To experience a tricycle landing gear, a SB M-103 (s/n 5.0, built in 1939) was allocated and modified in the TsAGI's Department n.8.
The original nose was replaced with a longer and more robust one with a mount for a fixed nose wheel. At first, a 470 mm x 210 mm wheel was installed, later replaced by a 600 x 250 mm wheel.
The main landing gear was moved rearwards and fixed.
A strong steel truss was added under the fuselage to stenghten it and the wing center section, because it was stated that the plane had to resist to a 3-g load and a vertical speed up to 4.8 m/s.
The program was headed by engineer I.P. Tolstykh, and flown by test pilot M.L. Gallay.
The plane was nicknamed Pterodactyl because of its strange look and long nose.
Its landing speed with flaps was of 140-150 km/h, while it was 190 km/h without flaps.
The experiments show good handling characteristics during takeoff and landing and on the ground, and ended in February 1941.
Of course, the tricycle gear was never intended for introduction on production SBs.
Above: general view of the prototype, that seems painted in the standard light grey AE-9, plus colored nose and engine cowlings, probably red.
The engine coolers with adjustable shutters are typical of the early produced SB with tunnel coolers.
Below: rear view, with many well recognizable details.
Aside and below:
photos of the plane, probably in the final stage of the tests that ended in February 1941.
It seems that the paint of the nose was ruined for some reasons.
It is unclear if the reinforcing struts were painted red or what else.
