Lions Of Punjab
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ADA Tejas (LCA) News and Discussions
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Lions Of Punjab
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Lions Of Punjab
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Lions Of Punjab
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Lions Of Punjab
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An aircraft's lift capabilities can be measured from the following formula:
L = (1/2) d v2 s CL
* L = Lift, which must equal the airplane's weight in pounds
* d = density of the air. This will change due to altitude. These values can be found in a I.C.A.O. Standard Atmosphere Table.
* v = velocity of an aircraft expressed in feet per second
* s = the wing area of an aircraft in square feet
* CL = Coefficient of lift , which is determined by the type of airfoil and angle of attack.
So v^2=2L/d*s*CL
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
Lift (N) = CL * area (sq m) * .5 * pressure (kg/cubic m) * velocity (m/s) squared
Coefficient induced drag (CDi) = (CL^2) / (pi * aspect ratio * Oswald efficiency)
Drag = coefficient * area * density *.5 * velocity squared
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
As per the above set of formulas Cl reduces when surface area increases,
And the co efficient of induced drag reduces by square of CL ,
SO even though it appears that plain drag increases with directly with surface area , since the co efficient of drag reduce by the square of CL(which reduces further directly with wing surface area )
So v^2=2L/d*s*CL
SO even though v decreases with increase in surface area this is even out by decrease in Cl with surface area which leads to higher v.
And most important of all the L (the all important lift thing which determines the higher v) is always higher for low wing loading fighter at any given bank angle.
To plug some figures in, an example aircraft with weight 3000 kg and wing area of 10 m^2, then the same aircraft with 20 m^2 wings. (this assumes weight doesn't increase with the larger wings, of course)
Assuming lift = 4 times weight, sea level density, speed = 400 km/h
117,600 = CL * 10 * .5 * 1.225 * 111^2
CL = 1.56
CDi = (1.56^)/(pi*6*.8) = 0.16
Induced drag = 0.16 * 10 * 1.225 * .5 * 111^2
Induced drag = 12,074 N
Now the same thing but with double the wing area
117,600 = CL * 20 * .5 * 1.225 * 111^2
CL = 0.78
CDi = (0.78^)/(pi*6*.8) = 0.04 (note how doubling the wing area results in a quarter of the CDi, because CL is squared)
Induced drag = 0.04 * 20 * 1.225 * .5 * 111^2
Induced drag = 6,037 N
Of course, parasitic drag increases with a larger wing area, but basically lower wingloading = an increasing advantage the tighter the turn, and the lower the IAS you fly (and IAS of course is lower at high altitudes)
Lift (N) = CL * area (sq m) * .5 * pressure (kg/cubic m) * velocity (m/s) squared
Coefficient induced drag (CDi) = (CL^2) / (pi * aspect ratio * Oswald efficiency)
Drag = coefficient * area * density *.5 * velocity squared
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
To plug some figures in, an example aircraft with weight 3000 kg and wing area of 10 m^2, then the same aircraft with 20 m^2 wings. (this assumes weight doesn't increase with the larger wings, of course)
Assuming lift = 4 times weight, sea level density, speed = 400 km/h
117,600 = CL * 10 * .5 * 1.225 * 111^2
CL = 1.56
CDi = (1.56^)/(pi*6*.8) = 0.16
Induced drag = 0.16 * 10 * 1.225 * .5 * 111^2
Induced drag = 12,074 N
Now the same thing but with double the wing area
117,600 = CL * 20 * .5 * 1.225 * 111^2
CL = 0.78
CDi = (0.78^)/(pi*6*.8) = 0.04 (note how doubling the wing area results in a quarter of the CDi, because CL is squared)
Induced drag = 0.04 * 20 * 1.225 * .5 * 111^2
Induced drag = 6,037 N
Of course, parasitic drag increases with a larger wing area, but basically lower wingloading = an increasing advantage the tighter the turn, and the lower the IAS you fly (and IAS of course is lower at high altitudes)
L = (1/2) d v2 s CL
* L = Lift, which must equal the airplane's weight in pounds
* d = density of the air. This will change due to altitude. These values can be found in a I.C.A.O. Standard Atmosphere Table.
* v = velocity of an aircraft expressed in feet per second
* s = the wing area of an aircraft in square feet
* CL = Coefficient of lift , which is determined by the type of airfoil and angle of attack.
So v^2=2L/d*s*CL
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
Lift (N) = CL * area (sq m) * .5 * pressure (kg/cubic m) * velocity (m/s) squared
Coefficient induced drag (CDi) = (CL^2) / (pi * aspect ratio * Oswald efficiency)
Drag = coefficient * area * density *.5 * velocity squared
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
As per the above set of formulas Cl reduces when surface area increases,
And the co efficient of induced drag reduces by square of CL ,
SO even though it appears that plain drag increases with directly with surface area , since the co efficient of drag reduce by the square of CL(which reduces further directly with wing surface area )
So v^2=2L/d*s*CL
SO even though v decreases with increase in surface area this is even out by decrease in Cl with surface area which leads to higher v.
And most important of all the L (the all important lift thing which determines the higher v) is always higher for low wing loading fighter at any given bank angle.
To plug some figures in, an example aircraft with weight 3000 kg and wing area of 10 m^2, then the same aircraft with 20 m^2 wings. (this assumes weight doesn't increase with the larger wings, of course)
Assuming lift = 4 times weight, sea level density, speed = 400 km/h
117,600 = CL * 10 * .5 * 1.225 * 111^2
CL = 1.56
CDi = (1.56^)/(pi*6*.8) = 0.16
Induced drag = 0.16 * 10 * 1.225 * .5 * 111^2
Induced drag = 12,074 N
Now the same thing but with double the wing area
117,600 = CL * 20 * .5 * 1.225 * 111^2
CL = 0.78
CDi = (0.78^)/(pi*6*.8) = 0.04 (note how doubling the wing area results in a quarter of the CDi, because CL is squared)
Induced drag = 0.04 * 20 * 1.225 * .5 * 111^2
Induced drag = 6,037 N
Of course, parasitic drag increases with a larger wing area, but basically lower wingloading = an increasing advantage the tighter the turn, and the lower the IAS you fly (and IAS of course is lower at high altitudes)
Lift (N) = CL * area (sq m) * .5 * pressure (kg/cubic m) * velocity (m/s) squared
Coefficient induced drag (CDi) = (CL^2) / (pi * aspect ratio * Oswald efficiency)
Drag = coefficient * area * density *.5 * velocity squared
If you look at the equations, induced drag increases with the square of CL, and proportionately with the increase in wing area. So double wing area = a quarter the CL = half the induced drag.
To plug some figures in, an example aircraft with weight 3000 kg and wing area of 10 m^2, then the same aircraft with 20 m^2 wings. (this assumes weight doesn't increase with the larger wings, of course)
Assuming lift = 4 times weight, sea level density, speed = 400 km/h
117,600 = CL * 10 * .5 * 1.225 * 111^2
CL = 1.56
CDi = (1.56^)/(pi*6*.8) = 0.16
Induced drag = 0.16 * 10 * 1.225 * .5 * 111^2
Induced drag = 12,074 N
Now the same thing but with double the wing area
117,600 = CL * 20 * .5 * 1.225 * 111^2
CL = 0.78
CDi = (0.78^)/(pi*6*.8) = 0.04 (note how doubling the wing area results in a quarter of the CDi, because CL is squared)
Induced drag = 0.04 * 20 * 1.225 * .5 * 111^2
Induced drag = 6,037 N
Of course, parasitic drag increases with a larger wing area, but basically lower wingloading = an increasing advantage the tighter the turn, and the lower the IAS you fly (and IAS of course is lower at high altitudes)
Last edited:
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Lift (N) = CL * area (sq m) * .5 * pressure (kg/cubic m) * velocity (m/s) squared
As per the above equation lift increases with wing surface area .
This means a higher wing loading plane will have lesser lift at speed v.
the lower wing loading plane will have more lift at the same speed v.
use the same v in the following equation
As per Newton's second law which gives the following equation
L sin(θ)=mv*2/R
A low wing loading air craft will always bring higher horizontal lift component into sustained turn turn for any given bank angle θ at a lower AOA (which means with lesser drag)and speeds much hihger than stall speeds.
So it naturally transpires the lower wing loading fighter entering sustained turn at any given bank angle will have much higher L sin(θ). So it basically means that either it will have higher speeds or lower turn radius which directly translates into higher sustained turn rate .
On the contrary a higher wing loading fighter entering the same sustained turn at the same bank angle will have to pull a higher AOA , which means it will have higher drag and and lesser horizontal lift component , so it naturally means that it should either have lower speeds or higher turning radius which means inferior turn rate.
As per the above equation lift increases with wing surface area .
This means a higher wing loading plane will have lesser lift at speed v.
the lower wing loading plane will have more lift at the same speed v.
use the same v in the following equation
As per Newton's second law which gives the following equation
L sin(θ)=mv*2/R
A low wing loading air craft will always bring higher horizontal lift component into sustained turn turn for any given bank angle θ at a lower AOA (which means with lesser drag)and speeds much hihger than stall speeds.
So it naturally transpires the lower wing loading fighter entering sustained turn at any given bank angle will have much higher L sin(θ). So it basically means that either it will have higher speeds or lower turn radius which directly translates into higher sustained turn rate .
On the contrary a higher wing loading fighter entering the same sustained turn at the same bank angle will have to pull a higher AOA , which means it will have higher drag and and lesser horizontal lift component , so it naturally means that it should either have lower speeds or higher turning radius which means inferior turn rate.
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There is butthurt all over the world , so great that many guys are repeatedly shouting it down with no reason to base their argument.
just go to another indian defence forum ------------------ and see how big the butthurt is!!!!!
Illusive
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The forums wouldn't be fun without thees butthurts, seeing their reaction now makes the occasion much more satisfying. You see once IAF pilots get the taste of this beaut they never look back again.
I predicted on this forum that GOI will ask HAL to increase LCA Tejas production from 8 to 16 aircrafts per year. Now it is public knowledge and such instructions have been given to HAL.
Both LCA Navy and LCA Airforce orders will increase to justify the increase in production numbers at HAL. Discussions are underway in this regards. Also LCA Tejas trainers may be acquired by both Navy and Air Force. The current committed orders from both AF and Navy stands at 46 single seat. The two seat trainers will be added to this number.
If a private line is established for Mark-2; then the target for overall LCA Tejas capacity will exceed 30; as private line will be in addition to the HAL line.
Good times ahead for LCA Tejas.
Both LCA Navy and LCA Airforce orders will increase to justify the increase in production numbers at HAL. Discussions are underway in this regards. Also LCA Tejas trainers may be acquired by both Navy and Air Force. The current committed orders from both AF and Navy stands at 46 single seat. The two seat trainers will be added to this number.
If a private line is established for Mark-2; then the target for overall LCA Tejas capacity will exceed 30; as private line will be in addition to the HAL line.
Good times ahead for LCA Tejas.
As already mentioned by @Illusive & @ersakthivel.
For those category of shouting(butthurts) peoples who always Criticize, no matters which side you are..Can be applied to those peoples.... Here are Few Lines from one of the World's Best Selling book, Shiv Khera's "You Can Win!"
(though Offtopic)
http://mikul262.webs.com/3755215-You-Can-Win-by-Shiv-Khera.pdf
Some people criticize no matter what. It does not matter which side you are on, they are always on the other side. They have made a career out of criticizing. They are "career critics." They criticize as if they will win a prize at a contest. They will find fault with every person and every situation. You will find people like this in every home, family, office. They go around finding fault and telling everybody how bad things are and blaming the whole world for their problems. We have a name for these people. They are called energy suckers. They will go to the cafeteria and drown themselves in 20 cups of tea and coffee and smoke to their hearts' content with one excuse: they are trying to relax. All that they are doing is causing more tension for themselves and for others around them. They spread negative messages like a plague and create an environment conducive to negative results.
Negative People will Always Criticize
--
"Robert Fulton invented the steamboat. On the banks of the Hudson River he was displaying his new invention. The pessimists and the skeptics were gathered around to observe. They commented that it would never start. Lo and behold, it did. As it made its way down the river, the pessimists who said it would never go, started shouting that it would never stop. What an attitude!"
--
"There was a hunter who bought a bird dog, the only one of its kind in the world. That could walk on water . He couldn't believe his eyes when he saw this miracle. At the same time, he was very pleased that he could show off his new acquisition to his friends. He invited a friend to go duck hunting. After some time, they shot a few ducks and the man ordered his dog to run and fetch the birds. All day-long, the dog ran on water and kept fetching the birds. The owner was expecting a comment or a compliment about his amazing dog, but never got one. As they were returning home, he asked his friend if he had noticed anything unusual about his dog. The friend replied, "Yes, in fact, I did notice something unusual. Your dog can't swim."
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indiatester
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Is the SP-1 still being flown by test pilots or by regular IAF pilots?
tejas warrior
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any good resolution pictures of Jejas with mid-air refueling probe ?
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MK1+ in between MK1 and MK2.
==========
Saurav Jha "@SJha1618
> Aerodynamics is not the main concern of the IAF via a via the Tejas MK-I. They want better maintainability & survivability aids.
> Both of these issues can be addressed to an extent in an improved Mk-I. See the push for a modern MAWS in this light.
> For instance even in the current series production Tejas Mk-Is, ADA believes that an engine change can be executed in under 2 hrs.
> It is also now being said that 36 out of the 40 MK-Is on order will be delivered in FOC standard.
Source : BR
smestarz
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I was reading some Rafale news and got this part
Dassault Aviation, the French manufacturer, has concerns about the carbon-fibre composite material that would be used by HAL to form the skin of the Rafale fighter. Though HAL prides itself in having mastered the use of these composites (which are also used on the indigenous Tejas fighter plane), HAL uses a manual technique. Dassault, on the other hand, uses an automated and much quicker process to manufacture super-critical carbon-fibre composite structures such as the wings of the Rafale. HAL and Dassault will now need to arrive at a consensus on how best to speedily develop carbo-composites to ensure that the time-frame for the manufacture of Rafale fighters is met.
Though this is Rafale news, what is important is the process of manufacturing of composites, HAL uses Manual system where as Dassault uses automation. As per me one of the way to increase the production of Tejas is to involve the private industry. For example if HAL asks private companies to be part of the project and to get ready to develop and build parts of the plane, then in a way that would benefit everyone here.
For example getting HAL to invest in an automated process for making composites will add to the cost but what if we ask the private firms to develop automated system to produce composite parts of the planes and HAL just procures these parts from these private manufacturers would it not benefit? And we can have an agreement like what is required from Dassault for GoI, this way HAL has to guarantee all the planes produced and the private manufacturers in turn give guarantees to HAL for the parts they produce. This way we start some sort of private participation and in a way improve the numbers. The planes produced by HAL using the manual process and the ones produced using the automation should be recorded and this data to track the performance of the plane and possibly improvements.
What do you guys suggest? This way, we get the private companies to start their contribution to the Indian aviation industry for an actual war plane of India. The private firm gets experience in developing the process as they understand it. and this experience of making the carbon composites can later be used for producing AMCA or FGFA also, hence in a way giving more business to private firms for their investment in automation process.
Dassault Aviation, the French manufacturer, has concerns about the carbon-fibre composite material that would be used by HAL to form the skin of the Rafale fighter. Though HAL prides itself in having mastered the use of these composites (which are also used on the indigenous Tejas fighter plane), HAL uses a manual technique. Dassault, on the other hand, uses an automated and much quicker process to manufacture super-critical carbon-fibre composite structures such as the wings of the Rafale. HAL and Dassault will now need to arrive at a consensus on how best to speedily develop carbo-composites to ensure that the time-frame for the manufacture of Rafale fighters is met.
Though this is Rafale news, what is important is the process of manufacturing of composites, HAL uses Manual system where as Dassault uses automation. As per me one of the way to increase the production of Tejas is to involve the private industry. For example if HAL asks private companies to be part of the project and to get ready to develop and build parts of the plane, then in a way that would benefit everyone here.
For example getting HAL to invest in an automated process for making composites will add to the cost but what if we ask the private firms to develop automated system to produce composite parts of the planes and HAL just procures these parts from these private manufacturers would it not benefit? And we can have an agreement like what is required from Dassault for GoI, this way HAL has to guarantee all the planes produced and the private manufacturers in turn give guarantees to HAL for the parts they produce. This way we start some sort of private participation and in a way improve the numbers. The planes produced by HAL using the manual process and the ones produced using the automation should be recorded and this data to track the performance of the plane and possibly improvements.
What do you guys suggest? This way, we get the private companies to start their contribution to the Indian aviation industry for an actual war plane of India. The private firm gets experience in developing the process as they understand it. and this experience of making the carbon composites can later be used for producing AMCA or FGFA also, hence in a way giving more business to private firms for their investment in automation process.
Khagesh
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@smestarz
I am not an engineer so standard caveats apply, but here is what I think about it (sorry for the longish post).
I think we should avoid thinking about the utility of manufacturing ToT in Rafale for LCA/AMCA. Both should be treated independent of each other. So much so that I believe we should not limit ourselves by counting French ToT towards our future needs either.
For one Rafale is a finished product. LCA Mk-1 and Mk-2 differ substantially in that these are developing products. AMCA is an entirely new idea which may eventually see just as much design inputs. FGFA when its going to get made in India would be a still outlier idea, fortunately we will have the ToT for it. And of all these types that we are going to make the only a low 100s of each type. Rafale alone has a planned production run of 286+24 confirmed and 126+60 possible. For such a big production run they could have afforded to look for new production techniques, which they did, to be used simultaneously with the metal machining and the autoclave processes. And all these development cost of the new production techniques have gone on to make Rafale one of the most expensive fighters in the sky, this also should not be forgotten. On the other hand LCA Mk-1 is already the cheapest product possible and we would obviously like Mk-2, AMCA and FGFA to be inexpensive too.
There has been a consistent criticism, though low key, that LCA is 'bespoke built' and 'hand built'. And while this is a statement of fact. It is only a misdirection to state it as a criticism. Firstly Bespoke built and even Hand built is the nature of the current (mature) CFC manufacturing. LCA Mk-2 is going to see around 75% of the parts re-designed. LCA Mk-1 itself may see some reworking, considering the report that came in just yesterday by Saurav Jha that the Mk-1 production run will be increased and the user/manufacturer may ask for some changes to be redesigned. AMCA will I am sure also see almost the same multiplication of efforts, if not for cramming things into it then for craming new mission plans into it. Besides the LRU count for just the Mk-1 has been reduced by the 100s. And despite all this they have been able to keep almost the whole development time of LCA, incident free. You can well guess the amount of design effort that goes into this and the margins of safety that they have been successful at maintaining. This effort level would be required not because our engineers are dumb but because we (design agency+user+manufacturer+certifying agency) have only in the last 15 years started to develop out system that starts from a GSQR and ends with a reliably placed bang right atop the opponent's head.
This sort of development effort will force you to work with low quality inputs procured at inopportune times and processed/cured at just the right time for it to be mounted on to the aircraft. This kind of lag will force you to work with processing technology that can turnout end parts that are reliable despite the inputs material (prepregs) not being of the exact kind required or even having gone out of the prescribed cold storage life-times for the B-stage prepregs. From my readings it seems the current system of Autoclaves allows that kind of flexibility for prepreg storage/usage, for both production and prototyping, without adversely affecting the output, albeit at some extra time getting consumed. Also mind you, this extra time budgeting required for Autoclaves should currently be compared with the time required to develop/absorb, new Out Of Autoclave (OOA) processes. (Comparison of Autoclave and Out-of-Autoclave Composites - ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110016095.pdf)
US and Europe have the vast size of its aerospace and marine engineering to amortize development cost of multiple CFC processing technologies. India does not have this luxury.
Having said all that, it is also true that OOA processes will be used and developed even further in future and they already give faster prototyping to product times. As we move from an autoclave only LCA Mk-1 to Mk-2 and eventually to AMCA we must increase our capability to develop our own OOA capabilities. However in this it may be pertinent to note that the input prepregs remain pretty much the same, in some types of OOAs. Firstly this must also change. We have to begin looking for newer materials also. Secondly I do not believe our existing technology base in India will not be able to do it alone. In itself the field of OOA processing is quite vast and varied and our final needs a few years hence may be completely different from what the French OOA is currently geared towards.
Personally I see OOA as being as much of a proportionate change in the final aircraft as the movement from Metals to Composites involved. 10-15 years down the line we will have Metals+Autoclave CFC+OOA CFCs sharing in the final product. Even in the real world while OOA is getting used more and more at larger scales still we have some of the largest autoclaves still getting made and used (30mtr long by 9mtr dia, Autoclave by Kawasaki for Boeing 787).
On the related question of seeding the private sector aviation industry, the approach should still remain to duplicate what is being done in the public sector by HAL. HAL already is the one of the most effective agencies in the large scale processing of CFC and I don't see any reason why private sector cannot just duplicate the HAL facilities considering the cost effectiveness of the existing HAL processes. There will be need to import some technology which again should be stabilized by HAL first.
Otherwise we will have a situation where suave Frenchmen will fool a big Indian lala and force the whole country to bear the cost of a bunch of wrong decisions by one Lala. It would be a fallacy to presume that everything that private sector does is going to be wise and best. A lala can be easily fooled by marketing catchphrases employed by his own employees the initial batch of which, in any given industry, almost always are basically technology importers and technology traders. I almost see a kala angrez NRI engineer from US telling Mukesh Ambani, how OOA from USA is the bestest and Mukesh would likely ask for only some financial sweetening of the deal on technology import. What would Mukesh have in this. He will simply load the cost of technology import on to the final product and we will have a number of kala angrez NRIs tell us how we are lucky that
Ideally I would like to see HAL moving from its existing role of manufacturing and systems integrator to that of research organization extracting royalty for the manufacturing systems it develops and farms out to private sector in India before farming out technology to companies outside India.
Basically OOA is important but not the only thing in life. Moreover the French should not be allowed to have a grip on our balls if only OOA is the thing that they want to contribute. Let us have OOA come to us as a natural process of our development and not as a high priced uber intellectual stuff adopted from the French.
I am not an engineer so standard caveats apply, but here is what I think about it (sorry for the longish post).
I think we should avoid thinking about the utility of manufacturing ToT in Rafale for LCA/AMCA. Both should be treated independent of each other. So much so that I believe we should not limit ourselves by counting French ToT towards our future needs either.
For one Rafale is a finished product. LCA Mk-1 and Mk-2 differ substantially in that these are developing products. AMCA is an entirely new idea which may eventually see just as much design inputs. FGFA when its going to get made in India would be a still outlier idea, fortunately we will have the ToT for it. And of all these types that we are going to make the only a low 100s of each type. Rafale alone has a planned production run of 286+24 confirmed and 126+60 possible. For such a big production run they could have afforded to look for new production techniques, which they did, to be used simultaneously with the metal machining and the autoclave processes. And all these development cost of the new production techniques have gone on to make Rafale one of the most expensive fighters in the sky, this also should not be forgotten. On the other hand LCA Mk-1 is already the cheapest product possible and we would obviously like Mk-2, AMCA and FGFA to be inexpensive too.
There has been a consistent criticism, though low key, that LCA is 'bespoke built' and 'hand built'. And while this is a statement of fact. It is only a misdirection to state it as a criticism. Firstly Bespoke built and even Hand built is the nature of the current (mature) CFC manufacturing. LCA Mk-2 is going to see around 75% of the parts re-designed. LCA Mk-1 itself may see some reworking, considering the report that came in just yesterday by Saurav Jha that the Mk-1 production run will be increased and the user/manufacturer may ask for some changes to be redesigned. AMCA will I am sure also see almost the same multiplication of efforts, if not for cramming things into it then for craming new mission plans into it. Besides the LRU count for just the Mk-1 has been reduced by the 100s. And despite all this they have been able to keep almost the whole development time of LCA, incident free. You can well guess the amount of design effort that goes into this and the margins of safety that they have been successful at maintaining. This effort level would be required not because our engineers are dumb but because we (design agency+user+manufacturer+certifying agency) have only in the last 15 years started to develop out system that starts from a GSQR and ends with a reliably placed bang right atop the opponent's head.
This sort of development effort will force you to work with low quality inputs procured at inopportune times and processed/cured at just the right time for it to be mounted on to the aircraft. This kind of lag will force you to work with processing technology that can turnout end parts that are reliable despite the inputs material (prepregs) not being of the exact kind required or even having gone out of the prescribed cold storage life-times for the B-stage prepregs. From my readings it seems the current system of Autoclaves allows that kind of flexibility for prepreg storage/usage, for both production and prototyping, without adversely affecting the output, albeit at some extra time getting consumed. Also mind you, this extra time budgeting required for Autoclaves should currently be compared with the time required to develop/absorb, new Out Of Autoclave (OOA) processes. (Comparison of Autoclave and Out-of-Autoclave Composites - ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110016095.pdf)
US and Europe have the vast size of its aerospace and marine engineering to amortize development cost of multiple CFC processing technologies. India does not have this luxury.
Having said all that, it is also true that OOA processes will be used and developed even further in future and they already give faster prototyping to product times. As we move from an autoclave only LCA Mk-1 to Mk-2 and eventually to AMCA we must increase our capability to develop our own OOA capabilities. However in this it may be pertinent to note that the input prepregs remain pretty much the same, in some types of OOAs. Firstly this must also change. We have to begin looking for newer materials also. Secondly I do not believe our existing technology base in India will not be able to do it alone. In itself the field of OOA processing is quite vast and varied and our final needs a few years hence may be completely different from what the French OOA is currently geared towards.
Personally I see OOA as being as much of a proportionate change in the final aircraft as the movement from Metals to Composites involved. 10-15 years down the line we will have Metals+Autoclave CFC+OOA CFCs sharing in the final product. Even in the real world while OOA is getting used more and more at larger scales still we have some of the largest autoclaves still getting made and used (30mtr long by 9mtr dia, Autoclave by Kawasaki for Boeing 787).
On the related question of seeding the private sector aviation industry, the approach should still remain to duplicate what is being done in the public sector by HAL. HAL already is the one of the most effective agencies in the large scale processing of CFC and I don't see any reason why private sector cannot just duplicate the HAL facilities considering the cost effectiveness of the existing HAL processes. There will be need to import some technology which again should be stabilized by HAL first.
Otherwise we will have a situation where suave Frenchmen will fool a big Indian lala and force the whole country to bear the cost of a bunch of wrong decisions by one Lala. It would be a fallacy to presume that everything that private sector does is going to be wise and best. A lala can be easily fooled by marketing catchphrases employed by his own employees the initial batch of which, in any given industry, almost always are basically technology importers and technology traders. I almost see a kala angrez NRI engineer from US telling Mukesh Ambani, how OOA from USA is the bestest and Mukesh would likely ask for only some financial sweetening of the deal on technology import. What would Mukesh have in this. He will simply load the cost of technology import on to the final product and we will have a number of kala angrez NRIs tell us how we are lucky that
Ideally I would like to see HAL moving from its existing role of manufacturing and systems integrator to that of research organization extracting royalty for the manufacturing systems it develops and farms out to private sector in India before farming out technology to companies outside India.
Basically OOA is important but not the only thing in life. Moreover the French should not be allowed to have a grip on our balls if only OOA is the thing that they want to contribute. Let us have OOA come to us as a natural process of our development and not as a high priced uber intellectual stuff adopted from the French.
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