast. I must read more about this designer, and the designs that came after these prototypes.

 

Great progress Pin, looking forward to seeing this one develop 

Best regards

TonyT

 

[Pin]

All of a sudden - it's nearly complete

[Pin]

Practically ready. Gallery photos to follow

 

Grey overall it is probably the most boring aircraft on my shelve. Even all green DB-LK is somewhat more flamboyant

 

[greggles.w]

Quick work!

 

Plain grey it may be, but it's still an exceptional design (.. though for my mind the Macchi MC.72 was a more attractive example of the S2 tandem engine, contra-prop configuration)

 

I look forward to to viewing the gallery photos when ready.

[Gorby]

I love to learn about obscure aircraft, and this is a new one for me, so thanks. Fascinating aircraft and excellent model. I'm off now to find out more info. 

[Pin]

Overall - a good quality resin kit with few minor problems

The canopy was a bit too wide so I had to squeeze it, I also replaced vacformed transparent belly hatch with a piece of CD cover.

A bit overdone with the weathering but I don't have inspiration to have it redone so this is it

 

  

  

  

  

  

  

[zebra]

I like it... good weird looking thing, perfect for this group build!

[Pin]

I should not have blindly trusted the assembly sheet. This photo is clearly showing the mistakes I made

 

so despite the premature announcement the build is not over yet

 

[Pin]

Spot the difference