LCA Tejas versus YF-16 in combat (Part-I)

[21 Dec 2012]

@gambit you are the only one with any insight in this matter. What do you say about the OP's analysis?

 

[SecularNationalist]

 

[zebra7]

Sir with all due respect, the article suggests its comparison of two platforms under combat situation, what i am suggesting is that until and unless you bring the pilot factor into the equation you cannot compare combat situation, that is my personal believe and last i checked i am allowed to express myself, in the end i have also specifically mentioned an apology just to avoid such arguments ...

Kindly stop making assumptions, i made a statement towards the approach towards the article NOT the facts and figures it is using suggesting the equation is not complete, i am not questioning the result of the equation.

My bad. Sir, this is just a computational self assesment of the LCA performance. The real wind tunnel data is with the organisation such as CEMILAC which is not assesible in the public domain. The purpose is to know whether there is any fault in the LCA design which is not very accurate, but gives fare idea. Hope you understand that.

@Blue Marlin Hi !!! following me

 

[Mrc]

LCA has a huge element of surprise...
It will be shooting while being parked in a hanger

 

[Basel]

In earlier post A preliminary performance review of the Indian Light Combat Aircraft
The Author talked about the general flight performance of the Indian LCA “Tejas” as evaluated from ADA data. In an extension to that article, we now talk about the relative performance characteristics of the LCA versus the Lockheed-Martin F-16A/B aircraft operated as the premier frontline fighter by the Pakistani Air Force.



This analysis is based on computationally evaluated performance characteristics models developed by the author. The aerodynamics and flight data for the two aircraft are obtained from the published sources listed in the references of this article. The LCA aerodynamics data is obtained from the Aeronautical Development Agency (ADA) publications and the F-16A/B data is extrapolated from public-domain NASA publications on the aerodynamics of the YF-16 prototype.
The aerodynamic force-coefficient matrix is plugged with a first-order propulsion module to simulate engine performance as a function of local atmospherics and altitude. The data generated by these routines are combined with the known mass properties of the aircraft to generate range and payload data which is then presented below for analysis.
Assumptions that went into the analysis include the empty weight of the LCA as being 6,500 Kg and that of the F-16A/B as ~8,500 kg. The LCA engine used was General Electric F404-GE-IN20 with a rated output of 54 kN and a rated TSFC of 0.77 lbm/lbf-Hr. Similarly, the engine assumed for the F-16A/B is the F110-GE-100 with a rated output 76 kN and TSFC of 0.763 lbm/lbf-hr. The internal fuel capacity of the LCA is assumed to be 3,034 Liters and the aircraft is assumed to be capable of carrying a centerline external drop tank of 725 Liters as well as one 1,200 Liter drop tanks on pylon stations 1 and 2, respectively. The cruise speed of both aircraft are evaluated for maximum range for each condition.
Whilst the LCA is now available in the air-force single-seat fighter (LCA), two-seat trainer (LCA-T) and navy (LCA-N) versions, the following analysis restricts itself to the single-seat air-force version only citing the lack of available information on the other two variants. However, performance for the other variants can be extrapolated from the single-seat air-force version, on which they are all based.
Aerodynamic comparisons and validations
The aerodynamic force coefficient comparison can be summarized in the form of lift-over-drag ratio (L/D) plotted versus lift coefficients (CL) for both the aircraft. The F-16A/B is generally seen to have a slightly higher peak L/D ratio (~11.0) compared with that of the LCA (~9.0) and the peak is attained at a slightly higher CL value of 0.40. The LCA attains this peak at a lower CL value of 0.20. The F-16A/B is generally a heavier aircraft than the LCA and larger in size, which explains why its design is tuned to attain the highest L/D ratio for a higher CL value compared to the much lighter and nimble LCA. The F-16A/B sustained-turn-rate (STR) data is corroborated with the NASA YF-16 flight test data as well. The author generated a series of maximum STR rates for the extrapolated NASA aerodynamic data and has plotted it against the available F-16A/B data for the same Mach number ranges. The comparison is significantly in line with each other, suggesting that the extrapolation models for the YF-16 data to that of the F-16A/B is acceptable for this analysis.



Performance comparisons
The performance of the LCA at 20,000 ft altitude is extracted from the earlier article on its performance. The plot is modified, however, to show the F-16A/B data. The latter aircraft is evaluated for the same equivalent fuel mass as that carried by the LCA when it is armed with a centerline drop-tank and two large pylon drop tanks for a maximum of 6,159 L of fuel. The range attained by the two aircraft are summarized in the form of payload and range plots. The payload is evaluated from 0 to 10,000 kg and is assumed to include the pilot weight and all auxiliary equipment excluding fuel. The vertical axis of the plots is range, measured in kilometers. The combat-radius of the aircraft is considered to be ~40% of the range. For example, a range of 1,000 km corresponds to a combat radius of ~400 km. Plots are provided for the LCA in three conditions: clean (internal fuel only), combat (internal + centerline drop tank) and ferry (internal + centerline drop tank + 2 x wing drop tanks).







The F-16A/B has a generally higher performance engine than that used in the LCA with regard to fuel efficiency. As a result, it attains a higher range (1,930 km at 0 kg payload) versus the LCA (1,553 km at 0 kg payload) under similar conditions. As payload increases the LCA and the F-16A/B maintain this slight difference in range performance at high altitude.
In the horizontal plane STR, the LCA outperforms the F-16A/B at high Mach numbers and the F-16C/D under all Mach number regimes. The nimble LCA can out-turn an F-16A/B at higher Mach numbers and an F-16C/D by a significant margin at lower Mach numbers, which are encountered in a turning fight within visual range. As Mach number increases, the turn rates lower for the F-16 models at a faster rate than that for the LCA with a crossover point at Mach 0.65. At all higher Mach numbers, the difference in turn rates increases substantially once more. The LCA can also pull higher “gee” forces at high Mach numbers than the F-16A/B in the horizontal plane. At high Mach numbers, the F-16 pilot remains at a significant disadvantage in the horizontal plane. Newer “Block” F-16 models only worsen this gap in performance between themselves and the LCA. They are heavier and even less nimble than the early “block” models currently operated by the Pakistani Air Force.
Conclusions
The F-16 pilots are advised to stay away from the LCA in the horizontal plane at high Mach numbers. At lower Mach numbers, they can fight the LCA on an equal footing. If they get into a turning fight with an LCA at high Mach numbers, the LCA will win.
Part-II of this analysis will focus on the maneuvers in the vertical plane.
References
1. Jebakumar, S. K., “Aircraft Performance Improvements: A Practical Approach”, Center for Military Airworthiness and Certification (CEMILAC), March 2009, Bengaluru, India
Dr. Vivek Ahuja

@gambit your opinion is requested on above.

 

[Paksanity]

In earlier post A preliminary performance review of the Indian Light Combat Aircraft
The Author talked about the general flight performance of the Indian LCA “Tejas” as evaluated from ADA data. In an extension to that article, we now talk about the relative performance characteristics of the LCA versus the Lockheed-Martin F-16A/B aircraft operated as the premier frontline fighter by the Pakistani Air Force.



This analysis is based on computationally evaluated performance characteristics models developed by the author. The aerodynamics and flight data for the two aircraft are obtained from the published sources listed in the references of this article. The LCA aerodynamics data is obtained from the Aeronautical Development Agency (ADA) publications and the F-16A/B data is extrapolated from public-domain NASA publications on the aerodynamics of the YF-16 prototype.
The aerodynamic force-coefficient matrix is plugged with a first-order propulsion module to simulate engine performance as a function of local atmospherics and altitude. The data generated by these routines are combined with the known mass properties of the aircraft to generate range and payload data which is then presented below for analysis.
Assumptions that went into the analysis include the empty weight of the LCA as being 6,500 Kg and that of the F-16A/B as ~8,500 kg. The LCA engine used was General Electric F404-GE-IN20 with a rated output of 54 kN and a rated TSFC of 0.77 lbm/lbf-Hr. Similarly, the engine assumed for the F-16A/B is the F110-GE-100 with a rated output 76 kN and TSFC of 0.763 lbm/lbf-hr. The internal fuel capacity of the LCA is assumed to be 3,034 Liters and the aircraft is assumed to be capable of carrying a centerline external drop tank of 725 Liters as well as one 1,200 Liter drop tanks on pylon stations 1 and 2, respectively. The cruise speed of both aircraft are evaluated for maximum range for each condition.
Whilst the LCA is now available in the air-force single-seat fighter (LCA), two-seat trainer (LCA-T) and navy (LCA-N) versions, the following analysis restricts itself to the single-seat air-force version only citing the lack of available information on the other two variants. However, performance for the other variants can be extrapolated from the single-seat air-force version, on which they are all based.
Aerodynamic comparisons and validations
The aerodynamic force coefficient comparison can be summarized in the form of lift-over-drag ratio (L/D) plotted versus lift coefficients (CL) for both the aircraft. The F-16A/B is generally seen to have a slightly higher peak L/D ratio (~11.0) compared with that of the LCA (~9.0) and the peak is attained at a slightly higher CL value of 0.40. The LCA attains this peak at a lower CL value of 0.20. The F-16A/B is generally a heavier aircraft than the LCA and larger in size, which explains why its design is tuned to attain the highest L/D ratio for a higher CL value compared to the much lighter and nimble LCA. The F-16A/B sustained-turn-rate (STR) data is corroborated with the NASA YF-16 flight test data as well. The author generated a series of maximum STR rates for the extrapolated NASA aerodynamic data and has plotted it against the available F-16A/B data for the same Mach number ranges. The comparison is significantly in line with each other, suggesting that the extrapolation models for the YF-16 data to that of the F-16A/B is acceptable for this analysis.



Performance comparisons
The performance of the LCA at 20,000 ft altitude is extracted from the earlier article on its performance. The plot is modified, however, to show the F-16A/B data. The latter aircraft is evaluated for the same equivalent fuel mass as that carried by the LCA when it is armed with a centerline drop-tank and two large pylon drop tanks for a maximum of 6,159 L of fuel. The range attained by the two aircraft are summarized in the form of payload and range plots. The payload is evaluated from 0 to 10,000 kg and is assumed to include the pilot weight and all auxiliary equipment excluding fuel. The vertical axis of the plots is range, measured in kilometers. The combat-radius of the aircraft is considered to be ~40% of the range. For example, a range of 1,000 km corresponds to a combat radius of ~400 km. Plots are provided for the LCA in three conditions: clean (internal fuel only), combat (internal + centerline drop tank) and ferry (internal + centerline drop tank + 2 x wing drop tanks).







The F-16A/B has a generally higher performance engine than that used in the LCA with regard to fuel efficiency. As a result, it attains a higher range (1,930 km at 0 kg payload) versus the LCA (1,553 km at 0 kg payload) under similar conditions. As payload increases the LCA and the F-16A/B maintain this slight difference in range performance at high altitude.
In the horizontal plane STR, the LCA outperforms the F-16A/B at high Mach numbers and the F-16C/D under all Mach number regimes. The nimble LCA can out-turn an F-16A/B at higher Mach numbers and an F-16C/D by a significant margin at lower Mach numbers, which are encountered in a turning fight within visual range. As Mach number increases, the turn rates lower for the F-16 models at a faster rate than that for the LCA with a crossover point at Mach 0.65. At all higher Mach numbers, the difference in turn rates increases substantially once more. The LCA can also pull higher “gee” forces at high Mach numbers than the F-16A/B in the horizontal plane. At high Mach numbers, the F-16 pilot remains at a significant disadvantage in the horizontal plane. Newer “Block” F-16 models only worsen this gap in performance between themselves and the LCA. They are heavier and even less nimble than the early “block” models currently operated by the Pakistani Air Force.
Conclusions
The F-16 pilots are advised to stay away from the LCA in the horizontal plane at high Mach numbers. At lower Mach numbers, they can fight the LCA on an equal footing. If they get into a turning fight with an LCA at high Mach numbers, the LCA will win.
Part-II of this analysis will focus on the maneuvers in the vertical plane.
References
1. Jebakumar, S. K., “Aircraft Performance Improvements: A Practical Approach”, Center for Military Airworthiness and Certification (CEMILAC), March 2009, Bengaluru, India
Dr. Vivek Ahuja

When i started to read the article i knew somehow the super duper Alien Tech LCA is gonna win the fight and it did in the end.

copy paste from BR threads and related member blog

@Manticore @TaimiKhan

LCA pilots will be TRAINED to fight with the F 16

So it is necessary to know the strengths and weaknesses of each Platform

----------------------------------------------------------------------------------------------------------------------------------------
Similarly JF 17 trains and fights with the Chinese Sukhois SU 30 MKK

Because in a real war situation ; they will come face to face with an SU 30 MKI

F-16 performance data has been faked just to make LCA look good. Here is the F-16 performance at same altitude with even higher weight (9460 kg) and it is obvious that F-16 turns tighter, sharper and for longer than it's been shown in fake graphs. Look at turn rate at Mach 0.8. Source is F-16.net - The ultimate F-16, F-22, F-35 reference and graph is from declassified documents of F-16.

F-16 is a mean machine perfected to kill. LCA won't have it easy especially by faking graphs!

 

[zebra7]

F-16 performance data has been faked just to make LCA look good. Here is the F-16 performance at same altitude with even higher weight (9460 kg) and it is obvious that F-16 turns tighter, sharper and for longer than it's been shown in fake graphs. Look at turn rate at Mach 0.8. Source is F-16.net - The ultimate F-16, F-22, F-35 reference and graph is from declassified documents of F-16.

View attachment 267898


F-16 is a mean machine perfected to kill. LCA won't have it easy especially by faking graphs!

Both data could only be compared when the conditions are same e.g altitude, payload, and the declassified data you have presented is with the Wet power which are different in both cases.

And by the way you posted the official/ or declassified data and the Author have use the software analysis which he have developed and used the public domain constants which was available, and plotted the LCA surface himself using open source software and using NASA published YF-16 prototype data. So why are you taking it too seriously. Its just the self assessment of aerodynamic performance of LCA compare to YF-16 prototype.

The real data will be with the Boieng/LM or HAL/CEMILAC

F-16 A/B is one of the best designed Multirole fighter plane and it is with 23 countries service, so why are you getting hyper, when in the modern time offbore wvr missile, and longrange bvr dominates, so why getting so much excited when there is no comparison of Combat capability.

The Purpose of the post to see the shortfall of the LCA or the fault in the design, range and to see in which role it is suited e.g it is only better in supersonic speed not subsonic speed. And YF-16 data is also ploted to validate the software result. Just cool down and think calmly.

Regards.

@amardeep mishra Sir your view on this thread is highly appreciable and your knowlege and technical view is needed. Thanking you in advance.

 

[Paksanity]

Both data could only be compared when the conditions are same e.g altitude, payload, and the declassified data you have presented is with the Wet power which are different in both cases.

And by the way you posted the official/ or declassified data and the Author have use the software analysis which he have developed and used the public domain constants which was available, and plotted the LCA surface himself using open source software and using NASA published YF-16 prototype data. So why are you taking it too seriously. Its just the self assessment of aerodynamic performance of LCA compare to YF-16 prototype.

The real data will be with the Boieng/LM or HAL/CEMILAC

F-16 A/B is one of the best designed Multirole fighter plane and it is with 23 countries service, so why are you getting hyper, when in the modern time offbore wvr missile, and longrange bvr dominates, so why getting so much excited when there is no comparison of Combat capability.

The Purpose of the post to see the shortfall of the LCA or the fault in the design, range and to see in which role it is suited e.g it is only better in supersonic speed not subsonic speed. And YF-16 data is also ploted to validate the software result. Just cool down and think calmly.

Regards.

Data parameters are same. Altitudes is same, weight is even worse for F-16. Aircraft version is same (Block-15). Maximum turn rates are always calculated at max wet power; no two ways about it. Only results are different??

F-16.net is very reputable site; best there is for information on F-16 through open sources. Your entire argument is based on these graphs and now you are saying you don't know the parameters at which these two were compared at? It isn't a rocket science to figure out these graphs are fake. May I ask what is the origin of these graphs so we can ascertain their authenticity? There is huge probability you won't have an answer and even greater probability that LCA performance was also faked.

 

[Mrc]

LCA can never be shot down...

How can u shoot sown a plane which iz already on ground??

Mind blowing genious

 

[Stag112]

Very difficult to make a technical comparison without some kind of official sanction. Of course full points for the effort, and infinitely better than idiotic trolling posts by pakistanis on all Tejas threads.

Tejas has had 2983 flights so far. Not that a good pakistani lets facts come in the way of their beliefs.

 

[vsdave2302]

I am very exited to read this comperision. Writer in an another article had written that even 5 to 10% weight reduction in Jejas will result in huge improvement in performance. 6% Aerodynamic improvement and 800 KG weight reduction is on card. Both put to gather should improve the LCA's performance by a huge margine. I believe that its speed will touch Mach 1.8 and turn rate will touch 18* per second, Climb rate and range will also improve a lot. If the planned Air intake redesign and wind redesign is also taken care of than this plane shall provide an unmatched performance in its class. I believe that nose cone is also redesigned aerodynamically. Hard work of our scientists is paying off. This plane is going to rule the sky for sure.

LCA can never be shot down...

How can u shoot sown a plane which iz already on ground??

Mind blowing genious

It seems that you guys are very eager to shoot down Tejas. If not in reality than in wishfull thinking. Even manufacturers of JF 17 China said that JF 17 is a plane of today when the Tejas is a plane of tomorrow.

 

[karakoram]

LCA is like penguin its a bird but can't fly

 

[kṣamā]

Hmm interesting. This just goes on to highlight much works need to be done. Its not that in its Current form Tejas is ineffective, rather the immprovements will make it a the best platform than what we had for the same role.

 

[GURU DUTT]

Till than an AMRAAM would exterminate it .. Or a SD-10B

not so easy want to know ...............why

1.tejas more than 95%skin area & 45% in overall body is made of carbon composites which is a bad conductor of radiation meaning lesser RCS look at it this way M2K was made to compete with F-16 & tejas RCS is 1/3rd of M2K hence less detectabl;e from distance

2.tejas has a radar that can track 2m2 RCS fighter sized target in acsess of 80KM

3.Tejas also has 100KM range range BVR I Derby ER which is same or maybe more than the range of AIM120C which PAF has with tejas also has 50KM+ Derby BVR & Python5 WVR

4.Tejas also has internal EW suite with external jammer pods

so dont worry it wont be a cake walk + tejas will also benefit from indian SAM network & multi band & multi layere PESA & AESA land , aerostat & AWACS based radar network but even if you forget all that to get a shot at tejas first your F-16 have to defete & kill IAFs first line of defence the MKIs,M2Ks,Mig29s7 bisons

 

[zebra7]

Data parameters are same. Altitudes is same, weight is even worse for F-16. Aircraft version is same (Block-15). Maximum turn rates are always calculated at max wet power; no two ways about it. Only results are different??

F-16.net is very reputable site; best there is for information on F-16 through open sources. Your entire argument is based on these graphs and now you are saying you don't know the parameters at which these two were compared at? It isn't a rocket science to figure out these graphs are fake. May I ask what is the origin of these graphs so we can ascertain their authenticity? There is huge probability you won't have an answer and even greater probability that LCA performance was also faked.

Dear Sir,
F-16.net is a forum, just like PDF and the information getting from it is not reliable nor official period.
Here the author have evaluated the LCA, aerodynamic performance using surface-vorticity solver called FlightStream, developed by the Research in Flight Company Flight Company (found here).The Author developed this software years ago as part of his academic research work and has applied this software to the LCA. In doing so, the primary aerodynamic data such as the force and moment coefficients can be evaluated as a function of angle-of-attack and altitude. The accuracy of FlightStream, for such an analysis, is acceptable only for the range of Mach numbers from low subsonic till the point of local supersonic flow over the wings and from small angles of attack till the point of flow separation over the wings. Working backwards from the available three-view data for the LCA available in the public domain, a surface mesh of the LCA was created using the open-source NASA software OpenVSP (found here). FlightStream has direct connectivity with OpenVSP and the surface mesh solution is evaluated for vorticity. The vorticity data is then used by the solver to generate aerodynamic loads data. Using this approach, the author was able to get reasonably close to the wind-tunnel data evaluated by the Aeronautical Development Agency (ADA) as shown below for the force coefficient matrix

The force-coefficient matrix is plugged with a first-order propulsion module to simulate engine performance as a function of local atmospherics and altitude. The data generated by these routines are combined with the known mass properties of the aircraft to generate range and payload data which is then presented below for analysis. The said analysis is simplified to allow the reader to grasp the essentials of the performance results for the LCA.
Assumptions that went into the analysis include the empty weight of the LCA as being 6,500 Kg. The engine used was General Electric F404-GE-IN20 with a rated output of ~54 kN and a rated TSFC of ~0.77 lbm/lbf-Hr.

F-16A/B data is extrapolated from public-domain NASA publications on the aerodynamics of the YF-16 prototype.

I would like to advice you to read the article completely. For any doubt and query pls contact the author of the article.