HAL Tejas Jet Fighter

Re: Hal tejas

Although small wing loading contributes to maneuverbility, the overall design of the aircraft and its use of tail elevon and carnard, counts too.

I know this isn't about J-10 but isn't it surprising that J-10 is in the top 3 of the double engined jet fighters when it comes to useful weight? That's provided J-10 performance data is already well known and those in the table are correct or are close to it.

Re: Hal tejas

Quickie said:

Although small wing loading contributes to maneuverbility, the overall design of the aircraft and its use of tail elevon and carnard, counts too.

I know this isn't about J-10 but isn't it surprising that J-10 is in the top 3 of the double engined jet fighters when it comes to useful weight? That's provided J-10 performance data is already well known and those in the table are correct or are close to it.

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Most of that table is total conjecture. The performance data for several of these fighters are unknown and have not been published anywhere AFAIK.

Re: Hal tejas

ZTZ99 said:

Most of that table is total conjecture. The performance data for several of these fighters are unknown and have not been published anywhere AFAIK.

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IN fact I really don't think that the fighters listed are comparable at all. Eurofighter is a twin-engine "heavy" fighter while J-10 is a medium fighter and LCA, alone with JF-17, are around the same size as MIG-21s.

I believe that the original topic about HAL Tejas's Cost Vs Performance thing is more or less finished.

Now this thread, if it proceeds, is going to talk about unrelated issues (and off course, I have no issues with that).

Actually, J-10 data needs revision:

As per wikipedia (which many people here don't trust) ... still:

Loaded Weight = 18,500 kg
Empty Weight = 8,850 kg (average of the range given on wikipedia).

As a formula I have used, Useful Weight = Loaded Weight - Empty Weight
(for all aircraft)

However, for J-10, another figure called "Useful weight" is quoted in wikipedia as 6000 kg.

So, possibly useful weight of J-10 is not 9650 kg, but 6000 kg, and it will then lie between Eurofighter and Sukhoi30MKI.

18.5 tons is quite a heavy aircraft to run on a single engine even though the engine used - AL31FN is quite a large engine (much larger than eurofighter's engines).

The empty weight of J-10 (= 8850 kg) is quite comparable to other single engined aircraft (One less engine does save weight !). But to carry a loaded weight of 18.5 tons, I think J-10 was better designed as a twin-engined aircraft.

I am beginning to suspect that J-10 could be underpowered with it's single engine.
(And this is a great statement to invite flaming and lead to closure of this thread).

Try to remain calm .... HAL Tejas can be BS on lot many features, too.
So, can be US / Russian or European fighters (You may have heard about Gripen's crashes, Sukhoi30MKI crashes). No aircraft if perfect on everything.

I am really keen to know the maximum AoA of J-10 (from a reliable source). Have not been able to find.

I'll write what I know:
HAL Tejas = 28 degrees (tested upto 24 degrees, as of now).
Sukhoi 30MKI = 50 degrees
F-18 Super Hornet = 58 degrees

Can anyone compile AoA of all the aircraft ?

Hi all,

Just out of curiosity, what was/is the Indian Air Force original or current plans for the LCA? I know there are much talk about it (the LCA) intended as a replacement for MiG-21, but in what (military) roles does the Indian Air Force intend to use the Tejas?

I'm not a military person myself and know little about operation of air forces around the world, but just brief description will be appreciated. Cheers!

Hal Tejas will mostly be used for air defence, and will fly in Indian air space.

(unlike Su30MKI, which is deep penetration fighter aircraft and is suited for combat over enemy territory ..... and achieve air superiority in enemy airspace).

Mig 21 is not only a 3rd gen aircraft (e.g. no Fly-by-wire). It can defend against Mig-21 type aircraft.

But more importantly it faces aging problems .... it has a metal airframe and is subject to seasoning. The oldest Migs in IAF may already be 30 years old.

But till Tejas is inducted, IAF will need to hold on to these (esp Mig-21 bis). I guess, atleast upto 2018 when last Mig-21 could be retired.

siegecrossbow said:

IN fact I really don't think that the fighters listed are comparable at all. Eurofighter is a twin-engine "heavy" fighter while J-10 is a medium fighter and LCA, alone with JF-17, are around the same size as MIG-21s.

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Exactly. It's like comparing F-22 to the F-35 or the F-15 to the F-16. Even forgetting the fact that these numbers are being created out of thin air by random internet people, the table needs to be split into heavyweight, mediumweight, and lightweight fighters. Cost vs performance analyses must at the very least take the fighter class in mind, as many fighters of different classes don't have the same roles.

bingo said:

I believe that the original topic about HAL Tejas's Cost Vs Performance thing is more or less finished.

Now this thread, if it proceeds, is going to talk about unrelated issues (and off course, I have no issues with that).

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I believe you don't have any say in what we talk about in this thread, as long as it is related to the HAL Tejas.

ZTZ99 said:

Exactly. It's like comparing F-22 to the F-35 or the F-15 to the F-16. Even forgetting the fact that these numbers are being created out of thin air by random internet people, the table needs to be split into heavyweight, mediumweight, and lightweight fighters. Cost vs performance analyses must at the very least take the fighter class in mind, as many fighters of different classes don't have the same roles.

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It's not the only mistake he made.Another one is the Eurofighter,the J10 and JF17 are all in service.The LCA, somehow is still on paper.We have no clue how long it will need to get matured.The Indians already spent 30 years on it while it's still not fully operational.

clone7803 said:

It's not the only mistake he made.Another one is the Eurofighter,the J10 and JF17 are all in service.The LCA, somehow is still on paper.We have no clue how long it will need to get matured.The Indians already spent 30 years on it while it's still not fully operational.

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Technically India has already built 10 operational planes (6 prototypes and 4 will enter service). However as you said India already spent too long (since 1975) and too much money (over 1 billion dollars) on this program and we must keep in mind that fighter capabilities have increased a great deal during this time period. It almost seems as if the LCA is India's answer to China's troubled J-8 which was already behind, technologically, when it was on the drawing board and required major modifications. Instead of investing too much on the LCAs I think India should use the valuable knowledge gained during the thirty year period to produce its version of "J-10".

Although the LCA has taken over 30 years to develop, India started from basically 0 knowledge of how to build a modern fighter. They had to develop all the basic material sciences, develop design houses, deal with embargoes, they have had a tough going. The knowledge gained from making the LCA has allowed them to install Indian designed systems into the SU-30MKI, Jaguar and Mig-27, so it has born them some fruit, but its comparable to the JF-17, so not outdated for its intended adversary.
India is also developing a stealth fighter, in addition to the one it is making with Russia, though I have no idea what progress, if any they made on that.