ADA Tejas (LCA) News and Discussions

[Decklander]

There are some open source info like air intake is aerodynamically modified in LSP-7 along with the addition of auxilary air intake like the one on JAGUAR.It is clearly visible in the you tube film on lsp-7's maiden flight.

Is it done to improve it's top speed at service ceiling? And considering the size of the aux air intake how much performance improvement it can give in high altitude?

There is also some info like these aux intakes are spring loaded andwill open only when engine needs more air.
So in future if higher thrust engine is installed on mk-1 will these aux intakes be sufficiently enlarged to cater to the higher airflow needs?

Will it also help in increasing AOA and STR? Because increased air suction with higher thrust will be beneficial to these parameters also.What is your opinion on that?

A proper airflow to the engine face is needed for engine to perform to its peak thrust levels and also accelaration times. If the intake size is smaller, that it allows lesser air to be ingested at low speeds, making the engine thirsty for air and reducing its thrust levels. If the intake size above the desired level, the blowout of air from the intake lips add to drag and this excess air needs to be bled away as is done in the case of F-18s.
LCA was designed to be a small fighter but the delay in project and continuously changing QRs by IAF saw it become overweight and bigger in size.the design was frozen in 1998 for a 84KN F404. But added features needed 90KN F404-IN20. This resulted in intake size becoming small and unable to sustain the airflow reqts of this engine. As you all maybe aware that after a speed of 0.4Mach, the ram effect sets in which pushes more air into the intakes there by increasing the thrust of a jet engine. LCA suffers from poor take off performance, poor accelaration at low speeds due to air starvation.
It was for this reason that a dive was done to reach its max level speed at sea level which it sustained thereafter. The aux intakes also have limitations as the air coming from them interferes with the aircoming from regular intakes thereby disrupting that flow. So increasing the size of the aux intake may have a limitation. MK1 will remain stuck at F404-IN20 engine.

 

[ersakthivel]

A proper airflow to the engine face is needed for engine to perform to its peak thrust levels and also accelaration times. If the intake size is smaller, that it allows lesser air to be ingested at low speeds, making the engine thirsty for air and reducing its thrust levels. If the intake size above the desired level, the blowout of air from the intake lips add to drag and this excess air needs to be bled away as is done in the case of F-18s.
LCA was designed to be a small fighter but the delay in project and continuously changing QRs by IAF saw it become overweight and bigger in size.the design was frozen in 1998 for a 84KN F404. But added features needed 90KN F404-IN20. This resulted in intake size becoming small and unable to sustain the airflow reqts of this engine. As you all maybe aware that after a speed of 0.4Mach, the ram effect sets in which pushes more air into the intakes there by increasing the thrust of a jet engine. LCA suffers from poor take off performance, poor accelaration at low speeds due to air starvation.
It was for this reason that a dive was done to reach its max level speed at sea level which it sustained thereafter. The aux intakes also have limitations as the air coming from them interferes with the aircoming from regular intakes thereby disrupting that flow. So increasing the size of the aux intake may have a limitation. MK1 will remain stuck at F404-IN20 engine.

Thanks for the reply.Can't the main air intake size be increased in LSP-8 onwards dispensing with aux intake? Because mk-1 is yet to enter into series production? Will it lead to major reengineering and delays?Why didn't ADA rectify this problem earlier?

For example all the LSPs and PVs were grounded for almost the 10 months in this year. Couldn't they have rectified this problem in this gap?

Or will it need deeper redesign resulting in rewriting of control laws and longer evaluation in wind tunnel leading to further delays and weight increase?

Or has ADA postponed it for mk-2?In mk-2 air intake size will increase by 5 percent only for GE-414-INS6 engine as per aeroindia 2011 ada specs.Will it be enough? Are they factoring in the availability of higher powered EPE version at a later date ?

Also what about the cemilac report which suggested some smoothening of cross section from x=5000 mm to x=6000 mm in fuselage length? Has it been done or not?
Please post your opinion on it.

 

[Decklander]

Thanks for the reply.Can't the main air intake size be increased in LSP-8 onwards dispensing with aux intake? Because mk-1 is yet to enter into series production? Will it lead to major reengineering and delays?Why didn't ADA rectify this problem earlier?

For example all the LSPs and PVs were grounded for almost the 10 months in this year. Couldn't they have rectified this problem in this gap?

Or will it need deeper redesign resulting in rewriting of control laws and longer evaluation in wind tunnel leading to further delays and weight increase?

Or has ADA postponed it for mk-2?In mk-2 air intake size will increase by 5 percent only for GE-414-INS6 engine as per aeroindia 2011 ada specs.Will it be enough? Are they factoring in the availability of higher powered EPE version at a later date ?

Also what about the cemilac report which suggested some smoothening of cross section from x=5000 mm to x=6000 mm in fuselage length? Has it been done or not?
Please post your opinion on it.

The airflow rate is dependent on intake size and flow velocity. As the velocity of the ac increases the airflow also increases so the intake design has to be such that it is able to supply sufficient air at all flight regimes.
Intake design is one very crucial factor and it is not just about increasing the inlet area by use of bigger intakes or aux intakes. The complete funnel has to be redesigned right upto engine face. this involves major design change as the space in a small fighter comes at a premium and any change will need relocating whole lot of equipment inside the ac to allow for the increase in any one parameter.
Installing F414 will need larger intake and airflow duct, relocation of certain internal euipment, stronger engine joints and the fuselage will need to accomodate newer one inch extra compressor face of the ac.
IMO, keeping MK1 with F404-IN20 is a good choice, but we must reduce the numbers from 40+8 to just 20+6. That will be a better choice keeping in view the delays to MK1 induction.

 

[ersakthivel]

The airflow rate is dependent on intake size and flow velocity. As the velocity of the ac increases the airflow also increases so the intake design has to be such that it is able to supply sufficient air at all flight regimes.
Intake design is one very crucial factor and it is not just about increasing the inlet area by use of bigger intakes or aux intakes. The complete funnel has to be redesigned right upto engine face. this involves major design change as the space in a small fighter comes at a premium and any change will need relocating whole lot of equipment inside the ac to allow for the increase in any one parameter.
Installing F414 will need larger intake and airflow duct, relocation of certain internal euipment, stronger engine joints and the fuselage will need to accomodate newer one inch extra compressor face of the ac.
IMO, keeping MK1 with F404-IN20 is a good choice, but we must reduce the numbers from 40+8 to just 20+6. That will be a better choice keeping in view the delays to MK1 induction.

Thanks, Any guess on LSP-7 and 8 achieving design mach-1.8 at service ceiling with these aux air intakes?

 

[p2prada]

IMO, keeping MK1 with F404-IN20 is a good choice, but we must reduce the numbers from 40+8 to just 20+6. That will be a better choice keeping in view the delays to MK1 induction.

I had pointed this out 2 years ago. But there were no takers for it.

 

[Kunal Biswas]

LCA Trainer :

 

[Kunal Biswas]

Some More :

 

[ersakthivel]

I had pointed this out 2 years ago. But there were no takers for it.

IMHO those 20 extra mk-1s in place of obsolete migs(which can crash any time) and jaguars(with 64 kn engine and no radar) are no harm.

It will train pilots in tactics like the sukhoi did without weaponisation for a decade in the IAF.
SO they can be used for the next 10 years for developing tactics for LCA and train pilots on it rather tahn wasting the pilots time in obsolete platforms that are going to be retired.

The the tejas mk-1--LSP-7 already has a significantly large aux air intake which will increase air flow when it is needed and the air intake has also been redesigned for optimum airflow .

Also air intake redesign is eminently doable, because most part of the air intake lies outside the plane and it does not disturb internal equipment layout in any major way.

SO attempts made in LSp-7 is already visible.Results will be known once it finishes the flight envelope opening ,100 percent .

ADA which designed a fully relaxed static stability full digital 4 channel redundancy along with composite tech and tail less cranked delta is eminently qualified to do this air intake job.

Many changes were made to fuel lines, retractable flight probe is to be added in mk-2 and aux air intake is added in LSP-7 means the tejas is going through it's final round of finessing.

 

[bose]

Some More :

Can this be a replacement for AJT Hawk HAL is building under lisence ??

 

[Kunal Biswas]

Hawk is replacement for Kirans, Hawk is used for Greens to learn fly Jets latter in different squadrons they trained on different fighter trainers to get to know about their own Aircraft aerodynamic behavior on different moves and tactics ..

LCA trainer is important just like about MIG-21 trainer, Jaguar trainer so does in MIG-29 trainer..

Can this be a replacement for AJT Hawk HAL is building under lisence ??

 

[Kunal Biswas]

The Trainer :

 

[Kunal Biswas]

At Leh :

 

[Decklander]

Thanks, Any guess on LSP-7 and 8 achieving design mach-1.8 at service ceiling with these aux air intakes?

only in A2A config.

 

[check1]

Just had to say this.

--------------------------- Have Issues PM admin ----------------------------------

 

[ersakthivel]

Re: Just had to say this.

So you subscribe to the points that

1.LCA has never crossed mach 1.4
2.400 MIG-21,23,27 ang JAgs are more state of the art than lca,
3.Upgraded mig-21 ++ are more 4th gen than LCA,
4.Grippen has a larger nose cone dia than tejas,
5.Low wing loading was related to passenger aircrafts,
6.Tejas has cranked delta because only it can afford it,
7.Misrepresenting ACM Naik's statement to beat down a finished product.

Certainly I quite dont have the extra ordinary amount of patience needed to sustain this ,that's why I posted my views.
Welcome to the forum.I gave source to most of my posts.

 

[Kunal Biswas]

Astra bang on target again

The launch of the Astra missile for the second day on Saturday from Chandipur, Odisha, was deadly in its accuracy. An air-to-air missile, it was launched from a fixed launcher on the ground and homed in on its target — Lakshya, a pilotless target aircraft (PTA) flying 15 km away. The warhead exploded within a metre of Lakshya, destroying it.

In the latest launch, the 3.8-metre long and more than 300 kg heavy Astra flew at Mach-3 — three times the speed of sound.Another DRDO missile technologist said the flight "went off well and all the events occurred as per requirements." Astra would be flight-tested again on Monday.

Three more flights in 2013,There will be three more flights from the ground in 2013. After that, it will be launched from different aircraft such as Sukhoi-30, MiG-29 and the Light Combat Aircraft, Tejas.

http://www.deccanherald.com/content/299951/india-successfully-test-fires-astra.html

:cool2:

 

[Kunal Biswas]

The Day LCA got Inducted into Indian Air Force >>

 

[ersakthivel]

difference is that we wanted to have twin seaters approximately 200+ plane and now the rumours are that the IAF want only 144 single seater plane. got the gist?

What I'm trying to say is that present and in coming 3-5years its practically impossible to have 6squadrons of tejas given that Mark 2 is still in design phase and Mark 1 is not in demand.

The IAF is settling for 144 single seaters only as there are no twin seaters available and wont be available anytime in the future because sukhoi has no intention of designing them.So actually Iaf is cutting down the order.

After promising to deliver 200+ twin seaters and making off with indian taxpayer money the sukhoi design team screwed the IAf by not developing twin seater version and dumped the responsibilty of making it a twin seater on the HAl.

Only ADA will try it's level best to upgrade tejas mk-1 to mk-2 level as per the IAf's request.You wont expect sukhoi to do it.That is the difference between indigenous equipment and foreign stuff.You are just one of the customers.

We all know the "TECHNICAL AND DESIGN CAPABILITIES OF HAL". The hal expressed it's inability to convert it into two seaters and now IAf responds with cutting down the order.

Other important questions are will russians transfer the full techs mentioned in the contract as IAf has cut down it's order? OR will the cost of TOT be viable for just 144 fighters? And if so what will be the per unit cost?

Already published reports say the PAKFA airframe will be just in F-35 stealth standard and not like the F-22 standard.And if so the pricing too should reflect this fact.And another important thing is avionics is indian responsibility.

Avionics contribute a substantial part of the fighter cost.The PAKFA price should be examined in the light of the fact that it is comming without avionics .

 

[SajeevJino]

During The F 35 design everyone blaming it's design and Performance ..But now they slowly accepting It's Performance and everyone knows they will update if any Failure Parts in future And Makes it Perfect...
same here with our Tejas..

@ersakthivel your words about Tejas RCS makes Chinese and Pakki pee in air warfare facing the Tejas

 

[p2prada]

Contacted a friend and found out something what I always mentioned. The F-414s ordered are not EPE. It is a derivative engine.

Anyway, things don't seem to be particularly hot on the schedule. ADA's current schedule of getting Mk2 flying by 2014 and IOC by 2016 is overly optimistic and will not be reached at the specs that IAF is demanding for. It may take that long just to certify the new engine on LCA. So flight testing may happen only after 2016.

Yeah, the Navy has a requirement for the EPE on their version. This was established partially through a news paper article a few months ago publicly. But even the developers are not entirely sure as of today. So, lets see what happens here.