Friday, April 06, 2012

Fifth Generation Fighter Aircraft, T-50 PAK-FA design & testing: Updates

The latest issue of Air International magazine has a fine article detailing the testing, development & future roadmap of the Fifth Generation Fighter Aircraft [FGFA], the T-50 PAK-FA, a Russian venture with Indian involvement. Written by the much respected Piotr Butowski, its filled with important nuggets of information. Paraphrasing the critical ones here.
  • Up until February, the multiple PAK-FA prototypes have made more than 120 test flights
  • The third FGFA prototype, the T-50-3, is now being equipped with the N036 Active Electronically Scanned Array [AESA] radar for testing.
  • For the T-50-3, air intakes in the roots of the vertical tail fins have been re-designed & so have its wing tips. The air intakes are used for cooling the engine bay.
  • Load-bearing structures in the first prototype, T-50-1, have developed cracks during the course of testing. It has been taken out of the flight rest regime & has not been seen to take to the air since August, last year.
  • Sukhoi boss, Mikahil Pogosyan promises that the fourth prototype too would be ready for testing in 2012, but no specific dates given.
  • Following the detection of cracks on the T-50-1, the fourth prototype is having to undergo major structural changes, leading to its eventual delay.
  • Russian Air Chief states that, by 2015, 14 T-50 PAKFA aircrafts would have been built - 6 prototype variants & 8 pre-production aircrafts.
  • 60 production variant T-50s would be bought in the period between 2016-2020
Izdeliye 30 [Item 30] Engine under development for the T-50 PAK-FA
  • Full-scale development for the engine that will eventually power the FGFA had begun since 2011. The engine would be ready for integration & testing with an aircraft by 2016.
  • The engine would have a re-heat thrust of 18 tonnes & dry thrust of 11.5 tonnes & would start powering production variants of the FGFA from starting 2020.
Patent submitted for the PAK-FA
  • Important features of the aircraft - blended body aerodynamic configuration
Layout diagram of the T-50 PAK-FA Fifth Generation Fighter Aircraft [FGFA]
  1. Lift-generating fuselage
  2. Fuselage extension
  3. Outer wing extension
  4. All-moving horizontal stabilizer
  5. All-moving vertical stabilizer [fins]. They can rotate along with the horizontal empennage or independently. The fins also act as air brakes.
  6. Engines are housed in the wide-spaced nacelles
  7. Engine air intakes
  8. Leading edge extensions [LEX or LERX]
  9. Leading edge flap
  10. Ailerons
  11. Flaperons
  12. Stub-pylons for mounting the vertical fins
  13. Air-intakes for engine bay cooling & air-conditioning
  14. Engine nozzles. They can either be directed in the same direction or even independently
Characteristic features of the T-50 PAK-FA:
  1. Small Radar Cross-Section [RCS]
  2. Super manoeuvrability at high Angles-of-Attack [AoA]
  3. High lift-to-drag ratio at Supersonic speed [retaining high value at subsonic speed]
  4. Large size internal weapons bay carriage
  • Widely housed engine bays allow for a large size internal weapon bay along with greater deflection of engine nozzles.
  • Greater nozzle deflection also allows aircraft control about vertical & longitudinal axes at low speeds.
  • Engines are mounted at an angle to the longitudinal axis of the aircraft. In case of a single engine failure, the direction of thrust of the other engine is closer to the centre of gravity of the aircraft. This makes it easier to control the aircraft with a single engine.
  • Reduced Radar Cross-Section [RCS] is achieved by articulating leading edges of the wings, tail planes & LEX parallel to each other. Additional RCS features include faceted fuselage sides & oblique engine air intakes.
News article shared by Austin. HT