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Future Carrier (Including Costs)

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Future Carrier (Including Costs)

Old 23rd Dec 2008, 00:07
  #2021 (permalink)  
 
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SRVL / bolter /

NoHoverStop,

we've conversed before on good terms, hope that may continue.

I presume all this talk of JBD's is the conventional U.S.Navy ' C ' version.

I suspect more than one Harrier pilot has played the throttle / nozzles on deck to avoid disaster ( Jerry Pook's description of as an RAF pilot unused to deck handling, having to reverse between parked rows of aircraft made my hair stand on end ) but the best description, naturallly, came from John Farley.

When asked by the late Raymond Baxter -commentator & ex-Spitfire pilot - what were his hairiest moments, John very modestly - compared to some of the things he did - related that during a sales push at the Spanish Navy, he challenged the captain of the small Spanish carrier 'Dedalo' " try to stop me landing on " !

This was in the Bay of Biscay - the Captain, up to the challenge, stopped engines, put her beam on to the sea, then made smoke.

J.F. put the aircraft down without much trouble, but found the deck lashing crews were not too keen to rush up and secure the aircraft down - as he said, " I thougt I'd done my bit " !

He ended up playing the nozzles fore & aft just to keep on deck as the ship rolled, and gather he didn't appreciate it much ( anything like a Hornet etc, even if the ship could handle it, would have been over the side long before then ).

So that's why I'm asking if the F-35B could handle similar conditions...

Modern Elmo,

The parked aircraft on deck & 'big volleyball net' / barrier has been tried extensively, my father's WWII photo albums of Seafires & Hellcats is a tiny illustration of such a systems' 'merits'.

DZ

Last edited by Double Zero; 23rd Dec 2008 at 15:23.
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Old 23rd Dec 2008, 20:42
  #2022 (permalink)  
 
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In discussing SRVLs for F-35B on CVF, one needs to appreciate the profound differences between this idea and trying it with Harriers on CVS (Invincible class).

Harrier can use partial nozzle braking (PNB) to quite good effect at higher landing speeds. The 10 degrees forward thrust, if used correctly, doesn't pose a major FOD issue at prepared bases, but it does make the aircraft lighter on the gear, and that is an issue. The Harrier is a fairly poor braking aircraft, as Nohoverstop correctly points out. Only 50% of the weight is on the main gears that only have a single set of brakes. Add in a wet surface. and the situation gets a lot worse. Directional steering on the Harrier is quite powerful (lots of weight on the front peg) , but it is not all that stable an aircraft directionally.

To get effective wing lift off a Harrier (especially the SHAR) you need around 80 knots plus airspeed. That probably raises the SRVL touchdown speed to around 60/70 knots, with the right wind and ship speed. At these sort of airspeeds, the Harrier is not an easy aircraft to fly, with marginal directional stability and VERY high pilot workloads to stay on a precision approach.

Finally, CVS doesn't have the space (lateral or lengthwise to foot of the ramp) required for SRVL in any normal configuration.

F-35B has a full tricycle gear, and I'd expect around 90% of the weight to be taken by the two main gears. Each leg has a very capable carbon fibre brake set, and a well sized wheel for braking. Finally, the brakes are controlled via dual redundant computer driven braking systems. However, it is not going to be a very effective PNB aircraft - only the rear nozzle can vector forward, meaning not all the thrust can help.

The 'B' has a LOT more wing than a Harrier. Likely SRVL airspeeds should be significantly lower than for a Harrier, reducing touchdown speed to the deck. Finally, CVF has much more space available for SRVLs - the deck area is actually quite close to the size of the USS Forrestal when she first entered service in the 50s.

Finally, the 'B' has a very advanced flight control system that should allow pilots to put it on the proverbial sixpence, reducing deck scatter and allowing touchdown much closer to the stern than for a conventional cat and trap approach. In the same vein, the propulsion system is going to be fairly 'Gucci', and restoring power for a 'bolter' won't necessarily depend on a big engine's spool up time.

Modern Elmo raises a very good point about the CVF deck layout. I've posted before that doing SRVLs axially is, in my view, not a good move as you end up rolling towards other stuff parked on deck, or the bottom of the ski jump, ruling put any bolter. CVF has the space to accommodate axial launches and angled recoveries, which in turn should allow the aircraft to perform a 'bolter' if required. (Note - two different versions were posted by 'GreenKnight 121' - the upper one is closer to the current configuration. Lower one is an old design).

As far as I know, there are no crash barriers on CVF. The JBDs have been shown on a number of pictures, they are there to allow greater use of the deck aft of a launching aircraft. They should raise and lower very quickly (~5 sec), so shouldn't get in the way of deck operations.

SSSETOWTF hits the nail on the head - F-35B SRVLs on to CVF are a totally different animal, and well worth looking at.
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Old 23rd Dec 2008, 21:00
  #2023 (permalink)  
 
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All I can say is I hope the spool up time on that engine is pretty sharp! Brakes fail, no matter how shiny and nice.

Even more important if we only buy about 2 of the jets!
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Old 23rd Dec 2008, 21:13
  #2024 (permalink)  
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One of the problems with running Ark or Illustrious on is that certain bits of them that were only fitted at the last refit need to be removed to complete both CVFs. Invincible has none of these, so I suspect we'll see Ark going one year before QE and Illustrious one year before PoW.
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Old 24th Dec 2008, 04:41
  #2025 (permalink)  
 
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GreenKnight121:

Thats actually one of the Older graphics of CVT and the design has changed somewhat. Lateset release image is this one; (Warning .pdf), Link
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Old 24th Dec 2008, 14:37
  #2026 (permalink)  
 
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Engines,

A thoughtful post. One comment: the B has more wing than a Harrier but it also at least 2x as heavy on approach and (relative to the Harrier II) has a faster, thinner wing with smaller flaps. How does that affect lift at low speed?
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Old 27th Dec 2008, 13:47
  #2027 (permalink)  
 
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LO,

The B has LOTS more wing (about 3X) and a lot more flap, as well as a Leading Edge device. It can also use all its control surfaces to get maximum lift at desired speeds, thanks to its integrated control system. (on a Harrier, integration of wing lift, propulsive thrust and attitude is done via pilot skill).

PBA,

If the aircraft lands in a semi jet-borne mode, the propulsion system should already be spooled up - in any case, response of the system has to be fast to provide the vertical hover control required. Don't forget that the Harrier's Pegasus was, for many years, the biggest and most powerful dry engine in any military aircraft, and also has the fastest throttle response - due to brilliant british engineers....same breed of guys now working on JSF.

Best Regards as ever,

Engines
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Old 27th Dec 2008, 15:22
  #2028 (permalink)  
 
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Engines

Thanks for illuminating a fascinating discussion.

Just a small query, I've just read Dave Morgan's excellent ''Hostile Skies'', (obviously) about his F. I. air war.

He actually mention doing ( if i rem correctly ! ) doing the first srvl, but also I believe he also says about being able to use 18 degrees forward nozzle.

Is this specific to the Shar maybe ?



(edit)

Aha ! Thanks John Farley, should have read Engines post more carefully, re; partial nozzle braking

Last edited by Tyres O'Flaherty; 27th Dec 2008 at 19:40.
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Old 27th Dec 2008, 18:30
  #2029 (permalink)  

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Is this specific to the Shar maybe ?
No. With all Pegasus variants the nozzles could be rotated to an angle 18.5 deg forward of the hover postion - known in the trade as 'the braking stop'.
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Old 27th Dec 2008, 18:34
  #2030 (permalink)  
 
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(on a Harrier, integration of wing lift, propulsive thrust and attitude is done via pilot skill).

On the early marks yes, but of course I stand to be corrected.
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Old 28th Dec 2008, 10:31
  #2031 (permalink)  
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Interesting article on CVF here. Can't wait for the airfix version.

here
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Old 28th Dec 2008, 14:09
  #2032 (permalink)  
 
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Glad rag,

What I meant here (sorry for not being clearer) is that control of the propulsion system on Harriers, via the throttle and nozzle control lever, is essentially separated from the aircraft's attitude control via the control column. These three 'inceptors' are managed by the pilot to carry out safe recoveries, at a cost of high workload. Interestingly, recoveries to ships were the drivers for the changes to the Sea Harrier cockpit and also the improved lateral reaction controls, or so I have been told.

F-35B is a totally different animal. The flight control system will automate many of the functions described above and leave the pilot with a much lower workload - this should lead to safer and more accurate recoveries.

JF, thank you for the correction on the value of the braking stop.

Best regards

Engines
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Old 30th Dec 2008, 17:05
  #2033 (permalink)  
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Interesting video on the F-35 on the NG site here. Comments welcome.

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Old 30th Dec 2008, 18:39
  #2034 (permalink)  
 
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Navaleye...

In post 2025 you stated that certain 'bits' of the current CVSs are due to go on the new carriers. Can you say what 'bits' you are refering to, or does OPSEC come into it?

If it is the CIWSs, e.g Phalanx and Goalkeeper, doesn't that mean they will be at least 10-15 years old when they go on the new ships? Or will they have been upgraded so often by them they will be like Triggers broom?
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Old 30th Dec 2008, 18:46
  #2035 (permalink)  
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Biggus,

Doubtless the Phalanx will come off and be upgraded to Block 1b standard. Some of the new comms and navigation equipment fitted to the CVS is slated for CVF.
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Old 30th Dec 2008, 20:49
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Navaleye - thanks!
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Old 31st Dec 2008, 13:44
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Navaleye -

Ares Homepage
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Old 8th Jan 2009, 15:31
  #2038 (permalink)  
 
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AW&ST
JSF News 2 - Stealth Questions Raised
Posted by Bill Sweetman at 1/7/2009 7:30 AM CST

The Air Power Australia team have produced an unprecedented report which asserts that the F-35 Joint Strike Fighter is much less stealthy than the F-22 - and in fact is comparable in radar cross-section (RCS), under some circumstances, to a conventional fighter in clean condition. APA's updated surveys of modern Russian radars - which are most likely to form the basis of the threat systems that it would encounter from the late 2010s onwards - have set the scene for this analysis.

The report is unprecedented because it's the first "civilian" use of radar scattering models to take a first-order look at an aircraft's RCS. It was the development of computer-based RCS models that opened the way to the development of stealth in the 1970s: the theory of scattering was well known but was too hard to apply to a 3-D shape without those tools.

The APA analysis will no doubt be countered by the JSF team in several ways. They'll argue that the APA team has an agenda. They will argue that the analysis is too crude to reflect reality; that anything it does show is not operationally relevant; and that the true picture is much more complex and (of course) secret.

The APA team does have an open agenda (as does the JSF team) but that does not mean that their data is bad.

The analysis is crude insofar as it doesn't make any detailed estimates of the effects of radar absorbent material (RAM). On the other hand, the doctrine laid down by Stealth pioneer Denys Overholser still stands: the four most important aspects of stealth are shape, shape, shape and materials.

On the other hand, the APA analysis is a lot more detailed than the cartoon representations in Lockheed Martin briefings. And more realistic than the claims of total invisibility made on JSF's behalf.

The APA team also makes the point that the F-35 doesn't look as much like an F-22 (or the X-35) as you might think. Those two aircraft both reflected a refined version of the F-117 shape - they are basically faceted designs, although they incorporate large radius curves and the lines between facets are smoothed. But the F-35 has acquired some very conventional-airplane-shaped lumps and bumps around its underside, not to mention the hideous wart that covers the gun on the F-35A. It's enough to raise questions.

Of course, it's possible to argue that the F-35 meets its stealth requirements (which may or not be the same for all F-35s), and that it will be stealthy enough to survive - combined with situational awareness and tactics.

But that in turn depends on what the requirements are, and what threats it was designed against. (That's why stealth air vehicles are as diverse as they are, from the DarkStar to the AGM-129, while submarines look pretty much the same.) In the design of the F-22, for example, features such as 2-D nozzles, edges swept at 42 degrees, and high-altitude, high-speed flight were required to address that threat set.

More recently, the Northrop Grumman X-47B and Boeing X-45C designs have clearly been aimed at all-aspect, wideband stealth - although that's particularly important for an unmanned vehicle, which may not be as flexible in its response to a pop-up threat.

The worst argument against APA, though, is that of secrecy. Implemented on an experimental airplane 30 years ago, stealth is no longer covered by Arthur C. Clarke's principle that "any sufficiently advanced technology is indistinguishable from magic." Competitors and potential adversaries around the world have assuredly run F-35 models in simulations, in RCS chambers and on open ranges. So if APA has got their models wrong, it probably wouldn't compromise security to explain why.
Assessing JSF Defence Penetration Capabilities

Thoughts?
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Old 17th Jan 2009, 10:30
  #2039 (permalink)  
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A few more orders for CVF this week. Good to see some good news for Appledore (a local yard).

50m for steelwork for bow sections of the two carriers, to be carried out at Babcock's Appledore Shipyard in Devon, sustaining some 150 jobs at peak production;
Galley equipment, 3.4m, Kempsafe Ltd (Southampton);
Modular cabins and wet spaces, 23m, McGill Services Ltd, sustaining about 40 jobs at peak production (Billingham, County Durham);
Furniture to be installed throughout the ships, 4.4m, McGill Services Ltd;
Windows, 1.3m, Tex Special Projects Ltd (Ipswich);
Doors and hatches, 3.9m, McGeoch Marine Ltd (Inchinnan, Renfrewshire);
Aircraft electrical supplies equipment, 4m, Ultra Electronics PMES (Rugeley, Staffs).


It is coming together, albeit slowly!
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Old 17th Jan 2009, 16:53
  #2040 (permalink)  
 
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That so-called APA team doesn't know the details of the F-35 design and concept of operation, nor do I think they have any real expertise in state of the art radar performance analysis.

How many military radars does Australia design and build?

..,. More querulous Karlo Kopp Krapp from the Wizards of Oz.
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