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.

The Air Show Experience !

"Why are you here at office today??" , " Will it be good this time?" , "Are you attending the air show?" , "Where is it? update me with the details?" , "I may not attend. I'm not as enthusiastic as you are!" ,"I'm sure you're not going to miss it" These are the reactions that i got from people around me about the Aero India 2011 which was held at Yelahanka Air Force Base in Bangalore.

On the inagural day, my cousin kept pinging me about what was going on at the Air Force Base(AFB).I was at office and couldn't stop thinking about how much fun it'll be tomorrow seeing the flying birds. I barely slept that night. I was so excited about attending my FIRST ! Air show tomorrow.

The D-day came and there we were, me, my brothers and a few friends. While driving to the AFB, we were greeted by the LCA doing some manoeuvres, a few kilometres from where we were parking the vehicle. Had to take a bus from the parking lot to the base and the F 16 and F 18s that flew during that time made the structure of the whole bus vibrate !!

We enter the gates and there's a long queue to put me into a sad state. Luckily, we got in soon.The first plane i saw from a very close distance was the GA8-TC Airvan from Mahindra Aerospace. It was quite good, but my eyes were searching for a special one ! I was looking for the Sukhoi Su 30 MKI. I've always been awe struck by the amazing manoeuvres it can do. I couldn't find it ! But there were all the planes that i wanted to see though. A whole bunch of private jets, heavy lift transport aircrafts, mid-air refuell tankers, attack helicopters,fighter jets, turbines and a lot more !! I then decided to take it slowly and see all of them one by one.Luckily, got a chance to talk to a french guy from Eurocopter who was kind enough to let me into their Fennec helicopter and feel the controls of the machine. Loved the whole experience with the helicopter. Asked a few questions about it and then took a few pics and headed into the business stalls at the large hangars.

I'd say i have a small collection of tiny model planes and its definitely hard to find good ones here. But, as soon as i entered the hangars, i was overwhelmed to see a lot of detailed large scale models. I have no idea if such big models are available for purchase; but,if it is, I so badly want a lot of them! Went through most of the stalls staring at all those pretty models and saw some cool hardware and test equipments used in the field of Avionics. It was lunch time by then and the weather was hot as hell, added to that was the open areas at the base,and we all were totally exhausted and needed some energy to keep going for the whole noon.

The first display again after lunch was by the Light Combat Aircraft and yes it did fly well, but wasn't that impressive when compared to other jets. I think the test pilots did not want to push the aircraft to its limits as the testing of that aircraft has just begun.And then there was the Intermediate Jet Trainer, it didn't fly fast or do any stunts in the air, but then its a trainer aircraft right?

The next display was by the Russian made Sukhoi Su 30 MKI of the Indian Air Force. Needless to say, its the emperor of the skies and it flew like one. Didn't do the breath taking stunts like the Cobra or the Kulbit, but that was the first aircraft on which i saw the afterburners on. The light blue colored flame from the exhaust nozzles looked great while the whole base was vibrating with its noise. I must say, roaring jet engines is an understatement !

Then was the display by the Eurofighter Typhoon. It's a very small aircraft designed for medium range operations but the capabilities it has are many.I had under estimated that its flying would be not that great and the typhoon took me by surprise.Then came the famous F 16 Falcon and the F 18 Super Hornets. Both the planes performed well and the F 16 pilot did a continuous vertical climb for more than 1500 feet over us and it was a delight to watch it. Low Fly-by, steep turnings, low fly-by with afterburners, steep vertical climbs and a whole lot of other manoeuvres kept the audience wanting to see more.The Sukhoi Superjet and a Saab private jet also did some stunts in the air and we simply hadn't expected such manoeuvres from them.

The red bull aerobatics team were really amazing. They were led by a lady ! Not many women pilots get to lead a stunt team and the stunts which the team performed were wonderful.Then was the turn of the MI 26 choppers and the Saarang team. They did quite well.At last was that of the Suryakirans, our aerobatics stunt team from the Indian Air Force. Used the tricolor of our flag for the trail on their flight path, flew overhead at high speeds, made some close encounter stunts and at last drew a heart with a pierced arrow in the air !

All those planes did so many stunts that are simply hard to explain. Added to that, in between those flight displays, the test pilots who flew the jets used to walk around and make the crowd envy them ! I'm not sure of the crowd, bit i did envy those pilots for sure.

It was just me and the planes all through the day. I realised that day how much more there is to learn about these machines.They still continue to impress me ! I have no clue how time flew so fast that day and towards the end of it, i had about 5 kilos of brochures, around 800 pictures of planes and helicopters, atleast 15,000 crores worth of planes behind me,a tired body but a very happy and satisfied me.

Wonders of FBW

Now that the FBW system related to Commercial aircrafts is clear, lets look at the more exiting part of this technology. That's the FBW Control system of military aircrafts !

Though the whole architecture remains the same,the way its tuned by software to operate for much more extreme conditions is what makes this architecture more interesting. The number of control computers and control surfaces will increase for sure as fighters and other military aircrafts are more agile and powerful than their commercial counterparts. Though the control
systems are customised with each and every aircraft, I'll be looking into a few popular aircrafts and their control systems.


For example, consider the Boeing B2 Stealth Bomber. Just at the first look, the plane seems to look too flat or thin for its size. Notice that the plane does not have a tail too !! It's a known that the tail of a plane is responisble for a large percentage of the Radar Cross Section (RCA) So,Boeing just decided to remove the tail itself ! But they are still managing to fly the plane by continuous control of two control surfaces on either sides of the wing which require frequent adjustments to be made, which can only be done through a computer.




So is the case with an F 117 Stealth Bomber. Its unique shape comes because Radar signals are completely reflected in some other direction instead of bouncing back to the transmitter.This is what makes it a stealth aircraft. The bad shape gives the plane bad aerodynamic efficiency and control ! This can obviously be managed by a computer alone.





Similarly, the V22 Osprey has a unique deisgn. It can operate both as a helicopter and a plane. It works as a helicopter during landings and take-offs. This dual functionality is a part of the design because this feature makes it a utility flying machine and does not need a runway and that makes it very mobile. It operates like an aircraft when its cruising as the efficiency of a plane is more than a helicopter. However, the transistion from the rotors being upright while landing and take offs, to tilting by 90 degrees while in cruise is very crucial and requires a lot of precision and is done by computers rather than pilots. This is one of the reasons why the Harrier Jump jets used to crash a lot during take offs while the F 35 on the other hand can operate smoothly without any considerable risk when compared to the harrier jet.



Artificial Stability is another advantage of the FBW. Instability is deliberately fed into the system and is then controlled by computers for better performance. Consider the Eurofighter Typhoon. While it is taxiing on ground or parked, the nose of the plane always pitches up. This means that the center of gravity for the plane is far from the center and this gives us an advantage! The plane has a tendency to pitch up very easily. The climb rate for such an aircraft is higher than a normal plane. However the plane operates as usual without pitching up all the time as it is controlled by a computer rather than direct control of the pilot. We induce instability into the system and then create stability artificially using computers,hence the name.

With this, posts related to FBW ends.That puts us into thinking about one thing.

Who do you think is really flying the plane ?? Computers or Pilots??