prototype high altitude soviet fighter aircraft built world war version variant fitted radial engine development prolonged successful time finished manufacturer trials early need high altitude fighter worth reducing production existing fighters convert factory development direct high altitude fighter prototype known late decision phase production engine favor engine design team created version called radial engine instead liquid cooled engine number changes order accommodate larger radial engine redesign engine failure proved slower flew july continued development prototype built improved engine improvements included aerodynamic engine cockpit moved aft oil cooler moved wing roots oil cooler moved entirely inside fuselage larger tail fitted armed cannon weighed possibly metal structure confirmed took design assembly begin december flight february reduction drag weight greatly improved performance speed mph height took minutes reach altitude originally planned build quarter manufacturer trials took unexpectedly long time complete finished quarter time little demand high altitude fighter project canceled single aircraft built nomenclature number older books called established designation reserved production version twin engine fighter enter production acronym comes long range escort fighter similarly designation intended production version radial engine reused shortly jet fighter operators soviet_union soviet air_force specifications data gordon soviet world war general characteristics crew length wingspan height wing area weight loaded weight powerplant air cooled radial engine performance maximum speed mph range service ceiling armament forward firing cannon mounted engine
Mikoyan-Gurevich I-211