China: First display of J-15 from carrier

[Nervous SLF]

China: First display of 'Flying Shark' Jet Fighter, Shenyang J-15-555 aircraft - YouTube

[FATTER GATOR]

Interesting. The jet seems to be held on the red chocks while the throttles are advanced, they then snap flush with the deck and off you go.

I have never seen that before. Anyone else seen that system?

[JFZ90]

hard to see, but the arresting wire looks unusual too - like multiple fibres, rather than a single cable.

[TBM-Legend]

Good to see they're still painting the wheels green...

[SpazSinbad]

Arresting Cables/Wires/Cross Deck Pendants whatever have a complex construction which is always being improved. In the Chinese case I have read they had to make their own because the Ruskies would not sell them any. :-(

SBIR/STTR Interactive Topic Information System (SITIS) (http://www.dodsbir.net/sitis/archives_display_topic.asp?Bookmark=28807)

PURCHASE CABLE (http://navyaviation.tpub.com/14001/css/14001_96.htm)

http://navyaviation.tpub.com/14001/img/14001_96_2.jpg

Russia refuses to sell arresters for Chinese aircraft carrier (http://www.freerepublic.com/focus/f-news/2816098/posts)

[Buster Hyman]

Flying Shark? We're gonna need a bigger boat!

[SpazSinbad]

Is there where the "Jumped the Shark" expression originated? :} Just add ski... :rolleyes:

Jumping the shark - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Jumping_the_shark)

http://upload.wikimedia.org/wikipedia/en/5/51/Fonzie_jumps_the_shark.PNG

http://upload.wikimedia.org/wikipedia/en/5/51/Fonzie_jumps_the_shark.PNG

[Fedaykin]

The hold back chocks are nothing new and in keeping with what the Russians do on the Admiral Kuznetsov and the INS Vikramaditya. The arrestor cables on the Liaoning appear to be similar to that fitted to the Russian vessels, whilst the Russians didn't sell the arrestor gear to China the Ukraine apparently gave full technical details and the designs.

You can clearly see the hold back chocks in this news report about flight trials of the Mig-29KUB on the Admiral Kuznetsov:
http://www.youtube.com/watch?v=2LPbvQpiJSk

[SpazSinbad]

There's no beating that Ruskie 'Jump the Shark' humour here: (and it is 'no suck back in the hold back for him' [being nervous before catapulting])

But first some RuskieChockieWockies: http://i98.photobucket.com/albums/l261/SpazSinbad/NewerAlbum/th_RussianChocks.jpg (http://s98.photobucket.com/user/SpazSinbad/media/NewerAlbum/RussianChocks.jpg.html)

http://i98.photobucket.com/albums/l261/SpazSinbad/NewerAlbum/RussianHumourScreenie.jpg~original (http://s98.photobucket.com/user/SpazSinbad/media/NewerAlbum/RussianHumourScreenie.jpg.html)

[SpazSinbad]

One day the most recent LSO Reference Manual PDF c.2010 will become available (re-edited / updated version of the old 1999 Manual). The old version seems to have disappeared from the interrubble.

http://i98.photobucket.com/albums/l261/SpazSinbad/NewerAlbum/ArrestorWiresCrossSectionUSNforum.gif~original (http://s98.photobucket.com/user/SpazSinbad/media/NewerAlbum/ArrestorWiresCrossSectionUSNforum.gif.html)

[FATTER GATOR]

Well, every day is a school day!

Love the Russian arrester-hook maypole...

[moggiee]

Interesting. The jet seems to be held on the red chocks while the throttles are advanced, they then snap flush with the deck and off you go.

I have never seen that before. Anyone else seen that system?
It's the system that the Russians use for the Flanker, so logically enough the Chinese use it for their Flankers :)

[Cameronian]

Wouldn't a ramp solve our catapult problem for other types and even help the 35? I understand that arrestors and an angled deck would be necessary to make the bolters less exciting. Cutting out the catapults would save a fortune in all sorts of ways, both in terms of provision and in ongoing costs, and an angled deck surely doesn't cost much to run once it has been built. Can none of the likely customers handle a ramp? I appreciate that my question may seem silly to some "in the know" because it must surely all have been assessed behind closed doors and discounted. It's just that, like some others here, I've never seen a launch by the Chinese way before.

[Tourist]

Cameronian

Actually, I think you might be on to something.

I wonder if the builders of our new carriers even considered these things at the design stage.

We could save a lot of money by skipping the catapults as you say, and this ramp thingy seems like a good idea.

So good an idea in fact I can't believe we didn't think of it before.

Sometimes you have to wonder if the MOD have any idea at all!!!

Copy the Chinese like you say.:*

[Engines]

Cameronian (and others)

Perhaps I can be of some help here.

Yes, this way of operating aircraft (often called STOBAR - Short Take Off Barrier Arrested Landing) was looked at in detail during CVF requirements development. It was also looked at by the USN many years ago (in the 70s, I believe).

The basic issue with it is that you get relatively poor launch performance with CTOL aircraft. The key to ramp launches is that you fly off the deck going upwards, which means you have more time to accelerate to a speed where you start flying at a positive rate of climb.

Any aircraft has to attain a ramp exit speed that allows it launch at an acceptable initial sink rate, plus it has to be controllable. That sink rate will be driven solely by wing lift and whatever thrust if can get by being pitched up - although that will in turn cause significant drag. That will delay the ability of the aircraft to accelerate to normal climb out speed. For a conventional aircraft with aerodynamic controls, and no thrust vectoring, a ramp launch will not be achievable at anything like MGTOW off a runway. In fact, probably quite a long way below. The sort of thrust/weight ratios used for flying displays are quite a long way away from what you get when fully loaded for a strike mission, or even air defence work.

A STOVL aircraft (e.g Harrier, F-35B) has a couple of massive advantages off the ramp. The first is that they have a control system that works at flying speeds down to zero, so they don't have to rely on control surfaces. The second is that they can launch in a powered lift mode, where they can vector their thrust through their CG. That means that they can launch at well below aerodynamic stalling speed, and then progressively shift thrust aft as wing lift builds up. Sea Harrier typically had ramp end speeds of around 85 kts.

The 'vanishing chocks' are used to allow the aircraft get into full reheat at higher weights before they start rolling, to try to get the best ramp end speed they can. At higher weights, the effect is minimal. Harrier did look at using a 'hold back' for deck launches, but it was realised that the gain was not worth the complexity.

Bottom line is that CTOL ramp launches are not going to deliver the sort of payloads (fuel and weapons) that operational air arms require. This is basic physics and is not solved by marketing. Ask the 'Sea Typhoon' salesmen after a few quiet beers. The Chinese have recently gone public with some fairly severe criticisms of their aircrafts' performance off their new carrier, which seems to confirm the point.

Hope this helps, best regards as ever to all those launching naval aircraft whatever way they do it

Engines