LCA TEJAS MK1 & MK1A: News and Discussion

[abingdonboy]

Very different principles.
The two projects are based on disjoint principal and technologies. Neither project would be much help for other.
Crew recovery module is designed for atmospheric re-entry. It will splash down in Indian ocean. The capsule itself will be protected/armored. Crew will never be exposed to the atmospheric elements.
Ejection seat is as name suggest for bailing out of lost aircraft. It will not be atmospheric re-entry. Pilot will be directly exposed to the atmospheric elements once rocket-power motor pushes him from the aircraft.

I don’t know much about space stuff or how the crew escape module is expected to function but one of the holy grails of ejection seats (and most troublesome parts) is zero-zero, safely getting a pilot out of a static plane and landing them safely on the ground despite only being ejected a few metres in the air is an incredibly complex chain of events that must happen sequentially (restraint, escape, seat separation, main chute deployment) and the margin for error is milliseconds.

one should not discount the engineering challenge this is and simply say this should be indigenised, it’s far from that simple. This is up there with core engine tech in terms of challenge and it doesn’t seem like india has particularly put much effort into their own system as of yet. And I’ll reiterate it’s a multi decade long process to even get to contemporary standards of today

 

[Blademaster]

Those who say getting rid of the British stuff is a waste of time and money, well looks like HAL doesn't agree with you.

 

[Dark Sorrow]

Those who say getting rid of the British stuff is a waste of time and money, well looks like HAL doesn't agree with you.

Aren't tyres supplied by MRF?
We don't use British Radar.

The article says India has announced it will begin replacing British-made components - I couldn't find any such announcements apart from this tweet or other articles/tweet referring to this tweet.

 

[Blademaster]

Aren't tyres supplied by MRF?
We don't use British Radar.

The article says India has announced it will begin replacing British-made components - I couldn't find any such announcements apart from this tweet or other articles/tweet referring to this tweet.

He most likely meant the radome.

India dispuesta a eliminar componentes británicos del HAL Tejas para poder venderlo a la Argentina

En el marco de la visita del ministro indio de Asuntos Exteriores de la India, S. Jaishankar, a Buenos Aires, trascendió él interés argentino por reforzar

www.zona-militar.com

 

[Blademaster]

If HAL can bag the Argentina contract, most likely it will bag Malaysia contract and interest Egypt and Indonesia into looking into the LCA program for their own needs.

 

[Blademaster]

 

[NutCracker]

He most likely meant the radome.

India dispuesta a eliminar componentes británicos del HAL Tejas para poder venderlo a la Argentina

En el marco de la visita del ministro indio de Asuntos Exteriores de la India, S. Jaishankar, a Buenos Aires, trascendió él interés argentino por reforzar

www.zona-militar.com

That ID 's followers/follwing ratio is sus..and that website is from Argentina I guess. better wait for some good source .

Also it says Russian.. not "indigenous". No one will be our guinea pig if their order is supposed to start delivering by 2026.

 

[IndianHawk]

Very different principles.
The two projects are based on disjoint principal and technologies. Neither project would be much help for other.
Crew recovery module is designed for atmospheric re-entry. It will splash down in Indian ocean. The capsule itself will be protected/armored. Crew will never be exposed to the atmospheric elements.
Ejection seat is as name suggest for bailing out of lost aircraft. It will not be atmospheric re-entry. Pilot will be directly exposed to the atmospheric elements once rocket-power motor pushes him from the aircraft.

Ok I made a mistake by typing crew recovery module.
What I wanted to talk about is the mechanism used to save astronauts of roket explodes while launching very well within the atmosphere. They did a test for it iirc.

Low altitude escape motor .

ISRO successfully completes Gaganyaan low altitude escape motor static test

According to ISRO, Crew Escape System takes away the Crew module in case of eventuality and rescues the astronauts

www.livemint.com

This is to work in atmosphere.

Now I'm aware it's not the same as ejection seat of fighter jet . But underlying principle for ejection by use of thrust is the same.

And once you eject the seat our of the plane at desired angle all you need to do is make sure is that parachute deploys in time.

What protect the pilot from atmosphere effects is his flying suit not the seat. What seat should protect is his spine while being eject which is more A function about ergonomics of seat shape which can be copied from existing designs.

 

[IndianHawk]

That ID 's followers/follwing ratio is sus..and that website is from Argentina I guess. better wait for some good source .

Also it says Russian.. not "indigenous". No one will be our guinea pig if their order is supposed to start delivering by 2026.

Makes sense for Argentina orders. Russia has all the alternatives for British components from ejection seat to refueling probes .

 

[Blademaster]

Makes sense for Argentina orders. Russia has all the alternatives for British components from ejection seat to refueling probes .

What is so special about the refueling probe that India has to outsource it? I get the gist about the radome. But refueling probes and tires?

 

[IndianHawk]

What is so special about the refueling probe that India has to outsource it? I get the gist about the radome. But refueling probes and tires?

I guess depends on time. Has indegenous probe developed as of now. If not it will take some time and if Argentina requires delivery faster this will need to be outsourced.

For mk2 we are developing refueling probe of our own .

 

[Dark Sorrow]

I guess depends on time. Has indegenous probe developed as of now. If not it will take some time and if Argentina requires delivery faster this will need to be outsourced.

For mk2 we are developing refueling probe of our own .

Even for indigenous refueling probe, we are have consulted/outsourced the development work for the retractable actuated probe to Cobham Limited.
The retractable actuated probe is expected to use several British and American sub-systems.

 

[IndianHawk]

Even for indigenous refueling probe, we are have consulted/outsourced the development work for the retractable actuated probe to Cobham Limited.
The retractable actuated probe is expected to use several British and American sub-systems.

Iirc for mk2 they have given up on retractable probe to save time . It will instead have a non - retractable probe just like rafale. But it will be removable for when it's not required. So a plug and play type system.

 

[Okabe Rintarou]

Ok I made a mistake by typing crew recovery module.
What I wanted to talk about is the mechanism used to save astronauts of roket explodes while launching very well within the atmosphere. They did a test for it iirc.

Low altitude escape motor .

ISRO successfully completes Gaganyaan low altitude escape motor static test

According to ISRO, Crew Escape System takes away the Crew module in case of eventuality and rescues the astronauts

www.livemint.com

This is to work in atmosphere.

Now I'm aware it's not the same as ejection seat of fighter jet . But underlying principle for ejection by use of thrust is the same.

And once you eject the seat our of the plane at desired angle all you need to do is make sure is that parachute deploys in time.

What protect the pilot from atmosphere effects is his flying suit not the seat. What seat should protect is his spine while being eject which is more A function about ergonomics of seat shape which can be copied from existing designs.

Dude, the same module has both High Altitude Escape Motor and Low Altitude Escape Motor in Gaganyaan.
As for ejection from fighter jet, its very different. Humans can take higher G loads of around 20G to 25G laterally (talking eyeballs in and eyeballs out acceleration respectively). Which is also why in the rocket, human is in a "lying down" position and the seat is such that the force is much more evenly distributed across the back (go check out seats of Gaganyaan crew module). Compare that to the position at which pilot is seated during ejection from a jet cockpit.
The biomechanics of ejection in both cases vastly change due to difference in seating position.

Everything else is also different. In rocket crew escape system, the crew is enclosed in a re-entry capable shell, while a fighter pilot is experiencing wind loads and is open to elements. Your entire ejection system also has to fit in a very small package in jets. Rocket motors in both are consequently different. Ejections from fighters can need to be from zero to very low altitudes and even underwater (happened once back in the 70s from Vikrant, the plane dived into the water right after take-off and started sinking, the pilot waited for the carrier to pass overhead before punching out, lol).
And the parachute opening is also different because rocket crew escape pods can carry heavier rocket motors that take the entire thing to an altitude that is sufficient for parachute to open and then terminal velocity to be achieved. But a fighter jet ejection seat can't carry such a heavy motor, so the parachute needs to open much more quickly and can't rely on air alone for the job.

There have got to be other major differences as well, that I don't know about. Point is, mastering one system is no guarantee that you'll master the other. They are both very different from each other.

 

[karn]

Ejections from fighters can need to be from zero to very low altitudes and even underwater (happened once back in the 70s from Vikrant, the plane dived into the water right after take-off and started sinking, the pilot waited for the carrier to pass overhead before punching out, lol).

Im surprised that the ejection seat was able to carry the pilots gigantic balls.

 

[Bleh]

Those who say getting rid of the British stuff is a waste of time and money, well looks like HAL doesn't agree with you.

Literally noone said that... We've been talking about how Tejas should be rated to work with every countries' subsystems & weaponary that we operate to boost its export chances, due to various political alignments.

 

[Blademaster]

Literally noone said that... We've been talking about how Tejas should be rated to work with every countries' subsystems & weaponary that we operate to boost its export chances, due to various political alignments.

PLease go through this thread again. I think you missed a couple posts there.

 

[IndianHawk]

Dude, the same module has both High Altitude Escape Motor and Low Altitude Escape Motor in Gaganyaan.
As for ejection from fighter jet, its very different. Humans can take higher G loads of around 20G to 25G laterally (talking eyeballs in and eyeballs out acceleration respectively). Which is also why in the rocket, human is in a "lying down" position and the seat is such that the force is much more evenly distributed across the back (go check out seats of Gaganyaan crew module). Compare that to the position at which pilot is seated during ejection from a jet cockpit.
The biomechanics of ejection in both cases vastly change due to difference in seating position.

Everything else is also different. In rocket crew escape system, the crew is enclosed in a re-entry capable shell, while a fighter pilot is experiencing wind loads and is open to elements. Your entire ejection system also has to fit in a very small package in jets. Rocket motors in both are consequently different. Ejections from fighters can need to be from zero to very low altitudes and even underwater (happened once back in the 70s from Vikrant, the plane dived into the water right after take-off and started sinking, the pilot waited for the carrier to pass overhead before punching out, lol).
And the parachute opening is also different because rocket crew escape pods can carry heavier rocket motors that take the entire thing to an altitude that is sufficient for parachute to open and then terminal velocity to be achieved. But a fighter jet ejection seat can't carry such a heavy motor, so the parachute needs to open much more quickly and can't rely on air alone for the job.

There have got to be other major differences as well, that I don't know about. Point is, mastering one system is no guarantee that you'll master the other. They are both very different from each other.

You are thinking too far with g loads and everything else. My point was only about escape motors mechanism which is an ejection system by all means.

 

[Okabe Rintarou]

You are thinking too far with g loads and everything else. My point was only about escape motors mechanism which is an ejection system by all means.

But your rocket motors' performance parameters, thrust profile, etc all depend on the biomechanics of the problem. Is what I am trying to highlight. Its different enough that you'll have to start from scratch almost.

 

[NutCracker]