Tejas MK1A vs Gripen NG & J 10

The recent article appeared in India Today, based on a decade old report triggered a series of debates about the capabilities of Tejas aircraft. So we decided to create an article comparing one of the world’s most dominant single engine fighter that is Gripen NG with Tejas. 

Introduction
 
The Gripen has American Engine, IRST and AESA radar made by an Italian-British company, missile launch rails made by an American company, Cockpit made by an Israeli company, many other foreign components and foreign weapons. Still the Gripen is called an Indegeneous Weapon nobody has any problem in buying Gripen. Because it is Gripen It is not HAL Tejas. In HAL Tejas apart from engine and Radar there is rarely anything that has been a foreign product. Still people say Tejas not indigenous.

Saab has been making aircrafts since the 1930s. They take 70 years to produce an aircraft like Gripen NG, we only take 30 years to develop an aircraft like Tejas. There is lot of problems faced from the start of the project and the western sanctions also affect the program still we managed to develop a world class fighter. 65% of Tejas is ingenuously developed. Tejas MK 2 will incorporate 90% indigenous tech and surely it can outperform Gripen NG in many areas. Gripen considered as one of the best multi role fighter in the world. Many defense analysts place Gripen inside the top 10 table. We must be proud of by our achievements and must support our great scientists.
​
The comparison between Tejas and Gripen is in the following 4 criteria’s

• Stealth
• Maneuverability
• Avionics
• Weapons
• Engine and Power

read the complete analysis of Tejas

Stealth

Both Tejas and Gripen incorporate a certain amount of stealth. Gripen uses 30% composites & Tejas uses 45 % composites. 90% of the surface of Tejas is made of composites. The RCS of Tejas not publically available. Tejas MK2 will contain 70% of composites surely MK2 will have a considerable advantage in stealth. Both Gripen and Tejas using Radar Absorbent materials and coating for reducing RCS.

RCS of Tejas = 0.5 m2
RCS of Gripen = 0.9 m2

Maneuverability

So far as aerodynamics is concern, Gripen is an excellently designed plane which gives it a very good speed and long range. LCA Mk1 was considered to be a bit draggy but a lots of studies have been made to improve its aerodynamics is concern. Making LCA Mk2 1m longer is  a part of Aerodynamic improvement process for better compliance of Area rule. There are some other aerodynamics changes which are coming in LCA Mk2. Study says that it will reduce drag by 8% and improve trans sonic acceleration by 20%.. So these aerodynamic changes should make LCA Mk2 a plane with very good aerodynamic characteristic.

For good turning performance wing loading should be low and thrust to weight ratio (TWR) should be high. Tejas has an advantage in both TWR and wing loading. The thrust-to-weight ratio of a combat aircraft is a good indicator of the maneuverability of the aircraft. So Tejas should have better turn rates than Gripen .Tejas shall be at a big advantage because of its light empty weight and should maneuver fast and probably can beat Gripen in close combat. Its small airframe makes it difficult for the enemy pilot to spot in a close combat. Tejas have an advantage of low wing loading also which should give it an edge at high altitude fighting. Some websites claims Gripen has superior Sustained turn Rate than any other aircraft anyway we are not considering it as a credible source. However airplane design always a compromise & both wing loading & TWR can be “adjusted” within some margins to enhance turning performance. We don’t know anything more about the specifications of Gripen to evaluate its maneuverability. Even though Tejas has better turn rates we consider both Tejas and Gripen almost equally maneuverable.

TWR Tejas = 1.07
TWR Gripen = 0.97
Wing loading Tejas = 247kg/m2
Wing loading Tejas = 283kg/m2

Avionics

Gripen got very good radar, a gallium Nitride based radar. LCA Mk2 is also all set to get top of the class AESA radar till Uttam is ready with 150 KM range. Israel has offered ELTA 2052. Recently Thales has flight-tested active array radar built specifically for Tejas. The radar is based on the company’s successful RBE2 radar installed on Rafale fighter jets. With the latest Thales AESA radar MK1A can kick out any of its adversaries. But still lags behind Gripens GaN Raven radar.
​
Gripen also going to get a world class IRST in the form of Selex skyward G and tejas doesn’t have any IRST till now. With the help of GaN radar and skyward G IRST gripen can detect stealthy fifth generation fighter aircraft's at long distances.

In Electronic Warfare Gripen is the first aircraft which uses electronic warfare system based on gallium nitride technology, India and Israel are making EW for Tejas and has designed MAYAVI Ew suite for Tejas and work is on for better EW. India has got spectra configured for Indian requirement. If spectra technologies goes in LCA MK2 by the way of buy back clause, it will be superior to Gripen. If not, Indo-Israeli EW will catch up with that of gripen .

So far sensor fusion is concern; Gripen is a top class plane. India is also working on sensor fusion but how much effective that will be is not known. Here is an area where I see gripen is significantly out performing Tejas in current scenario. Gripens sensor fusion is only inferior to F35 , and nobody knows how good will be India’s own sensor fusion.  In avionics Gripen is atleast a generation ahead than Tejas Mk1A. May be MK2 can catch up with Gripen NG.

Weapons

Both Tejas & Gripen have  very good targeting pod and weapons . India shall use Python, derby and Russian missiles along with Astra. Gripen uses AIM Series and Meteor missile. Meteor is a top class missile but new Israel claims I Derby can provide 80% of meteor performance. Astra 2 the desi meteor is under development can also be include in Tejas Mk2 weaponry. Both planes are neck to neck in A to A missiles but If Meteor is used, Gripen will have a superior edge. Both will have gun according to their requirement and both can use guided bombs. India has just tested SAAW bomb which will give LCA MK2 an edge in anti airfield strike capability.

Engine and Power

Both Tejas and Gripen deriving the power from same engine GE 414 with a Dry thrust of 62 KN and 98 KN in afterburner. However India is also working on indigenous kaveri engine with the help of Snecma France. New Kaveri engine is supposed to have same power as GE 414. LCA Mk1A has 13.2 M long which is 2 meter short in length of Gripen. Both planes have same g limits. LCA mk1As service ceiling is 16000 m which is higher than the 15240m of Gripen . This is because of low wing loading and will give protection to LCA against many short range and shoulder fire missiles and SAMs. MK2 may have even better service ceiling which will increase the advantage of MK2 over Gripen NG.

Gripen has better speed than Tejas which does not make a big difference. But the super cruising ability of Gripen gives it an advantage of Tejas Mk1A, but we can incorporate super cruise ability in Tejas MK2.  However, supercruising uses more fuel to travel the same distance than at subsonic speeds but uses less fuel than afterburner.  
Gripens Higher cruise speed allows pilot to surprise the enemy by approaching him from the rear, zone of poorest detection, and to avoid getting surprised by a slower-cruising opponent. It also allows the fighter to choose a time and place of engagement.

In the beyond visual range combat, super cruise capability increases range of the missile shot, and reduces the effective range of adversary’s missiles. If pilot decides to pursue a merge or a visual-range attack pass, its excess kinetic energy again allows it to dictate terms of the engagement. It can also offset a possible situational awareness disadvantage – knowing where the enemy is is of little use if you can’t engage him.

Super cruise is an area where MK1A lag behind Gripen.

Max Speed Of Tejas – mach 1.8
Max Speed Of Gripen – mach 2
 
LCA MK1A has 500 m take off distance (some sources says it is 700m). Gripen NG has a short take off distance of 400m which favors Gripen and it will reduce at least 15% in Mk2 so mk2 will have equal short take off distance.[Figures may not be accurate ].

Speed at sea level is also against Tejas compared to Gripen, Gripen got 1400 Km/H at sea level Tejas got 1300 Km/H. We believe things will change in Tejas Mk2 with better aerodynamic features Mk2 can catch up with Gripen .
 
The maximum takeoff weight (MTOW) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. MTOW is the heaviest weight at which the aircraft has been shown to meet all the airworthiness requirements applicable to it. Gripen has a MTOW of 16500 Kg Ideally it should be 2.5 times the dry thrust which comes around 15.62 tons but let us assume that it is 16.5 tons as stated in specification. LCA Mk2 uses the same engine so it should have an ability of 16.5 tons MTOW but let us apply that 2.5 factor rule. LCA Mk2 should carry atleast 15.62 MTOW. Now Gripen with 8 ton weight +3.4 ton fuel is left with 5.1 ton payload on plane. On the other hand LCA MK2 with 6.2 ton empty weight and similar fuel of 3.4 ton should left Tejas with 5.7 ton weight which compares favorably to Gripen.

Fuel fraction or propellant fraction, is the weight of the fuel or propellant divided by the gross take-off weight of the craft (including propellant). Fuel fraction of Tejas & gripen is almost similar. So far as range is concern, Tejas should have higher range as both planes are using same engine but Tejas being significantly lighter should have a longer range. But gripen has a considerable advantage in range. An aircraft with more and heavier load (Gripen) should have a smaller radius of action than the same one with less and lighter load (Tejas), due to higher fuel consumption at heavier weights.
 
Combat Radius of Tejas = 400 Km
Combat Radius of Gripen = 800Km

Why Tejas has less combat radius than Gripen even though both uses similar engines, this is a mystery.

Possible Reasons of Less Combat radius

• There is one possibility is that, Gripen has super cruise capability. That is Gripen shaped in such a way that it has the lowest drag as possible to make gripen super cruising so gripen can travel further. Increased drag of Tejas compared to gripen may be the one reason behind tejas less range.
• Range is a function of ground speed. But range is directly affected by wind. An extreme example occurs when the relative velocity of an airplane through the air is 100km/h and there is a head wind of 100km/h. the ground speed is zero the air plane just hover over the same location & the range is zero. Clearly range depends upon the wind. The thing is Tejas wing loading is smaller than Gripen , which is better for maneuvering. But smaller wing loading and relaxed static stability of Tejas may cause increased gust response, to stabilize the flight aircraft need to use more energy results in increased fuel consumption.
• The most suitable explanation for this paradox is Tejas air intake, the air intake is not good enough to tap the full potential of GE414 Engine. Current air intake is designed for indigenous Kaveri engine & is not 100% suitable for GE 414.  And we believe this is the primary reason behind Tejas less combat radius. Auxiliary air intakes are provided for Tejas but this may not be able to help in all the flight paths.  Hopefully the problem can solve in Tejas mk2.

​Conclusion
 
Both planes are very good having their edge over others in different area. However, Tejas with its small size and very high T/W ratio offers many advantages as a platform. Gripen has significant advantage over Tejas in Avionics and sensor fusion and have slight advantage in weapons its almost similar in all other criteria’s. Tejas MK2 with better Radar, Smart Skin, and Internal Unified Electronic Warfare (Under development) can catch up with Gripen NG. Overall Gripen is the only 4th generation single engine aircraft which has a significant advantage over Tejas.

Why IAF looking for another single Engine Fighter

The major reason behind this is HAL said Tejas MK2 will not come before 2024; HALs engineers and scientists are busy with AMCA project. IAF can’t wait for another 7 or more years for Mk2.And the future technologies expecting in Tejas MK2 will not be a proven one and IAF don’t know how good it will be, it’s a logical choice to go for a proven technology rather than puzzling with indigenous solution and getting hands into theses advanced western techs will positively added up with AMCA ,one more thing is both Tejas and Gripen will come into Air force in the same time, if we avoid foreign single engine fighters we only get 8 -10 Tejas in a year otherwise IAF will get 8-10 tejas plus 8-10 gripen in a year that is significantly adding more number of jets in IAFs fleet, that what exactly IAF want now to deal with the dwindling squadron numbers. IAF interested in Gripen mainly because of the advanced Avionics, sensor fusion, net centric capabilities and Electronic Warfare.
​
Note:- This is our own views, it dont have any relation with IAF sources. 

LCA Mk2 shall be very cost effective and offer India a platform to integrate its own weapon. It will have a lots of configuration options also. Once it is ready in next 5 years with Indian engine , Indian AESA, it will be a weapon very difficult for any other system to match and will give India an edge over any other rival in air combat. It will easily outclass anything china or Pakistan has. India can mass produce it and offer it to many friendly countries across the world including Vietnam, Indonesia, African countries and even to the countries like Brazil who are interested in Gripen. It will offer everything which Gripen offers. What India need at this stage is to expedite LCA Mk2 program and make it sure that it goes into production in as early as possible.

A rough comparison between J10 & Tejas
​
The J 10 started off as a Chinese attempt at reverse engineering a Pakistan bought US F-16. However it ended up being a modification of Israel’s Lavi multi role fighter, Lavi program was cancelled in 1987 in Israel due to threatening from US. China purchased the blue print from Israel and developed J 10.

The detail of J 10 is hardly available. From the available data it’s very clear that Tejas is not inferior to J 10. J 10 has advantage in weapon loads; range etc only because it is a bigger aircraft so J10 can carry more weapons.

​Both aircrafts are pretty much maneuverable. One noticeable aspect of Tejas is its wing loading 247 Kg/m2 is much lower than the 381 Kg/m2 of J 10, which results in better agility. This low wing loading of Tejas gives better climb of rate & also gives good cruising performance cause it need less thrust to maintain the stable flight. This better climb rate is a give Tejas advantage in Himalayan regions. Heavier loaded wing is efficient in higher speed because it causes less drag but in overall performance level low wing loading offers better performance. Another advantage is a fighter with low wing loading can maintain better sustained turn rate (maximum turn an aircraft can achieve) aircraft with higher wing loading may have better instantaneous turn rate. So it is clear that in Himalayan regions a low wing loading Tejas can outperform a higher wing loading J 10 in most criteria’s.
 
Another important factor affecting the performance of Chinese J10 is the altitude of China's main airbases "along with the prevalent extreme climatic conditions seriously restrains the performance of aircraft, which reduces the effective payload and combat radius by an average of 50%." In other words, the lower density of air at high-altitude Tibetan bases prevents Chinese Air Force fighters such as the Su-27, J-11 or J-10 from taking off with a full complement of weapons and fuel. These aircraft would, therefore, enter a fight with the IAF at a severe disadvantage in the event of a conflict. The IAF, on the other hand, operates fighters in the Northeast from bases such as Tezpur, Kalaikunda, Chabua and Hasimara which are located near sea level elevations in the plains. This means "the IAF has no such restrictions and will effectively undertake deep penetration and air superiority missions in the Tibetan Autonomous Region."

​Thrust to weight ratio of Tejas is 1.07, which is less compared to 1.15 of J 10. But it can be improved using a better power-plant. Overall the maneuverability is almost similar.

Both aircrafts are fitted with AESA radar, the capabilities of J10 B / J10 C is not available. According to some blogs “J10C is equipped with more advanced radar. It has a greater detection range than the J10 radar to simultaneously track 12 targets and against the ability of the six targets which pose the greatest threat” looks almost similar to Tejas AESA radar.

J 10C has better stealth features than J 10B. Chinese media calling it as a semi stealth fighter, but from our own research, it’s not going to be stealthier than Tejas, even though Chinese media claims it has a new technique to achieve stealth, and some of those claimed J10C is a threat to even F22. Whatever it is,their comparison of J 10C with F 22 is laughable.
​
Overall Tejas can give tough competition to J 10B and is slightly inferior to J10C, Tejas Mk2 with better aerodynamics and more stealth features, can catch up with J10C.