"Ski-Jumps" on Aircraft Carriers.

Little to do with the main topic but, for a bit of fun ……………….

HMS Argus, in 1941, had a ramp shielding the accelerator. We were told to hold the aircraft (Hurricane) down until it hit the ramp.

How stupid can you get? Two of us (not me) smashed our u/c on it & had to crash land in Russia. GREAT advertisement??

Personally I really like the stobar concept much better than the F35 concept,stobar means you have a relatively simple a/c (with lots of power :diablo:).
cheers baz

The Su-25UTG is not exactly endowed ‘with lots of power’ – yet it also manages to get airborne from the Kuznetsov’s deck using the ski jump…..

Ken

Personally I really like the stobar concept much better than the F35 concept,stobar means you have a relatively simple a/c (with lots of power :diablo:).
Some stobar footage here..landings/take offs start at approx 1.00…

http://uk.youtube.com/watch?v=z2SQuY0glvg

http://uk.youtube.com/watch?v=9J05XhJ-N_U&feature=related

cheers baz

When mentioning ski jumps, everyone seems to forget about the Russian Admiral Kuznetsov carrier – operating Su-33’s in STOBAR mode….

It has an 11 deg ski jump and arrestor wires…..

Ken

I believe that the Yeovilton T8 Ramp accident was caused by the pilot moving the throttle lever back instead of the nozzle lever…that would do the trick !!

Hasn’t that been one of the design flaws of the Harrier; the ergonomics of the throttle and nozzle levers? Too much chance of ‘finger trouble’ and too little chance to recover afterwards?

The simplicity of the whole ski-jump STOVL concept really appeals to me. I know there is a downside (especially with the replacement STOVL F-35) but defence budgets are limited and developing, fitting and maintaining steam catapults and arrestor wires cannot be cheap.

Are you sure? I know that a large part of the ski-jump is curved but the last part of it seems pretty ‘flat’ to me. I could be wrong but I seem to remember that the idea is that the landing-gear is compressed as the Harrier enters the curved part of the ski-jump but over the last flat part the landing-gear springs back past the ‘static’ position and then the Harrier goes off the end.

I was talking about the major part of the ski jump being curved to help ‘throw’ the a/c up,but of course also just before entering the ramp.. the pilot pulls the nozzle lever back to his preset S.T.O stop (50 – 55 deg ish).this will be calculated taking account of Wind over Deck,a/c All Up Weight etc and used to be shown to pilot on a board by the flight deck crew (not sure if still done this way ??). So when the a/c leaves the ramp it is airborne with a combination of a ballistic throw,slow airspeed and 50 – 55 deg nozzle thrust.
I believe that the Yeovilton T8 Ramp accident was caused by the pilot moving the throttle lever back instead of the nozzle lever…that would do the trick !!

cheers baz

The ski jump has a pronounced curve and actually does put quite a load on the landing gear as the a/c enters.
If it was more a flat plate then it would not launch the a/c as effectively.

Are you sure? I know that a large part of the ski-jump is curved but the last part of it seems pretty ‘flat’ to me. I could be wrong but I seem to remember that the idea is that the landing-gear is compressed as the Harrier enters the curved part of the ski-jump but over the last flat part the landing-gear springs back past the ‘static’ position and then the Harrier goes off the end.

Up or Down

This may help with the answer :

http://www.naval-history.net/xGM-Chrono-04CV-Furious.htm

The ski jump has a pronounced curve and actually does put quite a load on the landing gear as the a/c enters.
If it was more a flat plate then it would not launch the a/c as effectively.

cheers baz

Here’s the ski jump on ‘Lusty’ during her visit to Oslo in may last year (ZG480 is on the jump).

This photo roughly shows what the aircrafts attitude would be on take-off…… I guess the Harrier U/C is designed to take a lot of heavy use.

cheers,

-John

I’m not sure the ski-jump is all curved, although there is a generous ‘radius’ between the flat deck and the straight end portion of the ski-jump. The ski-jumps on the three Invincible class carriers are described by a single angle of 12° or 13° (HMS Invincible was 7° originally).

The ski jump has a pronounced curve and actually does put quite a load on the landing gear as the a/c enters.
If it was more a flat plate then it would not launch the a/c as effectively.

cheers baz

I used the term loosely of course, just as “Bloody Great Ramp” was obviously an exaggeration. Wellum’s book goes on; “It was put there to throw the old biplanes into the air on takeoff and slow them down on landing before the days of arrester wires” The point I was trying to make was that I didn’t realise there were anything but completely flat decks before the days of the Harrier.

The development of deck operations is a fascinating field, much of which is assumed ‘normal’ now. IIRC, the ramp Wellum mentions was one of the many inter-war pre-arrestor wire/hook bright ideas.

Surely a ramp and a ski jump are two entirely different things ??Ken

I used the term loosely of course, just as “Bloody Great Ramp” was obviously an exaggeration. Wellum’s book goes on; “It was put there to throw the old biplanes into the air on takeoff and slow them down on landing before the days of arrester wires” The point I was trying to make was that I didn’t realise there were anything but completely flat decks before the days of the Harrier.

I’m not sure the ski-jump is all curved, although there is a generous ‘radius’ between the flat deck and the straight end portion of the ski-jump. The ski-jumps on the three Invincible class carriers are described by a single angle of 12° or 13° (HMS Invincible was 7° originally).

Surely a ramp and a ski jump are two entirely different things ??

A ramp is just a straight slope – either desinged to slow an aircraft landing when at the rear end – or to increase the takeoff speed due to gravity when placed at the bow.

A ski jump is a continuous curved surface – probably with some complex mathematics involved – designed to impart a ballistic trajectory to any aircraft using it.

Russian Admiral Kuznetsov uses one to boost Su-33 Flanker takeoffs – as does the RN Carriers with Harriers.

Ken

Looks like a ramp up towards the front of the flight deck to me:

http://www.history.navy.mil/photos/images/h60000/h60976.jpg

(OK – and a downwards slope on the flying off deck )

Possibly this was an earlier configuration of HMS Furious (that was actually laid-down as a battle-cruiser) and the ‘ramp’ worked in the other direction to the later ‘ski-jump’ of the (1979) Invincible class. On early carrier conversions the take-off ramp would probably slope down towards the bow so that gravity would help build-up aircraft speed and a landing ramp would slope up to assist in stopping once the aircraft had landed.