Experimental fighter, far ahead of its time. Leaving alone its steel (so Stal) construction,
following features are to be mentioned:
Extremely clean shapes - pilot's cockpit was flush with top of the fuselage!
Material chosen to provide minimal possible weight: chromium-molibdenium steel tube frame, aluminum/magnesium alloys
(AltMag, Electron) used for front section skin (integrating oil tanks), thin steel tube bundles as a wing structure with thin
stainless steel skin, plywood skin on the tail.
Single-wheel landing gear with tail skid and small stabilizing skis on the wing tips. ALL landing gear elements are
completely retractable. At the time world new only semi-retractable gear with wheels going backwards and half-hide in the wing.
Water evaporative cooling system inside the wing surface, like in some racer aircraft.
Elevator controls had adjustable reduction number, allowing pilot to adjust force on the control stick depending on the
aircraft speed and flight conditions. This system was 'invented' again in 1944
by TsAGI and LII...
Stal-6 successfully passed all tests during Fall 1933. Pilots A.B.Yumashev and
P.M.Stefanovskij proved that 'one-wheel' landing
gear is as good as conventional on takeoff, landing and taxi. Speed on ground level was 420km/h, 150km/h faster than
typical speed of contemporary fighters.
Interestingly, that VVS leadership already pushed aircraft builders to increase speed
of their aircraft, but faced 'organised resistance'. Manufacturers did not believe that substantial speed increase is possible in
short time. They interpreted rumors about Stal-6 as a 'duck'.
On official meeting with K.E.Voroshilov and G.K.Ordzhonikidze representative of the
GUAP tried to prove that fighter with speed 400-450km/h is impossible. He was
corrected that such aircraft (Stal-6) already exists and its designer (R.L.Bartini)
is present on the meeting.
GVF received an order to build fighter based on Stal-6 design. Project was designated
68k drawing Stal-6/8 from 'Krylia Rodiny' magazine
courtesy of Sergey Andreev
"History of aircraft construction in the USSR" by
V.B.Shavrov, Vol.1 p.471-472;