by Massimo Tessitori
After the limited modernization of SB represented by SB-RK, the Archangelsky
bureau was charged of a more radical redesign to reach a speed of 600 km/h.
In 1939, they worked on a new fast bomber for close support of ground troops, called Skorostnoj Bliznyj Bombardirowszczik (fast short-range bomber) rsp. abbreviated SBB-1.
The prototype SBB-1 was equipped with M-105R engines, like MMN and Ar-2.
A performance of 612 km/h at 9.000 m was expected by installing Klimov M-105 TK engines with turbosupercharger, and of 587 km/h at 7.000 m with the new M-106 engines.
When compared to Ar-2, the SBB had :
images from http://www.ctrl-c.liu.se/misc/ram/
The first prototype (B-1) was built in the Factory No. 22 in Moscow
in late1940, and performed its first flight on February 20th, 1941.
Before this first flight, a special commission of experts from TsAGI (Central Aero-Hydrodynamical Institute), VVS (Air Force of the USSR) and NKAP (People´s Commissariat of Aircraft Industry) performed a tactical-technical comparison between PB-100 of Petlyakov (Pe-2 prototype), BB-22PB (Yak-4) of Yakovlev and SBB of Arkhangelsky, for the choice of the future standard medium bomber.
Arkhangelsky´s SBB was not taken into account, because at that date it had not performed any factory tests.
Factory trials started on March 24th and lasted until July 9th 1941, with test pilot Yuri K. Stankiewicz at the controls.
SBB achieved 540 km/h at 4.900 m and climbed to an altitude of 5.000 m in 6 min. 21 s.
Indeed, the performances were lower than planned, but after that some slight construction defects were removed ( including improving of the undercarriage doors and the ejector exhaust tubes) the speed grew by 20 - 25 km/h.
A second prototype, sometimes mentioned as B-2, was built during the summer of 1941. It achieved a speed of 40 - 60 km/h more than the B-1, but it wasn´t tested before the outbreak of war. The machine was planned to serve as a dive bomber.
In comparison with Petlyakov´s PB-100 (Pe-2), the SBB had better starting and landing characteristics and climbed faster. It was recommanded for series production by the test pilot, after troubleshooting. However the Pe-2 was fully satisfying, better armed and already in production.
Any further development was stopped when the war with Germany broke out.
Alexander A. Arkhangelsky was transferred to Factory No. 156 for to organize the repairing of the SB bombers.