June 24, 2013
Credit: Mike Vines/Aviation Week
The high agility demonstrated by the Sukhoi Su-35S fighter at the Paris air show is rooted in a Russian concept in which close-range, low-speed air combat remains important, according to Sukhoi chief test pilot Sergey Bogdan.
The aircraft, equipped with three-axis thrust-vectoring and fully integrated flight and propulsion control, performed maneuvers here which no other operational fighter can match. These include a controlled vertical, flat-attitude descent with the aircraft rotating, and a dynamic deceleration, or “cobra”, leading to a small-radius 180-deg. turn and course reversal. It demonstrated a dynamic deceleration followed by extremely slow flight at a near-90-deg. angle of attack.
“Most of the fighters we have available today with vectored thrust, the Su-30MKI and MKM, can perform these maneuvers,” Bogdan tells Aviation Week. “Where this aircraft is different is that it has more thrust, so when it performs the 'bell' maneuver, it can stand still, with afterburning on, and can sustain flight at 120-140 kph.”
The emphasis in “supermaneuverability” runs counter to much Western air combat doctrine, which stresses high speed, the avoidance of the slower “merge” and tactics that do not lose the aircraft's energy. Bogdan, however, says supermaneuverability can be essential.
“The classical air combat starts at high speed, but if you miss on the first shot—and the probability is there because there are maneuvers to avoid missiles—the combat will be more prolonged,” he says. “After maneuvering, the aircraft will be at a lower speed, but both aircraft may be in a position where they cannot shoot. But supermaneuverability allows an aircraft to turn within three seconds and take another shot.”
However, Bogdan adds, “you have to be careful using that weapon. It's like a sniper—you can't shoot many times from the same spot because you disclose your position.”
As for the doctrine that energy should be conserved, Bogdan notes: “The theory of air combat has always evolved. In the 1940s and 1950s, the first priority was height, then speed, then maneuver and then firepower. Then with the third and fourth generation, it was speed, then height and then maneuver. Supermaneuverability adds to this. It's the knife in the soldier's pocket.”