The J-9 was a 1960s Chinese attempt at building an incredibly fast Interceptor, largely with the intent of building an aircraft that would eclipse the F-4 Phantom II in air-to-air combat.

It was a highly ambitious design that was to wrap a delta-canard airframe around a Low-Bypass Turbofan with up to 27000lbs of thrust, in order to enable Mach 2.8 speeds at altitudes of up to 92000ft.
The design itself was sound, but needless to say, the technology required to actually *build* such a machine was largely non-existent in China in the 1960s and 1970s.

Moreover, the complaints to that effect of the design team behind the ill-fated J-9 fell upon deaf ears; they suggested a lighter, somewhat slower, Turbojet-powered version (a sort of a "Super Mig-21", if you will) with greater range and maneuverability, but the establishment would not be swayed.
The 1967 Border War with the Soviet Union and the Cultural Revolution also disrupted the development of the J-9, but it was ultimately the realization that China just didn't have the technology that killed the program --- and that was in *1975*.

In the VERY unlikely even that China WAS able to pull-off the J-9, it would have radically shifted the balance of power between Russia, USA, and China.
But it wasn't to be, and China would continue to have problems with the technologies that were to be used in the J-9 (notably high-performance, Low-Bypass Turbofans) for decades to come.

However, the very similar J-8 (the sister program of the J-9) ultimately *did* see completion, once funding was shifted away from the J-9, and it went-on to become the J-8 I Finback A.
Though it sucked... a LOT.


Also, note that the "Fastback" code-name is my own concoction. It seems perfect for the J-9, because it's layout is extremely similar to the J-8 Finback (hence, the "-back" part), and --- of course --- it's damned fast (hence, the "Fast" part).


The data below reflects what an *operational* J-9 would have performed like.
I "watered-down" a few of it's performance stats, since I have a VERY hard time believing that the official performance figures are actually possible in an airframe of this configuration (a 92000ft Service Ceiling? Seriously?!).

============ J-9 Fastback Data ============

Role: Air Superiority Fighter
Unit Price: $30 Million
Crew: 1
Size(LxWxH): ~59x40x18ft
Wing Area: 538ft2
Empty Weight: 28700lbs
Internal Fuel: ~12000lbs
Payload: ~12000lbs
Max. T/O Weight: ~55000lbs
Wing Loading: ~53.34lb/ft2
T/W Ratio: ~0.95
Fuel Fraction: ~48%
Range: 1000 miles
Ceiling: 80000ft
Cruise Speed: Mach 1.6
Top Speed: Mach 2.6
Climb Rate: 51000ft/min
Initial Turn Rate: 22 degrees/sec
Continuous Turn Rate: 15 degrees/sec
Max. G-Load: +8/-3
Sensors:Type 205 Pulse-Doppler Radar, RWR
Scan Range: 40 miles @ 30 degrees
Look Down: Yes
Shoot Down: Yes
Propulsion: WS-6 Low-Bypass Turbofan w/18700lbs Military Thrust, 27300lbs/AB
Thrust Vectoring: No
Weapon Stations: 2×Type 23-III 23mm autocannon w/400rds, 1x Centerline Hardpoint w/3000lb Capacity, 2x Underfuselage Hardpoint w/2000lb Capacity, 2x Underwing Hardpoint w/2000lb Capacity, 2x Underwing Hardpoint w/1000lb Capacity
ECMs: Chaff/Flare dispenser (30/30rds)
FBW: No
RCS: 60ft/2
Stealth: No
Tailhook: No
Catapult Hitch: No
Drag Chute: No
AAR: Yes
Other: Clamshell Canopy, Zero-Zero Ejection Seat