Combat Aircraft technology and Evolution

[ersakthivel]

Re: ADA LCA Tejas - IV

quite strange...I really don't understand you would show off such basic concept here, I thought you needn't push such so called' popularization of science' to me...actually some other members might need your so 'profound' knowledge more ...

what I did were:
1. correct the FC-1/JF17 internal Fuel weight ratio.
2. clarify the so called JF17's "a phenomenal claimed range of 3000 km"---it's a ferry range data, and it's official and possible.
3. also give a concept in China Military Standard of Airplane design ---airplane's Basic range. ...JF17 is designed under China's standard and evaluation system, different country has different concept and standard, I thought it might be helpful to open your mind...use your "@" to them please...LOL

actualy this screenshot of the PPT just explained these three concepts



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to some member on my ignoring list(maybe on many other's list as well...LOL), I do beg you put me on your ignoring list as well and enjoy your own wonderland...

I accept some decent BR member's suggest , I carefully chose a word' ignoring' not 'ignorance', I thought there was much difference...LOL...sorry for my poor English expression

Do you have any chinese power point presentation for your absurd claim ,"tail less deltas have high sub sonic drag , which reduces their operating range"? Mirage-2000 and F-16 XL seems to defy your theory here . Is Mirage-2000 not a tail less delta? How does it's range not getting affected by your claim of "tail less deltas have high sub sonic drag , which reduces their operating range".

you can explain it before advising other forum members to get education from another member.

or

Are you going to keep quiet as per your own statement of,"Ignorance is bliss "and enjoy the wonderland of "all tail less deltas have high sub sonic drag , which reduces their operating range with no proof worth the while" ?

Surely this statement of yours is not English grammatical error.

Mk-1'e empty weight increased due to higher requirements from IAF considering the need for staying up to date in close combat specs and the failure of K-9 to keep up with it. tejas mk-2 will have no problem in that department.

Tejas mk-2 will get the correct proportion of empty weight to optimum SFC of GE 414 INS 6 engine and have a comparable range to all other fighters. as per the following fuel fractions.

ejas:25%
EFT: 31%
F22: 29%
JF17:25%
Gripen C:3000*0.8/8500=28.23
F16 C: 3175/12000=26.4
Rafale: 4700/14900=31.5%
Mirage-2000 = 30%

Since tejas mk-2's empty weight will be tailored to the optimum SFC of GE -414 IN S 6 ,

and with one more ton of internal fuel it's fuel fraction too will come close to 30 percent of Mirage-2000 , allowing a half a ton weight increase for the lengthier fuselage.

So it will have a comparable combat range to Mirage-2000 perhaps. Hope it is not hobbled by your special theory of "tail less deltas have high sub sonic drag , which reduces their operating range",

You are simply confusing the high trim drag of older plain tailless deltas which are avoided by using canards or LREX or LEVCONS or strakes or cranked delta in almost all of modern day deltas to enable beneficial vortex creation to arrive at higher lift to drag ratio..

Since Mirage-2000 andf f-16 Xl don't get affected by this theory of yours , I hope Tejas too won't get affected by your theory.

Well keeping a long Ignore list saves you from such inconvenient question perhaps.Nice practice.

But what is the point of keeping long Ignore lists

and then logging on as an unregistered user

without giving your name in the User name dialogue box ,

to see what these guys who are on your Ignore list posted in threads.

Really tedious practice for me.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

Did it myself

IMHO these methods of calculation won't give you the correct answer as most of the variables you use in the calculation don't vary in a linear manner. Relationships between them is too complex to be arrived at in this manner.

Regards,

 

[Defcon 1]

Re: ADA LCA Tejas - IV

IMHO these methods of calculation won't give you the correct answer as most of the variables you use in the calculation don't vary in a linear manner. Relationships between them is too complex to be arrived at in this manner.

Regards,

What variables? What calculation? I have simply done internal fuel capacity/loaded weight. Nothing is varying here.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

What variables? What calculation? I have simply done internal fuel capacity/loaded weight. Nothing is varying here.

A Kg of fuel burnt supports the loaded weight which varies dynamically.

Also every fighter is built for a specific optimized flight regime and combat profile which will also affect the Lift to Drag ratio which plays a vital part in determining the combat range.

Also the wing shape is another factor in determining the efficiency of fighter ,like deltas are more efficient at trans sonic cruise speeds and high altitude flight than simple compound wings which are efficient in low altitude flight .

So ignoring all these you cannot simply multiply by a factor and divide by another factor to arrive at combat range like the way you described below in your previous post.

But that is incomplete explanation for its limited endurance. To dig deeper I would encourage you to find the Specific fuel consumptions of engines of these aircraft at military thrust, multiply it by the engine thrust and then divide it by internal fuel capacity of the aircraft to get an idea of how fast the aircraft is burning its stores. multiply SFC by 2 in dual engined planes. Though it will only serve as an rough indicator since aircraft don't always fly at military thrust, it will be an indicator nonetheless.

.

 

[Defcon 1]

Re: ADA LCA Tejas - IV

A Kg of fuel burnt supports the loaded weight which varies dynamically.

Also every fighter is built for a specific optimized flight regime and combat profile which will also affect the Lift to Drag ratio which plays a vital part in determining the combat range.

Also the wing shape is another factor in determining the efficiency of fighter ,like deltas are more efficient at trans sonic cruise speeds and high altitude flight than simple compound wings which are efficient in low altitude flight .

So ignoring all these you cannot simply multiply by a factor and divide by another factor to arrive at combat range.

Where the hell did I arrive at the combat range? I have merely written the fuel fractions at loaded weight, as another member asked me to.

 

[rvjpheonix]

Re: ADA LCA Tejas - IV

A Kg of fuel burnt supports the loaded weight which varies dynamically.

Also every fighter is built for a specific optimized flight regime and combat profile which will also affect the Lift to Drag ratio which plays a vital part in determining the combat range.

Also the wing shape is another factor in determining the efficiency of fighter ,like deltas are more efficient at trans sonic cruise speeds and high altitude flight than simple compound wings which are efficient in low altitude flight .

So ignoring all these you cannot simply multiply by a factor and divide by another factor to arrive at combat range like the way you described below in your previous post.
.

He wasn't talking about range but about fuel fraction which is fairly simple.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

Where the hell did I arrive at the combat range? I have merely written the fuel fractions at loaded weight, as another member asked me to.

OK then, sorry for the trouble.

 

[p2prada]

Re: ADA LCA Tejas - IV

...

These are the ranges of different fighters as listed by toan on the f-16 forum. Cross posting.

Declarations and Estimations of Combat Radius for Some Modern Fighters：

1. With internal fuel only：

F-35C：700 NM／1,300 km （AIM-120*2 + 2,000 Ib JDAM*2）.

F-35A：600 NM／1,100 km （AIM-120*2 + 2,000 Ib JDAM*2）.

F-35B：450 NM／830 km （AIM-120*2 + 1,000 Ib JDAM*2）.

EF-2000：350 NM／650 km （MRAAM*4 + SRAAM*2 + 7,000 Ib AG weapons, lo-lo-lo）.

F/A-18C/D：350 NM／650 km （2,000 Ib AG weapon*2）.

JAS-39C/D：350 NM／650 km （1,000 Ib AG weapon*3, lo-lo-lo）.

F-16C/D：260 NM／480 km （2,000 Ib AG weapon*2）.

AV-8B：250 NM／460 km （1,000 Ib AG weapon*2）.


2. With external fuel tanks +/- CFTs：

RAFALE：more than 800 NM／1,480 km（2,000 L tanks*3 + GBU-12*4 or SCALP-EG*2 + AAM*4；Another 15~20% increase in combat radius with the help of CFTs）.

F-16IN：918 NM／1,700 km（3,300 Ib weapons + The help of CFTs）.

EF-2000：800 NM／1,480 km（1,000 L tanks*2 + 1,000 Ib LGB*4 + AAM*6）.

F-16C/D：450 NM／833 km（2,000 Ib AG weapon*2 + The help of 1,400 L tanks）.

JAS-39C/D：450 NM／833 km（1,000 Ib AG weapon*2 + external fuel tank*1, lo-lo-lo）.

So are you saying JF-17 has completely surpassed the F-16? Let's not forget both designs are very similar, JF-17 and F-16.

Note that these are the "actual" ranges of the fighters when you consider radius of action or combat radius.

Range on internal for F-16C is around 1600 Km while lugging 2 big bombs and 3x1400 L tanks. On internal it is around 1000 Km. That's an extra 600 Km with 3 tanks with 3600 L of fuel. Let's not forget JF-17 carries only 3000 L in tanks in comparison.

You want realistic figures. Yes, LCA has a ferry range of around 3000 Km, it is actually lesser. But internal fuel range or the so called "basic" range with only two R-73s is 800-900 Km. Gripen C, a little better. Of course, LCA is currently not meeting such figures as already explained by Decklander.

So, JF-17's basic range is not 1800 Km, it even beats Mirage-2000 and F-16 by a huge margin, let alone LCA.

LCA's combat radius with just internal fuel and two R-73s should be around 400 Km or double that with three tanks.

Of course, JF-17's basic range may be 1800 Km if you add three tanks on it. But the slide doesn't explain anything. It is too much by any logic.

Ferry range by itself is entirely pointless.

If your officials are actually claiming that JF-17 can provide 1800 Km with just 2.3 tons of fuel or around 3000 L of fuel, at 0.6 Km per litre within mission parameters, yeah right. That's why "Chinese" physics. That information is bogus. Actually, with those figures the Russians are practically Gods for making such an engine. With Mig-29K's specs, both the engines give roughly 0.31 Km/L performance, with superior engines. Funny that. The latest F-16IN with 11000 litres of fuel, roughly 0.4 Km/L. LCA should give 0.34 Km/L. Of course, this calculation does not take into consideration take off loss and reserve fuel. So, the figures are actually higher. But considering the same, JF-17 is twice as efficient as some of the best fighters there are. This cannot be achieved by simple reduction in drag or optimizing the airframe for better mileage.

Interestingly, while I have seen the slide many times, you will notice that the actual range performance figures in A/A and A/G mode are not mentioned.

Sorry, Shiphone, you are going to have to do way better if you want to convince me.

 

[p2prada]

Re: ADA LCA Tejas - IV

Infact even I am surprised to read that tailless delta design has higher subsonic drag.

Mirage-2000 has a significantly higher fuel consumption at low altitudes compared to F-16 at same parameters, according to Dassault's flight data.

 

[shiphone]

Re: ADA LCA Tejas - IV

in China standard, we usually use the another concept: basic range with full internal fuel+basic armaments(2 SRAAM+Gun's Ammo in this case), JF17's Basic range is 1800km

and 3000Km is the ferry range with the max external tanks. the FC-1's long range ability is a proved one and the design and test flight team claimed that this little bird has longer ferry range than another product from the same team with the Delta wing--J10

I thought I have made it clear...

1.I introduced a common concept in china military standerd here: the basic range--- which reflects some basic flight performance of a airplane...it's more simlar to the internal fuel range,but with 2 PL5IIE SRAAM and full 23mm Gun ammo in JF17's case... I thought western fighter have something similar---Load range, but maybe more combat payloads considered in that concept . JF17's 1800km basic range doesn't automatically mean the so called Combat Radius would be 900Km or 1500Km(1800/2 or 3000/2)...basic range is a data tested and evaluated in a serial of test flights under the specified conditions.

obviously as Mr Decklander said , the real Combat Radius data would be much complicated.and I didn't say a word about it before...and in china's military standard, we would find some statement like " Typical A2A or A2G Combat Rdius" with the listed typical payload and flight profiles.

2, the questioned 3000 KM is the so called Max Range and ferry range. I'm afraid it is possible even for such a little plane with drop tanks only.

 

[shiphone]

Re: ADA LCA Tejas - IV

BTW, I thought you might think about Mig29 varient's ferry range without drop tank listed on the MIg website...I thought it could be considered to be the internal fuel range...MIg29 used to be labelled as some 'short-leg' by the west.

Mig29 old varients: 1400KM-1500km
Mig29SMT(UPG): 1800KM
Mig29K/KUB: 1800-2000KM

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F16C/D's nearly 4000km ferry range with 3 drop tanks might be able to explain something as well

 

[ersakthivel]

Some interesting comparison of grippen and Tejas in the comments section between Abhiman and Mihir Shaa with some weapon load and combat range figures for both,

ink below, busts many a misconceived myths as tejas being light fighter.

It has almost same empty weight , same weapon load and same range figures as Grippen(mk-1 equivalent to Grippen C/D and tejas mk-2 equivalent to Grippen NG).

Both use the same engines Ge-404 and Ge-414 for two versions and tejas mk-1 is almost in the same weight class as that of grippen C/D . So it will have the same range as that of grippen.





SO the argument that the Tejas's empty weight of 6.2 ton does not match with GE-404's optimum SFC and that is the reason for lesser range of Tejas is not correct I suppose, Because Grippen C/D with an empty weight of 6.5 tons was designed to match the best SFC of Ge-404 right from the design start phase.So 6.2 ton empty weight of tejas will also match the optimum SFC of GE-404.

The reason for lesser range quoted for tejas may be due to the fact that in hot and arid indian climate condition the range of all fighters will decrease dramatically for ALL Fighters,

So when Grippen NG can be called as MMRCA why is Tejas repeatedly being called a light rthat can only replace Mig-21.

true the LCA project was discussed in the 1970s with the aim of it being Light fighter in the class of Ajeeth, or Mig-21,

But subsequent spec revisions make it equivalent to two MMRCA contenders F-16 and Grippen,


Livefist: Why isn't the HAL Tejas part of the MRCA push?

below are the stats listed for tejas in HAL product website, correct or not members can give opinion.

Tejas is a single engined, light weight, highly agile, multi-role supersonic fighter. ... The aircraft with delta wing is designed for 'air combat' and 'offensive air support' ... Agency is the designated project manager for the development of LCA. ... of 750 km/h, max. range of 1500 km, max. endurance of 2 hrs. with internal fuel.

 

[ersakthivel]

considering the INS 20 GE-404 version was a better model giving more thrust than the engine on grippen C/D ,

the 6.5 ton empty weight of tejas also in the same league as that of grippen C/D they may have comparable ranges only.

 

[Defcon 1]

Re: ADA LCA Tejas - IV

BTW, I thought you might think about Mig29 varient's ferry range without drop tank listed on the MIg website...I thought it could be considered to be the internal fuel range...MIg29 used to be labelled as some 'short-leg' by the west.

Mig29 old varients: 1400KM-1500km
Mig29SMT(UPG): 1800KM
Mig29K/KUB: 1800-2000KM

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F16C/D's nearly 4000km ferry range with 3 drop tanks might be able to explain something as well

That range come with 6750 kg of fuel. JF17 will carry only around 4500 kg of fuel with all the drop tanks.

 

[Defcon 1]

Re: ADA LCA Tejas - IV

I thought I have made it clear...

1.I introduced a common concept in china military standerd here: the basic range--- which reflects some basic flight performance of a airplane...it's more simlar to the internal fuel range,but with 2 PL5IIE SRAAM and full 23mm Gun ammo in JF17's case... I thought western fighter have something similar---Load range, but maybe more combat payloads considered in that concept . JF17's 1800km basic range doesn't automatically mean the so called Combat Radius would be 900Km or 1500Km(1800/2 or 3000/2)...basic range is a data tested and evaluated in a serial of test flights under the specified conditions.

Forget combat radius. Basic range of 1800 km will still mean 0.6Km/L. No fighter provides such a good efficiency.

 

[shiphone]

Mig29C powered by two RD33 with 4540 liters internal fuel ...the ferry range： 1500KM... let's make a simple but not very suitable calculation: 0.66KM/L
F16C with 3 drop tanks (around 8000-8400L) ...the ferry range: 4220KM

FC-1 powered by one RD93 with 3000 lithers internal fuel ... the ferry range(≈basic range): 1800KM.....so called 0.6KM/L
FC-1 wiht 3 drop tanks (around 6000L)... the ferry range: 3000KM

 

[Decklander]

Mig29C powered by two RD33 with 4540 liters internal fuel ...the ferry range： 1500KM... let's make a simple but not very suitable calculation: 0.66KM/L
F16C with 3 drop tanks (around 8400L) ...the ferry range: 4220KM

FC-1 powered by one RD93 with 3000 lithers internal fuel ... the ferry range(≈basic range): 1800KM.....so called 0.6KM/L
FC-1 wiht 3 drop tanks (around 6000L)... the ferry range: 3000KM

It seems that you have a different yardstick when it comes to range calculations compared to what the world normally believes in. We are probably arguing on non issues.

 

[shiphone]

obviously , it's not me but someone else was doing such things to question other plane except your glorious LCA...and I just follow his logic...no double standard here please...I don't like to use the 'quote' , but you could read the above posts.

once again. the FC-1's 1800Km' basic range and 3000KM ferry range is the official one...and quite normal one in my mind...I had an official " China Aircraft handbook' in hand. which listed almost all the basic range and ferry range of china's military planes.
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actually you'd better spent more effort on finding the LCA's exact internal fuel capacity and the range ,ferry range ,and endurance...and back to your LCA topic...I have been watching LCA project for about a decade....too many version of these data here and there...

 

[Defcon 1]

obviously , it's not me but someone else was doing such things to question other plane except your glorious LCA...and I just follow his logic...no double standard here please...I don't like to use the 'quote' , but you could read the above posts.

once again. the FC-1's 1800Km' basic range and 3000KM ferry range is the official one...and quite normal one in my mind...I had an official " China Aircraft handbook' in hand. which listed almost all the basic range and ferry range of china's military planes.
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actually you'd better spent more effort on finding the LCA's exact internal fuel capacity and the range ,ferry range ,and endurance...and back to your LCA topic...I have been watching LCA project for about a decade....too many version of these data here and there...

What is this? You have multiplied the km/L ratio of mig 29 by two. Its 0.33km/L, not 0.66km/L

For F16C, there is no established value of its ferry range. most common one is of 2000 nm, not 4220 km. Funnily enough, even in post #91 you yourself have claimed that F16C's ferry range is 2450 miles, which gives 3920 km. Now for the sake of winning argument you change your range.
At 3920 km, it gives 0.46 km/L
mirage 2000 gives 0.34 km/L

And the above numbers are at ferry range. Not basic range. Calculating at basic range, @p2prada has already shown you the difference become more stark.

Only the super duper JF17 gives km figures of more than 0.5km/L both at ferry range and basic range (fuel capacity will be 5900L, not 6000 L) while the mirages and falcons of the world toil themselves away.

 

[shiphone]

1.obviously so called' KM/L' or 'L/KM'(car driver?) is your own invented 'method of calculation'.I just follw you logic for fun...you chose or invented such funny method as some one said....and in mig 29's case,that was powered by two RD33...LOL

2. FC-1's fuel ： 2300kg/0.775=2967L , external drop tanks=3000L

3. you needn't teach me how to get 'basic range' ...basic range is our concept and defined in china military standard, tested and evaluated in the Real flight tests not a model computing data... I'm afraid you'd better find the internal fuel range data of different airplanes for some estimated comparation...

4. F16C blocks 30/40/50 's 2450 Mile should be from the F-16.net...4220km from the wiki...and so called 8000-8400L was a range which varies according the sources...actually we often see such data for ferry range config: 1050 + 2*370+300 gallon=7911L and another saying--around 14000lb fuel in total=8200L...once again ,I do suggest doing some simple estimate with a range...sometimes this way might be much better than so called precision calculation. as a fan or enthusiast, I don't think we have such abilities.