Tupolev ANT-21 (MI-3)
|FIGHTER||Virtual Aircraft Museum / USSR / Russia / Tupolev|
Designed at the KOSOS (Konstruktorski otdel opytnovo samolyetostroeniya, or Design Department for Experimental Aircraft Construction) within TsAGI by a brigade headed by Aleksandr A Arkhangel'sky, the ANT-21 MI (mnogomestnyi istrebitel - multi-seat fighter) was, by international standards of its day, very much state-of-the-art. Featuring all-metal stressed-skin semi-monocoque construction with partial flush-riveting and a retractable main undercarriage, the ANT-21, which was assigned the service designation MI-3, was powered by two M-17B (BMW VI) 12-cylinder water-cooled engines of 680hp. Proposed armament consisted of one 12.7mm machine gun or 20mm cannon on a pivoted nose mounting, two 7.62mm guns firing from a dorsal position and a single 7.62mm gun firing from a ventral tunnel. Three crew members were carried.
Work on the ANT-21 began on 18 January 1932, first flight taking place in August 1933. On 14 September, the starboard rudder suffered damage and separated as a result of violent flutter in a shallow dive. Arkhangel'sky elected to undertake major redesign as the ANT-21bis.