LCA TEJAS MK1 & MK1A: News and Discussion

[standard snowball]

About the Fuel capacity, I did some digging and found out the internal fuel capacity is 2486kg, which is more than any other comparable fighter of its class (JF 17 = 2400kg, FA 50 = 2124kg, Gripen C/D > 2400kg) what more did IAF wanted from this aircraft, asking for more fuel capacity and less weight in the same breath seems like a tom foolery of the highest order.

This image from a ADA/DRDO confrence about Tejas mk2.

 

[standard snowball]

Is alpha defence a reliable source?

Well seems legit to me.

he has revealed exclusive information many times and seems to have link inside the establishment.

 

[Tejbrahmastra]

About the Fuel capacity, I did some digging and found out the internal fuel capacity is 2486kg, which is more than any other comparable fighter of its class (JF 17 = 2400kg, FA 50 = 2124kg, Gripen C/D > 2400kg) what more did IAF wanted from this aircraft, asking for more fuel capacity and less weight in the same breath seems like a tom foolery of the highest order.

View attachment 220503
This image from a ADA/DRDO confrence about Tejas mk2.

 

[standard snowball]

View attachment 220515

Source ?

 

[Tejbrahmastra]

I heard from some Twitter account and even alpha defence about some ballast weight being removed by rearranging LRU's and how mk1a will have slightly more fuel capacity as some modifications were made in the fuel system.

Some ballast weight has been removed and LRUs rearranged. But there is no any official source on how much the weight has been reduced. The open sources quotes from 300-500Kg as per Ajay Sukla, Livefist. But then the MK1A has also got newer and heavier sensors/equipment's like heavier radar, refueling probe etc. So the internal fuel capacity may not have changed.

 

[standard snowball]

Some ballast weight has been removed and LRUs rearranged. But there is no any official source on how much the weight has been reduced. The open sources quotes from 300-500Kg as per Ajay Sukla, Livefist. But then the MK1A has also got newer and heavier sensors/equipment's like heavier radar, refueling probe etc. So the internal fuel capacity may not have changed.

Refueling probe was there in the mk1 variant too, AESA radars (specially GaN ones) are lighter than Mechanically steered radar so logically Uttam is going to be lighter than EL/M 2032.
The only thing I can think of that can increase the weight of mk1a is the OBOGS present on the mk1a.
On a side note didn't ADA also promise to made the landing gear more simpler (in theory thereby reducing some weight there too).

I think fuel capacity will increase, the increase may not be huge but it would 60 - 100 kg minimum

 

[Tejbrahmastra]

Refueling probe was there in the mk1 variant too, AESA radars (specially GaN ones) are lighter than Mechanically steered radar so logically Uttam is going to be lighter than EL/M 2032.
The only thing I can think of that can increase the weight of mk1a is the OBOGS present on the mk1a.
On a side note didn't ADA also promise to made the landing gear more simpler (in theory thereby reducing some weight there too)

They did say that. But i think a lot of them were for MK2, so there is no clarity about that, unless we get an official confirmation!!

 

[NutCracker]

Refueling probe was there in the mk1 variant too, AESA radars (specially GaN ones) are lighter than Mechanically steered radar so logically Uttam is going to be lighter than EL/M 2032.
The only thing I can think of that can increase the weight of mk1a is the OBOGS present on the mk1a.
On a side note didn't ADA also promise to made the landing gear more simpler (in theory thereby reducing some weight there too).

I think fuel capacity will increase, the increase may not be huge but it would 60 - 100 kg minimum

Balast was indeed replaced by IFR and heavier AESA radar. AESA needs lots off cooling . That makes up the incrresed weight.

 

[Tejbrahmastra]

US Congress clears landmark India-US fighter engine deal

No-objection paves the way for the implementation of GE’s agreement with HAL on the F-414 engines, including manufacturing and technology transfer.

www.hindustantimes.com

A person familiar with developments on Capitol Hill, the home of the US Congress, said, “It is all clear from the legislative end. The sale was approved before Prime Minister Narendra Modi’s visit itself. But, as per the process, the state department notified the House and Senate foreign relations committee on July 28.” If, for 30 days after the notification, no Congressional representative or Senator objects, it is treated as assent. “There has been no objection. The administration can go ahead with the next steps,” the person added, asking not to be named.

 

[standard snowball]

I did some searching and came accross this NASA webpage that explained preliminary range calculation of an aircraft in simple yet detailed terms.

Range Summary

Note: I am taking a very simplistic view of aircraft range here for academic purposes. In reality, calculating the range is a complex problem because of the large number of variables involved. An aircraft's flight is not conducted at a single ground speed but varies from zero at take-off, to cruise conditions, and back to zero at landing. Extra fuel is expended in climbing to altitude and in maneuvering the aircraft. The weight is constantly changing as fuel is burned, so the lift, drag, and thrust and fuel consumption rate are also continually changing. On real aircraft, just like with our cars, there is usually a fuel reserve and the pilot makes sure to land the plane with fuel still on board, however we are going to neglect all of these effects for keeping our calculations simple

R (Aircraft Range) = V (cruise speed) × T (Maximum time in air)

[ Generally military aircraft cruise at a height of 30k feet with a speed of 0.8 to 0.85 mach, given that the speed of sound at 30k feet is near near 305m/s, V would be near 260m/s ]

T = M/(SFC × F)

[ M = Fuel Load (the amount of fuel an aircraft is carrying in Kg), in our case M = 2486kg ]
[ SFC = amount of fuel needed to be burned in 1 sec to produce 1kN of thrust, in our case SFC = 23g/(kN.s) ]
[ F = Thrust needed to keep the aircraft cruising at the given parameters ]

[ Note : At cruise speed an aircrafts Lift (L) = aircrafts Weight (W) and Thrust Required (F) = Drag (D) or in other words L/D ratio (lift to drag ratio) = W/F ]

So now F = W ÷ (L/D ratio)

in other words an aircrafts Range R = {V × M} ÷ {SFC × F}

So our Tejas will have a range of {260 × 2486} ÷ {23 × F}

Given that we don't know the required F for keeping the Tejas crusing we would have to look for another aircraft of similar profile and extract the data from there using the above equations.
Gripen C/D seems to be the closest fighter to Tejas with similar empty weight (6800kg), fuel capacity (2340 kg) and same GE 404 engine, so now using the Gripen's data we can calculate the required F

F = {260 × 2340} ÷ {23 × 1600km (Conservative Range)}
F = 16.5 kN

Assuming that Tejas will need similar (or even greater) thrust for crusing we can now calculate the range of Tejas

Range of Tejas = {260 × 2486} ÷ {23 × 17} = 1653km.

This range however is highly conservative as we don't know the actual L/D ratio or the thrust required for crusing and thus have taken the most conservative values of all the variables, (Eg. Range of Gripen C/D, Fuel Capacity of Tejas etc).

 

[Raj Malhotra]

There was some vague reports or discussions on military forums that Internal fuel for LCA MK1A is now 2900kg & MTOW is 14200kg

 

[NutCracker]

There was some vague reports or discussions on military forums that Internal fuel for LCA MK1A is now 2900kg & MTOW is 14200kg

Mtow yes. Fuel no.

 

[ersakthivel]

I did some searching and came accross this NASA webpage that explained preliminary range calculation of an aircraft in simple yet detailed terms.

Range Summary

Note: I am taking a very simplistic view of aircraft range here for academic purposes. In reality, calculating the range is a complex problem because of the large number of variables involved. An aircraft's flight is not conducted at a single ground speed but varies from zero at take-off, to cruise conditions, and back to zero at landing. Extra fuel is expended in climbing to altitude and in maneuvering the aircraft. The weight is constantly changing as fuel is burned, so the lift, drag, and thrust and fuel consumption rate are also continually changing. On real aircraft, just like with our cars, there is usually a fuel reserve and the pilot makes sure to land the plane with fuel still on board, however we are going to neglect all of these effects for keeping our calculations simple

R (Aircraft Range) = V (cruise speed) × T (Maximum time in air)

[ Generally military aircraft cruise at a height of 30k feet with a speed of 0.8 to 0.85 mach, given that the speed of sound at 30k feet is near near 305m/s, V would be near 260m/s ]

T = M/(SFC × F)

[ M = Fuel Load (the amount of fuel an aircraft is carrying in Kg), in our case M = 2486kg ]
[ SFC = amount of fuel needed to be burned in 1 sec to produce 1kN of thrust, in our case SFC = 23g/(kN.s) ]
[ F = Thrust needed to keep the aircraft cruising at the given parameters ]

[ Note : At cruise speed an aircrafts Lift (L) = aircrafts Weight (W) and Thrust Required (F) = Drag (D) or in other words L/D ratio (lift to drag ratio) = W/F ]

So now F = W ÷ (L/D ratio)

in other words an aircrafts Range R = {V × M} ÷ {SFC × F}

So our Tejas will have a range of {260 × 2486} ÷ {23 × F}

Given that we don't know the required F for keeping the Tejas crusing we would have to look for another aircraft of similar profile and extract the data from there using the above equations.
Gripen C/D seems to be the closest fighter to Tejas with similar empty weight (6800kg), fuel capacity (2340 kg) and same GE 404 engine, so now using the Gripen's data we can calculate the required F

F = {260 × 2340} ÷ {23 × 1600km (Conservative Range)}
F = 16.5 kN

Assuming that Tejas will need similar (or even greater) thrust for crusing we can now calculate the range of Tejas

Range of Tejas = {260 × 2486} ÷ {23 × 17} = 1653km.

This range however is highly conservative as we don't know the actual L/D ratio or the thrust required for crusing and thus have taken the most conservative values of all the variables, (Eg. Range of Gripen C/D, Fuel Capacity of Tejas etc).

Air Force Tejas Mk1: News & Discussions: 02 January 2022 - Page 2 - Bharat Rakshak

Tejas flew non stop from sulur to singapore without refueling with 3 drop tanks, that too the centerline drop tank is just 800 liters in capacity,

in optimum flying altitude , with atleast 20 prcent fuel to spare,

That settles any question about range , I think

Rafales fly non-stop from France to the southern Indian Ocean

In an impressive demonstration of its strategic reach, two Rafales – supported by a C-135 FR air refueller – flew on a very long-distance practice exercise to the French island, Reunion, in the southern Indian Ocean. The Rafales' non-stop flight, which took 10 hours and 35 minutes and involved...

in.ambafrance.org

last time dassault advertised with great fanfare, the record breaking flight of 10000 kms from france to reunion islands which is a distance of 10000 kms ,

It needed 5 refuelings for that flight

Rafale Sets New Record, Flies Non-Stop For 17000 kilometers In 12 Hours

The Rafale fighter jet keeps displaying its dynamic features from time to time. Equipped with special firepower, Rafale on Friday covered a distance of 17000 kilometers without stopping in just 12 hours.

news.abplive.com

"
This French fighter aircraft covered a distance of 17000 km in 12 hours during its journey to the airbase located in the Pacific Ocean. Before this, no Rafale aircraft has been able to travel this distance without stopping.

The French Air Force's air-to-air refueling operator Major Pierrick said that three Rafale aircraft set a new record by flying 12 hours non-stop.

The Rafale planes have covered this distance while flying from California to reach the French airbase Tahiti located in the South Pacific Ocean.

During the flight, the Rafale aircraft refueled 7 times in the air. Major Pierrick said that Rafale is Europe's first fighter jet to fly continuously for 12 hours.

Record Flight Of Three Rafale Planes

According to French media, 7 aircraft of the French Air Force, including 3 Rafale fighter jets, had taken off from France to go to Tahiti. In the first flight, the aircraft reached the airbase in California, USA."

 

[omaebakabaka]

Is alpha defence a reliable source?

No, only official sources are reliable. Internet blogs/vlogs/wiki and so on are not at all reliable.

 

[ersakthivel]

I dont know tejas got refuelled in flight to singapore airshow

cant find any link for that

This is the wikipedia page of Jf17

Fuel capacity: 3,000 L (2,449 kg) internal; 1 x 800 L (180 imp gal) centre-line drop tank; 2 x 800 L (180 imp gal) or 1,100 L (240 imp gal) inboard under-wing drop tanks

• Combat range: 1,200 km (750 mi, 650 nmi) (without refueling)

• Ferry range: 3,482 km (2,164 mi, 1,880 nmi)

wikipedia for gripen C the equivaalent of tejas mk1

Fuel capacity: 3,000 L (790 US gal) (2340 kg) (internal); 3,500 L (920 US gal) (2730 kg) (external)

• Combat range: 800 km (500 mi, 430 nmi)
• Ferry range: 3,200 km (2,000 mi, 1,700 nmi)

compared to them tejas km1 has 2 x 1200 liters & 1 800 liters external drop tanks

 

[ersakthivel]

he is

No, only official sources are reliable. Internet blogs/vlogs/wiki and so on are not at all reliable.

credible to a very large extent

 

[omaebakabaka]

he is

credible to a very large extent

Not credible as they change their song on a timeline that is derived but no worse than current news corp and probably 1000 times better...one might get close to good idea though....

 

[ersakthivel]

man just search his name on DFI search bar,
at least 20 posts are there criticizing that jackass here,
half of them are by our own @ersakthivel only who also dueled with another known tejas critic and gripen fan @Sancho time to time.

Prodyut Das is a motivated troll

A pathological liar as well

His garbage is printed in vayu aerospace

sancho guy is gripen troll

Goto #TejasMk1 #TejasMk1A tags in twitter to know thei lies

 

[ersakthivel]

Not credible as they change their song on a timeline that is derived but no worse than current news corp and probably 1000 times better...one might get close to good idea though....

I dont remember him change his "song"
I follow him for the past few years on twitter
I hvnt watched his Youtube channel much

 

[ersakthivel]

Here is an article on Gallium Nitride technology, now in use on an Indian Navy radar and planned in the upcoming radars for LCA2 and Sukhois in place Gallium Arsenide.

Is India Edging Ahead In A Global Radar Race?

A Hyderabad-based company is poised to manufacture state-of-the-art radars for India's Sukhoi-30 MKI fighter jets.

swarajyamag.com

Do the experts believe in what is written in the article Is correct then a huge progress has been achieved.

This has been officilly denied by Astra microwave on twitter today

so real status is fuzzy for now, whether for secrecy or not, I dont know