General Information
Type Su-9, 'K'
Function Fighter-bomber
Year 1946
Crew 1
Powerplant
Type 2*RD-10
Thrust 2*900kg
Size
Length 10.55m
Height ?m
Wingspan 11.2m
Wing area 20.2m2
Weights and loads
Empty 4060kg
Loaded 5890kg
Wing Load (kg/m2) 292
Thrust
to
Weight
0.31
Thrust
to
Weight (RATO)
0.51
Speed
at 0m 847km/h
at 5000m 885km/h
Landing 150km/h
Roll
Takeoff 910m
Takeoff (RATO) 475m
Landing 960m
Landing (brake parachute) 660m
Range
Practical 1200km
Ceiling
Ceiling 12800m
Climb
5000m 4.2min
Payload
Fuel 1750kg
Guns
2*23mm NS-23 200rpg
and one of the following:
  • 1*37mm N-37 30rounds
  • 1*45mm N-45 30rounds
  • 2*23mm NS-23 100rpg
  • bomb load
  • Bombs
    2*FAB-250
    or 1*FAB-500

    Su-9 ('K') by P.O.Sukhoj

    Su-9 trials
    Su-9 during trials, (46k b/w) from the Su-9 front line fighter and its modifications page;

    The first jet powered aircraft of the P.O.Sukhoj OKB was an experimental fighter with two RD-10 engines fitted in underwing gondolas. Program started in 1944, but was slowed down because small design bureau was overloaded with more conventional projects. Indeed, P.O.Sukhoj 'inherited' development of series aircraft after deaths of N.N.Polikarpov and V.G.Yermolaev plus urging orders to built Yer-2ON and UTB-2 prototypes.

    Jet fighter project entered its pre-assembly stage only in late 1944. Full-size mockup was ready on January 31, 1946. After being inspected by mockup commetee and introducing recomended modifications, blueprints were sent to the workshop for final assembly. This happened on April 25.

    In July 1946 static tests began on the 'static airframe' and engine installation on the 'flying' one. Some delays were caused by late delivery of the engines, and only in mid-October assembly of the first aircraft was finished. About same time static tests program was also fulfilled.

    Su-9 trials
    Su-9 during trials, (46k b/w) from the Su-9 front line fighter and its modifications page;

    Aerodynamic scheme of the new front line fighter (designated Su-9) resembled one of famous German Me-262. This caused series of attacks from the Ministry of Aviation Industry, despite Sukhoj fighter had number of differences:

    Su-9 was an all-metal mid-wing monoplane, designed for 8g service and 12g destructive limit loads. Slightly tapered wing and tailplane (fitted to the tailfin) were unswept. Wing was equipped with extending flaps to improve takeoff/landing characteristics. Airbrakes were installed on both wing surfaces between the engines and fuselage. Lover part deployed alone served as a flap, while for slowing down both upper and lower brakes were deployed at angle up to 57.5°.

    Su-9 braking chute
    Su-9, braking parachute deployed (11k b/w) from the Su-9 front line fighter and its modifications page;

    In addition to the airbrakes, Su-9 had a braking parachute. This measure saved 300m of landing roll.

    Fuel was contained in two soft protected fuselage tanks, located in front of and behind the cockpit. Engines RD-10 (Jumo-004) were installed in underwing gondolas. Removable covers allowed easy access to the engines. Rear sections of the gondolas were of 0.5mm heat-resistant steel. In addition to RD-10 engines, Su-9 had attachment points for RATO solid boosters bottles U-5 (575kg thrust each, 8sec burning time) on fuselage behind the wing. With boosters takeoff run was cut by half. Once fuel is burned out, bottles were dropped automatically.

    Su-9 RATO takeoff
    Su-9 rocket-assisted takeoff (12k b/w) from the Su-9 front line fighter and its modifications page;

    Tricycle landing gear had pneumatic brakes on every wheel. Landing gear was retracting into the fuselage. Both struts and covers of main gear were hydraulically actuated, while the nosewheel had cover mechanically attached to the strut.

    Prototype aircraft was armed with one N-37 and two NS-23 cannons, installed on platform in the fuselage nose. Construction of the platform allowed to remove N-37 cannon (in fighter-bomber configuration) or to replace it with two NS-23 weapons (or one 45mm NS-45). All guns had electrical trigger and electro-pneumatic reloading system. Individual ammo counters were installed on the instrument panel, as well as gun readiness indicators.

    Bombing gear was also included in standard configuration. PBP-1B sight could be repositioned from 'cruise' to 'aiming' position and back as necessary. Light 'snap-on' racks allowed Su-9 carry two FAB-250 or single FAB-500 bombs.

    Pilot's cockpit had front and rear armor protection. Front armor included two steel plates and 90mm bulletproof glass. Addition 15mm plate was installed to protect ammo boxes from the front. Headrest and plate behind the seat were made of 12mm armor, plus 6mm plate covering the cockpit from above. Normal conditions for pilot on all service altitudes were guaranteed. Radio equipment provided reliable two-way contact within normal operational range of Su-9 and allowed operate under complicated meteo conditions. Jetissonable canopy and ejection seat (same design as on He-162) allowed pilot to bail out safely at high speed.

    Su-9 factory trials began on November 1946. Team included test-pilots LII G.M.Shiyanov and S.N.Anokhin, pilot NII VVS engineer-colonel A.G.Kochetkov - all experienced aviators, flew most of modern domestic and foreign aircraft. Leading engineer - M.I.Zuev. After series of high speed taxies (and curing revealed defects) G.M.Shiyanov took the Su-9 into the air on November 13.

    Trials conclusion was very favorable. Despite wide range of the flight speeds (183 to 885km/h) aircraft is easy to fly. According to Shiyanov's notes, takeoff and landing behaviour was similar to those of the Pe-2. After trimmer balancing, Su-9 could fly with released controls - even if one engine is cut off. Landing with both engines off did not present any difficulties. Access to all major systems is very convenient. Moreover, aircraft layout allows simultaneous service on all vital systems. Sole noted problem was increased controls load on high speeds. Design bureau team immediately started working on boosters. Rudder also was enlarged.

    Second stage of factory trials took place in 1947. On August 3 pilot A.G.Kochetkov flew the Su-9 at Tushino aviation parade, and on August 10, 1947 aircraft was taken to NII VVS for the State Trials. General conclusion was same as of earlier factory flights, and aircraft was returned to factory for controls boosters installation. Full program of test flights was performed again. Special program was carried out in period March 27 to May 25, 1948. Eleven flights were performed at LII MAP to study controls loads with and without boosters.

    So the Su-9 became the first domestic aircraft with hydraulic booster controls. According to test-pilots LII G.M.Shiyanov, boosters radically changed the feel of the aircraft. High speed operation was exhaustive no more. Maneuvers became easy practically in whole speed range. Switching boosters on and off is not accompanied by any peculiarities.

    34k b/w "History of aircraft construction in the USSR", Vol.1 p.470

    Total 136 flights (58h58min) were performed on the Su-9. Aircraft was in good flying conditions, but was scrapped due to financial cut.But at the time P.O.Sukhoj had even more advanced and better performing Su-11 'KL' aircraft was ready.

    Designation later was used for unrelated Su-9 known on the West as a "Fishpot".

    PredecessorsVariantsModifications
    None Su-9UT Su-9 'Dubler' Su-11 'KL'
    ReferencesLinks
  • "History of aircraft construction in the USSR", Vol.2 p.341-342;
  • "First jet fighters of Sukhoj"
  • Su-9 front line fighter and its modifications with a lot of photos and drawings;
  • Su-9 (K) at Virtual Aircraft Museum
  • Su-9, Sukhoi

  • Created January 25, 1996
    Modified February 4, 2000
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