Naval LCA - News and Discussion

[NRao]

Funny you should mention .....

This entire STOBAR with conventional aircraft is so sub optimal. In a hot day , with no sea breeze and if you have mechanical problems /battle damage and the carrier can't put out the required speed , the planes can't take off

Have not had the time to post a response to my previous post on CAT vs. Ski sortie rate. But, one plug on what you mention. The HMS QE, the one that is used to make pro or con args on umpteen matters, has 6 engines. She normally runs on 4. But to launch - with her ski jumps and F-35 Bravo - at times, needs all 6 engines. Except that these two idle engines need time to come up to speed. And if they cannot within a window, then it is no use launching the F-35B.

Go figure.

Ski jump.

F-35B.

There is so much to this whole discussion that it is ridiculous.

[shiv]

a. The CAS of the LCA as it hits the ramp is about 100 to 110 knots, the end of the ski jump to when it starts "flying" is around 150 knots

Interesting. There are 2017 images of LCA formating with Su-30, Do 228 HTT 40 and something else - and I heard from a birdie that they were all doing 180 kmph. Kmph. If true the LCA flies, and does not stall at 180 kmph. How much is 150 kt in kmph?

[NRao]

280 kmph

[Indranil]

280 kmph

Way off! Also, you were speculating while you wrote about the launch rate of CATs too. Operationally, in both cases, the rate is more dependent on how quickly you can line up the next aircraft for launch. Otherwise theoretically, ski jumps are going to be faster. It is a matter of taxiing to a chalk.

Your most recent post has nothing to do with dispatch rates. It is about the basic shortcoming of a ski jump: no additional oomph for launching heavier aircrafts.

CATs have their problems too. They are a lot of mechanical parts which need constant maintenance. When the CAT fails, you can't launch. End of story.

a. The CAS of the LCA as it hits the ramp is about 100 to 110 knots, the end of the ski jump to when it starts "flying" is around 150 knots

Interesting. There are 2017 images of LCA formating with Su-30, Do 228 HTT 40 and something else - and I heard from a birdie that they were all doing 180 kmph. Kmph. If true the LCA flies, and does not stall at 180 kmph. How much is 150 kt in kmph?

You are close Hakeem. At Aero India, LCA was flying just a shade above 200 kmph. When it is cleared for 26 degree AoA, its lowest speed would be in the range of 185-195 kmph. When it is cleared for carrier operations, CAS at ramo exit will be lesser than 85 knots.

Vina, those measures were taken to remove the variability for the first test. In each test, they add back one source of variability.

[Indranil]

Vina, you bring out a great point. TVC cannot help with pitch control if the wings are stalled. That is absolutely true of the maneuvers we see in airshows. The airspeed is close to zero (in one of IAF's favourite Su-30MKI manuevers, it is negative). Obviously, the engine is not used to support the weight of the aircraft. The nose drops and the aircraft trades altitude for speed quickly to support its weight through its wings.

However, this is very different from the scenario of the ski jump. One, the wings are not stalled, they are still developing significant amount of lift. and Two, the TVC is not being used to generate lift either. It is just used to hold the musharraf down. Most of the thrust is used to increase airspeed only. And given, that operationally, all ski jump launches are realized with no loss of altitude anywhere after ramp exit, I will wager a bet. It has the potential to work.

I will read around a bit more and get back.

[Indranil]

I was not wrong. EADS and Eurojet pretty much agree with me.

Eurojet pushes thrust-vectoring technology for Typhoon

"There are benefits all over the place," says Eurojet's Sterr. "You can reduce your take-off distances considerably because you are able to rotate the aircraft much earlier with thrust vectoring to generate the lift. You can't generate a moment without thrust vectoring to rotate earlier."

More details in the now unclassified report: Thrust Vectoring Nozzle for Modem Military Aircraft

The rotation of the aircraft for take-off and landing can be accelerated by using Thrust Vectoring. Also, Thrust Vectoring can be used to increase angle of attack, hence lift,while maintaining a trimmed aircraft. The combination of all these effects gives an important reduction in the take-off and
landing runs for an aircraft such as Eurofighter.

[vina]

Vina, you bring out a great point. TVC cannot help with pitch control if the wings are stalled.

They can. In fact that is the easy part. The pitch attitude can be maintained by vectored thrust. If the wings are not generating enough lift, the plane will lose altitude. It will just sink down, with the same pitch attitude.

However, this is very different from the scenario of the ski jump. One, the wings are not stalled, they are still developing significant amount of lift. and Two, the TVC is not being used to generate lift either. It is just used to hold the musharraf down. Most of the thrust is used to increase airspeed only. And given, that operationally, all ski jump launches are realized with no loss of altitude anywhere after ramp exit, I will wager a bet. It has the potential to work.

The pitch control is the least of the problems with thrust vector control available in the pitch axis or if both pitch and yaw are available, you can control both pitch and yaw. The more troubling issue is roll control . That is not possible to do with one engine , even if it has both pitch and yaw thrust vectoring.

It is like this. If there is a even a small slide slip angle (i.e. the plane not launched exactly into the wind or if there is a sudden gust with even a small change in wind direction) due to relative wind (dayumm, the same apparent wind and the Polynesians Sails vs Roman Square rigs again) one of the wings will have different angle of attack than the other ,the wing aero characteristics will be different and the plane will start rolling (and yawing) . If the launch speed is not sufficient enough , the ailerons are not effective and you have no roll control (even if you have pitch and yaw control with a 3D nozzle). So net-net, there is a minimum speed that you will need to hit the ramp exit at, so that the control surfaces have sufficient control authority and are effective at that instant so that the plane is controlled in the pitch , roll and yaw axis.

If you have a 2 engine plane with 3D nozzles, with active control in pitch , yaw and roll axes, in the ballistic phase until the aero control surfaces are fully active and the wing generates enough lift to support the plane, congratulations, you have a plane with the control characteristics of the Harrier and the F35B

[Philip]

59 new naval strike birds may too many birds "too far",cost-wise. Naval Rafales will cost almost double of the massive cost of a mere 36 IAF Rafales.If the In ants new fighters sooner rather than later,as I said before,return any problematic 29Ks to Russia to be replaced by perfected new 29Ks,which they're building for the RuN. We got the 49 29Ks at a low cost of just $32< a pop.At least 1/3rd of the [price of a single Rafale. I can't see the GOI spending so much moolah on carrier aviation,aircraft and carrier at the cost of a balanced fleet with more subs and surface combatants.

[vina]

59 new naval strike birds may too many birds "too far",cost-wise. Naval Rafales will cost almost double of the massive cost of a mere 36 IAF Rafales.If the In ants new fighters sooner rather than later,as I said before,return any problematic 29Ks to Russia to be replaced by perfected new 29Ks,which they're building for the RuN. We got the 49 29Ks at a low cost of just $32< a pop.At least 1/3rd of the [price of a single Rafale. I can't see the GOI spending so much moolah on carrier aviation,aircraft and carrier at the cost of a balanced fleet with more subs and surface combatants.

I am not sure they will "accept" any "returns" . But the Mig 29Ks have been around for what 12 years now ? The recent Russian deployment in Syria did not see any action by these Mig 29Ks. However, if like you said, if we can get the "perfected" ones to replace our duds, then it sure is a great deal. There is a lot of good sense in what you say. I doubt 57 Rafales or F35Bs are practical at around $100m upwards a pop. We simply don't have that kind of money.

But then, as always,you can BUILD a Navy, not buy one. So let us build the N-LCA and perfect it. That will sort of overlap with whatever the Russian manage to perfect (at our expense as always, we were the guinea pigs, who actually paid money to get experimented on) the Mig 29K into something useable.

[shiv]

Eurojet pushes thrust-vectoring technology for Typhoon

"There are benefits all over the place," says Eurojet's Sterr. "You can reduce your take-off distances considerably because you are able to rotate the aircraft much earlier with thrust vectoring to generate the lift. You can't generate a moment without thrust vectoring to rotate earlier."

But the same "rolling" (nose up moment) is achieved by a ramp in a ski Jump. One might do away with a ski jump with TV, but TV on top of a ski jump is the logic that is not clear to me.

[Singha]

perhaps they are targeting austere STOL airfields in the mountains like thoise or a couple of scary ones in nepal and bhutan.

[Cain Marko]

Dunno about 57 raffles or jsf but a few of the latter.. About 36 in stovl mode @ 12 per carrier complementing the fulcrums would give IN Cbgs a cutting edge in land attack, fleet protection and anti ship roles

[shiv]

perhaps they are targeting austere STOL airfields in the mountains like thoise or a couple of scary ones in nepal and bhutan.

No No. No one is actually doing that. This was a completely theoretical discussion. I don't think TV can even be considered without full ownership of the engine tech.

[Indranil]

Eurojet pushes thrust-vectoring technology for Typhoon

But the same "rolling" (nose up moment) is achieved by a ramp in a ski Jump. One might do away with a ski jump with TV, but TV on top of a ski jump is the logic that is not clear to me.

Hakim you are confusing attitude with AoA.

[shiv]

But the same "rolling" (nose up moment) is achieved by a ramp in a ski Jump. One might do away with a ski jump with TV, but TV on top of a ski jump is the logic that is not clear to me.

Hakim you are confusing attitude with AoA.

Please explain that because I don't think you follow what I am getting at.

[vina]

Hmm. So lets do some "speculative" math.

From the presentation we see that the ramp exit speed of the N-LCA is around 110 KCAS. They said they built in a margin of 10 knots. So lets assume it is 10 KCAS.

The carrier can put out something like 25 knots , which will be Ground Speed. So let us assume zero wind and a delta of around 25 deg over standard atmosphere (i.e. 15 deg C + 25 deg, i.e. 40 C) . This would be around the worst case corner conditions for take off . Now if you assume zero wind. The carrier is actually putting out a TAS of 25 knots.

Nice thing about something called internet is that stuff which you had to manually calculate is available in just a google search away, like this Aviation Calculator

So the carrier speed translates roughly to 23.4 KCAS (just plug in the 25 knots and delta temp and 15.00m altitude). So it needs to make up around 66.5 knots.

Let us convert everything into "civilised" metric units and not the uncouth and clunky imperial units and convert all this knots business into m/s

So required speed at ramp exit = 100 kcas * 0.514 = 51.44 m/s CAS
Initial speed due to ship = 23.5 kcas * 0.514 = 12.09 m/s CAS (lets call it u)
MTOW = 13.5 tons (from wiki for LCA MK1)
Thrust = 90 KN (GE F404 - IN 20)
Derated Thrust @ 90% = 90% * 90 KN = 81 KN (well known issue that the F404 guarantees full thrust only after 20 mins)
Take off run length available = 200 m (I think, if different , let me know, I can put it into the spreadsheet) .

So with 13.5t MTOW & 81KN thrust the acceleration is 6 m/s^2 and plugging it into the high school kinematics , ignoring for a moment , the work done in climbing the ramp against gravity, we find that the speed at ramp exit is 50.45m/s , which is less than the 51.44m/s that is required.

Using a solver /goalseek, let us look at what the needed acceleration will be for 51.44/ms . That works out to 6.25m/s^2 using Goalseek.

If we need to get 6.25m/s^2 acceleration , with a thrust of 81KN (derated due to temp over IS and lower installed thrust in first 20 mins), then the MTOW would be 12.96 Tons.

If we assume that the NLCA is 1.5 Tons heavier than LCA MK1, the empty wt = 8 tons. Fuel is 2.5 tons.
Payload of NLCA as it seems per current data is 12.96 ~ 13 tons - 8 tons - 2.5 tons = 2.5 Tons. in WORST CONDITIONS.. Zero wind and 40 degree ambient and carrier doing less than Max Speed

J-15 ding dong flying out with full fuel load out of Liaoning/Varyag < 2 TONS!

Have a nice day folks.

[Indranil]

Hakim you are confusing attitude with AoA.

Please explain that because I don't think you follow what I am getting at.

Let's take off from SBTF when there is no breeze. The take off attitude is 14 degrees and the AoA is zero degrees. For increasing and maintaining AoA, you have to create a pitching moment.

[shiv]

Please explain that because I don't think you follow what I am getting at.

Let's take off from SBTF when there is no breeze. The take off attitude is 14 degrees and the AoA is zero degrees. For increasing and maintaining AoA, you have to create a pitching moment.

Please explain how a plane coming off a ramp with a forward speed of say 150 kmph with its nose pointed up at 14 degrees to the horizontal has zero AoA.

[Indranil]

What is the AoA of a plane going straight up at whatever speed you want?

And that's why I am asking you to understand the difference between attitude and AoA. They are not the same thing.

[shiv]

What is the AoA of a plane going straight up at whatever speed you want?

And that's why I am asking you to understand the difference between attitude and AoA. They are not the same thing.

This is the problem. By definition the AoA would be zero because it is the angle of aircraft axis relative to the airflow.

But that does not answer my question

An aircraft flying horizontally would also have an AoA of zero degrees.

What is the angle of the aircraft coming off a ski jump relative to the airflow? Here you have a plane that is moving forwards horizontally at (say) 100 kmph and a further headwind component of 50 kmph. But the nose is pointed up at 14 degrees.

Are you saying the AoA is still zero? I cannot understand that - although I have found a paper that is saying exactly what you are saying about ski jumps and will post subsequently.

[shiv]

As far as I can make out this paper says:

It is worth having thrust vectoring to rotate the aircraft even with a ski jump. But the TV must simply rotate the aircraft - or provide the rotating moment and quickly return to the longitudinal axis after initiating the rotation. This answers my question about loss of longitudinal thrust - it is lost only momentarily.
http://www.icas.org/ICAS_ARCHIVE/ICAS19 ... -7.4.2.pdf

On the other hand, this screen grab from an old issue popular mechanics shows that the Harrier TV does exactly the opposite. The thrust is vectored down as it enters the ski jump but is turned to horizontal when the ski jump is cleared.

[vina]

Please explain how a plane coming off a ramp with a forward speed of say 150 kmph with its nose pointed up at 14 degrees to the horizontal has zero AoA.

This is what I wrote much earlier as "basics" . On the ramp (when there is no breeze), the plane has Zero AoA. It is the same as the plane climbing an inclined plane of 14 deg or a plane climbing through the air at 14 deg. The AoA is the angle between the line joining the nose and tail of the plane and the direction in which it is flying/ moving.

For e.g., in an airshow when the plane is flying slow at a high AoA , the nose is pointed up towards the sky, the Musharraf towards the ground , while the plane is flying PARALLEL to the run way. So that is why the plane has an angle of attack . A plane flying parallel to the ground (flat ground) with its wings level has zero angle of attack (not exactly , there usually is a small angle of attack even when the plane is flying level , but that is by design).

Notice, the take off from the SBTF ramp does not exactly replicate the conditions of a moving ship. There because the plane is climbing a 14 deg ramp , while the air due to ship motion comes parallel to the water, the effective angle which the wings feel is not zero deg, like it is climbing up the ramp in still air in the shore based test facility. In the ship, it will have an angle of attack. This is what I tried explaining to even the last time we had this discussion and that is exactly why I posted all those links again (including the stuff about relative wind and how sailboats can go upwind , polynesians vs. romans etc).

Let me post that bit about carrier vs. SBTF difference again. It is just high school physics and vectors

Forget about anything more "high flying" beyond high school physics and vector algebra. The physics of this is pretty simple. There are two things at work.

1. The ski jump is exactly that, a ski jump, which launches you in the air in a ballistic trajectory and since you spend more time in the air, the horizontal distance you travel will be higher before you hit the sea surface if you just went straight off the end of the bow. Of course, in the meantime, the engine keeps working and you get up to flight speed before you hit the water.

2. If the carrier was stationary, like in a ski jump in Switzerland, then that is all there is to it. The angle of attack in this case is zero ! However, the carrier will be moving into the wind while launching aircraft, and so there is a relative wind. Now since the carrier is moving into the wind, there will be an angle of attack. It is easy to calculate that from 10th grade vector algebra, assuming the carrier is going at 25 knots, the aircraft is launched at 175 knots at a 15deg angle (the apparent wind will look like it is coming from below the carrier on to the wings of the plane, the angle at which it comes AoA is the angle between the flight vector and apparent wind vector).

[Indranil]

I dwelled in this too Hakeem. Theoretically, it is arc-tan(vertical speed of the plane/horizontal speed of the ship). In practice, it changes very quickly. When the nose wheel leaves the ramp, the normal force on the MLG creates a pitch down decreasing AoA. The plane then encounters air flowing around the ski jump. This air is actually moving up, just like the leading edge of a wing. Here AoA increases sharply. As the plane, continues to fly higher it leaves the ground effect, and pitches down again.

P.S. This post is redundant to the above post.

[Indranil]

Vina,

You and me are on the same page except you feel that even if we can leave the ramp at slower speed using TVC to augment pitch authority, the plane would be susceptible to insufficient authority in roll. I had written exactly this before: we can lower the ramp exit speed from the current speeds at which we have sufficient pitch authority using conventional surfaces to the speed at which we have sufficient roll authority using conventional surfaces. The latter is lower by 10-15 knots.

[vina]

Ok. What is the take off run lengths for 1) Vikramaditya and 2) Vikrant.

I notice that the VikAd has two take off run lengths , one a "short one" and another a "long one". Same I would suppose is true for Vikrant. what are both the lengths for both the ships.

If we have a good handle of the t.o run length, we can calculate what the payloads at the extreme corners of take off conditions are for the N. LCA and see if it made sense for the IN to reject the current config.

My guess was 100m and 175m for the VikAd. Also does anyone have an idea of exactly what the wt. difference between the LCA MK1 and the N-LCA Mk1 is. I took it as 1.5 tons. Is that in the ball park ?

[geeth]

My understanding about ski ramp is that the aircraft leaving the flight deck quickly gains altitude by converting part of the kinetic energy to petential energy. This is very helpful at the crucial point when the craft leaves the deck, because:
1) in a normal flight deck, the height of flight deck is only few metres above sea and hence no reaction time if things go wrong
2) Part of the thrust in a skijump assisted flight is converted to assist lift due to change in attitude of the aircraft at the fag end of the runway. This helps in keeping the deflections of flaps and other lift enhancement control surfaces to a minimum - therby helps in keeping drag on the runup to a minimum and increase in speed.

Thrust vectoring will not have any appreciable effect as long as the aircraft wheels are touching the deck

[sankum]

As per IN RFI for INS Viramaditya(inferred) it is 13 degree skijump with restraining gear launch distance @125m, 190m and 195m while for INS Vikrant it is 14 degree skijump with launch distance at 144m, 203m and 213m.

As per AI2017 reports in this forum NLCAmk1 is 800Kg heavier than LCAmk1 so can be taken at 7.3T empty weight and clean weight at 10.6 T with full internal fuel of 2.5T and 2 CCM. If max MTOW from carrier is 13T then we have 2.4Tpayload and if it is 13.5T like LCA mk1 then the payload is 2.9T from carrier.

Production standard NP5 trainer and fighter NP6 and NP7 are planned of mk1 class.

While NLCAmk2 will feature only single seater fighter and Trainers will come from NLCA mk1 line.

[vina]

we can lower the ramp exit speed from the current speeds at which we have sufficient pitch authority using conventional surfaces to the speed at which we have sufficient roll authority using conventional surfaces. The latter is lower by 10-15 knots.

Ok. If you have any wind tunnel studies or anything else on that do share. I have no idea about which starts working first, ailerons or elevators. In any case, even in stalls etc, the rudder is always active and available.

[Indranil]

Thrust vectoring will not have any appreciable effect as long as the aircraft wheels are touching the deck

There is no question of thrust vectoring before the NLG exits the ramp.

[Indranil]

we can lower the ramp exit speed from the current speeds at which we have sufficient pitch authority using conventional surfaces to the speed at which we have sufficient roll authority using conventional surfaces. The latter is lower by 10-15 knots.

Ok. If you have any wind tunnel studies or anything else on that do share. I have no idea about which starts working first, ailerons or elevators. In any case, even in stalls etc, the rudder is always active and available.

I don't know about LCA but I would not expect it to be different from the typical (especially given its large ailerons). During take off, typically yaw kicks in first (reason why many smaller aircrafts don't even have steerable nose wheel), followed by roll and pitch. Although pitching moment is present, it is not strong enough to maintain the AoA for take off. For that the plane has to reach "rotate" speed V-r, which you know is very close to take off speed. Until then the elevator is actually used to push the nosewheel into the ground for a safe and efficient ground roll.

[Indranil]

Currently, the NLCA Mk1 can take off with 725 ltr tanks + 2 WVR missiles. They are trying to push it to be able to carry 2 more BVR missiles. NLCA is expected to take much more.

[vina]

As per IN RFI for INS Viramaditya(inferred) it is 13 degree skijump with restraining gear launch distance @125m, 190m and 195m while for INS Vikrant it is 14 degree skijump with launch distance at 144m, 203m and 213m.

As per AI2017 reports in this forum NLCAmk1 is 800Kg heavier than LCAmk1 so can be taken at 7.3T empty weight and clean weight at 10.6 T with full internal fuel of 2.5T and 2 CCM. If max MTOW from carrier is 13T then we have 2.4Tpayload and if it is 13.5T like LCA mk1 then the payload is 2.9T from carrier.

Excellent. Now , I plugged in the numbers for that into my spread sheet. I derated the LCA's thrust by 5% instead of the 10% earlier (which I think was excessive).

But let us look at the bare minimum , I think the N-LCA must carry .

Air to Air -> 2* 1000 kg drop tanks, 2* CCM, 2* AAM, SPJ pod. --> Approx 2000 + 300 + 500 + 150 = approx 3T in Air defence
Strike -> 2* 1000 kg drop tanks, 2* CMM, 1*LDP, 1*SPJ ,2*AAM --> Approx 3T + 750KG class anti ship (Harpoon/Exocet) or 2*500Kg bombs --> Apporx 3.75t to 4 ton in strike

Let us look at VikAd first.

For 195m t.o run , the MTOW is 13 tons (with the 100KCAS as the ramp exit speed and the ship putting out 25kts ~ 23.5kCAS). The payload will be 2.84tons .. Not good enough in even A2A role.

Now for Vikrant
For 203 m t.o run , the MTOW is 13.6 tons (with the 100KCAS as the ramp exit speed and the ship putting out 25kts ~ 23.5kCAS). The payload will be 3.77tons .. Good enough in A2A role only.

For 213 m t.o run , the MTOW is 14.4 tons (with the 100KCAS as the ramp exit speed and the ship putting out 25kts ~ 23.5kCAS). The payload will be 3.77tons .. Good in A2A role AND strike, both anti shipping and land.

Now let us look at Mig29K with the VikAd
With the MTOW of the Mig29K and the installed thrust (derated by 5%) from Wiki, plugging in the values for the 190m take off run (with carrier 23.5 kCAS), we find the ramp exit speed is 104 KCAS! This is exactly similar to the numbers we saw for the LCA in the presentation.
However, the Mig29 in this case is carrying 5.5 tons of fuel and 6 tons of payload. A pretty potent package.

It is obvious from the numbers that the N-LCA (as is, with 100kCAS ramp exit) is of little utility in the VikAd. For the Vikrant, it is fully useable in the A2A and strike role. However the Mig29K offers far greater capability (as it obviously will, it is a bigger plane and can carry bigger payload to a longer distance) and has the installed thrust to take off even from the VikAd.

So the Navy's decision on the N-LCA Mk1 makes a lot of sense.

What lets the NLCA MK-1 as-is, down is the following. The full 90KN thrust is NOT available on the deck. If the 90KN was available, then the MTOW on the VikAd is 13.7Tons and the payload is 4Tons and it would have been FULLY useable in both A2A and Strike.

In addition, the VikAd itself is a piece of garbage. It is 20 m longer than the Vikrant, but has a t.o run that is actually 20 m shorter. It is an EXCUSE of an aircraft carrier. It was not designed as one, and the conversion to a VikAd from Adm. Gorshkov has kept the bulk of it's short comings in place. It is something that should NEVER have been acquired. We would have been indeed better off in acquiring the Varyag hull like the Chinese did and refurbishing it, by the Russians if need be .

The one-two punch of shortfall in installed thrust and the sub optimal rubbish of VikAd lets the NLCA MK-1 down in it's present form.

However, IF they manage to bring the ramp exit speed to 95 KCAS from the current 100 odd KCAS , a difference of just 5 to 7 kCAS, the NLCA Mk1 becomes fully useable in both A2A and strike, on the VikAd with MTOW of 14 tons.

Oh, btw, the 125m t.o run for the VikAd and the 144m run on the Vikrant is a JOKE . Plugging in the numbers for the Mig29K ,for the 125m T.O, the MTOW is 15.4 Tons. Now the loaded wt of the Mig 29K is 18.5 tons. That means that the Mig 29K on the 125m run is taking off from with 3 TONS less than usual 5.5 tons and is carrying just 2.5tons of fuel and no allowance for ANY weapons.

And looking at it more broadly, the joke becomes even more obvious. The CATs on the US carriers are roughly 300 ft long which is approx 100m. Now in 100m, a CAT , throws out a F18 (E/F) @ approx 165kts . Now , a similar sized and loaded plane with similar powering to reach 100 knots its on it's own power is impossible. (the 144m run, will see a MTOW of 18tons, which means the fully fuelled up Mig 29 can't take off!).

The best hope is if the aero and controls guys do some magic and can get the launch exit speed close to 90 KCAS or thereabouts, the LCA MK1 will be in full play in the VikAd and the Vikrant. The LCA Mk2 will of course bring far greater capability to the table and is probably well worth it.

[Indranil]

I can say this for sure. Navy understands that without LCA Navy Mk1, there would be no naval fighter of Indian design. It is not without reason that they are funding more the 25% of LCA Mk1 and Mk2 designs.

And I will say one more thing, Mao sir is a godsend. A pragmatic guy who knows how to lead from the front.

[Neshant]

If India does go with EMALS or something equivalent, can the existing carriers be retrofitted with it or will that be a major re-engineering effort?

There is no point in having just one carrier with EMALS and the other not.

Ideally planes from all carriers need to be able to takeoff & land on each other's decks to promote commonality and cost reduction.

Otherwise yet another assortment of planes will be purchased in an ad-hoc manner due to incompetent planning.

One more question :

These back blast plates shown below, do they offer any benefit to planes taking off or are only to prevent flying debris from hitting objects and personnel onboard.

[Neshant]

I can say this for sure. Navy understands that without LCA Navy Mk1, there would be no naval fighter of Indian design. It is not without reason that they are funding more the 25% of LCA Mk1 and Mk2 designs.

I am willing to bet the IN will not induct MK2 even if it developed to their specs.

There are too many short comings for single engined aircrafts to be used on carriers, especially for strike roles.

1) Once loaded, single engine plane maneuverability is greatly reduced compared to twin engine planes.

2) They are typically smaller and have limited ranges, cannot loiter or patrol for long.

3) Unless lightly loaded, they are slower and cannot intercept fast moving inbound intruders to defend the fleet.

4) They cannot take off with a load of significance.

5) Short landings on one engine at low speed with a heavy load can be hazardous.

6) Flying with one engine over the vast ocean is a potential hazard.



Single engine aircraft only make sense on land.

1) They are cheaper to build & deploy in great numbers. Its primary purpose is to over-whelm the enemy with sheer numbers.

2) They can be used to do the grunt work of CAP or bombing enemy ground forces. It frees up the top line aircraft for air-to-air and deep strikes.

3) They are cheaper to maintain, have fewer parts and don't guzzle fuel in peace time. They consume a lot less of the budget.

None of the above 3 conditions are relevant for planes on carriers at sea. Only a limited number of planes can be deployed on a carrier and due to circumstances, they have to be the best & most sophisticated twin engine planes money can buy. There is no concept of over-whelming the enemy with massive number of single engine medium tech planes by launching them off a carrier because there is no space for such planes.

The era of single engine planes on a carrier will come to an end. Battles at sea will be between top of the line twin engine planes in the early 21st century.

Now sure as hell someone will post a picture of the F-35 with 1 engine which is totally irrelevant to the issues above. That plane has an incredibly powerful single engine and is not in the category of the Tejas which is a low cost, medium tech, light fighter.

[shiv]

1) Once loaded, single engine plane maneuverability is greatly reduced compared to twin engine planes.

The twin engine Jaguar can hardly manoeuvre. But the MiG 21 and F-16 retain agility though single engined. Manoeuvrability is not about the number of engines.

2) They are typically smaller and have limited ranges, cannot loiter or patrol for long.

Patrols are for slow/low flying patrol aircraft not supersonic fighters

3) Unless lightly loaded, they are slower and cannot intercept fast moving inbound intruders to defend the fleet.

Light single engined fighters were designed to be fast to intercept fast moving targets

4) They cannot take off with a load of significance.

A statement of no significance

5) Short landings on one engine at low speed with a heavy load can be hazardous.

Loads are jettisoned before landing even in twin engined aircraft

6) Flying with one engine over the vast ocean is a potential hazard.

That is why SeaHawk, SkyHawk, Grumman Panther, Etendard and A-7 Corsair were all land based fighters.
The Etendard served alongside Rafales and retired only in 2016


Single engine fighters consume less fuel and have less engine maintenance overhead, need to house fewer personnel on board and the carrier can send them on more missions for a given amount of resources on board. And also carry more fighters

[Indranil]

I can say this for sure. Navy understands that without LCA Navy Mk1, there would be no naval fighter of Indian design. It is not without reason that they are funding more the 25% of LCA Mk1 and Mk2 designs.

I am willing to bet the IN will not induct MK2 even if it developed to their specs.

I don't even know why they funded LCA Navy Mk1 in spite of the great reasons that you mention. What were they even thinking? Thankfully, they have now reached your level of wisdom and will not induct Mk2.

[Dileep]

Nice calculations Vina. So, between 203m and 213m is 0.8 ton, so 0.08ton per metre at this range.

Now, the question is.. how do you determine the effective TO run length? Is it nose to nose, or tail to tail? In other words, when do we want pitch authority? The moment the nose wheel leaves the ramp? Or, the moment MLG leaves the ramp? Or a couple of seconds later? You are moving at 50m/s at the end of the TO run, which means an extra second gives you 50M extra effective TO length, which actually solves the MTOW problem.

The point is.. cutting such fine levels by guesstimating wouldn't work.

[srai]

For heavy loads, the planes need to take off with less fuel and then top-up in air with buddy AAR.

[chetak]

I am willing to bet the IN will not induct MK2 even if it developed to their specs.

I don't even know why they funded LCA Navy Mk1 in spite of the great reasons that you mention. What were they even thinking? Thankfully, they have now reached your level of wisdom and will not induct Mk2.

They also funded the ALH when funds were scarce or not forthcoming. They did not get much returns there either but nevertheless, they persisted and went ahead.