Combat Aircraft technology and Evolution

[ersakthivel]

Internal fuel capacity of world 4th ~ 5th Gen fighters

Su-30MK: 34.9%（Empty weight: 17,700 kg，Internal fuel: 9,500 kg）

Rafale: 31.4% ~ 33.6%（Empty weight: 9,500 ~ 10,220 kg，Internal fuel: 4,680 ~ 4,800 kg）

JAS-39NG: 30.6%（Empty weight: 7,100 kg，Internal fuel: 3,130 kg）

MIG-35: 28.6%（Empty weight: 12,000 kg，Internal fuel: 4,800 kg）

Tejas: 27.0%（Empty weight: 6,500 kg，Internal fuel: 2,400 kg）

JF-17: 26.3%（Empty weight: 6,450 kg，Internal fuel: 2,300 kg）

JAS-39C: 25.0%（Empty weight: 6,800 kg，Internal fuel: 2,268 kg）

This is a fair comparison of fuel fractions with just internal fuel , and the same percentage will more or less reflect with external fuels also,

So Tejas mk-1(which still has 400 KG of flight test equipment on board, removal of them will lead to even better fuel fraction) itself has much better fuel fractions than grippen C/D with more TW ratio and lower wing loading,

Tejas mk-2 will easily compare to RAFALE which has just 4 percent more in fuel fractions than Tejas mk-1.

So in indian conditions there won't be no issues with range of tejas mk-1 or mk-2 in useful combat configuration if we take into account that four tejas can be operated for one RAFALE if we include total lifecycle costs and upgrade costs,

So there is no way Tejas can be faulted on weapon load or range.

 

[gadeshi]

Vortex aerodynamics IRL (F-18):

 

[gadeshi]

Self-sustained synthesis of intermetallides on the TiAl (Titanium Alluminide) example:
http://archive.nbuv.gov.ua/portal/natural/smm/SSh/2008_1/Statyi_tom1/15..pdf

 

[gadeshi]

Planar LTCC-Ceramics GaN-based DAESA X-TRMs from NIIP for G6 fighters - full version:
Трайсель :: Планарные многоканальные приемные модули АФАР Х диапазона
http://www.myshared.ru/slide/264263/#

 

[gadeshi]

European military aviation industry is in danger:
Opinion: Europe Faces Smaller Role Without Next-Gen Fighter

 

[Austin]

Planar LTCC-Ceramics GaN-based DAESA X-TRMs from NIIP for G6 fighters - full version:
Трайсель :: Планарные многоканальные приемные модули АФАР Х диапазона
http://www.myshared.ru/slide/264263/#

Ok I didnt get the technical stuff .....can you explain in simple English what it is trying to say ..... and why is this 6th G AESA module ?

 

[gadeshi]

Planar LTCC-Ceramics GaN-based DAESA X-Band TRMs have completely different structure and layout. Different from traditional vertical-layered GaAs TRMs. New layout allows flat, less-weighted modules with rather less power consumption and TDP. This allows to build any antenna configurations of any sizes using them. Manufacturer even suggests to build a "smart skin" (a wide TRM layer under the wing or fuselage radio-transparent skin) panels of any shape and curveness with RF qualities remaining intact. This technology will be used to build embedded compact radars for helicopters and UAVs/UCAVs and piloted next-gen planes as well.

Also they are completely digital devices (they use no ACP/CAP transievers which translate digital signal into analog one and back) which simplifies the signal control and amplification thus much reduces the ECM impacts and have the other sweety bonuses.

That's why they call them G6 TRMs technology.

These document and presentation say that Russians (NIIP) have already established production facilities for those TRMs and DAESA radars based on them.

 

[gadeshi]

Vortex aerodynamics IRL - F-14:

 

[gadeshi]

NPO "Start" to develop multi-position stealth containers and launchers for aircrafts and helicopters until Y2016:
Росинформбюро: «Авиационное оборудование» разработает системы запуска высокоточных ракет для российской авиации к 2016 году

 

[SajeevJino]

.

Take scenario

If Pakistan announced war against us ..

They Send their Fleet of F 16 (2 sq) and another two squad of Mirage 5 with an Saab AEW ..so we need to respond them with a Match of 2 Squad of Su 30MKI along with Two Squad of Mig 29 or Mirage 2000 along with an Phalcon AEW ..both will be involved in Dog Fighting ..

Both of them send their MRCA (Mirage 5 PAF and Mig 29 or Mirage 2000 from IAF ) to Bomb the Strategic location if they get Air Superiority

at the mean time we will again send a Batch of 2 squad of Mig 29 or Mirage along with an Mig 27 or Jaguar same with Phalcon AEW to bomb their Strategic Location since their front Line fighters are busy with Indian Intercept squad .. to intercept this Team PAF will send their all flyable Machines may be a combination of 100 of F 7 JF 17 and Mirage 3 along with their Saab AEW ..

so now this Time both will match it ..But IAF has still some Players The Jaguars and Mig 21 they again go for another mission deep inside Pakistan to make more troubles to PAF


as of Tejas It can give boost to our Front line fighters to get the Victory




---

The above Scenario was in my Mind if an Air battle with IAF and PAF

There are nothing second and first line, Its always the first line with mix of fighters, Let me elaborate some positive points compare to other fighters ..

Sir ..In the second part we will send Mig 29 or Mirage 2000 ..I may called as Second line of Interception ..that's why I wondered that How Tejas become Replace Mig 29 OR Mirage in that Position

 

[Kunal Biswas]

If such a air fleet in air then it can be easily detected, If not radars then forward observation post ..

----------------------

Let me give you a picture based on your senerio, If PAF attack India then it would go for Oil Installations, Army & IAF HQs, Politically important targets but very unlikely Airbases as they are guarded by SAMs such as Akash and SA-6 ..

Lets say the enemy air fleet made an incursion from Jammu area ..

4 X Tejas & 4 X SU-30MKI will be scrambled from Leh..
4 x MIG-29 from Srinagar..
4 X Tejas & 4 x MIG-29 will be scrambled from Awantipur..
1 X AWACS & 8 x SU-30MKI from Chandigarh ..

------------>>

Here Aircraft from LEH will cover the left and rear flank of intruding air fleet, MKI will be at high altitude from where they can guide Tejas with there powerful radars and engage enemy aircraft at longer ranges, where as Tejas at low altitude from where they can surprise enemy with their low radar signature and small size, Their objective to block enemy escape routes and engage any enemy in sight..

Aircraft from Chandigarh will provide long range surveillance, and will cover the rear and right flank of invading force, there task is to protect the AWACS and engage enemy aircraft at longer ranges so does discourage any enemy reinforcement..

Aircraft from Srinagar & Awantipur were meant to attack enemy force head on, Luring them towards AKASH or SA-6 SAM battery positioned over Major Airbases in J&K, In the mean time the forces at the rear will close the gap, trapping the invading force ..

==================

The objective is to separate enemy fleet, disperse them in a wide area in an unorganized formation, by attacking them from all direction creating panic and confusion, As that happens more wings will join the hunt, Attacking back the enemy is another senerio ..

This is a complete theory ..

Sir ..In the second part we will send Mig 29 or Mirage 2000 ..I may called as Second line of Interception ..that's why I wondered that How Tejas become Replace Mig 29 OR Mirage in that Position

 

[Twinblade]

BTW,ADA old website used to claim the LCA's internal fuel endurance--around 30-40 minnuts...and your saying --around 45 minuts is not very reasonable to me...I have questioned the old 40 minutes claim for quite a while...but I didn't find too much discussion on BR forum and here.

I believe that should be 'on station' time. There are a lot of inaccurate and dated figures on Tejas out there, many of them from older official sources. Even the internal fuel figures quoted on wiki for Tejas are quite outdated, in fact the numbers quoted in the document from which it was sourced from do not add up, with a discrepancy of about 400 to 800 Kgs. There is no other mention of Tejas' internal fuel in any other official document. However, looking at the empty and fueled up weights should give you a fair idea of fuel carried internally by small fighters. Anecdotal evidence suggests that Jf-17 would need an external fuel tank just to cope up with the fuel Tejas carries internally, and that is weight off it's external capacity, which again adds to drag and reduces range. Of the small fighters, Gripen is the king when it comes to range due to its best in class usable external payload, rest are just vying for the second place. Had Tejas been built to the empty weight of 5500 Kg and MTOW of 13500 kg as was the plan a decade back, it would have given Gripen C run for its money in range and payload.

As far as range is concerned, the official range released for Tejas is 500 Km combat radius and 1700 Km ferry range, both on internal fuel. The ferry range on external fuel has not been disclosed.

Gripen's combat radius on internal fuel alone is 800 Km (on internal fuel) and 1550 Km with drop tanks and a ferry range of 3200 Km.

What kind of external loading and on station time is being talked about in combat radius in either case has not been disclosed.

(All figures sourced from official sites, brochures, info boards and presentations, recommend corrections wherever required)

Aircraft	Empty Weight	Take off weight (clean)	Hard point capacity (max)	Take off weight (max)	External usable load when fully fueled (max)
Jf-17	6450 Kg (link)/6577 Kg (PAC)	9100 Kg with 2 SRAAM (link)	4600 Kg (link)	12700 Kg (link)/12367 Kg (PAC)	3500 to 4000 Kg considering whichever statistic is accurate
FA-50	6470 Kg (KAI)/6354 Kg (LM)	8890 Kg (link)	4400 to 4500 Kg (link)	12300 Kg (KAI)/ 13500 Kg (LM)	3400 to 4500 Kg considering whichever statistic is accurate
Gripen C	6800 Kg (SAAB)	SAAB cites 2400 Kg of onboard fuel (link) which should imply 9300-9400 Kg	5300 Kg (link)	14000 Kg (SAAB)	Should be in the range of 4600 to 4800 Kg
Tejas	6560 Kg (ADA)	9500 Kg (ADA) / 9800 Kg (ADA) (even though it says clean, the 9800 Kg weight is supposed to be with two SRAAM)	5500 Kg/5700 Kg if you include the hard point for pod(link)	13200 Kg (ADA)	3600 to 3700 Kg

 

[shiphone]

great and meaningful job with a objective and fair performance table and I have read it in the T50 golden eagle &JF17 thread on Keypublishing forum already.

Anecdotal evidence suggests that Jf-17 would need an external fuel tank just to cope up with the fuel Tejas carries internally, and that is weight off it's external capacity, which again adds to drag and reduces range.

but this statement is questionable, I'm sure JF/17( the same in J10 ,or F16, or M2K cases...) would sortie with at least two Drop tanks during the most Mission Profiles, and in my understanding , no much exception in this generation fighters' design, especially for the light and medium fighters...
I also read the so called ' UP TO' 500 km radius and 1700 KM ferry range from the official docs and your particular note in LCA thread, it might be the data with 2 1200L drop tanks. if any chance, we should figure it out ...waiting for more reports or any intentional interview on next Aero India, etc...

and obviously ,I'm not the only one think so....just happen to read this via a link from BR forum..

The Tejas Mk1 can now fly without any telemetry support and a claimed radius of action up to 500km (310 miles) with a ferry range of 1,750 km (using 800/1,200 litre drop tanks).

PICTURES: India's Tejas receives initial operational clearance

 

[Twinblade]

and obviously ,I'm not the only one think so....just happen to read this via a link from BR forum..



PICTURES: India's Tejas receives initial operational clearance

That is from the flightglobal report, which has had hot and miss accuracy on Indian projects. Chacko Joseph, one of the publishers at Frontier India portal has clarified on BR that it is on internal fuel.

 

[shiphone]

Thank you KaranM and RahulM

nachiket, internal fuel. Enough for atleast 250 kms deep ingress and ops. Tankers are there if it ever required additional fuel.

(PS.nachiket is a BR member who raised the question "Chacko, are these numbers confirmed? 1700 km ferry range seems awfully low. Or is that on internal fuel alone (no drop tanks)?")

this should be the so called 'confirmation' ....but this sir's following explaination is not that professional and convincing....

 

[p2prada]

@shiphone @Twinblade

We have to be careful of these figures since we do not know at what parameters they were calculated. Operational altitudes, speeds, payloads and mission times will be completely different from manufacturer data in ideal conditions.

For eg: LCA is not built as a strike aircraft while JF-17 is. So, JF-17 will fly more at lower altitudes than LCA will. You can say there is a similar difference between Su-30MKI and Jaguar where one will operationally fly at a much higher altitude than the other. So, it won't be a fair apples to apples comparison.

LCA's combat radius figure of 500 Km could very well be an operational figure versus Gripen's 800 Km. So Chacko Joseph saying the range of LCA is 1750 Km with two drop tanks might be correct if we consider LCA is rigged for strike as it will fly at a lower altitude during the mission.

It would have been great if manufacturers also provided operational range data when the aircraft is at different altitudes and carrying different payloads like how the Americans provided for the F-16 in a proper operational scenario. Simply throwing numbers around is useless after all.

 

[ersakthivel]

First of all tejas was never built with the aim of having 5.5 tons empty weight and 13.2 ton MTOW,

it's original mtow was 12.5 tons with 5.5 ton empty weight.

The LCA is tailless with a double-sweep delta wing. Its wing span is 8.2 m, length 13.2 m, height 4.4 m. TOW clean 8.500 kg, MTOW 12500kg. It will be super-sonic at all altitudes, max speed of M 1.5 at the tropopause. Specific excess power and g-over load data has not been published. Maximum sustained rate of turn will be 17 deg per sec and maximum attainable 30 deg per sec.

Now with 6.5 ton empty weight it lifts 13.2 ton mtow,SO not much of a deviation from original 4 ton pay load even though it's empty weight has gone up after the FSED- phase -II from IAF for higer launch stress inducing higher weight R-73 WVR missiles.

Even after a ton increase in empty weight it has achieved a top speed of mach 1.6 and design speed is supposed to be 1.8 mach.

So it is wrong to attribute tejas weight carrying capacity reduction to a ton increase in empty weight.Most of the structural stiffening as per new demands from IAF which led to tejas weight increase by 1 ton did not affect the performance specs of tejas other than just 0.4 ton decrease in weapon weight.

it's top speed , STR and Mtow all increased after the one ton weight increase, not decrease.

And to say Grippen is the king we need comparison in indian hot climate conditions for range with equal payload and equal altitude flight.

Also we need to check if grippen C lifts it's full weapon load with full internal fuel in inidan hot climate conditions which significantly degrades the engine thrust levels due to high atmosphere temp.

As F-16 XL vs F-16 analogy showed that the increased wing area of F-16 Xl compared to F-16 resulted in the increased range with increased weapon load!!!!, all due to lower wave and interference drag components of the shape.tejas has similar shaping of F-16 XL wings,

while grippen has a very busy frontal fuselage populated with canards, and air intakes all jutting out at right angles contributing hugely to wave and interference drag.



Wave and interference drag must be much worse for grippen than tejas because it presents two planes to the rushing air namely wing and canards,

Tejas has much more stream lined frontal fuselage with less drag due to absence of canards at right angle to fuselage and the two huge boxy air inlets,

And the sudden cross sectional increase at around 4 meters along the length of fuselage in teja shas nothing to do with range or drag as this comes into effect only in supersonic flight(even that seems to be resolved now)Also we must note that Grippen too has sudden cross sectional increase along the fuselage length at the point of air intake just like tejas.In fact pretty much all fighter planes do

SO right now fair comparison is fuel fraction which takes nothing away from tejas in comparison with grippen C.

 

[ersakthivel]

Saab JAS 39 Gripen - Wikipedia, the free encyclopedia

Also how come grippen with an empty weight of 6.8 and loaded weight of just 8.5 ton have a higher range than tejas , with just internal fuel only config?

For tejas empty weight is 6.5 ton and loaded weight is 9.8 ton, so what is the extra weight in tejas's higher loaded weight which is omitted in grippenC?


The difference between the loaded weight and empty weight of Tejas is 3.3 tons.

The difference between loaded weight and empty weight of grippen C is just 1.7 tons.

Why this particular gent who made the comparison table chose to omit it?


Most probable explanation is that ADA included the weight of ammo, pylons, two shortranged WVR missiles and litening pod and some other things in take off clean and SAAB did not include them in their take off clean.


IMHO grippen c does not carry that much more weapon than tejas and with 300 Kg extra empty weight has no chance of having a hihger range than tejas in inidan hot conditions


So both will carry same weapon load and tejas may end up with better range due to lower empty weight perhaps

 

[Twinblade]

@shiphone @Twinblade

LCA's combat radius figure of 500 Km could very well be an operational figure versus Gripen's 800 Km. So Chacko Joseph saying the range of LCA is 1750 Km with two drop tanks might be correct if we consider LCA is rigged for strike as it will fly at a lower altitude during the mission.

It would have been great if manufacturers also provided operational range data when the aircraft is at different altitudes and carrying different payloads like how the Americans provided for the F-16 in a proper operational scenario. Simply throwing numbers around is useless after all.

A correction. Tejas 1700 Km range is its ferry range on internal fuel, not combat range.

I'd like to say that Gripen's Combat radius on external fuel is BS, pure and simple. Why? Because the aircraft has a ferry range of 3200 Km and a combat radius of 1550 km is just half of that figure. Which would imply pure air to air load and zero on station time.

An 800 km combat range on internal fuel would mean give or take two hours of endurance at 0.7 mach, which would be stretching it for a light fighter. That 800 km figure is also possibly with negligible on station time and air to air load. Where Gripen though does make the difference is carrying air to ground munitions where it's usable external payload capacity gives it an advantage over Tejas.

 

[ersakthivel]

What is the usable external wepon load capacity of grippenC?

Also how come grippen with an empty weight of 6.8 and loaded weight of just 8.5 ton have a higher range than tejas , with just internal fuel only config?

For tejas empty weight is 6.5 ton and loaded weight is 9.8 ton, so what is the extra weight in tejas's higher loaded weight which is omitted in grippenC?


The difference between the loaded weight and empty weight of Tejas is 3.3 tons.

The difference between loaded weight and empty weight of grippen C is just 1.7 tons.

Why this particular gent who made the comparison table chose to omit it?


Most probable explanation is that ADA included the weight of ammo, pylons, two shortranged WVR missiles and litening pod and some other things in take off clean and SAAB did not include them in their take off clean.


IMHO grippen c does not carry that much more weapon than tejas and with 300 Kg extra empty weight has no chance of having a hihger range than tejas in inidan hot conditions


So both will carry same weapon load and tejas may end up with better range due to lower empty weight perhaps

So it is entirely possible that grippen C doc which show a huge weapon load capacity include pylon weight gun ammo weight , litenning pod weight and two short range WVR missile weight ,

But in tejas all the above items are not included in the 3.5 ton weapon load figure.

pertinent stats are

Empty weight--------------grippen c-6800 kg-------------tejas -------------6500 kg,
fuel weight-----------------grippen C-2400 kg------------tejas---------------2400 kg,
max take off weight-------grippen C-14000kg-----------tejas---------------13200 kg,

if grippen has 800 Kg excess maximum take off weight, it's empty weight is 300 kg more.

So useful weapon load carried by grippen might be just 500 kg more than tejas mk-1, provided grippen C takes off with it's max take off weight of 14000 kgs in hot indian climate where the higher air temp means air density is less .Which significantly affects engine thrust.

For tejas the loads were given for indain amospheric conditions as it was tested here.

but grippen figures of 14 ton Mtow was not in indian conditions.

So even that extra 500 kg is suspect if we take that into account.