LCA News and Discussions

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Lalmohan
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Re: LCA News and Discussions

Postby Lalmohan » 08 Oct 2013 21:41

^^^ yes, as long as the auxilliary power unit (if fitted), ram air turbine generator and batteries remain operational

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Re: LCA News and Discussions

Postby nachiket » 08 Oct 2013 22:14

indranilroy wrote:.... So within a couple of seconds, his commands will go out of sync. The plane would start oscillating around the pitch axis. Instead of mitigating the problems, the pilots inputs would be aggravating the problem. In the best case, the amplitude of the oscillations would increase till in a matter of seconds, the plane would reach AoA, where it stalls. The same thing happens if your flight computer is slow in providing control commands. In case that you are close to the ground, you will crash like the F-22 incident. If you are in the air, the characteristics is highly non-linear and unpredictable. If you are flying fast, there is a good chance that you would roll over backwards like a leaf. If the pilot has not ejected, he won't be conscious to eject later, and even if he manages to remain conscious, most probably his ejection will be fatal. Beyond this point the plane is just a rock in ballistic trajectory affected by aerodynamic forces.

I guess this is what happened here:


@Nachiket ji
It is actually not as bad as you think. The wetted aspect ratio is not that bad for a fighter (flying clean) vis-a-vis a airliner. For example this is a F-16 landing with main engine out.

Thanks. And please drop the ji.

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Re: LCA News and Discussions

Postby Indranil » 08 Oct 2013 23:30

nachiket wrote:
indranilroy wrote:.... So within a couple of seconds, his commands will go out of sync. The plane would start oscillating around the pitch axis. Instead of mitigating the problems, the pilots inputs would be aggravating the problem. In the best case, the amplitude of the oscillations would increase till in a matter of seconds, the plane would reach AoA, where it stalls. The same thing happens if your flight computer is slow in providing control commands. In case that you are close to the ground, you will crash like the F-22 incident. If you are in the air, the characteristics is highly non-linear and unpredictable. If you are flying fast, there is a good chance that you would roll over backwards like a leaf. If the pilot has not ejected, he won't be conscious to eject later, and even if he manages to remain conscious, most probably his ejection will be fatal. Beyond this point the plane is just a rock in ballistic trajectory affected by aerodynamic forces.

I guess this is what happened here:



No. This was a case of Pilot Induced Oscillations due to different reasons.

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Re: LCA News and Discussions

Postby SBajwa » 09 Oct 2013 00:23

There is a something called "Glide Ratio" for each plane.
http://in.answers.yahoo.com/question/in ... 433AA1bxGF

" For example, a 747 Jumbo Jet has a glide ratio of 15:1. This means that without power, it can travel 15 miles for every mile of altitiude so at typical cruise altitude of 35,000 feet (a bit over 6 1/2 miles) it can travel about 99 miles. By comparison, the Space Shuttle's glide ratio is a measly 1:1 and we manage to get it on the ground safely every time; the two Space Shuttles lost to date had nothing to do with glide issues.

So, if you should find yourself in a 747 over the Continental US that loses it's engines you can rest fairly easy as there's probably a suitable airport within a 100 mile radius of nearly every point along the route of flight. Landing it without engines does take some skill but most senior pilots could do this without too much difficulty at all."

Most FBW (F-16) planes have glide ratio of 1:1 (just like Shuttle)
Last edited by SBajwa on 09 Oct 2013 00:28, edited 2 times in total.

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Re: LCA News and Discussions

Postby SaiK » 09 Oct 2013 00:23

did not understand the reason for that crash? definitely the altitude was there for the corrections to happen.. stall happened, and then the pilot gave up! something was not controlling correct.

^from your link:
At the crash, the flight control computer was severely damaged, but all pieces were recovered and all memory circuits identified, which allowed the information in them to be read, so full data from the whole crash sequence was available to the investigators.
The way the display was planned was not in accordance the goals stated for the flight test programme. Nor were any reasons stated for the exceptions made from the Pilot's Manual.
Limits set for the display were exceeded by the pilot, which didn't directly contribute to the accident.
The control laws are complex, which means that there have been problems to fully analyse their function.
The effects of control surface movement speed limitations had not been fully investigated for the full flight envelope.
The validation process hadn't successfully identified the pilot induced oscillation properties of the aircraft.
When flying the simulator, less work with the control stick was needed than when flying for real.
Simulator studies have showed that it is possible to stall Gripen at less than 20 deg angle of attack during similar conditions.
During the low speed left turn, the automatic roll trim was disconnected, exactly as automatically is intended to at angles of attack over 20 deg. Because of this, the control stick had to be kept 2 deg to the right in order to maintain constant bank angle.
The stick movement to the right at the end of the turn was the same as during training, but as it was begun 2 deg to the right already, it reached the end position, leading to a larger roll rate than during training.


it is easy to go OT on these matters. i leave it to the mods.

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Re: LCA News and Discussions

Postby Indranil » 09 Oct 2013 02:28

@Negi ji,

F-16 has something called the Emergency Power Unit (EPU). EPU is powered in two modes: bleed air from the main engine (in which case the EPU can work longer), but in case the hydraulic pressure falls below a threshold, the EPU uses hydrazine. Under the second mode, the EPU can operate for up to 10 minutes. In the video in question, you can hear the operator warn the groundsmen about hydrazine (which is highly toxic), meaning the EPU had started working in the second mode (automatically or manually) in this case.

@SBajwa ji,

Glide ratio is not a constant and depends on the air speed. What you are quoting is called the best glide ratio, which is achieved at a particular speed for a particular airplane. The pilots know this speed for the plane that they are flying. On losing power, the pilot will settle into this speed for covering furthest distance. The best glide ratio of F-16 is nearly 6:1. This ratio was also shown in the video. If you read is HUD displays, he covered about 7 miles by losing about 9000 feet.

@Saik ji,
I agree that summary might be quite involved to understand. I will try to simplify. What happened was they had changed the plane a little from the prototypes. The new planes were more nimble and afforded the pilots more margins of play. They knew that PIO can happen, but the chances were so remote that they did not feel the need to convey it to the pilot. But Murphy's law struct.

While coming out of the turn, during a series of maneuvers, the pilot maxed out the elevon deflection leaving no play for the FCS. Beyond this point, the FCS and the pilot working out-of-sync provided pitch up commands which added up and made the plane quickly increase it's AoA to 90 degrees. Obviously the plane stalled (and I think the engine flamed out too). I don't know why you think there was enough altitude to recover. Certainly, the pilot had no chance to save that plane at the altitude.

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Re: LCA News and Discussions

Postby negi » 09 Oct 2013 03:11

Hydrazine is very old tonic , during the WWII ME 163 B was powered by Hydrazine hydrate, even to this day onboard motors for attitude/orbit correction on satellites use hydrazine as it is an excellent monopropellant.

Btw what does Tejas use for EPU ? Also what about EF and Rafale , googling does not yield much and at this time of the night I kind of give up. :)

The closest I found on Tejas was an old paper by Wg Cdr Vikram Singh

http://www.scribd.com/doc/78345390/Appr ... -LCA-Tejas

The critical period for consideration whilst sizing the back up Emergency power Unit (EPU) pump will be from recovery to relight,when the chute would have been released and the ac flown in frozen gains until relight and recovery of on board hydraulics. While an APU could be used, it would probably not be able operate at the test altitudes. Currently the international standard is to use a hydrazine driven pump. However handling of this fluid has its own safety requirements and the EPU would have to be replenished at the taxy holding point prior to take off and a EPU contents indication should be available at telemetry.


I won't be surprised if modern AC do not have a dedicated EPU as such and instead rely on APU .

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Re: LCA News and Discussions

Postby RKumar » 09 Oct 2013 13:18

Flight test update

LCA-Tejas has completed 2334 Test Flights Successfully. (01-Oct-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-372,LSP1-74,LSP2-286,PV5-36,LSP3-157,LSP4-94,LSP5-220,LSP7-61,NP1-4,LSP8-28)

to

LCA-Tejas has completed 2344 Test Flights Successfully. (08-Oct-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-374,LSP1-74,LSP2-286,PV5-36,LSP3-159,LSP4-94,LSP5-220,LSP7-64,NP1-4,LSP8-31)

good going, approaching IOC-2 (??). Wish NP also starts flying soon as it is last months of the year...

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Re: LCA News and Discussions

Postby bhart » 09 Oct 2013 13:49

LSP 1 and LSP 4 don't seem to fly as regularly as others. Any idea why?

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Re: LCA News and Discussions

Postby SaiK » 10 Oct 2013 10:19

@indranilroy ji, wiki says PIO was a result of over sensitive, yet slower responding steering system being the cause. later on they went and redesigned the steering system.

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Re: LCA News and Discussions

Postby Indranil » 10 Oct 2013 15:30

^^^Yes I know that. I did not say anything to the contrary.

No 'ji' please.

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Re: LCA News and Discussions

Postby Indranil » 10 Oct 2013 17:46

negi wrote:Hydrazine is very old tonic , during the WWII ME 163 B was powered by Hydrazine hydrate, even to this day onboard motors for attitude/orbit correction on satellites use hydrazine as it is an excellent monopropellant.

Btw what does Tejas use for EPU ? Also what about EF and Rafale , googling does not yield much and at this time of the night I kind of give up. :)

The closest I found on Tejas was an old paper by Wg Cdr Vikram Singh

http://www.scribd.com/doc/78345390/Appr ... -LCA-Tejas

The critical period for consideration whilst sizing the back up Emergency power Unit (EPU) pump will be from recovery to relight,when the chute would have been released and the ac flown in frozen gains until relight and recovery of on board hydraulics. While an APU could be used, it would probably not be able operate at the test altitudes. Currently the international standard is to use a hydrazine driven pump. However handling of this fluid has its own safety requirements and the EPU would have to be replenished at the taxy holding point prior to take off and a EPU contents indication should be available at telemetry.


I won't be surprised if modern AC do not have a dedicated EPU as such and instead rely on APU .

Negi sahab,

Please keep us informed of your research. I know that all modern fighters more or less have a starter unit and a APU for the emergency system. Rafale has a Microturbo APU and starter. Don't know about EF. LCA's Mk1 starter is called GTSU-110 and GTSU-127 is being developed for Mk2.

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Re: LCA News and Discussions

Postby SaiK » 10 Oct 2013 17:48

ji, was tit-4-tat onlee. feelings of ji is mutual among many /ot. i was not contradicting you, but i was trying to find what was the actual cause of failure.

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Re: LCA News and Discussions

Postby pragnya » 10 Oct 2013 18:58

indranilroy wrote:Negi sahab,

Please keep us informed of your research. I know that all modern fighters more or less have a starter unit and a APU for the emergency system. Rafale has a Microturbo APU and starter. Don't know about EF. LCA's Mk1 starter is called GTSU-110 and GTSU-127 is being developed for Mk2.


The Typhoon has essentially two electrical systems, the primary power generation and distribution system and the secondary systems (including the auxiliary power unit). Primary power is supplied via the engine turbines through a LucasVarity/BAe Systems supplied distribution and rectification system. Using this electrical power can be supplied at a number of voltages and AC phases as well as supplying a DC output. The DC system is fully redundant with two back-up rectifier units in case the two primaries fail. Additionally a DC battery source is available in emergencies as well as to power up the APU.

The secondary system provides a back-up using air-driven turbines in case of total engine (or engines) failure or partial (gearbox, turbine, etc.) failure. Since the Typhoon is designed for autonomous operation the aircraft includes an Auxillary Power Unit, or APU as part of the secondary system. Before the engines are started the APU generates all the AC/DC power required to operate the aircraft's systems. The engine start systems, supplied by AlliedSignal and Microturbo are also powered by the APU.


EF Electrical Systems

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Re: LCA News and Discussions

Postby Kakkaji » 10 Oct 2013 22:32

Woo-hoo! Hakeem Sahib is back! 8)

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Re: LCA News and Discussions

Postby Philip » 12 Oct 2013 18:55

Air Cmde. Khokar sounds a warning that the LCA MK-2 might not perform as expected due to various factors that involve much redesign,more powerful engine requiring larger fuel tanks,etc. One key point he makes is that while it takes just 33 min. to replace a
Gripen's engine,it takes two+ days to replace an LCA's engine because of the arrangement of connectors,etc. The full article is in the print edition and those who can access the article in full on the F mags website.

A Better Alternative
http://www.forceindia.net/ABetterAlternative.aspx

Before Tejas Mk II is brought in, experts should weigh all the pros and cons

Xcpt:
y Parvez Khokhar

Now that sounds coming from the ministry of defence (MoD) and Aeronautical Development Agency (ADA) seem to be suggesting that the Tejas Mk I is just around the corner, the focus seems to be shifting to the Tejas Mk II. This variant appears to be gathering momentum in the eyes of clairvoyant chair-borne pundits, who profess that this will be the panacea for all the ills that beset the indigenous aircraft industry and will also address the desire of the Indian Air Force (IAF) to have a super-duper fighter.

ADA and Hindustan Aeronautics Limited (HAL) have even widely publicised a time schedule for the induction of this aircraft (too fictional to be mentioned). The granting of permission by the MoD to commence this project and its acceptance by the IAF by placing some initial orders, is not in the public domain. In order to take an educated decision on what the Mk II aims to be and the challenges involved therein, it is imperative to comprehend the facts, as they exist today.

ADA and HAL have made public statements that work on the airframe will begin by end 2013. Whilst it is apparent that the qualities envisaged in the Mk II are all commendable, they require a closer examination to comprehend the challenges involved in reaching this target without unacceptable time and cost overruns. So what are the major changes envisaged in the Mk II in order to be a quantum leap over the Mk I?

These are: More powerful engine F-414-GE-INS6; New Flight Control Computer; Upgraded avionics; Retractable In Flight Refuelling probe; On Board Oxygen Generating system (OBOGS); AESA radar; Cockpit upgrade; New Electronic Warfare(EW) suite; and Ability to super cruise (fly supersonic in level flight in dry power).

These changes will lend value throughHigher thrust; More ordnance carrying capacity; Better avionics; Longer endurance with On Board Oxygen Generating System (OBOGS); State-of-the-art radar; Better man-machine interface and situational awareness through larger displays in the cockpit and easier management drills; and Better survivability through better EW suites. This factor will also enhance the operational performance.

ADA’s contention that all this can be done within two years is based on the example of the Swedish Gripen NG (called Gripen E for in-service usage). ADA has also sought guidance through consultancy from Saab for the Mk II. Before proceeding further, we need to factor in some extremely relevant points, otherwise this comparison becomes rather odious.....

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Re: LCA News and Discussions

Postby SaiK » 12 Oct 2013 19:42

well.. the on paper design aspects should have already be frozen.. it is all those v&v details, modeling the entire integration process of LRUs, components, interaction and scenarios, especially for man-machine interface changes (might exceed schedule depending on the change), and we are increasing the ops profile as well by these.. so more testing.

i guess, they take the modeling route ahead... a model as real as possible.

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Re: LCA News and Discussions

Postby abhik » 12 Oct 2013 19:55

Philip wrote:A Better Alternative
http://www.forceindia.net/ABetterAlternative.aspx

Before Tejas Mk II is brought in, experts should weigh all the pros and cons

Er... what's the better alternative?

also address the desire of the Indian Air Force (IAF) to have a super-duper fighter.

Ouch! :twisted:

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Re: LCA News and Discussions

Postby chackojoseph » 12 Oct 2013 19:59

Guess who is one of the clairvoyant chair-borne pundits being refereed to ;)

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Re: LCA News and Discussions

Postby SaiK » 12 Oct 2013 20:14

can someone post full article if it does not cross the copy rights?

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Re: LCA News and Discussions

Postby vasu raya » 12 Oct 2013 22:30

Good to know Mk2 can supercruise, now at what altitude is a question, given that Tibet is already at 5km ASL from Shiv's post in the China mil watch thread, its probably high enough for nape of earth flight over Tibet without losing too much range to drag but low to be able to supercruise which allows for reduced time to target.

With mountains, things get better because flying alongside ridges at even higher altitudes and still not be tracked by enemy radar.

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Re: LCA News and Discussions

Postby SaiK » 13 Oct 2013 02:46

looking both at NW & NE direction means I would like to have 20 squadrons with 20 refuler tankers, and 20 AWACs. 1 AWAC+ 1 refueller + 20 LCA Mk2 squadron. All homegrown is an option except the refueler - Airbus/Boeing.

5 such squads facing NW is good enough, and the remaining taking care of massive air ops from NE over the mountains. Our MKIs also need to be engaged for firing those extended range BVRs.

400 LCA Mk2 at a min.

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Re: LCA News and Discussions

Postby Philip » 13 Oct 2013 08:34

We would all love to have a few hundred LCAs in service,but if what the good Air Cmde. Parvez Khokar says is true,we are in for a very heavy landing. I'll try to be as brief and concise as poss. in condensing the article as the postman.Some of the alleged "facts" can only be verified by those in the know,not available in open sources.

Air Cmde. (retd.) Parvez Khokar
ADA has no clue and that is a charitable observation.Having been brought up for decades on self-delusion.delays and cost overruns that have always been condoned,they no longer acknowledge the word "accountability".

With airframe work expected to be completed by end 2013,the ADA claims (based upon the Gripen's dev. schedule) that it will take just 2 years to develop the MK-2. SAAAB is being roped in as consultants for MK-2.PK says comparisons are odious because:

Gripen E is a dev. of the A to D designs in service.MK-1 hasn't entered service at all.Saab have a 75 yr. old history of dev. fighters as against ADA/HAL's nascent experience.

ADA's record of non-adherence of consultant's recommendations especially when it runs counter to its grain,involving a lot of rework,is well known.Will the consultants merely review the work and say "yes or no",or withhold reports that will "rock the boat".The ADA should understand that SAAB will neither build/design the aircraft or give them drawings for the same.

(There is a long explanation how SAAB went about developing the Gripen E,time frames given in detail)

Major challenges for the LCA MK-2.


ADA's studies and results shrouded in secrecy.Educated guesses from within the ADA.
"Let's see how it goes" to the more horrifying prospect,"Less than MK-1".

ADA very reluctant to part with improved figures of MK-2's performance.It will first have to contend with the MK-1s shortcomings.

*Weight reduction

*New engine (414) fitment requirements

*Redesign of intakes

*Better cooling of the avionics bay

*Estate management of ancillaries around the engine,for swift change,(Gripen takes 33mins,LCA 2 days)

*Brakes

These are not exhaustive,more will appear in MK-2s dev.New design features will include:

*Fuselage modification,lengthening and strengthening the fuselage and redesigning contours

*More thrust,more fuel consumption,larger fuel tanks needed

*Penalty for more weight,changes in area ruling,increased drag index,disadvantages of a more powerful engine,but would give more room for redistribution of avionics components,LRUs,and those of the new radar to get rid of the 200kg ballast in the nose cone for COG reasons,unheard of in modern fighters! (Is this true?)

*Air intake redesigning,one area where the ADA has shied away for decades.Understandable that they lack expertise,why not get specialised help?

*Fool-proof cooling of the avionics bay is a safety requirement,since the bay houses the quad-FBW system of the DFCC and inadequate cooling can be disastrous.

*Maintenance practices the most primitive in this class of aircraft,not conducive to operational efficiency.Gripen 33mins for engine change,MK-1, 2 days.

*With hot-refuelling (engines running),Gripen back in the air in 22mins.Hot refuelling is not permitted by Indian OIl,who seem to dictate the Tejas operational efficiency,forgetting that in air-to-air refuelling,engines aren't shut down!

*Enhanced weight due to longer fuselage,can be compensated in part by redesigning the overdesigned undercarriage.There are many other issues that have been "swept under the carpet",and unless these are redressed,the ghost will return to haunt the programme.

PK suggests a complete feasibility report by the 2 OEMs,clearly stating the aims of the exercise,details of changes,improved performance,realistic timeframes,plus costs."If the Gripen E took SAAAB 12 years to develop,at a conservative estimate it would take the ADA/HAL 16 years (your guess is as good as mine).Does this version really add value to the IAF when it would've already inducted a 5th-gen fighter?

PK's Viable Alternative

In short,the IN's requirement for a more powerful engine saw the IAF "Piggy back" on to it in general as it would give greater all-round performance (same logic on BRF).However,the IAF's MK-2 configuration is still "not frozen",though discussed internally.PK says that modifying/improving the MK-1 as MK-1A/MK-2 whatever nomenclature is used,other than the engine change,will involve only intake redesign,the rest being only improvements and modifications. He asks whether this option has been done,as it would not result in a design of virtually a new version with the MK-2.

Volvo tweaked the 404 to give it some incremental extra power.Strengthened fan modules for better bird strike capability.We would have to redesign the intakes for the same.The ADA could request SAAB or Boeing for intake redesign help.Another Q.,whether the ADA has measured the static thrust of the engine in MK-1 and determined its shortfall,to s ee if this improved Mk-1 will meet IN requirements? Without undertaking this test,it would be impossible to achieve the latter.If it is insufficient,a more powerful engine would be required by the IN,but its version may not be what the ADA has in mind for MK-2.

PK concludes wanting a comprehensive ,transparent study of changes,redesign details,timeframe,costs,etc.,that would provide us with answers ,before embarking upon the MK-2 in present ADA avatar,lest the taxpayer's money is squandered away."Is anyone listening?" he asks.

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Re: LCA News and Discussions

Postby chackojoseph » 13 Oct 2013 10:07

I had a small discussion with him and that's where the LCA intake issue was discussed. I showed him the Tejas MK-II new intake and mentioned GE's offer for consultancy (Error 404 – Performance Not Found). He said that there is no such deal with GE, in his knowledge. Upon being asked why ADA cannot design an intake on its own, there was silence. He believes that only consultancy can help intake redesign.

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Re: LCA News and Discussions

Postby Austin » 13 Oct 2013 10:23

SaiK wrote:can someone post full article if it does not cross the copy rights?


For sake of discussion I will post the article but mods can delete if they think its inappropriate.

All Credits FORCE

A Better Alternative
Before Tejas Mk II is brought in, experts should weigh all the pros and cons

By Parvez Khokhar


Now that sounds coming from the ministry of defence (MoD) and Aeronautical Development Agency (ADA) seem to be suggesting that the Tejas Mk I is just around the corner, the focus seems to be shifting to the Tejas Mk II. This variant appears to be gathering momentum in the eyes of clairvoyant chair-borne pundits, who profess that this will be the panacea for all the ills that beset the indigenous aircraft industry and will also address the desire of the Indian Air Force (IAF) to have a super-duper fighter.

ADA and Hindustan Aeronautics Limited (HAL) have even widely publicised a time schedule for the induction of this aircraft (too fictional to be mentioned). The granting of permission by the MoD to commence this project and its acceptance by the IAF by placing some initial orders, is not in the public domain. In order to take an educated decision on what the Mk II aims to be and the challenges involved therein, it is imperative to comprehend the facts, as they exist today.

ADA and HAL have made public statements that work on the airframe will begin by end 2013. Whilst it is apparent that the qualities envisaged in the Mk II are all commendable, they require a closer examination to comprehend the challenges involved in reaching this target without unacceptable time and cost overruns. So what are the major changes envisaged in the Mk II in order to be a quantum leap over the Mk I?

These are: More powerful engine F-414-GE-INS6; New Flight Control Computer; Upgraded avionics; Retractable In Flight Refuelling probe; On Board Oxygen Generating system (OBOGS); AESA radar; Cockpit upgrade; New Electronic Warfare(EW) suite; and Ability to super cruise (fly supersonic in level flight in dry power).

These changes will lend value throughHigher thrust; More ordnance carrying capacity; Better avionics; Longer endurance with On Board Oxygen Generating System (OBOGS); State-of-the-art radar; Better man-machine interface and situational awareness through larger displays in the cockpit and easier management drills; and Better survivability through better EW suites. This factor will also enhance the operational performance.

ADA’s contention that all this can be done within two years is based on the example of the Swedish Gripen NG (called Gripen E for in-service usage). ADA has also sought guidance through consultancy from Saab for the Mk II. Before proceeding further, we need to factor in some extremely relevant points, otherwise this comparison becomes rather odious.

• The Gripen E is an off-shoot of the highly successful Gripen A/B/C/D. The Tejas Mk I is yet to enter service.

• Saab has over 75-year-old history of design and development of fighter aircraft vis-a-vis ADA/HAL’s nascent experience in producing fighter aircraft.

• ADA’s record of non-adherence to consultants’ recommendations, especially when it runs against their grain and involves redoing certain aspects of work, is well known.

• Then there are consultants who merely review your work and either tell you that it is okay or withhold comments that may rock the boat. It is to be seen how much Saab would be involved; ADA should be absolutely clear that Saab will neither build/design this aircraft for them nor give them a blueprint to follow.

Let us take a cursory glance at the summary of how Saab went about making the Gripen E, which has fairly similar improvements as envisaged for the Tejas MK II. The stated aims of the Gripen E were: Increased thrust; Decision support; Sensor fusion; Superior HMI; Improved communication; More weapon stations; Superior target acquisition; Airframe upgrades; External sensors; General systems upgrade; New avionics architecture; and Electronic Warfare

These changes led the demonstrator aircraft (the NGs) to achieve the following:Enhanced range; Morepayload; New sensor suite/weapons/electronic countermeasures; Engine with higher thrust; AESAradar; New avionics system; More internal fuel; and Super cruise ability. This also permitted reduced cost and lead time by 60 per cent, thanks to new processes and new supplier strategy (very significant in the Indian context).

The programme followed a time-bound schedule that went through the following steps:

• Early 2006: Demonstrator development started in Saab with the aim to fly in 2008

• 27 May 2008: Maiden flight of the Demonstrator(NG). This segment of the test programme was concluded in only 79 test flights with the new engine (414), larger internal fuel tank and more pylons (increased payload).

• 27 October 2009: Introduced AESA (limited version), MAW and SATCOM. Flown and tested in 73 flights including flights with a larger drop tank. Next step planned was to introduce new avionics.

• By 19 December 2012 the demo aircraft had accumulated over 250 hours.

• 15 July 2013: Saab started the assembly of the Next Generation Gripen, the Gripen E. First to be constructed is the front fuselage of the first pre-production test aircraft 39-8.

• 15 August 2013: Saab claimed they reduced cost and lead time by 60 per cent, thanks to new processes and new supplier strategy

• 2018: Delivery of first Gripen E planned for the Swedish Air Force. Saab managed the weight issue rather cleverly through extensive use of aluminium alloys and composites for the airframe. The major lesson that this remarkable programme brought was that it is extremely important to work with the customer to achieve success in record time.

Challenges for the Tejas Mk II


ADA has certainly conducted some studies on this subject, but the extent to which they have proceeded and the results achieved are shrouded in secrecy. Educated guesses from within ADA vary from the ‘let’s see how it goes’ to the more horrifying prospect that it may do ‘less than the MK I’. The latter view seems to justify ADA’s reluctance to even part with the projected improved performance figures. Remember, unlike the Gripen E, the Tejas Mk II will first have to contend with the shortcomings and flaws that it will inherit from the Mk I. These include:

• Weight reduction;

• New engine F414 fitment requirements;

• Re-design of air intakes;

• Better cooling of the avionics bay;

• Estate management of ancillaries fitted around the engine to facilitate a swift engine change (Gripen engine change takes 33 minutes); and

• Brakes

These are only representative and by no means, exhaustive. Corrective measures for all shortfalls will have to be addressed along with the challenges that the new design will throw up.

The new design features would include modification of the fuselage to accommodate the larger and heavier F414 engine. This would entail lengthening the fuselage, strengthening the fuselage and redesigning the contours. More thrust being produced by this engine (35 per cent more than the F404) means more fuel consumed and hence, the necessity for larger capacity fuel tanks. The obvious penalty would be in adding more weight, changing the area ruling (contours of the fuselage) which would increase the drag index, thereby negating some of the advantages of having a more powerful engine. The addition of more weight would be counter-productive. However, some saving grace could be sought from redistribution of segments of the avionics components/LRUs and those of the new radar to get rid of the 200kg ballast that is carried in the nose bay to keep the centre of gravity within limits, an unheard of solution in good modern day fighters!

The air intakes would have to be redesigned to ensure full benefit is derived from the new engine. This is one area that ADA has shied away from doing for decades. It is both understandable and acceptable that they lack expertise in this area, but it has to be addressed, so why not get specialist help for this.

Fool-proof cooling of the avionics bay is a safety requirement, since this area houses much sensitive equipment, including the four channel cards for the quadruple fly-by-wire system of the Digital Flight Control Computer, which, if affected by thermal transfer due to inadequate cooling, can have disastrous consequences. The quadruple control system will come to naught if all four systems fail in quick succession. Other sensitive equipment can also get degraded and thereby, jeopardise mission accomplishment.

Maintenance practices in the Tejas are probably among the most primitive in this class of aircraft and certainly not conducive to operational efficiency. The Gripen requires all of 33 minutes to replace the engine. The Tejas takes a couple of days because of poor estate management of ancillary connections on the engine. With a Hot Refuelling (engine running after landing) and rearming with air-to-air missiles, the Gripen is back in the air in 22 minutes. Hot refueling is not permitted by Indian Oil, who seems to dictate the Tejas operational efficiency. The IAF could circumvent this issue by getting their own refuellers that are manned by IAF personnel. (I wonder whether Indian Oil is aware that air to air refueling does not require the engines to be shut down in the air! So much for their safety practices).

The extended fuselage will also enhance the weight. A small portion of the additional weight can be shed when the undercarriage is redesigned for a larger track. The undercarriage is over designed in the Tejas Mk I, as it caters for a far more vertical landing speed than is even required by the naval version. This extra strengtheningmeans extra weight and can easily be dispensed with. While this will not make a significant difference, but will contribute to the overall weight reduction.

There are a host of other issues that have been swept under the table ever since the first aircraft was designed and manufactured. Unless each one of them is addressed, their ghost will always return to haunt this programme.

So, how does this translate into time required and cost involved?ADA has no clue and that is a charitable observation. Having been brought up for decades on self-delusion, delays and cost overruns, that have always been condoned, they no longer acknowledge the word ‘accountability’. HAL keenly aids and abets this philosophy. Before the ‘go-ahead’ is given to this project, a complete feasibility report must be produced by the two Original Equipment Manufacturers (OEMs), clearly stating the aim of this exercise, with details of changes planned, the improved performance that would accrue and realistic timelines, plus costs.

It would not be out of place, based on past performance, to state that performance, costs and timelines will have to be critically examined and the casual figures bandied about by non-involved individuals/bodies must be totally ignored. If the Gripen E, with Saab’s extensive experience, is realistically pitched at 12 years from conception to manufacture to delivery of first aircraft to the Swedish Air Force, it would behove ADA/HAL to add on a few more years to the Tejas Mk II. At a conservative estimate of 16 years (your guess is as good as mine), does this version of the aircraft really add value to the IAF, when it would have already inducted the fifth generation aircraft?

A Viable Alternative

The rationale of making the Tejas MK II is centred around the Indian Navy’s requirement of having a greater initial acceleration for deck operations. Hence, the choice of a more powerful and bigger engine, the F414. The IAF has piggybacked on this solution since it promises a greater all round performance.

The navy’s requirement is well focused on the engine, though they would not be reluctant to avail of any other benefit that this aircraft would bring as a bonus. The IAF’s configuration for the MK II, though discussed internally, is still not frozen. Therefore, to consider a viable alternative is not too late.Give a serious thought to modifying the Mk I with all the changes envisaged for the Mk II, other than the engine change. The only major challenge is to redesign the air intakes to ensure optimum pressure recovery. The rest would entail only modifications and improvements.

The question that comes up is whether a serious study has been done to explore this alternative. It would not need rocket science to presume that the time, effort and money required to do this would be far less than design and development of a ‘new’ aircraft. Whether this version is called theMK IAor Mk II is of no consequence, since such nomenclature is pure semantics.

The prime focus will have to be on ensuring that the rated thrust is allowed to be produced by the engine. The Swedish version of the F404 is the RM 12, made by Volvo. Some tweaking by Volvo has enhanced the dry thrust from 49.9 kN to 54kN and in the after burner regime, from 78.7kN to 80.5kN. It has also strengthened fan modules to withstand bird strikes. The F404-IN-20 also incorporates these modifications, but the Tejas Mk I intake design does not allow this full thrust to be built up. Hence, it is mandatory to redesign the intakes. Both the Gripen and the older version of the F-18 have air intakes that permit optimum pressure recovery. Can ADA not consult both Saab and Boeing to overcome this problem?

The other unresolved issues that have defied a solution are not because of ADA’s capability, but their reluctance to address them, since it is far easier to sweep them under the carpet, to be looked at later. ‘Later’ has arrived now and procrastination cannot be condoned any further. The work force, which is familiar with the MK I and is relatively unoccupied, can now be gainfully diverted to carrying out structural and other reviews to resolve pending issues, instead of waiting to tackle the MK II, as and when it emerges.

Will this avatar of the Tejas meet the requirements of the Indian Navy? Has ADA measured what the static thrust of the engine is in the MK I as of now and determined how short it falls of the manufacturer’s figure? Unless that is known, how can we aim to achieve the latter? A comprehensive study would provide the answer. In the event that the enhanced initial thrust still falls short of the navy’s requirement, the F 414 may be the only answer, but not in the form that ADA envisages the Tejas Mk II. Before giving a ‘green light’ to the Tejas Mk II, a transparent study of the enhanced performance, with specific facts and figures, along with a realistic timeframe and cost, must be scrutinised by a competent body of the users (IAF and IN) and financial wizards, lest the taxpayers money is again squandered away. Is anyone listening?

Austin
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Re: LCA News and Discussions

Postby Austin » 13 Oct 2013 10:25

This is what I could find about the author Parvez Khokhar

http://www.bicentre.org/events/pakistan_the_psyche.html

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Re: LCA News and Discussions

Postby chackojoseph » 13 Oct 2013 10:45

If everything goes by these clairvoyant ch-air-borne pundits, this aircraft will never be completed. If we say that IAF (generically) does not know where to draw a line for projects, the above is an example. SU-30 would have never been made if Russians did not draw a line and then improve it.

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Re: LCA News and Discussions

Postby chackojoseph » 13 Oct 2013 11:35

The heavy engine argument is as old as the GE-414 proposal with Navy . Its almost 8 year old and so are the studies. Air intake models exist in opensource. For IAF, added performance is required, which is logically taken by redesign based on GE-414. The drag part is a suspect as neither PK or open source has a whiff of it. Weight reduction to what? Is there a benchmark to weight reduction to 1984 ASR levels with 2004 ASr specs? Weight reduction is generically required.

Navy is not asking for worlds smallest combat aircraft. It requires a combat aircraft which can take off and land on carrier. PK says that landing gear is strong even for Naval requirements and we know ADA is struggling to make a strong landing gear for deck landing. :lol:

At the same time, what he has written is over all correct in a generic way. Practicality over LCA is missing. If ADA can manage to accommodate redesign for IAF requirement, (patch up), Navy is willing to take it through multiple marks.

Now comes the argument for Mk3, which some here have various ideas. One should understand Mk1 and mk2 designations are created to freeze the first 2004 ASR. technically, it is Mk 1.

The Mk 3 will be the actual going forward to next level of LCA, where the existing issues will be addressed. So, logically, we might be cutting short mk2 production and a good number will be mk3.

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Re: LCA News and Discussions

Postby vic » 13 Oct 2013 11:45

I think that first batch of LCA should aim to be better than "non upgraded" Mig-21s and then take it up from there. IAF wants the world in the first batch of LCA itself but on the other hand is content to fly Mig-21s

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Re: LCA News and Discussions

Postby ArmenT » 13 Oct 2013 12:15

Anyone know what the hardware and programming language used for the LCA's flight control system are? This article mentions that DRDO bought dev. tools to build code for VME PPC-based single board computers with VxWorks 6.x OS and Ada.
http://www.adacore.com/press/mistral-solutions

Is that what they are using on the LCA?

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Re: LCA News and Discussions

Postby Sagar G » 13 Oct 2013 12:39

^^^ AFAIK Ada it is.

Edit:- This was posted here before by another BRFite

LCA AVIONICS AND WEAPON SYSTEM MISSION COMPUTER SOFTWARE DEVELOPMENT: A CASE STUDY

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Re: LCA News and Discussions

Postby Ramu » 13 Oct 2013 12:50

chackojoseph wrote:If everything goes by these clairvoyant ch-air-borne pundits, this aircraft will never be completed. If we say that IAF (generically) does not know where to draw a line for projects, the above is an example. SU-30 would have never been made if Russians did not draw a line and then improve it.


+1

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Re: LCA News and Discussions

Postby Sagar G » 13 Oct 2013 13:02

chackojoseph wrote:If everything goes by these clairvoyant ch-air-borne pundits, this aircraft will never be completed. If we say that IAF (generically) does not know where to draw a line for projects, the above is an example. SU-30 would have never been made if Russians did not draw a line and then improve it.


Exactly CJ and that's why you must listen to PK's advice only i.e.

the casual figures bandied about by non-involved individuals/bodies must be totally ignored


Yawn and move on onlee.

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Re: LCA News and Discussions

Postby Sagar G » 13 Oct 2013 13:05

A reminder of what is trying to be achieved in mk.2

Image

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Re: LCA News and Discussions

Postby RKumar » 13 Oct 2013 13:10

Flight test update

LCA-Tejas has completed 2334 Test Flights Successfully. (01-Oct-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-372,LSP1-74,LSP2-286,PV5-36,LSP3-157,LSP4-94,LSP5-220,LSP7-61,NP1-4,LSP8-28)

to

LCA-Tejas has completed 2344 Test Flights Successfully. (08-Oct-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-374,LSP1-74,LSP2-286,PV5-36,LSP3-159,LSP4-94,LSP5-220,LSP7-64,NP1-4,LSP8-31)

to

LCA-Tejas has completed 2348 Test Flights Successfully. (08-Oct-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-375,LSP1-74,LSP2-286,PV5-36,LSP3-161,LSP4-94,LSP5-220,LSP7-65,NP1-4,LSP8-31)

chackojoseph
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Re: LCA News and Discussions

Postby chackojoseph » 13 Oct 2013 16:01

Over the years, we have forgotten why LCA was conceived. Me and Ex DRDO Navneet Bhushan jointly did an article after ROFLing about assertion that LCA is a replacement of MiG-21.

LCA Tejas, MIG-21s and IAF – Opportunity missed – hope it is not lost!

Sagar G
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Re: LCA News and Discussions

Postby Sagar G » 13 Oct 2013 16:04

CJ can you get in touch with your sources and do an article having point by point rebuttal of PK's article ???

chackojoseph
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Re: LCA News and Discussions

Postby chackojoseph » 13 Oct 2013 16:17

SG, it can be done, but a waste of time. Reporting achievements is much better way, which we do it.

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Re: LCA News and Discussions

Postby Karan M » 13 Oct 2013 18:39

Not a waste of time at all. You let such inaccurate commentary persist and it takes on a life of its own.
Eg 200 kg weight of the ballast when no radars were fitted into the LCA..

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Re: LCA News and Discussions

Postby SaiK » 13 Oct 2013 18:52

Sagar G, I don't see the imageshack jpg.. others have the same problem?


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