HAL Tejas | Updates, News & Discussions-[Thread 2]

[cerberus]

@MilSpec @AUSTERLITZ @Oscar
Can you Help Please

One Question in My Mind Puzzling Me

Internal Fuel Capacity of LCA is 2,458 kg
2 x 1,200-litre drop tank at inboard, 1 x 725-litre drop tank under fuselage




For JF-17 its Internal 2,350 kg (5,130 lb)
External Fuel 2x1100Ltr +800 Ltr

• 
  
  
  • External Fuel
    • a- One centre line drop tank 800 liters
    • b- Two under wing drop tanks 800/1100 liters

So My question is Ferry Range of LCA is 1700 Km Whereas JF-17 has 3482 Claimed by Various Sources Can you Guys Help ????

 

[longewala]

@MilSpec @AUSTERLITZ @Oscar
Can you Help Please

One Question in My Mind Puzzling Me

Internal Fuel Capacity of LCA is 2,458 kg
2 x 1,200-litre drop tank at inboard, 1 x 725-litre drop tank under fuselage
=1200+725=1925
Total Fuel Capacity 2458+1925= 4383 Kg or Litre


For JF-17 its Internal 2,350 kg (5,130 lb)
External Fuel 1500Kg

Total Fuel Capacity 2350+1500= 3850 Kg or Litre

So My question is Ferry Range of LCA is 1700 Km Whereas JF-17 has 3482 Claimed by Various Sources Can Guys Help ????

The numbers speak for themselves, don't they? Use your common sense.

 

[GURU DUTT]

@MilSpec @AUSTERLITZ @Oscar
Can you Help Please

One Question in My Mind Puzzling Me

Internal Fuel Capacity of LCA is 2,458 kg
2 x 1,200-litre drop tank at inboard, 1 x 725-litre drop tank under fuselage
=1200+725=1925
Total Fuel Capacity 2458+1925= 4383 Kg or Litre


For JF-17 its Internal 2,350 kg (5,130 lb)
External Fuel 1500Kg

Total Fuel Capacity 2350+1500= 3850 Kg or Litre

So My question is Ferry Range of LCA is 1700 Km Whereas JF-17 has 3482 Claimed by Various Sources Can Guys Help ????

so in short either HAL/DRDO guys are deliberatelli hiding the true range of LCA or pakistanies ... i mean chinese are overplaying/boasting JF-17s range

im confused

 

[sathya]

@MilSpec @AUSTERLITZ @Oscar
Can you Help Please

One Question in My Mind Puzzling Me

Internal Fuel Capacity of LCA is 2,458 kg
2 x 1,200-litre drop tank at inboard, 1 x 725-litre drop tank under fuselage




For JF-17 its Internal 2,350 kg (5,130 lb)
External Fuel 2x1100Ltr +800 Ltr

• 
  
  
  • External Fuel
    • a- One centre line drop tank 800 liters
    • b- Two under wing drop tanks 800/1100 liters

So My question is Ferry Range of LCA is 1700 Km Whereas JF-17 has 3482 Claimed by Various Sources Can you Guys Help ????

I am not sure of the answer..

But delta wing has more drag.. Our Tejas even more I think ..
So energy bleed is more..

 

[1ndy]

I am not sure of the answer..

But delta wing has more drag.. Our Tejas even more I think ..
So energy bleed is more..

Engine of both the fighter produce more or less the same amount of thrust and both has almost same top speed(~1960km/h).

So if the drag is so high that it decreases the range by more than 50% then Tejas would require a higher thrust engine to attain the top speed.

 

[cerberus]

I am not sure of the answer..

But delta wing has more drag.. Our Tejas even more I think ..
So energy bleed is more..

@sathya @1ndy
Argument is Flawed Because Saab Gripen is Also is A Delta Wing uses Same Engine with Low Thrust But Still has Ferry Range of 3200 Km
Also LCA build on The relaxed static stability (RSS) Principle Like Eurofighter Tryphoon

 

[MilSpec]

Lets hope it dont become a maintenance nightmare like MKI has become or else little wear and tear on composites make it impossible to maintain required fleet strength most of the time

Where did you get your MKI info from, let me assure you nothing can be farther from the truth. Service rate doesn't correspond maintenance but the complexity of the aircraft, every x number of operations fuel pups need to be calibrated, hydraulic fluid needs to drained, sensors need calibration, that is what contributes to the service rate among all major combat platforms. it's not that something gets broken and has to welded together.

 

[1ndy]

@sathya @1ndy
Argument is Flawed Because Saab Gripen is Also is A Delta Wing uses Same Engine with Low Thrust But Still has Ferry Range of 3200 Km
Also LCA build on The relaxed static stability (RSS) Principle Like Eurofighter Tryphoon

Whose argument is flawed?
Well if the Gripen also has ferry range above 3000km then the ferry range of LCA Tejas is seriously underrated.

PS: RSS reduces the fuel consumption.

 

[cerberus]

RSS reduces the fuel consumption.

relaxed stability is the tendency of an aircraft to change its Attitude Control and angle of bank of its own accord.In Modern military aircraft, particularly low observable (Stealth) designs, often exhibit instability as a result of their shape. Fighter aircraft Like LCA often employ design elements which reduce stability to Increase Maneuverability . Greater stability leads to lesser control surface authority, therefore a less stable design will have a faster response to control inputs.

 

[1ndy]

@cerberus
Relaxed stability designs are not limited to military
jets. The McDonnell Douglas MD-11 has a relaxed
stability design which was implemented to save fuel.

Relaxed stability - Wikipedia, the free encyclopedia

 

[cerberus]

@cerberus
Relaxed stability designs are not limited to military
jets. The McDonnell Douglas MD-11 has a relaxed
stability design which was implemented to save fuel.

Relaxed stability - Wikipedia, the free encyclopedia

My dear McDonnell Douglas MD-11 is a Jet Airliner We are discussing Military Aircraft here.

In LCA relaxed static stability (RSS) was an ambitious requirement. In 1988, Dassault had offered an analogue flight control system (FCS), but the ADA recognised that digital FCSs would supplant it. First flying in 1974, the General Dynamics F-16 was the first production aircraft designed to be slightly aerodynamically unstable to improve maneuverability.Many aircraft have positive static stability to induce them to return to a straight, level flight attitude when the controls are released, maneuverability is reduced as the inherent stability has to be overcome. Aircraft with negative stability are designed to deviate from controlled flight and thus be more maneuverable.

Attitude control - Wikipedia, the free encyclopedia
Simple harmonic motion - Wikipedia, the free encyclopedia

 

[1ndy]

I know MD-11 is a jet airliner but physics rules are same for both jet airliner as well as military fighter jets.
My point is that RSS doesn't increase the fuel consumption if not reduce it.

 

[knight11]

@MilSpec @AUSTERLITZ @Oscar
Can you Help Please

One Question in My Mind Puzzling Me

Internal Fuel Capacity of LCA is 2,458 kg
2 x 1,200-litre drop tank at inboard, 1 x 725-litre drop tank under fuselage




For JF-17 its Internal 2,350 kg (5,130 lb)
External Fuel 2x1100Ltr +800 Ltr

• 
  
  
  • External Fuel
    • a- One centre line drop tank 800 liters
    • b- Two under wing drop tanks 800/1100 liters

So My question is Ferry Range of LCA is 1700 Km Whereas JF-17 has 3482 Claimed by Various Sources Can you Guys Help ????

If the Ferry range is 3482 KM, and combat range is 1200 Km, then there is no need for any SU-35 for the naval strike and deep strike missions period. LOLZ

Ferry Range at what altitute and at what speed ??

Many of time the OEM deliberately confused the common reader by over stated its performance. e.g the BVRAAM range varies due to launch altitute, speed of the aircraft, air density etc. So the range given for it reflects when it is fired from high altitude 30,000-50,000 feet to the target which is coming toward the launch aircraft at x speed. But here it is not the case. Tejas ferry range is 1700 with its internal fuel i.e it can fly 1700 Km from its base maximum at speed below 1 mach. This was the range what the ADA had given since at time the subsonic fuel tank was not flight certified.

Now if we look at the JF-17's ferry range figure of 3482 Km it is definitely with the drop tank, but under what condition ??
Pls note that the performance of the engine aka the thrust also depends on the environment. Our Indian subcontinental condition lowers the thrust produced upto 20% than the condition in ambient conditions of europe, and russia.

Drags plays part in lower range but at higher altitude the wind resistance is very low and the Delta wings drag is mostly in the high AoA not when cruising straight.

 

[Rehan khan 1]

@sathya @1ndy
Argument is Flawed Because Saab Gripen is Also is A Delta Wing uses Same Engine with Low Thrust But Still has Ferry Range of 3200 Km
Also LCA build on The relaxed static stability (RSS) Principle Like Eurofighter Tryphoon

hint is combate radius of 500km, because combate radius is absolutely dependant on internal fuel capacity which is said to be no more than 1.8 to 2 ton max (i think its even less than that). which is why LCA troubles with IAF too much weight and too low fuel fraction.

 

[cerberus]

hint is combate radius of 500km, because combate radius is absolutely dependant on internal fuel capacity which is said to be no more than 1.8 to 2 ton max (i think its even less than that). which is why LCA troubles with IAF too much weight and too low fuel fraction.

who told you that Internal fuel capacity of LCA is 2458 Kg Already demonstrated in IOC-2 as-well published in DRDO Published Papers