Soviet Aviation enthusiast
- Jun 7, 2009
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Not quite, but in some way...Alcides said:I've to say maybe we need to start a thread about Borovkov-Florow projects because I didn't know about the Aircraft 10 and 11 projects. A search in on the web shows a lot about the I-207. Are these advanced versions of 207?
The I-207 program came to its final, but Alexei Borovkov and Ilya Florov didn’t think it was all over for the biplanes. They actually believed that biplane can fly as fast as monoplane… at least as fast! So, the “10” and “11” projects appeared…
Borovkov/Florov “Aircraft No.10”
Design date: 1940
Purpose: high-speed maneuverable fighter, escort fighter, dive bomber
Engine: 1x Shvetsov M-71 (1700/2000 hp); 1x Merkulov DM ramjet
Wing span: 9.5 m
Length: 8.35 m
Wing area: 24.0 m2
Takeoff weight: 3500 kg
Wing loading: 146 kg/m2
Maximum speed without ramjet: 650 km/h
--//-- with ramjet active: 750…800 (840?) km/h
Climbing to 8000 m (with ramjet active): 8.0 min
Flight range: 800 km
Turn time: 14…16 seconds
Weapon: 1x 12.7 mm Berezin BS, 2x 7.62 mm ShKAS. Can be easily replaced with 2x 23 mm cannons.
Significant features: Cantilever biplane with no struts and wires. Upper wing is “gull” type, lower is “inverted gull”. The aircraft featured tricycle landing gear, because tail part was occupied by DM ramjet and there were no place for the tailwheel. The ramjet (already tested by Borovkov and Florov on the I-207/3) was used only for short time as a booster. When it wasn’t active, the inlets were closed by special doors.
Borovkov/Florov “Aircraft No.11”
Design date: autumn 1940
Purpose: maneuverable fighter only.
Engine: 1x Shvetsov M-71 (1700/2000 hp); 2x Merkulov DM ramjets
Wing span: 8.5 m
Length: 7.85 m
Wing area: 22.0 m2
Takeoff weight: 3250 kg
Wing loading: 148 kg/m2
Maximum speed with ramjet active: 750…800 km/h
Climbing to 8000 m (with ramjet active): 6…7 minutes
Flight range: 800 km
Other technical data unknown.
Significant features: It was smaller and lighter derivative of the “10”. Instead of one large DM ramjet, it has two smaller ones placed side-by-side. The “11” was a taildragger back again, and the tailwheel was placed between the two ramjets.
Despite of high proclaimed performance, any of these projects wasn’t supported by both the VVS and NKAP. The common position was that biplanes belong to the past. According to Maslov, when Borovkov discussed his work with Yakovlev the latter said that any biplane will not get support anymore.
Source: Mikhail Maslov "Borovkov and Florov fighters". - Aviatsiya (Aviation) magazine Vol.2 (2/99), p.15-16.
P.S. It’s interesting that, according to Maslov, the DM letters stood not for Dvigatel Merkulova (Merkulov’s engine) but simply for Dopolnitel’nyi Motor (additional motor).