There is no extra weight while determining ferry range. Only full internal fuel and 3 fuel tanks(in case of LCA) is taken to determine it.
It is no wonder Indians are dumb when it comes to engineering and science. Now I know why it has taken 30 years to develop LCA.
Ferry range is not calculated on full load, Dumb Bharthi *****. Only 3 fuel tanks are taken. Not even wing tip missiles are taken for the ride. Most 2 X 800l and 1 X 1100l fuel tanks are taken. Fuel weighs less than water so 800lt will not be 800kgs. Lets take 700 + 700 + 1000kgs. That's still 2400kgs only. Add full internal fuel of 2450kgs with that, we get 4850kgs. That is way less than 6740kgs it can carry in maximum take off weight. Also ferry range is not calculated in afterburner mode *****. In afterburner mode it won't even reach 100km, let alone 3000km. Only Dry Thrust is employed to achieve maximum ferry range. That too 80-90% of dry thrust is employed which is the most fuel efficient compared to 100% dry thrust.
Low by-pass ratio does not necessarily mean low thrust. Low by-pass ratio means engine is underutilized it's potential, to act like a turbo-prop engine by pushing air backwards while propelling aircraft forwards, without letting the air go through the compressor. So most of the thrust in low by-pass engine is from jet of air directly from the compressor rather than what is mentioned above. So it is less fuel efficient than high by pass ratio engines.
That Thrust to weight ratio is bogus. It is calculated differently. Although still not perfect, it is more perfect than what wiki says -
Thrust to Weight Ratios of all Fighters The only reason why tejas has a higher thrust to weight ratio is because of higher thrust engine, and that too only 0.04 advantage, which is negligible.
Oh Man poor undergraduate man....
Range
A jet fighter's range includes two specs,
the "ferry range" or
maximum travel distance, and
the combat radius. This latter spec denotes the range at which a fighter can engage in operations and still have enough fuel for the return flight. For example,
the F-22 Raptor can fly 2,000 miles but has a combat radius of only 471 miles. A MiG-25 Foxbat has a much more limited range of 1,390 miles and a small combat radius of 186 miles. This smaller range indicates the MiG-25's role as an "interceptor" plane designed to engage other aircraft, while the F-22 is a "multi-purpose" fighter capable of multiple combat roles.
JF-17
Empty weight: 6,586
Loaded weight: 9,100 kg
Max. takeoff weight: 12,383 kg
Powerplant: 1 × Klimov RD-93 or WS-13 turbofan (testing phase)
Dry thrust: 49.4 kN[25] / 51.2 kN (WS-13)
Thrust with afterburner: 84.5 kN
G-limit: +8 g / -3 g
Internal Fuel Capacity: 2,300 kg
Performance
Maximum speed: Mach 1.6[9]
Combat radius: 1,352 km
Ferry range: 3,482 km
Thrust/weight: 0.95
LCA
Empty weight: 6,560 kg
Loaded weight: 9,500 kg
Max. takeoff weight: 13,300 kg
Powerplant: 1 × F404-GE-IN20 turbofan
Dry thrust: 48.9 kN
Thrust with afterburner: 89.85 kN
Internal fuel capacity: 2,458 kg
External fuel capacity: 2 x 1,200 litre drop tank at inboard, 1 x 725-litre drop tank under fuselage
Performance
Maximum speed: Mach 1.8 (1,920 km at high altitude)
Range: 850 km without refueling
Ferry range: 3,000 km
Thrust/weight: 1.07
g-limits: +9/−3.5 g
Now , JF-17 and LCA almost carry same Internal Fuel but JF-17 goes longer why? because they carry less weight becasue they carry less no of missile then LCA
If external Fuel also added then its range will increase many fold.
Lets take an example of Land Rover having engine of 3000 CC generating power of 120PS while your Maruti 800 (entry level) having engine of 800 cc with Power of 60 PS
Now which engine can take Max load? Land Rover, 3000cc
Which engine can run more give same amount of fuel ? 800cc engine
Which engine generate max speed ? 3000 cc
Same logic use in planes and also missiles , if you reduced the weight of warhead the range of missiles increases and if increase the weight of warhead its range decreases.
LCA have max take of weight and max power generate.
moreover :
JF-17 :
7 in total (4× under-wing, 2× wing-tip, 1× under-fuselage; pylon stations number 3, 4 and 5 are wet-plumb capable) with a capacity of 3,629 kg for external fuel and ordnance
LCA:
8 total: 1× beneath the port-side intake trunk for targeting pods, 6× under-wing, and 1× under-fuselage with a capacity of 4,000 kg external fuel and ordnance
for those extra, 300 + kg LCA can have 4-5 short range type air -air missile or 2-3 mid range air to air or 2 long range air -air missile then JF-17
Our Plane is designed to Carry more weapons so that they carry more air -air missile in combat and if we take external fuel tank then it range will become equal to your JF-17 , there LCA given more flexibility to carry arm.
