PLAN Aircraft Carrier programme...(Closed)

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Jeff Head

General
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edit: are nimitz class carriers able to launch two jets from their bow catapults simultaneously, or is it common practise? A quick google search with relevant key words don't give me any pictures. I'm aware that simultaneous launch from a waist and bow catauplt are common, but more often than not it seems either one bow cat is either used for parking, or if both cats are used for launching, the launches seem to be staggered.

This is the closest picture I've found; a staggered launch. I imagine of both bow cats launched at the same time simultaneously, the two jets would crash into each other shortly after launch, or at the very least they would be unacceptably close to each other and be very dangerous. And of course this doesn't include the launch of an E-2 with a jet in close proximity given the greater wingspan of an E-2.
Perhaps there is a misunderstanding.

My point was not at all that the two cats on the bow would shoot aircraft off together. They do not.

My point was that two cat operations from the bow are possible while simultaneously recovering aircraft.

Of course they stagger the launches. But with two, and a staggered launch, you can put more planes in the air in a quicker time frame than with one.

That's all. Hope this clarification helps.

Sometimes I take things for granted.
 

Jeff Head

General
Registered Member
The bonus of the use of a ski ramp is that you use less deck real estate.
In terms of operations...this is not a positive condition.

You have real estate along the forward part of the bow (on both sides) where no planes can be spotted when using a ski ramp, limiting the number of planes capable of being spotted on the deck for any large air operation.

When using one of the launch spots, you have very little space on the other side for spotting aircraft, where as with two cats forward and a flat deck, you have significant space.

Having that much less space for spotting is a negative, not a positive when it comes to air operations, and this further limits what such a carrier can do.

Do nto get me wrong. The Liaoning and the Kuznetsov are good carriers and represent a HUGE increase in capability over not having a carrier, or over something like a Kiev. but they are still inherently limited when compared to a Nimitz class.
 
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delft

Brigadier
Oh boy, another round of "extrapolating", and arguing for the validity of your "extrapolations".

I have however "proven your theory" by flying a low powered aircraft off of a hill/rise on a grass airstrip on a farm. As the aircraft leaves the hill without sufficient energy to fly away, you must increase the angle of attack in order to prevent an accident, as you apply aft stick?? you increase drag as you increase your angle of attack and the aircraft will most likely settle back onto the runway, having much less energy than it did when it departed the rise???, this will lengthen the take off run?

If on the other hand, your are already 50ft in the air as you depart the ramp, in an aircraft with sufficient thrust, you are able to "slightly reduce" that angle of attack to decrease that drag and allow the aircraft to accelerate to "flying speed", whereby you then "fly-away"?

operating safely off the ramp is enabled by the "Flankers" sufficient lift and excess thrust, you most likely will have to lower the weight of the aircraft, and leave below max gross in order to "fly away" with a sufficient margin to allow for losing an engine on the ramp?

as weight goes up, your "margin" goes away??
As for every take off you calculate what in the given circumstances is safe procedure to be used, for you the centre of gravity, V1, VR, V2 &c. ( Sorry, no V1 for a single engine aircraft ). For a cat it will be the speed to be reached at the end of the track. For a fighter bomber being launched from a flattop when an engine fails it might mean dropping your external ordnance as soon as you are clear of the ship. As you probably can't bring that ordnance home anyway that is not a great sacrifice.
 

delft

Brigadier
In terms of operations...this is not a positive condition.

You have real estate along the forward part of the bow (on both sides) where no planes can be spotted when using a ski ramp, limiting the number of planes capable of being spotted on the deck for any large air operation.

When using one of the launch spots, you have very little space on the other side for spotting aircraft, where as with two cats forward and a flat deck, you have significant space.

Having that much less space for spotting is a negative, not a positive when to comes to air operations, and this further limits what such a carrier can do.

Do nto get me wrong. The Liaoning and the Kuznetsov are good carriers and represent a HUGE increase in capability over not having a carrier, or over something like a Kiev. but they are still inherently limited when compared to a Nimitz class.
They are smaller ships and carry fewer aircraft. It, as always, is a matter of compromises.
 

Jeff Head

General
Registered Member
It needs to be pointed out, that when an aircraft is launched off a cat, the engine is not idle. They bring it up to full military thrust, so you get the energy imparted by the cat plus the energy being imparted by the engine.

US Navy aircraft are designed to be able to launch and recover in the event of a failure of one engine.

Now, with aircraft like the A-4, the F-8, and the A-7, where there was only one engine...of course you went into the drink if that engines completely failed. But this would also be the case with a single engine aircraft off of a ski jump


A ski-jump is an instrument that nations have used to provide an option when not having a catapult. Any nation that can...and who plans to have any type of large carrier force...will almost invariable gravitate to catapults because of the advantages they bring.

Clearly, the UK decided not to...but they are only building two carriers...and IMHO, they made a serious mistake in not providing catapults for those two large carriers when they most certainly could have. They admin at the time played politics with them...and when it comes to a fifty year plus national defense asset, IMHO, all of that should have been put aside and allowed the design to be maximized for national defense.

The F-35B is a GREAT aircraft, but IMHO, it is well suited for the Marines who need very limited numbers to use for CAS for Marines off of and LHD/A. Not for a large air wing off a large full deck carrier. By not going with cats, they limited several things:

1) Had to use a shorter range, less capable F-35B VTOL aircraft
2) No fixed wing AEW&C (this is also a MAJOR deficiency)
3) Less volume for any high tempo operations
4) Less space for spotting than they would otherwise have had.

I believe the Chinese recognize all of these things. I believe that once they build their own improved version fo the Liaoning, they they will repaidly move to having CATOBAR carriers.

Time will tell.
 

Air Force Brat

Brigadier
Super Moderator
It needs to be pointed out, that when an aircraft is launched off a cat, the engine is not idle. They bring it up to full military thrust, so you get the energy imparted by the cat plus the energy being imparted by the engine.

US Navy aircraft are designed to be able to launch and recover in the event of a failure of one engine.

Now, with aircraft like the A-4, the F-8, and the A-7, where there was only one engine...of course you went into the drink if that engines completely failed. But this would also be the case with a single engine aircraft off of a ski jump


A ski-jump is an instrument that nations have used to provide an option when not having a catapult. Any nation that can...and who plans to have any type of large carrier force...will almost invariable gravitate to catapults because of the advantages they bring.

Clearly, the UK decided not to...but they are only building two carriers...and IMHO, they made a serious mistake in not providing catapults for those two large carriers when they most certainly could have. They admin at the time played politics with them...and when it comes to a fifty year plus national defense asset, IMHO, all of that should have been put aside and allowed the design to be maximized for national defense.

The F-35B is a GREAT aircraft, but IMHO, it is well suited for the Marines who need very limited numbers to use for CAS for Marines off of and LHD/A. Not for a large air wing off a large full deck carrier. By not going with cats, they limited several things:

1) Had to use a shorter range, less capable F-35B VTOL aircraft
2) No fixed wing AEW&C (this is also a MAJOR deficiency)
3) Less volume for any high tempo operations
4) Less space for spotting than they would otherwise have had.

I believe the Chinese recognize all of these things. I believe that once they build their own improved version fo the Liaoning, they they will repaidly move to having CATOBAR carriers.

Time will tell.

Exactly, only when you have an abundance, should you begin to search for "efficiencies".

That single engine aircraft off the cat will be flying for possibly 20 to 30 seconds even after engine failure, that aircraft off the ramp will NOT be flying for that 20 to 30 seconds, those are precious moments to save your life.
 

kwaigonegin

Colonel
Common sense is not an imposter...it just does not necessarily apply in this example.

Clearly, the Chinese have shown that they can do both form the Liaoning as your picture attests.

Why?

Because the launch area forward on the port side does not extend far enough back into the landing area to prevent it.

Just the same, I would not recommend it for any high volume air ops requiring simultaneous launch from the two positions forward (particularly the port side) and recovery

Kwaig, you have been in flight ops on US carriers...what do you think of that photo?

Popeye?

I think you're right. To be honest that photo doesn't tell me much other than a landing. Unless there is a video instead of a just single frame there is no way to tell what the flanker on the right is doing. Is it being ready for launch or just there? is it truly in the spot where launch is or is it much further forward? hard to tell on that pic.

I do know that it is NOT ready immediate launch with all those folks around it and the deflectors in down position.
 

Engineer

Major
delft, this is getting absurd. To argue a ski ramp added to a CATOBAR carrier is better is like arguing a crutch helps a person walk better, when the person can walk fine without the crutch and even run! One doesn't go cripple the person purposely as a proof that the crutch is better.

Wouldn't Chine be better served by more smaller ships that were just as efficient as the USN behemoths?
Big carrier or small carrier, it requires similar crew size to run. With smaller ship, less aircraft can be carried, so it is actually less efficient.

You make the cats as short as possible, and don't sacrifice deck real estate unnecessary, by going to the highest acceleration the pilots can routinely accept and you don't go to an even higher acceleration.
When using cats with the ski ramp there won't be a third launch position.
To get two launch positions, simply install two catapults only. There is no need for an additional ramp just to install two catapults. See Charles de Gaulle carrier.

The bonus of the use of a ski ramp is that you use less deck real estate...
It is the other way around. Ski ramp takes up real estate, catapult takes none. Aircraft can be parked right on top of an unused catapult, but none can be parked on the ski ramp even with just one launch position being used.

the energy storage for the cats can be smaller just as the cats themselves...
No, because of Laws of Conservation of energy. With or without catapult, an aircraft must require a minimum speed for flight, and that speed is determined by the amount of acceleration, which is determined by the combined energy input of the plane's engines and catapults. One way or another, the same amount of energy is needed. Now, the whole purpose of a catapult is to provide that energy externally. It is unreasonable to argue the other way is better, just because you purposely shut off the output of the catapult to a trickle.

and you get a ship that is as efficient as a super carrier but at two third of the size and so at two third of the efficacy. The price might also be at two third of that of a super carrier. The main advantage would be that China gets more aircraft carriers in the same time frame and for roughly the save price to learn to use them.
A smaller ship will not be as efficient, because larger size has benefits of economy of scale. A smaller ship will not result in cheaper price tag, because there are R&D and maintenance costs, not just building cost.
 
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delft

Brigadier
Exactly, only when you have an abundance, should you begin to search for "efficiencies".

That single engine aircraft off the cat will be flying for possibly 20 to 30 seconds even after engine failure, that aircraft off the ramp will NOT be flying for that 20 to 30 seconds, those are precious moments to save your life.
Still the British, the US Marines and several other services use(d) Harriers.
 

kwaigonegin

Colonel
I think you're right. To be honest that photo doesn't tell me much other than a landing. Unless there is a video instead of a just single frame there is no way to tell what the flanker on the right is doing. Is it being ready for launch or just there? is it truly in the spot where launch is or is it much further forward? hard to tell on that pic.

I do know that it is NOT ready immediate launch with all those folks around it and the deflectors in down position.

Get me a trap AND a blast deflector raise at the same time then I'll be convince.
delft, this is getting absurd. To argue a ski ramp added to a CATOBAR carrier is better is like arguing a crutch helps a person walk better, when the person can walk fine without the crutch and even run! One doesn't go cripple the person purposely as a proof that the crutch is better.


Big carrier or small carrier, it requires similar crew size to run. With smaller ship, less aircraft can be carried, so it is actually less efficient.


To get two launch positions, simply install two catapults only. There is no need for an additional ramp just to install two catapults. See Charles de Gaulle carrier.


It is the other way around. Ski ramp takes up real estate, catapult takes none. Aircraft can be parked right on top of an unused catapult, but none can be parked on the ski ramp even with just one launch position being used.


No, because of Laws of Conservation of energy. With or without catapult, an aircraft must require a minimum speed for flight, and that speed is determined by the amount of acceleration, which is determined by the combined energy input of the plane's engines and catapults. One way or another, the same amount of energy is needed.


A smaller ship will not be as efficient, because larger size has benefits of economy of scale. A smaller ship will not result in cheaper price tag, because there are R&D and maintenance costs, not just building cost.

I see a lot of confusion here people! For the most part Engineer is actually right in this case. As to the size of a carrier (and I believe I've touch on this many hundreds of post ago) the Nimitz class size is the 'optimum' carrier size give or take a few tons and a few feet :)

As much as I like to say they are giants of the seas, the truth is CVNs are far from the biggest ships in the world. Many civilian classes of ships like cargo haulers, tankers even the darn cruise ships are FAR FAR larger than aircraft carriers. The size of the carrier IMHO is the 'optimum' size in terms of effectiveness, practicality and functionaility.

When you built a carrier you take a million things into consideration. Other than the obvious like costs (capital and operating), manpower,, need etc you also have to take into consideration things like practicality.

Can she transit the Suez? Can she dock in most ports? How many minutes does it takes to walk from one end to the other? how many stairs u gotta climb to go from engine room for chow? The sizing of USN carriers and the components of her airwing are deliberately optimized for most operations while still maintaining an optimum balance in crew sustainability, maintenance and effectiveness.

People much much smarter than me have determined long time ago that a nice mixture of approx 60-80 aircraft is enough to neutralized most threats the USN may face. Anything far greater will have a diminishing return because it would be global in scale and have since gone past the 'air battle' portion.

I guess what I'm trying to say is ASSUMING cost is NOT a factor, it still doesn't make a lot of sense to build a 1 million ton carrier that's a mile long, carries 400 birds etc because it's just impractical as heck from a maintenance, support etc standpoint.

How are you going to do unrep for a carrier a mile long with a complement of 25,000? Do you need to park 5 or 6 AOEs next to it? It's dangerous and would take a day to replenish LOL.

As to carriers smaller than the CNVs? well obviously the same reasons apply but in the other direction. Most is not all countries do not need to have the 'optimum' mixture simply because their threat environment is very very different. Their operating environment is different and certainly their support environment is very different.

China WILL have CVNs or at least CVs with the 50-80 airwing because that IS the optimal balance. They will have it for the same exact reasons why USN has them. Optimum balance or size, power projection and practicality. Since carriers have very very long lifespan, any new class of CVs or CVNs China put into sea tomorrow will likely be sailing close to the end of the century and China being known for their long term planning will most definitely consider that variable. Will PLAN be a true blue water global Navy in 2100? or even 2075? Every single naval asset they put into place in the next 10-20 years will have to consider that eventuality.

PLAN is in a VERY unique position (and probably India as well) because there are very very few navies in the world that has to plan (no pun intended) for that eventuality. 99% of the navies in this world only need to maintain status quo. PLAN has no choice BUT to plan for the eventuality of becoming a true global navy like what the USN is today if China is to maintain their economic growth, trade routes and global influence in different continents far away.
 
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