By ubiquitous08 from secretproject
First impressions....A Ray tracing approach to stealth not having a supercomputer and RCS prediction programmes at hand...
Clearly a VLO design. Shaping appears robust in X band, L band and probably S band in front and side quaters. Facets are large in the order of over 1 meter which satisfy these frequencies.
In the VHF band side on its flat profile should give it very good RCS versus F 22 / F 35 dominated by large if canted tails. Rear quadrant RCs appears disappointing with a clear emphasis on maneouvrability over YF 23 style aft sector facets to which the design clearly has been influenced. Cockpit canopy bow a disappointment but canted. Planform has more lobes than classic 4 lobe YF 23 layout but Lerxes will generate greater maneouvrability at high AOA and ability to dynamically control direction of lerx airflow clearly an innovation intended to work with 3d nozzles and total vehicle management / control surface scheduling system (a technology pioneered in the preceding rival MFI project).
Platform:
Clearly a hybrid between the Yf 22 and the Yf 23 this design appears to combine the best features of both, much as the Su 27 Flanker incorporated the best lessons of the teen generation that preceded it. Wing planform appears F 22 optimised for supercruise but with all moving butterfly tails an attempt to wring out maximum control authority from tails deliberately sized to reduce supercruise drag and side RCS spikes much as the Northrop Grumman McDonnell Douglas JSF contender utilised butterfly tails to reduce weight and reduce tail size increasing range. Overall crossection appears to be YF 23 influenced to presumably take a advantage of volume and RCS advantages inherent to a flatted diamond (in crossection) design. Forward fuselage appears to blend F35 cockpit canopy integration with the Yf 23 moldline presumably to maximise visibility from the upper half of the diamond crossection unlike the F 22 and Yf 23 that seated canopy moldlines far further up.
Operational Factors:
Clearly the Russians sought the range and volumetric advantages inherent of the Northrop design but without the limitations of this design in maneouvrability. Given the size and reputed loadout of 10 missiles, a Yf 23 design would be a logical choice. Likewise in regards to the nose and tail, the T 50 can be seen as an "2010 update" on the YF 23 concept integrating 3D nozzles for maneouvrability at the expense of aft sector RCS, a similar approach to that taken by the F 35 with its circular nozzles (driven by Stovl and weight saving factors). As such like the F 35 a small narrow lobe in the aft RCS sector may exist. Note in the much lauded VHF band this may even be true of the F 22. Other examples of this "update" include some very F 35 reminiscent shaping solutions in the front assembly and a willingness to try the umproven small tail concept proposed by McDonnell Douglas Grumman Northrop in their JSF contender and later X 36 demonstrator. Unwilling to leave the concept of supermaneuvrability we see some curious nods to Russian obsession with post stall combat; namely a moveable lerx lip above the intakes and integration of 3 d nozzles on a 5th generation design, a first.
Conclusion: A very Russian response to the requirements of range, large loadouts and low RCS performance leveraging the many RCS solutions proposed and / or utilised by the U.S.