STOBAR aircraft Ski-jump performance (SU-33/J-15)

Continued....

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^^^Also talking about taking off with one engine (now you see the importance of a twin engine carrier plane)

Su-33 cannot take-off from any possible position with one engine under no headwind. At 25 knots, from the longest 195m take-off position 3, it may be possible if:

under 22300kg there will be no dip in take-off profile.

22300-23500kg there will be dip, but plane can pull up naturally before minimum safety height of 20m.

About crew Training:

1. Pilot needs about 50 take-off and landing experience on the carrier to complete the last stage of flight training.

Elementary flight crew training starts under the conditions listed for single engine take-offs (NOT that they take-off with one engine (!), but that they start from take-off position 3 and with 25 knot headwind available)

First 10 flights - TOW within 22300kg, 25 knot headwind, no external weapons load. 3500kg fuel, of which 2500kg can be used to simulate a 55min 800km flight, or one take off, 4 approach towards airspace around the carrier, 4 touch and goes, and one arrested landing.

Above needs to be repeated 10 times before progression to other tasks.

2. Normal operations

All onboard personelle needs to participate in this exercise. Plane needs to have over-capacity to take-off under one engine. various take-off position training with various load weight. But take-off is not allowed under no wind from the first two take-off positions. At 25 knots headwind TOW at position 1,2 is limited to under 28100kg. (Russia navy limits at 28000kg). From 3rd take-off position at 0 knots headwind TOW also limits to below 28000kg. With 25 knots headwind there is no weight limit from position 3.

3. Emergency take-off from position 3 (I suspect this is to rapidly respond to serious air threats)

Only used under wartime situation, when training need approval from flight bridge officer (<-any idea the proper title?). Sill operates under single engine take-off overcapcity assumptions, but relaxes the take-off profile to allow for dip in altitude. Taking off from position 1,2 under 0 knots headwind, TOW is limited to 22700kg, 25 knots, under 30000kg.


==end==
 

Bltizo

Moderator
Staff member
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  • #12
Completely not agree, i don' t know where you catch these files... and all experts say ONLY CATOBAR aircrafts carriers allow fighters to get a full weapons load, you can see video the speed, much more low with CATOBAR no doubt and Jeff have confirmed many times and i have also see sailors confirmed again it during interview.

An Su-33 or J-15 is limited to about half payload or eventualy less fuel.

Expert for naval matters...
Yes, I do believe that the commonly circulated notions of ski jumps unable to launch heavily loaded fighters is possibly inaccurate or at least overly simplistic, because they do not consider the important factor of over deck headwind.

The numbers for Su-33s take off weights are also said to correspond with numbers from aviation journalists like Yefim Gordon, as well as Andrei Fomin, in their respective books on the Su-27 development and on the Su-33.


I believe what catapults offer is the ability to more reliably launch heavily loaded fighters under a variety of conditions (including minimal head wind) as well as if a fighter's engine fails during a launch, thus making a catapult safer and more flexible in launching fighters compared to ski jumps.
Catapults also of course are the only reliable way to launch aircraft like fixed wing AEWC, which a ski jump likely cannot do.
Catapults therefore offer a far greater margin for safety and flexibility when launching heavily loaded planes than ski jumps, but that does not mean ski jumps cannot inherently launch heavily loaded planes -- they just need the sufficient ampu

So yes, I believe the discussion around ski jumps and fighter take off weights has been significantly dumbed down, not only in the sphere of defence media but also in the sphere of defence experts.
 
Yes, I do believe that the commonly circulated notions of ski jumps unable to launch heavily loaded fighters is possibly inaccurate or at least overly simplistic, because they do not consider the important factor of over deck headwind.

The numbers for Su-33s take off weights are also said to correspond with numbers from aviation journalists like Yefim Gordon, as well as Andrei Fomin, in their respective books on the Su-27 development and on the Su-33.


I believe what catapults offer is the ability to more reliably launch heavily loaded fighters under a variety of conditions (including minimal head wind) as well as if a fighter's engine fails during a launch, thus making a catapult safer and more flexible in launching fighters compared to ski jumps.
Catapults also of course are the only reliable way to launch aircraft like fixed wing AEWC, which a ski jump likely cannot do.
Catapults therefore offer a far greater margin for safety and flexibility when launching heavily loaded planes than ski jumps, but that does not mean ski jumps cannot inherently launch heavily loaded planes -- they just need the sufficient ampu

So yes, I believe the discussion around ski jumps and fighter take off weights has been significantly dumbed down, not only in the sphere of defence media but also in the sphere of defence experts.
There was an extremely well developed discussion about take-off weights and fuel load outs early on involving the Liaoning, and the J-15. This discussion was never "dumbed down", and I believe most of us agreed the J-15 would likely operate off the ramp with a modest load of AAM and likely about 1/2 fuel, hence the need for J-15 tankers to launch and "top up" fighters that might see actual combat, and extended Combat Air Patrol hours due to "alert status"!

the carrier always launches aircraft into the wind, and carrier speed is factored into "every departure", don't take my word for it, check it out? Every departure calculates wind speed over the deck?? to state that it was not "factored in" is simply "naïve".
 

Bltizo

Moderator
Staff member
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  • #14
There was an extremely well developed discussion about take-off weights and fuel load outs early on involving the Liaoning, and the J-15. This discussion was never "dumbed down", and I believe most of us agreed the J-15 would likely operate off the ramp with a modest load of AAM and likely about 1/2 fuel, hence the need for J-15 tankers to launch and "top up" fighters that might see actual combat, and extended Combat Air Patrol hours due to "alert status"!
I disagree, I believe the discussion most definitely has been dumbed down, especially by defence media.
All the discussion about Liaoning and take off weights and fighters taking off from ski jumps in general have been made with the immediate assumption that they simply could not do so, and all of the citations seem to be from various defence media articles who do not have studies or reports of their own to back it up.

And over my years on this forum I have not seen any in depth discussion presenting any studies or reports about the supposed inability of fighters to take off from a ski jump with heavy loads.

The argument, as I've seen over the years, generally boils down to:
-We've never seen Su-33s or J-15s or Mig-29Ks take off from the ski jump with heavy loads, and
-"Everyone" knows fighters cannot take off from ski jumps with heavy loads
But no one's shown any actual studies of how fighters actually can take off from ski jumps, it's all about the lack of photo or video evidence, and how it's a seemingly universally accepted fact that is beyond challenge.


However, in this thread I have shown some documents which I believe support the notion that fighters can take off with heavy loads from ski jump, depending on the over the deck headwind, and there are substantive reports from Russian military aviation reporters and followers who state that aircraft like Su-33 are able to take off with MTOW or near MTOW from their ski jump.


the carrier always launches aircraft into the wind, and carrier speed is factored into "every departure", don't take my word for it, check it out? Every departure calculates wind speed over the deck?? to state that it was not "factored in" is simply "naïve".
Let's put it this way, if defence media did factor it in, then I think they've factored it in incorrectly.
 

FORBIN

Lieutenant General
Registered Member
the carrier always launches aircraft into the wind, and carrier speed is factored into "every departure", don't take my word for it, check it out? Every departure calculates wind speed over the deck?? to state that it was not "factored in" is simply "naïve".
Obviously ... all aircraft carriers use wind CATOBAR or not to create a relative wind on the flight deck and favorised air operations.
 
There was an extremely well developed discussion about take-off weights and fuel load outs early on involving the Liaoning, and the J-15. This discussion was never "dumbed down", and I believe most of us agreed the J-15 would likely operate off the ramp with a modest load of AAM and likely about 1/2 fuel, hence the need for J-15 tankers to launch and "top up" fighters that might see actual combat, and extended Combat Air Patrol hours due to "alert status"!

the carrier always launches aircraft into the wind, and carrier speed is factored into "every departure", don't take my word for it, check it out? Every departure calculates wind speed over the deck?? to state that it was not "factored in" is simply "naïve".
It honestly appears that the Admiral Kuz has proven this statement and Master Forbin's statement to be the more accurate statements about the very real limitations of the Admiral Kuznetsov to launch The SU-33 and the Liaoning the J-15, with a modest load-out of air to air missiles and about 1/2 fuel. Since the Carrier should be capable of steaming 20 to 25 Knts everyday, any prevailing wind in addition to that 25 knts, would figure to the good.

For the carrier to reduce speed much below 25 knts would be figured to the bad.

In other words, aircraft launches are calculated at the normal max cruise of the Kuznetsov, while a catapult might be capable of launching an aircraft at gross weight with the ship underway at say 5 to 10 knots, that will never be willingly done on a carrier with a "ski ramp", it is just "too dangerous", even at lighter weights, and would be impossible at gross weight, there's really no doubt about that, look at the daily launch practices of the Russians, and Chinese,,, I'v yet to see a Flanker launch with a high gross weight weapons load off either ship??? and if you find one with lots of hardpoints full??? I would wager that aircraft is launching with minimal fuel for a local "sortie", not a full combat load-out.
 

delft

Brigadier
The way to solve this problem is to simulate take off by a chosen aircraft at several take off weights in a computer taking account of engine failure and the dropping of all external loads after clearing the ski ramp in that case. I have done this for a civil aircraft pre-design accounting for all FAA regulations some thirty years ago. You need to have approximate aircraft and engine characteristics.
 

SamuraiBlue

Captain
The way to solve this problem is to simulate take off by a chosen aircraft at several take off weights in a computer taking account of engine failure and the dropping of all external loads after clearing the ski ramp in that case. I have done this for a civil aircraft pre-design accounting for all FAA regulations some thirty years ago. You need to have approximate aircraft and engine characteristics.
Or try it with actual planes,,,,although the pilots would probably not agree with that kind of testing.LoL
 

delft

Brigadier
On another country's flattops, from Marine Forum Daily News:
02 December

INDIA

Navy Chief Adm Lanba: indigenous Tejas Light Combat Aircraft (LCA) "not up to the mark yet" for carrier operations (too heavy, no take-off with full weapons load) ... while still „encouraging DRDO to further develop it, will seek a fighter aircraft from elsewhere ... within the next five years“
(rmks: French Rafale come to mind)
Would Rafale be able to take off with a full weapons load from Vikramaditya, which is smaller than Liaoning? :rolleyes:
 

schenkus

Junior Member
Registered Member
On another country's flattops, from Marine Forum Daily News:

Would Rafale be able to take off with a full weapons load from Vikramaditya, which is smaller than Liaoning? :rolleyes:
I don't think they could manage a full 9.5 tons weapons load (MTOW ~25t) with only about 150kn thrust, but they might manage ~3t weapons plus full internal fuel (~18t in all).
 
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