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The J-8 design is an old one, with more weaknesses than strengths. It’s based on the 60s design philosophy of minimising drag to achieve high speeds and acceleration - at the expense of manoeuvrability, structural strength and visibility - features of which are so important to modern multi-role fighter jets, but which perversely has little affect on the primary role the J-8’s now been handed down – BVR engagements.

The overall configuration is generally similar to the J-7/Mig-21, the plane on which it was based. A pair of mid-mounted deltas form the wings, which unlike the Mirage deltas, are supplemented by a pair of elevators. This ‘tailed delta’ configuration gave the J-7 a good instantaneous turn rate at subsonic speeds; however, a higher weight and a longer airframe has prevented the J-8 from inheriting the same trait, weight and the distance of its distribution from the centre-of-gravity being the primary factor affecting pitch inertia (and therefore turn rate). Further hampering its manoeuvrability is the type’s lack of good structure integrity, with the maximum Gs possible being only +6.9, compared with the Mig-21’s +8.

One positive characteristic which has been passed on from the Mig-21 design, however, is the low drag. The sleek shape is helped by the cockpit lying flush against the fuselage, which itself is shaped using the Coke-bottle ‘area rule’ principle, both features of which help to decrease drag. This low drag combined with a high thrust-to-weight ratio has imparted the type a very respectable energy performance. Indeed, energy performance was the only thing which managed to earn the praise of those US pilots who tested the type for Peace Pearl.

Other problems which affected the original J-8 were inadequate directional stability, and a nose too small to accommodate large radars. These problems have been fixed starting from the J-8II (J-8B) onwards, on which SAC engineers added a large ventral fin that folds during takeoff and landing, and a solid nose cone; the original nose intake being replaced with Mig-23 style side intakes. In all, about 70 percent of the airframe was redesigned, although the overall configuration was unchanged. Apart from the improved all-weather capability from the new radar, the more powerful engines also gave the J-8II improved manoeuvrability at low and medium altitude, and improved energy performance.

The ultimate design of the J-8 might yet still arrive, however. Based on the J-8ACT (Active Control Technology) technology demonstrator, the J-8III (J-8C) variant will have a shortened airframe, and use canard foreplanes, to produce vortices, and induce pitch instability. When used in combination with an FBW system, the J-8III should have a significantly improved manoeuvrability. The J-8III will also have a bubble canopy for improved visibility, and more powerful WP-14 (16,535lb) engines. However, whether there be a J-8III or not, the J-8 family has in the writer's opinion, already come of age.

Late model J-8IIs, such as the J-8IIH, which combine superb energy performance with modern avionics and weapons, provide a credible challenge to any aircraft in BVR engagements. In the BVR regime, energy performance is a good substitute for turn performance, and visibility. Apart from being able to give more kinetic energy to any missiles launched, good energy performance would allow J-8IIHs to simply turn tail when faced with an incoming missile. This would either allow them to outrun the missile completely, or bleed its energy, which can then be followed by a wide ascending barrel roll out of its plane of motion. This is one of the most effective evasive manoeuvres available, and one well suited to the J-8IIH’s unique blend of strengths and deficiencies, although it is pure speculation whether this has become a part of Chinese doctrine.