Round One JF17 - Poor Display By Tejas Took 10 more sec Than JF17 To Go Up

[SQ8]

The Point is : THERE IS A REASON , why the 4.5 Gen Typhoon, Rafale , Mirages and Gripens , The Famous, Delta daggers And My fav Jet : Pure Interceptor, Avro Arrow , The Most Advanced Jet of 50s are/were ALL DELTA.
Period.

Now carry on, .. Mine is better than Yours.. !

Yes, there is a reason.. and with that reason.. all the jets except the Mirages are canard coupled deltas that aim to avoid the pitfalls that the Tejas faces currently. I dont think bringing in "advanced jets of the 50's" is a good idea to come up with an example.

However your example with the Arrow is both ironic and befitting.. since both it and the Tejas suffer bring being excellent platforms plagued by either poor management or a poor customer.

Your points are pertinent for a traditional "naked" delta with no canards or compound geometry (which is effectively a canard attached to a delta for tejas) due to the excessive drag caused by flow separation in high alpha (and hence also high STR) regimes. So quite true for the mirage series and Mig 21.

However with the addition of canards and compound geometries like in the Eurofighter, Gripen and Tejas etc.., this issue has been mitigated quite considerably through flow direct re-energisation and/or higher spanwise flow from the greater incidence angle. The exact specs given their maximum STR is therefore something we cannot automatically to be inferior to regular conventional layouts...while they keep their superior ITR parameters because of their relatively lower wing loading (ceterus paribus). The exact trade-offs and balances are of course quite hush hush, high quality turn performance data is only really released for aircraft that have already been retired or are currently/close to ending their service lives.

Maybe in my free time I will attempt to do some CFD modelling using the geometries of canards and compound deltas as opposed to regular simple deltas so we can all have some layman data as to what the possible improvements might entail in rough % terms.....since gaining access to this online is quite difficult from what I have seen.

The compound geometry is NOT a canard attached to a delta. The compound delta is an attempt to solve the drag issue generated as shown in your figure by creating an energized vortex that allows for better manoeuvrability at supersonic speeds.

Also, the exact trade-offs are not "HUSH HUSH". Over 50 research papers can be found on the effects of various delta designs and especially the compound delta used on the Tejas which is also present on the 1960's Saab Viggen.

 

[mansour313]

all the jets except the Mirages are canard coupled deltas that aim to avoid the pitfalls that the Tejas faces currently.

hmm.. that's a pretty strong word that you use there. 'pitfalls'.
you are saying you found out design 'pitfalls' from a 10 min clip. Something that scientists did after hours of wind tunnel tests and design development were not able to comprehend. If I were to make such a blanket 'word' all encompassing then I would just go with the technicians and design experts who evaluated and developed such a platform.

a 10 sec vertical climb is in league of raptor. It too loses power easily in conventional take off and vertical climb. Unless the pilot really uses and sustains full throttle, which is not really a design advantage.

 

[MimophantSlayer]

Guys pulling out BS. Here you are wasting

Guys here are stating their Own Laws of Aerodynamics from just looking 20-30 seconds videos
Look how they trying to be expert in field where the possess Zero Factual
Knowledge.



Lost my will even to comprehend now Leave debate aside

What ?
What did I say wrong?
I'm only mentioning what I saw on the JFT Paris video and the Tejas Bahrain video.

Do explain, at what level I'm wrong?

 

[cerberus]

Yes, there is a reason.. and with that reason.. all the jets except the Mirages are canard coupled deltas that aim to avoid the pitfalls that the Tejas faces currently. I dont think bringing in "advanced jets of the 50's" is a good idea to come up with an example.

However your example with the Arrow is both ironic and befitting.. since both it and the Tejas suffer bring being excellent platforms plagued by either poor management or a poor customer.

Sir I understand you concern
It's expected that's why we don't see the tailless delta wing aircraft as they bleed energy during ITR and face high drag during low altitude flight

I think ADA that's why made it improvised compound delta Design
For high vortex lift and to reduce drag.
Well there is still has its limits
Even canard base fighter's like
Typhoon or Rafale as the mach number increases so as the centre of lift shifts. But this is a minor drawback which can be compensated with skilled pilot.

Sir ADA must have looked at every aspects during wind tunnel testing in its Labs.
I think we can't judge it just by looking at few minutes videos as it all controlled manoeuvre in Airshow which are conducted for public amusement which are quite different from what we see in Training or in actual Combat

 

[SQ8]

hmm.. that's a pretty strong word that you use there. 'pitfalls'.
you are saying you found out design 'pitfalls' from a 10 min clip. Something that scientists did after hours of wind tunnel tests and design development were not able to comprehend. If I were to make such a blanket 'word' all encompassing then I would just go with the technicians and design experts who evaluated and developed such a platform.

a 10 sec vertical climb is in league of raptor. It too loses power easily in conventional take off and vertical climb. Unless the pilot really uses and sustains full throttle, which is not really a design advantage.

Sure I would. All the technicians and scientists cannot change the laws of physics unless you wish to defined "Vedic Physics" which is the trend in India. The pitfalls of the delta were WELL KNOWN to the Tejas team but they chose to pursue it for their design constraints. It is called trade off in design to achieve requirements based on the needs of the user which are not always limited to aircraft performance. The biggest constraint being that the Tejas was told to be carrier capable which meant that it had to be a compact design, which is also where the compound delta has its play in trying to achieve the same aerodynamics as the M2K along with mitigating the issues that aircraft faces due to its pure delta design.

Moreover, the Tejas team.. like that on the F-22 did not achieve any miracle and essentially did the best they could with the budget given to them. Although in fairness, the F-22 had a much more flexible, and much less idiotic program management and indecisive customer than the Tejas has. To use the right stinging word, the Tejas program was essentially "raped" by the bumbling bureaucracy and poor cooperation between the IAF and the development team.
A fine aircraft that should have been on the front line some five years ago is still flying constrained and almost over cautiously due to mismanagement.

 

[thinkingcap81]

A fine aircraft that should have been on the front line some five years ago is still flying constrained and almost over cautiously due to mismanagement.

So if it is inducted in more numbers in 3-4 years from now it should be ok for Indo-Pak and Indo-China scenarios?

No sane person will deny the humongous issues that plagued the development of LCA, these kind of issues still persist in different areas in India.

 

[SQ8]

Sir I understand you concern
It's expected that's why we don't see the tailless delta wing aircraft as they bleed energy during ITR and face high drag during low altitude flight

I think ADA that's why made it improvised compound delta Design
For high vortex lift and to reduce drag.
Well there is still has its limits
Even canard base fighter's like
Typhoon or Rafale as the mach number increases so as the centre of lift shifts. But this is a minor drawback which can be compensated with skilled pilot.

Sir ADA must have looked at every aspects during wind tunnel testing in its Labs.
I think we can't judge it just by looking at few minutes videos as it all controlled manoeuvre in Airshow which are conducted for public amusement which are quite different from what we see in Training or in actual Combat

Please look at my post above. The ADA did look at it in the labs and did very through testing, the issue is your expectation with the design. The ADA chose a design based on meeting various criteria and with that design came its disadvantages which they tried to mitigate as much as possible. Credit goes to the CLAW team which really did very well in getting this design to work.

The rest is what and ANY other Indian will likely do in national fervour to try and justify it as some supermachine which it isnt nor ever will be. It is a fine fighter for the purpose it is designed to achieve; a Mig-21 replacement.
Sadly, it is this very "Superman" expectation that has left the program in doldrums along with other disasters such as Arjun.

As the thread shows, people of the subcontinent have issues with knowing exactly how much credit to take and give.. and realizing limitations. For them I have only pity, but none of my time.

As for the display, I will repeat my dissappointment....as I stated in my first post here. It is not disappointment in the Aircraft and its design, but how badly it has been managed that they are not willing to push it where its strengths are.

So if it is inducted in more numbers in 3-4 years from now it should be ok for Indo-Pak and Indo-China scenarios?

No sane person will deny the humongous issues that plagued the development of LCA, these kind of issues still persist in different areas in India.

It has a role to play in the Indian Air Force Staff requirement for 2025 now, and for those roles this aircraft would be just satisfactory and the proposed Mk2 (if it happens and the Indian Babus both civilian and military dont screw it up) would be pretty good in.

 

[Manas]

this is impressive package .. for JF-17 apart from Russian engine and Martin backer ejection seat .. every component is Chinese if I am not mistaken. oh yea the paint job on both LCA and JF-17 is local like dil hey hindustani/ Pakistani

you forget to acknowledge Design , air frame to its FBW software of LCA are all indigenous . You are just too eager to prove equality with India like every other Pakistanis do in every aspects of life . LOL

Okay , Any Videos of LCA flight display on the 2nd day from the Bahrain air show , or LCA display was slated for just one day of the air show ?

 

[mansour313]

Sure I would. All the technicians and scientists cannot change the laws of physics unless you wish to defined "Vedic Physics" which is the trend in India. The pitfalls of the delta were WELL KNOWN to the Tejas team but they chose to pursue it for their design constraints. It is called trade off in design to achieve requirements based on the needs of the user which are not always limited to aircraft performance. The biggest constraint being that the Tejas was told to be carrier capable which meant that it had to be a compact design, which is also where the compound delta has its play in trying to achieve the same aerodynamics as the M2K along with mitigating the issues that aircraft faces due to its pure delta design.

Moreover, the Tejas team.. like that on the F-22 did not achieve any miracle and essentially did the best they could with the budget given to them. Although in fairness, the F-22 had a much more flexible, and much less idiotic program management and indecisive customer than the Tejas has. To use the right stinging word, the Tejas program was essentially "raped" by the bumbling bureaucracy and poor cooperation between the IAF and the development team.
A fine aircraft that should have been on the front line some five years ago is still flying constrained and almost over cautiously due to mismanagement.

you cannot hold a delay in development as critique against a platform.

but more importantly, when a country wants to develop a critical subsystem like fbw from scratch, then the only way to do that is to accumulate flying hours and slowly debugging a few codes at a time. If say Pakistan were to even attempt to get an fbw validation software from the really few who can sell it like LM or EADS, then the phone calls would start ringing from Virginia to Westminster that the pakstanis were out to get a flight program, and apart from that very little would happen. Even China could only generate enough interest to develop a pitch only fbw on the FC-1. Why until today the fbw for the same is incomplete and pitch-only ? Someone obviously doesn't want to go through the hassle of debugging the entire flight envelope. Even with resources in their hands.

First there are platforms and sub-systems and there are validation tools for these very sub-systems to perform optimum. There are only 2 countries that are capable of cradle-to-grave systems development, which means they have a solution to every issue in-house. The rest have to borrow tech, which is pretty normal for OECD and EU countries, which reduces time of platform development, for everyone else it is a tough grind and there are barriers all throughout. Even in procurement of gyroscopes and inertial navigation systems, there are sanctions.

this is is one instance wherein the journey is as important as the destination and the journey can teach one things which was never possible were the going so easy.

 

[SQ8]

you forget to acknowledge Design , air frame to its FBW software of LCA are all indigenous . You are just too eager to prove equality with India like every other Pakistanis do in every aspects of life . LOL

Okay , Any Videos of LCA flight display on the 2nd day from the Bahrain air show , or LCA display was slated for just one day of the air show ?

The fact that you needed a LOL shows that your argument rest entirely on the genetic requirement to diss Pakistan rather than actual analysis. Not that we blame you for it, after all.. you are an Indian on a Pakistani forum

you cannot hold a delay in development as critique against a platform.

but more importantly, when a country wants to develop a critical subsystem like fbw from scratch, then the only way to do that is to accumulate flying hours and slowly debugging a few codes at a time. If say Pakistan were to even attempt to get an fbw validation software from the really few who can sell it like LM or EADS, then the phone calls would start ringing from Virginia to Westminster that the pakstanis were out to get a flight program, and apart from that very little would happen. Even China could only generate enough interest to develop a pitch only fbw on the FC-1. Why until today the fbw for the same is incomplete and pitch-only ? Someone obviously doesn't want to go through the hassle of debugging the entire flight envelope. Even with resources in their hands.

First there are platforms and sub-systems and there are validation tools for these very sub-systems to perform optimum. There are only 2 countries that are capable of cradle-to-grave systems development, which means they have a solution to every issue in-house. The rest have to borrow tech, which is pretty normal for OECD and EU countries, which reduces time of platform development, for everyone else it is a tough grind and there are barriers all throughout. Even in procurement of gyroscopes and inertial navigation systems, there are sanctions.

this is is one instance wherein the journey is as important as the destination and the journey can teach one things which was never possible were the going so easy.

You are throwing strawman arguments at what is not even up for debate in an attempt to avoid the primary issue which is poor program management. Considering that everything beyond the 90's has been open arms to India, your entire argument falls flat on its face or only reaffirms the state of pithy bureucracy in India. Considering that the CLAW team had access to US facilities and testing and the French gave massive input to the LCA design and testing along with the Israelis being ever present even before the nuclear sanctions gave up; it all points to gross indecisiveness or genuine lack of interest in the development team to get anything done for the aircraft.

Your beating around the bush posting paragraph after paragraph of semantics has nothing to do with the plain and simple truth of the Tejas being in its current conundrum solely due to poor utilization of resources by whosoever was managing the program from both the manufacturer's and customer's end.

 

[Irfan Baloch]

to performing vertical takeoff you need enough speed and have some lift and then use your pitch to move up.

pitch axis is controlled by elevators which are control surfaces on horizontal stabilizers of an aircraft.
whenever elevators are lifted up a downward force is created that will push down empennage of aircraft lifting up the nose of aircraft.

for a sustained vertical take off you need higher thrust such that the force produced should be greater than combination of drag force of an aircraft and weight of an aircraft.

according to available information nether jf17 nor LCA has required thrust to overcome both weight and drag force for vertical flight(remember there is no lift produce by wings during vertical flight)
but by building up momentum such maneuver can be performed.
momentum=force*velocity.

you cannot hold a delay in development as critique against a platform.

but more importantly, when a country wants to develop a critical subsystem like fbw from scratch, then the only way to do that is to accumulate flying hours and slowly debugging a few codes at a time. If say Pakistan were to even attempt to get an fbw validation software from the really few who can sell it like LM or EADS, then the phone calls would start ringing from Virginia to Westminster that the pakstanis were out to get a flight program, and apart from that very little would happen. Even China could only generate enough interest to develop a pitch only fbw on the FC-1. Why until today the fbw for the same is incomplete and pitch-only ? Someone obviously doesn't want to go through the hassle of debugging the entire flight envelope. Even with resources in their hands..

welcome to forum . if these are really your only accounts

otherwise why dont you come on your main accounts?

 

[Mrc]

What advantage does a automatic canopy has over manual canopy. Intact a manual canopy takes less time to close. Further LCA is a very small jet, infact the smallest jet in the world, a manually closed canopy was delebaretely placed in order to reduce weight and save space.

Do you know what the hallmarks of a true modern 4th gen fighter? Extensive use of composites, AESA/PESA radar, full FBW system, EW system, good engines (not a outdated Russian one whose after burner mode is almost useless) and Tejas has all of those.



Please go through the below post.
And btw, have you heard something about 'low fly past-vertical take off'??

So basically small and mannually clising windows.....

Gentleman we have suzuko alto of fighter industry....please now stop comparing it to mercedes s class

 

[Bilal9]

So which one is original? BKK117 or EC 145.

BKK 117 was the closest prototype for the HAL Dhruv. The elastomeric rotor design and in fact the whole design of Dhruv was lifted from that rotorcraft. BKK-117 was phased out in 2004, replaced by a similar but improved EC 145, which is now known as Airbus Helicopters H 145. Dhruv is a bit bigger though.

 

[Irfan Baloch]

I never seen passenger plane doing
Vertical take off or pulling Negative G

lol I did

 

[mansour313]

You are throwing strawman arguments at what is not even up for debate in an attempt to avoid the primary issue which is poor program management.

Ok so has poor program management resulted in poor platform. If so, what is so poor about the platform. Kindly do not confuse the two so that we can learn what platform-specific issues you have squared in on.

Considering that everything beyond the 90's has been open arms to India, your entire argument falls flat on its face or only reaffirms the state of pithy bureucracy in India.

You have no idea. Sanctions are not there on systems. But you still, till today, cannot buy certain sub-systems off-the-shelf such as advanced gyroscopes and INS from USA. I don't know if other countries can but DRDO, HAL, ADA cannot. They will sell it to GCC, but GCC doesn't have any platforms in development. Once a country begins to threaten on developing competing platforms and sub-systems, it is a different ballgame, you lift the level of insecurity amongst suppliers to another level.

Considering that the CLAW team had access to US facilities and testing and the French gave massive input to the LCA design and testing along with the Israelis being ever present even before the nuclear sanctions gave up; it all points to gross indecisiveness or genuine lack of interest in the development team to get anything done for the aircraft.

After sanctions LM confiscated all that data and left the team willy nilly hanging onto air. Israel though is eager to please but does not have the testing facilities and wind tunnels and labs to validate everything.

Your beating around the bush posting paragraph after paragraph of semantics has nothing to do with the plain and simple truth of the Tejas being in its current conundrum solely due to poor utilization of resources by whosoever was managing the program from both the manufacturer's and customer's end.

I don't see what the issue is. It is true that apathy has caused a lag in development. But that lag period has been used for debugging and other critical areas. There was a waste of time but it isn't significant in overall context. Could it have been faster, yes it could.