Sunday 5 June 2011

Sukhoi- The Emperor of the Skies !!


Military information from the Soviet Union was subject to the most stringent secrecy until the Paris Air Show in 1989. The Sukhoi Design Bureau displayed their Su-27 to the public and it instantly became a sensation! The public display not only amused the experts, but also baffledthe enthusiasts with its stunning display of aerobatic maneuvers.

The “Cobra” is the most popular among them. The Sukhoi could fly in level and pitch up its nose by 120 degrees and return back to the same leveled flight and still be in the control of the pilot. The manoeuvre gets its name because a cobra does the same with its hood.

I’d say that the Sukhoi Su-27 completely redefined the meaning of maneuverability.

The prototypes built in 1980’s came with the FBW control system and backed up with a manual control too. Though the Russians didn’t like to use much of electronics in their jets, the Su-27 surprisingly came with electronic displays and HUDs. Hands on Throttle and Stick (HOTAS) principle was used where all critical operating elements and controls are available on the thrust control lever and the control column (joystick).

Notice that the Su-27 has a hanging nose and a rolling front fuselage. Many pilots still call the Su series as the CRANE. No doubt, the Sukhoi looks elegant. But there are more aerodynamic reasons to its beauty rather than the aesthetic ones. The drooping nose for instance gave the pilot a near to 360 degree view of the environment he was around. Of course there are electronic displays that can give you all the information you need, but the pilot’s capability to understand the environment around him is higher if he can see through his eyes!

The Sukhoi also came with a revolutionary wing design, which makes it unbeatable. It is called as the “Strake Wing”.

The striking features are its variable sweeps within a wing. Closer to the Fuselage is a steep sweep, which makes it more efficient when flying at supersonic speeds, preventing the appearance of rhythmic shock waves. It is then followed by a gentle slope which is a common practice in wing design. Thus the steep sweep improves stability at high speeds; while the gentle sweep along with the fuselage provide a good lift to the massive fighter at low speeds.


Even, the cockpit is elevated from the fuselage as seen from the figure. This not only allows for a good view around, but also has some aerodynamic importance. The air flowing over the cockpit creates a natural low pressure region right behind the cockpit thus providing a good lift without the use of any thrust vectoring principles.

Further improvements over the initial Sukhoi design was done over the years and each of those fighters and bombers are brilliant in their own way! Thrust Vectoring, Canards instead of steep slope to provide additional maneuverability at low speeds was introduced in Su-30. A long range bomber version was also developed. It was so massive that the Su-34 could fly from Moscow to Paris with only a full load of fuel in its internal tanks!!

All these improvements over the years have earned Sukhoi a great deal of respect in the fighter jet community. Most of the manoeuvres that the fifth generation fighter jets do today, the Sukhoi was able to do the same back in 1990s!!! It is evident that the Sukhoi did designs that were more practical and simple.

It was estimated that the design was future proof for at least 20 years. But, that design is still in use and is evolving into more advanced fighter jets. All these make the Sukhoi an EMPEROR of the skies.