soviet fighter aircraft developed crash program develop high performance fighter counter german powered aircraft design bureau decided focus design mature jet engine experimental stage soviet_union chose mixed power solution air reaction jet powered engine successful worked maximum speed mph reached trials production problems fatally delayed program canceled obsolete design development january soviets aware successful british american jet aircraft projects germans deploy jet rocket propelled aircraft ordered february people aviation industry jet research control present proposals alleviate situation month result meeting ordered design develop build jet aircraft dispatch aware earlier problems encountered novel propulsion systems chose use engine development rudimentary type jet engine external power source drove engine forced air steel chamber fuel sprayed seven ignited exhaust variable rear horsepower engine primary powerplant takeoff clutch end engaged drove step gearbox ratio extension shaft powered air fed long ran inlet underneath propeller spinner engine belly aircraft fed air oil cooler near engine water positioned maximize secondary led main running secondary diverted additional air boosted engine output horsepower increased engine helped dump engine excess heat exhaust stream limited minutes operating time sortie meant useless weight rest flight low wing metal aircraft fuselage aircraft largely conventional layout cockpit set far fuselage base vertical tail wings thickness preserve control avoid tip stall fitted flaps fuel contained imp gal gal fuselage tank imp gal gal tank wing conventional landing gear suspension retracted tail wheel retracted aft small ventral fin engine initially drove metre propeller asked begin preliminary design work high altitude january ordered prototypes metal testing february march aircraft reach altitude minutes power minutes engine maximum speed mph power mph intended armament machine guns assist ordered provide help aerodynamic stress calculations test size wind tunnel month time ordered deliver engines lbf specific fuel consumption hour plane designated internal designation approved preliminary specifications september included maximum speed mph weight time metres minutes mock inspected october rejected poor cockpit layout decision reversed fuselage prototype far major changes significantly delayed program month chamber sent testing revealed weak complete powerplant tested december drive shaft connecting failed times prototype completed february ready fitted new metre propeller making flight april according gordon march armed cannon rounds gun fitted nose fired hollow propeller shaft tested time april dive attaining speed mph leak found oil cooler landing returned factory repairs april troublesome twice reached mph early tests service life exceeded returned postponed tests second aircraft finished unarmed second prototype completed flight later discovered major defects including oil leak sleeve designer summoned attempt solve problems design issues prototype grounded june remedy problems add extra air cool spark attained speed mph july unfortunately port failed low altitude days later killing test pilot parachute failed open time post crash analysis revealed exceeded airframe limit maneuvering despite accident pre production batch aircraft ordered july felt mixed power aircraft use transition pilots engine fighters jet engined ones time cancelled judged inferior meantime horizontal second prototype strengthened resumed flying july pilot complained excess pull right vertical enlarged numerous problems ready pass state acceptance trials development work powerplant second prototype continued flight testing july engine fire forced emergency landing damaged repair order pre production placed factory moscow aircraft delivered september october remainder end year proved optimistic revised single aircraft end year airframe completed revised schedule engine ready time factory management criticized problems entirely control changes design drawings constant criticism limited program jet programs developed fast leadership wanted head map predecessor arrested march sign displeasure new minister severely designer factory directors april set commission determine factory failed meet refused accept findings blame fairly evenly responsible production program director factory quality control manager arrested industrial sabotage despite production problems fact submitted state acceptance trails order placed aircraft february aircraft referred presumably designation actually entered service new deadline july set delivery pre production aircraft lack engine time seven completed lacked engines finally accepted august flown time days later engine seals failed number cables engine replacement repairs forced aircraft miss scheduled appearance air display handed september finally begin state acceptance tests aircraft delivered october construction number factory batch seventh aircraft static test airframe static engine convened meeting november settle future policy jet fighters selected primary fighter relegated conversion training imminent availability british jet engines access german jet technology engineers meant longer need mixed power aircraft insisted finish trials drawings retained parts program cancelled completion trials delayed trials completed tried sell aircraft use escorts torpedo bombers additional fuel tanks fitted wings fuselage carry additional litres imp gal gal fuel capacity oil tank increased litres imp gal gal changes increased weight weight new round state trials began october delayed bad weather reliability issues flights totaling hours minutes completed january run minute half ground test declared failed trials april specifications prototype data gordon history characteristics crew length wingspan height wing area weight gross weight fuel capacity litres imp gal gal powerplant liquid cooled engine powerplant air reaction jet lbf thrust propellers bladed diameter performance maximum speed mph range nmi service ceiling time altitude min wing loading armament guns cannons rounds
Mikoyan-Gurevich I-250