LCA News and Discussions

[Kartik]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

[Indranil]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

^^^ They said so. But what is surprising that they want 8 units.

[member_23657]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

The SGSI lights used on an aircraft carrier are mostly red and white in colour, not red amber and green.

The lights used in Precision approach path indicator (PAPI) on aircraft carriers do not show angle of attack but glide slope required for landing.

When the lights show white-white-red-red the aircraft is on the correct glide slope for landing, usually 3.0°. Three red lights (white–red–red–red) indicate that the aircraft is slightly below glide slope (2.8°), while four red lights (red-red-red-red) indicate that the aircraft is significantly below glide slope (<2.5°). Conversely, three white lights (white–white–white–red) indicate that the aircraft is slightly above glide slope (3.2°), and four white lights (white-white-white-white) indicate that the aircraft is significantly above glide slope (>3.5°).

The stabilized glide slope indicator(SGSI) is used on moving landing platforms such as aircraft carriers. The stabilization is required to factor the pitch of the ship in high seas.

[Indranil]

^^^ I did not know this. Thank you for the information. Is this the standard followed by naval aircraft of any origin?

[Vivek K]

Give HAL to Pakistan - they will buy the LCA in numbers. Such potent aircraft - Mk1, Mk2, N-LCA and India is shopping abroad to throw its money. A fool and his money are easily parted.

[member_23455]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

The SGSI lights used on an aircraft carrier are mostly red and white in colour, not red amber and green.

The lights used in Precision approach path indicator (PAPI) on aircraft carriers do not show angle of attack but glide slope required for landing.

When the lights show white-white-red-red the aircraft is on the correct glide slope for landing, usually 3.0°. Three red lights (white–red–red–red) indicate that the aircraft is slightly below glide slope (2.8°), while four red lights (red-red-red-red) indicate that the aircraft is significantly below glide slope (<2.5°). Conversely, three white lights (white–white–white–red) indicate that the aircraft is slightly above glide slope (3.2°), and four white lights (white-white-white-white) indicate that the aircraft is significantly above glide slope (>3.5°).

The stabilized glide slope indicator(SGSI) is used on moving landing platforms such as aircraft carriers. The stabilization is required to factor the pitch of the ship in high seas.

The above is true for only some landing aids and some aircraft carriers. Red-Amber-Green and IFLOLS with 3.5 degree glidescope is what the US uses...no clue what the specs and systems on Viraat and Vik are.

[RKumar]

No. We are not accepting imperfect missile systems.. It is just that R&D cycle, we can afford to make mistakes and it is not that safety-critical as would LCA is. When you are in missile development, normally safety-critical aspects catering to human-machine interface is taken care and any accident preventions are preplanned and risks are mitigated properly. in the case of test launch and deviations like that happened for nirbhay, the safety aspect was engaged, and the missile system was destroyed.

The program logic is entirely different for LCA. The safety-critical aspect is orthogonal to missile system logic. Here, we have to be critical to provide systems to land the instrument and platform safe, and the worst case is to ensure the pilot safely ejects. Lot of critical aspects from oxygen sensors to precision decision support system that has only a delta time left for the system to either decide to save the human and destroy the mission.

I used imperfect intentionally, Prithvi with liquid fuel and 150 km range was imperfect if you compare to Agni-III. Agni-III is imperfect when compare with Agni-IV/V. If you get what I mean. I also don't agree that missiles are less safety-critical as would LCA. Even I would wish it other way around, LCA can fail but missiles should not. Our major deterrent is based on missiles, we can't lower the standard but we had no choice but to start from basic.

Anyway, we can't deny there are problems with IAF and HAL. IAF and HAL don't see eye to eye. Even at Aero 2013, it was all open in public. Which is not bad in my pov, if relation as really that bad let them break it. So that IAF and HAL can learn to value each other then just take each other for granted.

They could have done better then what they are currently doing. That was the main point. I am happy my comments started this discussion where people can brain storm and come out with different reasoning which can help us in future. As long as intention is pure, everything is fine.

<indranilroy>
I don't think LSP-6 is coming to town any time soon if they just started with tender process. So I would keep my hopes low and don't fix a date but I am open for treat

[Gurneesh]

The SGSI lights used on an aircraft carrier are mostly red and white in colour, not red amber and green.

The lights used in Precision approach path indicator (PAPI) on aircraft carriers do not show angle of attack but glide slope required for landing.

When the lights show white-white-red-red the aircraft is on the correct glide slope for landing, usually 3.0°. Three red lights (white–red–red–red) indicate that the aircraft is slightly below glide slope (2.8°), while four red lights (red-red-red-red) indicate that the aircraft is significantly below glide slope (<2.5°). Conversely, three white lights (white–white–white–red) indicate that the aircraft is slightly above glide slope (3.2°), and four white lights (white-white-white-white) indicate that the aircraft is significantly above glide slope (>3.5°).

The stabilized glide slope indicator(SGSI) is used on moving landing platforms such as aircraft carriers. The stabilization is required to factor the pitch of the ship in high seas.

The above is true for only some landing aids and some aircraft carriers. Red-Amber-Green and IFLOLS with 3.5 degree glidescope is what the US uses...no clue what the specs and systems on Viraat and Vik are.

This is the walk-around of Mig29K.

The three lights are explained 5:35 onwards.

[member_26622]

Give HAL to Pakistan - they will buy the LCA in numbers. Such potent aircraft - Mk1, Mk2, N-LCA and India is shopping abroad to throw its money. A fool and his money are easily parted.

If your dad says he can afford to give you a BMW, will you ask for an Indica instead?

[SaiK]

RKumar, of course you can disagree.. norm is to have that freedom on open discussions.

But, if you want to make others or contending definitions and understandings change, you will have to post much more than what you are saying at a blanket level of understanding.

If you say specifically the case where missile system is more safety-critical than LCA systems, then that would add values to the thread.

[Kartik]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

The SGSI lights used on an aircraft carrier are mostly red and white in colour, not red amber and green.

The lights used in Precision approach path indicator (PAPI) on aircraft carriers do not show angle of attack but glide slope required for landing.

When the lights show white-white-red-red the aircraft is on the correct glide slope for landing, usually 3.0°. Three red lights (white–red–red–red) indicate that the aircraft is slightly below glide slope (2.8°), while four red lights (red-red-red-red) indicate that the aircraft is significantly below glide slope (<2.5°). Conversely, three white lights (white–white–white–red) indicate that the aircraft is slightly above glide slope (3.2°), and four white lights (white-white-white-white) indicate that the aircraft is significantly above glide slope (>3.5°).

The stabilized glide slope indicator(SGSI) is used on moving landing platforms such as aircraft carriers. The stabilization is required to factor the pitch of the ship in high seas.

Watch the MiG-29K walk around and you'll see the red green and amber lights. Glide slope is nothing but one way of looking at angle of attack- the AoA while approaching to land.

[Vivek K]

Give HAL to Pakistan - they will buy the LCA in numbers. Such potent aircraft - Mk1, Mk2, N-LCA and India is shopping abroad to throw its money. A fool and his money are easily parted.

If your dad says he can afford to give you a BMW, will you ask for an Indica instead?

So you think that LCA vs Rafale comparison is like comparing Indica vs BMW?

[Sid]

If daddy wanna buy his kid high end BMW, instead of second hand car, then no wonder kid is such a spoiled brat. Kid needs to earn his BMW through hard work.

Instead of bragging about 10 year "world class aircraft selection process", if IAF had invested 10 years their effort in LCA then we could have been through by now. Pour as much money to make it work, by hook or crook.

We have to start somewhere and LCA is the go to place. With the price we are paying to buy Rafael, we can actually buy their whole production line. They will close their production line anyway without any orders. France is officially under recession.

[Kartik]

Indranil, how do you know that the AoA indicator is for LSP-6? This kind of system with the green, amber and red lights is used by naval aircraft to allow a flight officer on the carrier deck to be able to tell if the approach angle is correct, too much or too little. Could also be for the N-LCA.

^^^ They said so. But what is surprising that they want 8 units.

any chance of posting the link to the tender?

[member_26965]

Instead of bragging about 10 year "world class aircraft selection process", if IAF had invested 10 years their effort in LCA then we could have been through by now. Pour as much money to make it work, by hook or crook.

You are so right. MMRCA tender was thought in NDA time. So, the time spent must be 15 years or even more. LCA development is 20 years is a standard whine.

[Indranil]

any chance of posting the link to the tender?

Invitation to tender for Development & supply of Angle of Attack (AOA) indicator and Angle of Side Slip (AOSS) indicator.

[sivab]

But what is surprising that they want 8 units.

http://www.thehindu.com/todays-paper/tp ... 398822.ece

The Navy has initiated the process of procuring eight LCA Navy aircraft — four fighters and four trainers — in the Mark1 configuration, while it intends to buy at least 42 aircraft in the lighter, more powerful Mark2 configuration, which is expected to take to the skies in eight years from now.

[Kartik]

any chance of posting the link to the tender?

Invitation to tender for Development & supply of Angle of Attack (AOA) indicator and Angle of Side Slip (AOSS) indicator.

thanks. that explains that this is for LSP-6 and that the AoA and AoSS indicators will be mounted in the cockpit itself. Interesting to note that the RFQ was not sent to any Indian manufacturers. Such instruments could surely have been manufactured in India, but perhaps no manufacturer exists in India for such avionics. They've asked for adequate spare instruments, which is perhaps why they asked for 8 nos. of both instruments.

[Lalmohan]

kartik - glide slope is not aoa; it is the trajectory of the aircraft as a function of its lift/weight and thrust/drag balances - which can be achieved at different aoa's

[member_26622]

Sid is bang on the money. Thanks a bunch!

[member_20292]

With the price we are paying to buy Rafael, we can actually buy their whole production line. They will close their production line anyway without any orders. France is officially under recession.

The production line comes with engineers and scientists willing to work in India as well?

Does the figure include material costs for then, subsequently building the 126 aircraft required?

[member_20292]

So you think that LCA vs Rafale comparison is like comparing Indica vs BMW?

IMO its more like Mini Cooper vs BMW 3 series.

[SivaVijay]

Watch the MiG-29K walk around and you'll see the red green and amber lights. Glide slope is nothing but one way of looking at angle of attack- the AoA while approaching to land.

My Understanding is the AOA and glide path are related but for different purposes, one is to check the landing speed and the other is to check if the aircraft got the impact point correct(i.e. not to overshoot the arresting wires or ram into the aft of the carrier), Gurus correct me if I am wrong.

I have one question, if the angle of attack indicator is in the landing gear how does it help the pilot, or is it to warn the carrier crew so as they can adjust the tension on the wires? or abort the landing altogether?

[Kartik]

kartik - glide slope is not aoa; it is the trajectory of the aircraft as a function of its lift/weight and thrust/drag balances - which can be achieved at different aoa's

yes, its the trajectory, but the trajectory is maintained by keeping a certain AoA, right? I'm not sure you can approach a runway with 0 deg AoA unless you don't want to generate lift at all.

So, what I meant was that it was another way of looking at the AoA of the aircraft while it approached the runway. I didn't say that AoA and glide slope are the same thing - but from a point on the carrier where the flight officer sits, looking at the lights on the aircraft nose gear (on the MiG-29K), he gets an idea of the AoA of the aircraft approaching and from that can tell whether the trajectory is correct or not. thats the reason for the 3 lights- green to indicate too low alpha, amber for perfect, red for too high alpha.

Am I getting this wrong?

[Lalmohan]

glide path descent has to happen within a tight range (2-4 degrees for normal runway landings) - on the ground 2 sets of lights set at special angles indicate to the pilot if he is out of that range - 2 yellow good, 2 red bad (too high), 1 of each - need to adjust, cant see lights - really bad! (too low)

note - this has nothing to do with angle of attack - which may be something like 10-12 degrees or more depending on the wing flaps and slats configuration

i am sure a similar lights set up is on the carriers. i guess you could have similar indicators on teh undercarriage to allow the deck crew to alert the pilot/wave off if the approach angle is incorrect

kartik - aoa is the angle the aircraft is making to the airflow, glide path is the angle the aircraft is making w.r.t. the ground, you can have the latter at different values of the former - depending on the L/W+T/D ratios; i.e. you can pitch the nose up to increase lift and improve the visibility downwards, but this creates additional drag - which has to be compensated for with additional thrust to maintain the attitude. you will have different a-o-a at the same glide path angle by setting different flaps for example - you have to compensate with thrust changes

[Kartik]

glide path descent has to happen within a tight range (2-4 degrees for normal runway landings) - on the ground 2 sets of lights set at special angles indicate to the pilot if he is out of that range - 2 yellow good, 2 red bad (too high), 1 of each - need to adjust, cant see lights - really bad! (too low)

note - this has nothing to do with angle of attack - which may be something like 10-12 degrees or more depending on the wing flaps and slats configuration

i am sure a similar lights set up is on the carriers. i guess you could have similar indicators on teh undercarriage to allow the deck crew to alert the pilot/wave off if the approach angle is incorrect

then how do the 3 lights on the MiG-29K's landing gear tell the officer on the carrier that the approach angle of the MiG-29K is alright and he can proceed or needs to correct the approach angle?

kartik - aoa is the angle the aircraft is making to the airflow, glide path is the angle the aircraft is making w.r.t. the ground, you can have the latter at different values of the former - depending on the L/W+T/D ratios; i.e. you can pitch the nose up to increase lift and improve the visibility downwards, but this creates additional drag - which has to be compensated for with additional thrust to maintain the attitude. you will have different a-o-a at the same glide path angle by setting different flaps for example - you have to compensate with thrust changes

and under most circumstances, the way I see it based on simple trigonometry, the alpha (AoA) and the angle the aircraft is making wrt the ground will be nearly the same.

even with flaps set at the max settings, the aircraft needs to maintain quite a bit of alpha in order to have a low enough approach speed. The rate of descent is what the glide slope is all about- maintaining that while not losing all lift is what going to a higher alpha is all about.

[SaiK]

sid is not just only bang on target, but has indirect message for IAF. nice!!!

15 years to select MMRCA, and still going strong in competition to their "vested interests".
20 years to help bring up to speed LCA.. and going strong in keeping their "vested interests".

bottom line, there is no security problems for IAF's need of the hour. plain and simple., else why would they get into these kinds of methods?

[Victor]

Lalmohan is correct. AoA is angle of longitudinal axis wrt ground and it is ideally zero (parallel to ground) on approach. Glide path can be adjusted by a combination of engine thrust, flaps and even landing gear. With full flaps and gear down close to touch down, the adjustment is by engine only. High angle of attack (nose up) during the approach is done as a last resort if the aircraft is below the glide path and full engine thrust is not enough. This is dangerous, specially in a carrier landing and would normally lead to an abort. High AoA is done at the last moment (flare out) with engine cutoff to lose lift and stall onto the ground but this is haram in a carrier landing where there is no margin for error and an abort (and climb out at full power) is a split second away.

In a carrier, not only is the "airfield" extremely short, it is also pitching nose-to-tail and side-to-side (hence need for side-slip indicator) while rising and falling. You need a point of reference both on the aircraft and the carrier whereas wihen the airfield is stationary, only a ground indicator is needed. It is truly a controlled crash and needs extra beefy landing gear which adds a weight penalty.

[Singha]

I figure the rafale had it been designed for land use would not be as stubby and lose some 500kg . compare to the stick thin legs of a much heavier bird the Eagle which always operates from well paved runways and does not claim the rough field abilities of russian a/c. being a 1m longer would have permitted more fuel , bigger avionics bay and perhaps even a bigger nose with less drag due to slimmer shaping.

[SaiK]

(on approach -> landing assumption) α can't be zero on approach is my understanding, but will tend to zero once touch down to land. what am i missing? are you guys talking about zero lift axis?

need more clarity gyan.

[neerajb]

Angle of attack is not the angle of wings with horizontal axis or ground. Angle of attack (AOA) is the angle the wings make with the incoming air. An aircraft with level attitude but zero forward velocity (and falling down) will have a pitch angle of zero but AOA will be 90 degrees. You don't need to pull the nose high up to stall the plane, put the engines on idle and maintain level pitch and the plane will eventually stall.

Case in point, AF447 maintained a pitch angle of 12 degress which is ok, but had AOA of 35 degrees during most of it free fall.

AOA of zero will mean the thing is no longer flying but has become a ballistic object. Generally the wings of commercial aircraft have an incidence angle of 4-5 degrees so that at level flight they have an AOA of 4-5 degrees so that they can fly.

Cheers....

[SaiK]

when you say incoming air, are you talking about inlets?

[Indranil]

Angle of attack is not the angle of wings with horizontal axis or ground. Angle of attack (AOA) is the angle the wings make with the incoming air. An aircraft with level attitude but zero forward velocity (and falling down) will have a pitch angle of zero but AOA will be 90 degrees. You don't need to pull the nose high up to stall the plane, put the engines on idle and maintain level pitch and the plane will eventually stall.

Case in point, AF447 maintained a pitch angle of 12 degress which is ok, but had AOA of 35 degrees during most of it free fall.

AOA of zero will mean the thing is no longer flying but has become a ballistic object. Generally the wings of commercial aircraft have an incidence angle of 4-5 degrees so that at level flight they have an AOA of 4-5 degrees so that they can fly.

Cheers....

I agree with you and hence the aircrafts landing on deck require vortex generators for higher AoA requirement.

The only thing I don't agree is "AOA of zero will mean the thing is no longer flying but has become a ballistic object". That will only be the case for a symmetric airfoil.

[neerajb]

@Saik : Incoming air is the air which is moving across the wings.

@Indranilroy : Thanks for correcting.

Cheers....

[SaiK]

vikrant, okay then that is clear.. i was confused when you said "incoming air".. i think you meant on-coming air.

[SaiK]

http://www.eurofighter.com/capabilities ... ystem.html
Got to see how do they do this show on sci ch. awesome. not sure how they convert those all IR LEDs to an x-ray vision? anyone? i am sure this technology should interest our LCA pilots of the future. Mk2++

[member_23657]

LCA Flight test update

from

LCA-Tejas has completed 2161 Test Flights Successfully. (14-May-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-364,LSP1-74,LSP2-267,PV5-36,LSP3-130,LSP4-74,LSP5-172,LSP7-34,NP1-4,LSP8-4)

to

LCA-Tejas has completed 2174 Test Flights Successfully. (25-May-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-364,LSP1-74,LSP2-273,PV5-36,LSP3-132,LSP4-76,LSP5-172,LSP7-37,NP1-4,LSP8-4)

[member_26965]

Oh dear! Yet another gloom and doom report about the LCA-Naval this time.There are ew details too other than few test flights.

http://www.dnaindia.com/bangalore/18308 ... all-at-sea

Four flights in one year. That’s the flight track record of the naval variant of Light Combat Aircraft -LCA Navy (NP-1) since it made its maiden flight on April 27 last year in Bangalore.

The NP-1 which is the sole prototype build under the LCA Navy programme by the Aeronautical Development Agency (ADA) has been bogged down with a few problems that it has not been on a flight sortie since July last 2012.

The aircraft since its first few flights has been undergoing a few modifications with regard to the landing gear and a few other systems to meet the ski jump requirement, said Ministry of Defence sources.The LCA Navy is being developed to operate from an aircraft carrier with a concept of ski-jump take-off but arrested recovery (STOBAR). The aircraft to prove that it is fit for carrier-borne operations it would be subjected to ski-jump launch and arresting recovery tests at the naval air station in Goa.

Sources added that a few hiccups which are being sorted, after which more flights would follow.The LCA Navy programme commenced in 2003 and the development plan of the Naval version envisages building of two prototypes, a two-seat trainer (NP-1) and a single seat fighter (NP-2), as technology demonstrators to carry out carrier suitability certification and weapons integration.

Compared to its Air Force counterpart, the LCA is different as it has a new stronger and longer landing gear, arrester hook for ship deck landing, front fuselage drooped for better over the nose vision to facilitate ship landing, an additional control surface to reduce ship landing speed and consequential changes in various systems.The NP1 aircraft would be flying with the GE-F404-IN20 engine.

The LCA will replace the depleting Sea Harrier squadron and operate along the MiG29 K’s by 2014 from the Indigenous Air Craft Carrier which is being constructed at Kochi.The Government has already sanctioned limited series production of the LCA Navy under which eight aircraft would be developed.

Arrester gear of Shore Based Test Facility for Naval LCA passes test

http://frontierindia.net/arrester-gear- ... asses-test

VADM Sinha speaking about NLCA.

[Philip]

Indian Express:30/5/13.

AKA ,"rapping the DRDO on its knuckles",tells the DRDO "Perform or perish"!

The LCA is given its IOC-2 date and this was final said AKA,"I am waiting for the LCA to become a reality".AKA asked the IAF,DRDO,HALto work together so that the final IOC-2 would be achieved by 2014 end.

AKA while saying that it was a "Herculean task" to meet deadlines,there was also a "limit ti slippages".
"In times of cut-throat competition,the choice is very clear-perform or perish.n delivery of strategic systems,the timelines must be adhered to and user satisfaction is the litmus test",Anthony said.

While asking the DRDO not to fritter away its core competence,he also said that "countries depending upon imports cannot be great nations".

Well,this is the clearest statement yet to come from AKA regarding the LCA to the DRDO/HAL which have been given their final cut-off dates.He also emphasised most importantly "user satisfaction",meaning that systems that did not meet standards expected of them would be rejected by the end-user.The line has been drawn in the sand,let's hope that the DRDO/HAL rise to the occcasion in the national interest.

Now,if final IOC-2 is only going to come by "end 2014",which effectively means 2015,I frankly doubt that even 40-50 LCAs will be produced by 2020.This means that the IAF will have to look elsewhere for a suitable aircraft to augment its dwindling numbers,especially in the face off sustained provocation from the PRC.Time to shortlist the candidates.

[SaiK]

I think perform or perish model fits all walks of life., from babooze to real-time systems, it is a valid statement. It applies everywhere, and especially to slipped projects. Is there any doubt in public mind that LCA project was poorly handled in terms of deliverable, resource planning and budgeting. I think sub systems to aggregated systems are the way to go.. and LCA platform now can become a test platform for many aggregation of technologies.

Resource utilization is vital for desh..as babooze allocated relatively relaxed budget on time, but tight on the money compared to the project-time line span... basically $/per hour is poor, forget about what works gets done per hour...plus the brain drain to firang lands.

We have long way to go to capability and maturity. We will get there.. and this same model of workign might hamper in the future.. and I am dam sure, AMCA will never go with nothing on paper to begin with if LCA does not get its FoC clearance.