After the "Object 10" project, the Borovkov and Florov working group got to work on a new version known as "Object 11" or simply No.11. In some literature it has also been called I-207/6. This new project owed its origin to the intention to comply with the requirements issued by BN Yuriev during the review of the “Object 10” project as a way to achieve its serial production.

 

This new project returns to the conception of pure fighter with high manoeuvrability and to the conventional type landing gear. The armament included two 12.7 mm machine guns and two 7.62 mm ShKAS, but the possibility of carrying two FAB-250 250 kg bombs or instead two detachable containers with PTB-23 23 mm cannons remained.

 

It was smaller and lighter derivative of the “10”. Maintaining the same wing configuration of gull and inverted gull, the new model included two Merkulov DM ramjets in its metallic tail section, located side by side and with side gates for the air intakes. Instead of one large DM ramjet, it has two smaller ones placed side-by-side. This arrangement made it possible to install the tail wheel between them.

 

The project kept the Shvietsov M-71 engine, but in this case a variant with an elongated shaft was used, which made it possible to improve the aerodynamics of the forward section of the fuselage.

 

All efforts in the design of this new version were directed to obtain the lowest possible weight. The calculated speed of the project in fighter configuration at 5830 meters and without the auxiliary engines gave 654 km / h. With the bomb load the speed decreased to 611 km / h. The ascent time to 5000 meters was 3.7 and 4.5 minutes respectively.

 

The conceptual project for "Object 11" was presented in the fall of 1940. The evaluation commission considered that the calculated speed was a bit high and recalculated it to 630 km / h, leaving the speed with bombs at 585 km / h. The commission proposed to include the model in the plan of experimental works for the next year, obtaining the approval of AS Yakovlev.

 

In October 1940 the project was presented at the NII VVS and the conclusions of its evaluation were signed by PV Rychagov on December 9 1940. In general, the evaluation was positive and it was again recommended to include the fighter in the experimental construction plan for 1941 with the condition of increasing its range to 1000 km in normal version and 1400 km with auxiliary fuel (taking into account that "Object 11" it was not foreseen as an escort fighter, such range value was exaggerated and forced to considerably increase the weight of the aircraft in fuel).

 

The position of the GUAP, together with the negative perception of the industry and the air forces towards the biplane wing structure, resulted in the work on the project being closed. The deputy commissioner for experimental aviation AS Yakovlev, in a meeting informed the constructors of the decision not to include new proposals for two-plane configurations in the future work plans of the Narkomat.

 

Borovkov-Florov Object 11

Powerplant: One Shvietsov M-71 (1700/2000 hp) and two Merkulov DM ramjet

Wingspan: 8.5 m

Wing area: 22.0 m²

Length: 7.85 m

Flying weight: 3250 kg

Wing loading: 148 kg / m²

Maximum speed: 790 - 800 km / h

Ascent time at 8000 m: 6 - 7 min

Range: 800 km

Accommodation: 1

 

Object 11