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Shipboard Rolling Vertical Landing - The saviour of Dave-B?

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Shipboard Rolling Vertical Landing - The saviour of Dave-B?

Old 26th Aug 2008, 19:54
  #21 (permalink)  
 
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but then we do want to retain an organic defence/aerospace manufacturing capability dont we?
Yes, but let's face it, BAE will get a pretty big piece of the action even if Dave-C were chosen.

It would be diabolical if Dave-B became another Spey Phantom debacle. Should it turn out that SRVL is a tricky manouver, even the advantage of reduced time spent practicing landing will be lost. And the penalties of vertical lift are then going to be very hard to justify. Of course by that time the carriers will be built, (even now the excuses for how difficult it will be to retrofit the new carriers with CATS are being rehearsed) and Dave-B WILL go ahead regardless.

As I recalled in the Future Carrier thread; the Spey Phantom was always going to pay for itself in exports to re-engine F4s the world over. In fact, it did no such thing, and the RAF ended up with the worlds slowest, and most expensive F4s, all 'justified' by an alleged need to generate a bit more thrust to improve bolter performance.

I would suggest that the rational for Dave-B is starting to look at least as tenuous.
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Old 26th Aug 2008, 20:53
  #22 (permalink)  
 
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jetex - simple question:

Do you know what the procurement and through life costs of Dave-B are compared to that of Typhoon? If you did and it was your choice you'd have Daves coming out of your armpits!

oh oh ..... can't help this postis going to be used extensively for quotes....incoming!
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Old 26th Aug 2008, 21:08
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There's a lot of supposition going on here - and that's OK, it's a discussion forum. However, some of it is a bit wide of the mark.

SRVL relative approach speed to the deck is around the 40 knot mark, I guess. The available landing area on CVF is generous (especially if we were to use an angled landing area) and the F-35B brakes are extremely powerful. Distance from the round down to the touch down point will be a key parameter. The guys working this are not going to recommend an unsafe landing method to justify buying the B. The TPs involved are experienced, smart and operationally aware. They are working to devise a safe manual technique that can be easily automated to improve safety - very much as the USN do for their cat and trap operations.

Spey Phantom - yes, definitely a good bit of work for RR, in the wake of TSR2, P1154 and HS681 cancellation. But the driver for the UK changes was the need to get the aircraft off the shorter catapults and slower carriers the UK had in the 60s. In addition, Bolter performance was a very real issue. Landing gear was beefed up and heavily modified, more weight and so more thrust required. The problem was taking an aircraft designed in detail to operate from the USN CVN flight deck, and trying to get it to work from a smaller deck on a slower ship.

When looking at taking F-35C and putting it on CVF, we could consider this piece of history....
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Old 26th Aug 2008, 21:10
  #24 (permalink)  
 
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Dirty B
Do you know what the procurement and through life costs of Dave-B are compared to that of Typhoon?
Well, why compare it with Typhoon? I'm talking about carrier aircraft alternatives, Dave-C.

In any case, isn't it a little too early in the project lifecycle for anyone to say what the procurement and life cycle cost are really going to be?

And that's just thinking about the cost of the aircraft. If we adopt the view that in order to justify developing Dave-B we have had to buy a couple of STOVL carriers, we add in another big chunk of change.

I'd like to see an analysis of the cost of fully automating Dave-C CAT/TRAP landings. If it's possible, and cheaper than developing Dave-B it becomes a no-brainer right? More capability, without the need to wear out the airframes practicing the basics of carrier recovery.
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Old 26th Aug 2008, 21:18
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Jetex - true, but.....

Dave was designed to meet Defence Strategic Guidence 05 (and previous instantiations) and did so in spades. Dave C did it in bigger spades but cost more so it was a no-brainer to go for the cheaper version (from what I've heard!).
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Old 26th Aug 2008, 21:26
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Granted,

I thought the 'near crawl' approach of 140kts - rather than the more likely sounding 40kts was a bit dubious.

As mentioned previously, the VAAC Harrier ( thus leading to the F-35 systems ) and to some extent the F-18E, UAV's etc have 'autoland'.

'Bring-back' seems likely to remain an issue for carrier aircraft, no matter how they land, be it cat & trap, vertically or on a rubber mat alongside !
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Old 26th Aug 2008, 21:32
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F-35C is designed to operate from USN ships - CVN-68 class (Nimitz). They will be designed to use the new JPALS landing system, and it will have an autoland capability.

BUT - there is very little chance that the USN will rely only on an automatic landing system to avoid training aircrew in manual landings. F-35C CONOPS will be a development of those used for F/A-18E/F and other manned jets. Trying to go for an F-35C option without training our aircrew would be, in my view, plain unsafe.

I'd suggest that the autoland issue is not the central one for SRVLs. (The one area where it might pay off is a automated braking function). The teams at Fort Worth and Warton are, I believe, working to develop a safe SRVL capability which can be carried out manually. JPALS could then be used to provide various levels of assistance, depending on weather and operational needs.

Hope this helps,

Engines
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Old 26th Aug 2008, 21:43
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Engines.
Yes the Spey story is a good one. For RR. On the strength of equipping the ARK with its single squadron of F4Ks, the entire UK F4 buy were equipped with Speys. Which cost about twice what the standard F4J was then going for. Amazingingly enough, sufficient to have procured three new carriers, (with decent sized decks) I believe. That the Spey Phantoms were pretty duff can be seen from the fact that the Air Force got rid of 'em with almost indecent haste, (to replace 'em with the lovely F3, of course) And the Luftwaffe has only just retired the last of its ancient F4s, but even these were not too shabby at the end, with AMRAAM and decent radar.

When looking at taking F-35C and putting it on CVF, we could consider this piece of history....
Well yes, but the CVFs are big boats, over 60K tons. If the frogs can operate RAFALE off the C de Gaulle, about 45K tons, are you telling me that we can only operate a STOVL off these big, brand new ships?

Plus of course by going ski jump we then have to make do with rotary wing early warning aircraft, the frenchies have E2C, and so it goes on...
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Old 27th Aug 2008, 00:55
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Engines, could you remind us all what the term co-efficient of friction refers to please?
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Old 27th Aug 2008, 08:54
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Jetex - I hope they haven't quite retired the last of their F-4s, as I'm pretty confident there's one coming to an airshow north of the border in the none to distant future....
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Old 27th Aug 2008, 10:35
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regarding the braking system - do any aircraft/could this one be designed to have ABS type systems?
How about install some very large fans/blowers on the bow of the ship to increase the WOD during finals :-)
Or if bringback is such a driver for SRVL, tow a large dinghy behind the CVF and jettison stores before transition......I'll get my coat!
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Old 27th Aug 2008, 12:44
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QA - most fast jet a/c have an "anti-skid" system of some kind or another. The main drama with it compared to your common garden ABS is that braking is only being applied to two wheels, thus the ABS sensor system only has two wheels to compare. Thus if you have a snag with it it can lead to you getting no braking at all!
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Old 27th Aug 2008, 16:59
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Jetex - I hope they haven't quite retired the last of their F-4s, as I'm pretty confident there's one coming to an airshow north of the border in the none to distant future....
Yes indeed, those at least one squadron of those venerable Luftwaffe F4s has to soldier on until 2015! (Now there's an Air Force that knows how to get value for money!!)
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Old 27th Aug 2008, 17:20
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Good point about the μ factor of a wet, kerosened deck. Particularly in lively sea states.

Perhaps a hook-like thing on the arse end of the jet and some wires across the deck might be in order?
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Old 27th Aug 2008, 17:36
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BUT - there is very little chance that the USN will rely only on an automatic landing system to avoid training aircrew in manual landings.

Avoiding aircrew training isn't the point of an automated aircraft carrier landing system. ( At least that's what they tell naval aviators. ) It's there to make landings possible in worse weather, and to assist an aviator in distress for whatever reason when necessary.

Would you say that existing IFR equipment is there to avoid crew training?

Now, everyone who's for skipping the F-35 and moving on to shipborne UCAV's please raise your hand.
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Old 27th Aug 2008, 17:53
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Modern Elmo

Don't think a complete fleet makeup of UAV's is the way to go as both manned and unmanned can REALLY complement each other operationally.

However..

....If you look at the toll of US Naval aircraft landing on bolters/incidents/accidents with aircraft who, for want of a better term, "relatively simple landing phase systems" (sorry) how do you see the complicated setup of the JSF coping? (IMO it's a fudge)
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Old 27th Aug 2008, 18:43
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Glad Rag and others,

The JSF team are definitely considering deck conditions, including coefficient of friction. The USN take quite good care of their landing areas, incidentally, with frequent washes and prompt removal of fuel and oil. UK should do the same with CVF.

JSF has a very advanced braking system, large wheels and substantial brake units. Braking performance at 40 to 50 knots is good, and the system is designed to handle wet surfaces as best as laws of physics will permit.

ME, landing aircraft on CVNs with wires at 140 knots is a hazardous undertaking and not at all simple. The USN keeps accident rates low with very good aircrew, lots of very good training, lots of practice at sea, closely managed authorizations (takes a while to get night qualified and hard work to keep it) and well worked up CVN crews to run the ATC, approach, autoland and arresting systems. They are the masters at it, but it costs a fortune to do it.

JJ - Rafale performance off CdG is rumoured to be not good. The cats are a shortened version of the USN pattern, giving lower launch speeds. A problem, especially as CdG is not a fast ship. Spey buy - the F-4K buy had to equip the RN's complete fleet, a lot more than one squadron. In the end, the F-4K/F-4M split was about 50/50. Yes, it was a job creation scheme for RR - but as I said, the only real way to get F-4s to sea on UK ships. The USN had already learned that trying to convert WW2 ships to handle F-4s and larger (A-3 and A-5) was not a good way to go. Sadly, the UK just could not afford Forrestal class ships.

Best Regards

Engines
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Old 27th Aug 2008, 18:52
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One thing I haven't seen mentioned yet - sorry if I missed it ! - is why on earth the SRVL is a 'new' idea, not designed in from the start ?

We all know Harriers like to creep forward on landing ( and certainly a bit more for take-off ! ) for reasons of hot gas re-ingestion & FOD, maybe a little wing lift - you tell me, I'm not a Harrier pilot...

Maybe the F-35B doesn't suffer as badly from hot gas into the intakes as the Harrier, what with the fan rather than close nozzles ( even the aft hot ones ).

Another point raised by a very accomplished VSTOL aircraft researcher is " how does it taxy backwards ?"- using braking Viffing - for landing rather than combat manouvres largely invented by the media - also handy for deck parking, though not easy, as related by Jerry Pook.

My father was crew-chief on a Harrier at the Paris Salon show, and after one attempt at taxying backwards then finding out the reverse castoring effect on the noseleg the hard way, it was quietly decided by all concerned to forget it unless the pilot had someone ahead directing - obviously a different deal on a carrier at war.

However braking / reverse parking thrust would seem handy to me.

As for the weight issue, remember the P1127 could barely lift itself when stripped right down to start with, but the Pegasus ended up with a lot more than twice that thrust !

Last edited by Double Zero; 27th Aug 2008 at 19:17.
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Old 27th Aug 2008, 19:05
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Engines, I beg to differ, regarding your numbers of Spey Phantoms
from
Military Power: F-4 Phantom II
In 1964, the Royal Navy ordered a 'anglicized' F4K, which had a wider fuselage to house the Rolls-Royce Spey, fan engines. Forty-eight machines were delivered to the United Kingdom as the Phantom FG.1. However the premature retirement of the Carrier HMS Victorious coupled with the prohibitive cost of refitting HMS Eagle meant that only the carrier HMS Ark Royal was available to operate the Phantom. As a result twenty aircraft of this order were transferred to RAF Strike Command, equipping No. 43 squadron at Leuchars. The twenty eight Royal Navy aircraft began trials by No.700P squadron based at Yeovilton in Devon before being passed to No.767 squadron for type conversion training, and finally becoming operational with No.892 squadron, also at Yeovilton. From March 1969 No.892 squadron made a number of cruises with these aircraft aboard HMS Ark Royal using the Phantom. In 1978 these aircraft were transferred to the RAF'S No.111 Squadron for Air Defense of the United Kingdom.....The use of Rolls-Royce Spey engines in the British Phantoms dramatically increased the unit price of the aircraft whilst decreasing maximum speed, height and performance at altitude.
Wow, 10 years worth of carrier ops from 28 aircraft. 48 F4K were made and 116 F4M, and of course, the Ms had Speys as well, and each Spey aircraft DOUBLE the price of the standard model.

Pretty pricey cocktails.
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Old 27th Aug 2008, 19:20
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based at Yeovilton in Devon
finally becoming operational with No.892 squadron, also at Yeovilton

Blimey!!! Not only did they transfer tho 'Tooms to the RAF in order to cut costs, they also seem to have managed the spectacular feat of moving Yeoves from Devon to a county nearer to London too!!! Just think what could be achieved if we were still using Lsd.............
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