Chinese J-20 stealth fighter on trial flight

Prototype Chinese J-20 Stealth Fighter 

Technical Observations on the Prototype Design

1. The J-XX/J-20 is a large fighter, similar in size to an F-111. This first-of-type aircraft presents with a large dihedral canard-delta wing configuration; with a pair of outward/rearward canted all moving combined vertical/horizontal tails; and, similarly large, outward canted ventral fins/strakes which, if all moving like the tails and retained on any production version, will make for some quite advanced capability options in the areas of controllability and manoeuvrability. There is little doubt this configuration is intended to provide good sustained supersonic cruise performance with a suitable engine type, and good manoeuvre performance in transonic and supersonic regimes.
2. The stealth shaping is without doubt considerably better than that seen in the Russian T-50 PAK-FA prototypes and, even more so, than that seen in the intended production configuration of the F-35 Joint Strike Fighter.
3. The J-XX/J-20 design appears to be largely built around the stealth shaping design rules employed in the F-22A Raptor:
4. The chined J-XX/J-20 nose section and canopy are close in appearance to the F-22, yielding similar signature performance in a mature design.
5. The J-XX/J-20 trapezoidal edge aligned engine inlets are closest to the F-22, though appear to be larger and employ an F-35 style DSI (Diverterless Supersonic Inlet) design, obviously intended to improve on F-22 inlet edge signature.
6. The J-XX/J-20 wing fuselage join, critical for beam and all aspect stealth, is in shaping and angle very similar to the F-22, and clearly superior to both the Russian T-50 PAK-FA prototypes and the F-35 Joint Strike Fighter.
7. The J-XX/J-20 flat lower fuselage is optimal for all aspect wideband stealth, and emulates the F-22 design closely.
8. Planform alignment of the J-XX/J-20 shows exact angular alignment between canard and delta leading edges, and exact crossed (starboard to port, port to starboard) angular edge alignment between canard and delta trailing edges. Leading edge sweep is ~43°, clearly intended for efficient supersonic flight.
9. The J-XX/J-20 nose and main undercarriage doors employ X-band optimised edge serration technology, based on F-117A and F-22 design rules.
10. The aft fuselage, tailbooms, fins/strakes and axi-symmetric nozzles are not compatible with high stealth performance, but may only be stop-gap measures to expedite flight testing of a prototype.
11. The airframe configuration and aft fuselage shape would be compatible with an F-22A style 2D TVC nozzle design, or a non-TVC rectangular nozzle designed for controlled infrared emission patterns and radio-frequency stealth.
12. The airframe configuration is compatible with ventral and side opening internal weapon bays, and large enough to match or exceed, by some degree, the internal weapons payload of the F-22A Raptor.
13. Internal fuel fraction is also likely to be high, given the fuselage configuration and large internal volume of the big delta wing. This indicates an intent to provide a sustained supersonic cruise capability, in the manner of the proposed FB-22.
14. The PLA have not disclosed the engine type. There are claims that the Russians supplied supercruise capable 117S series engines, though, subject to the overall efficiency of the aircraft’s aerodynamics, these would likely not be sufficient to extract the full performance potential of this advanced airframe.
15. The intended sensor suite remains unknown. China has yet to demonstrate an AESA radar, or an advanced indigenous Emitter Locating System (ELS). However, these could become available by the time this airframe enters production. Suitable Russian hardware is currently in late development and/or test.

Australia Air Power

J-20 stealth fighter on trial flight

Xinhua