On a slightly more serious note, I was a bit bemused by "fueldraulics". If anyone else is thinking 'wtf?', I've teased out a smidgeon of explanation from Wiki.

Apparently the vertical thrust bit of Dave B (well, actually anything other than straight fore-and-aft thrust) comes from two things. The first is the forward lift fan - a sort of vertical, ducted turboprop in the centre of the fuselage. But the other is a bit more complicated. It's at the back, and it vectors the full thrust of the P&W135 engine anywhere between straight back and vertically down (or even a bit forward).

The major bit of this gizmo is the three-bearing swivel module (3BSM to its mates). That has to take the full force of the hot exhaust gases and point them in the right direction. To do that, it uses actuators that would perhaps in a more conventional machine, be powered by hydraulics. In Dave B, to save weight, they use fuel instead of hydraulic fluid. That saves weight and complexity, apparently. And they've christened it "fueldraulics". Not very elegant perhaps, but kind of self-explanatory.

Sorry if I'm telling you things you already know. It puzzled me.... But that's not difficult.

airsound

Fueldraulic actuation within the engine is not uncommon:

Aviation Fuels with Improved Fire Safety: A Proceedings

F-35 Stealth Longevity
 

Above 'glad rag' asked: "...Will the overall LO characteristics of the airframe "last" the for it's full service life?..."

The F-35: Creating a 21st Century Fighter A White Paper By: Lockheed Martin

The F-35: Creating a 21st Century Fighter | SLDInfo

"...As Bill Grant, Lockheed Martin F-35 Supportable Low Observables Integrated Product Team leader, has put it:
From day one, supportable LO has been a key entity on the program and has had a profound influence on the very design of the airplane. In fact, the element that is manufactured into the skin was an initiative brought about by our LO maintenance discipline. We’ve also had a profound influence on the selection of the materials and then once they were decided upon, we helped refine the properties to make them more workable for field use.

And Grant added:
Our system requirement was for end of life, which means that throughout the 8,000-hour service life of the jet, it is to remain fully mission-capable. So we anticipated that the amount of maintenance that would be done over the life of the airplane and anticipated that in the design.

So when we deliver the jet, it’s delivered with a significant margin of degradation that’s allowed for all of these types of repairs over the life of the airplane, again, without having to return to the depot for refurbishment. 
There may be some cosmetic-based reasons why the jet might go back to a facility to get its appearance improved, but from a performance-standpoint we recognize no need to do that...."
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The F-35’s Race Against Time | Nov 2012 By John A. Tirpak Executive Editor

The F-35

"...When it comes to maintainable stealth design, the F-35 represents the state of the art, O’Bryan said, superior even to the F-22 Raptor, USAF’s top-of-the-line air superiority aircraft.

The F-22 requires heavy doses of regular and expensive low observable materials maintenance. F-35 stealth surfaces, by contrast, are extremely resilient in all conditions, according to the Lockheed team.

"We’ve taken it to a different level," O’Bryan said. The stealth of the production F-35—verified in radar cross section tests performed on classified western test ranges—is better than that of any aircraft other than the F-22.

This, he went on, is true in part because the conductive materials needed to absorb and disperse incoming radar energy are baked directly into the aircraft’s multilayer composite skin and structure.

Moreover, the surface material smoothes out over time, slightly reducing the F-35’s original radar signature, according to the Lockheed Martin official. Only serious structural damage will disturb the F-35’s low observability, O’Bryan said, and Lockheed Martin has devised an array of field repairs that can restore full stealthiness in just a few hours.

Dramatic Stealthiness
The F-35’s radar cross section, or RCS, has a "maintenance margin," O’Bryan explained, meaning it’s "always better than the spec." Minor scratches and even dents won’t affect the F-35’s stealth qualities enough to degrade its combat performance, in the estimation of the company. Field equipment will be able to assess RCS right on the flight line, using far less cumbersome gear than has previously been needed to make such calculations...."
____________________

F-35C STEALTH ON THE CARRIER DECK MEANS HIGH PERFORMANCE, LOW MAINTENANCE

http://www.jsf.mil/news/documents/20...LM_CARRIER.rtf

"...The F-35 achieves its Very Low Observable stealth performance through its fundamental design, its external shape and its manufacturing processes, which control tolerances to less than half the diameter of a human hair. Special coatings are added to further reduce radar signature.
The package is designed to remain stealthy in severe combat conditions, and tests have validated that capability. After obtaining baseline radar cross section (RCS) measurements from a highly detailed, full-scale Signature Measurement Aircraft (SigMA), a team of Lockheed Martin and Northrop Grumman engineers intentionally inflicted extensive damage – more than three dozen significant defects – on the model. The damage represented the cumulative effect of more than 600 flight hours of military aircraft operations. RCS measurements taken after the damage showed that the stealthy signature remained intact.

“Even operating in harsh carrier-deck conditions, the F-35C will require no special care or feeding. In fact, its stealth adds very little to the day-today maintenance equation,” O’Bryan said. “We’ve come a long way from the early stealth airplanes, which needed hours or even days of attention and repair after every flight. The F-35 not only avoids that intensive level of upkeep, it will require significantly less maintenance than the nonstealth fighters it is designed to replace.”
_______________________

Production techniques gear F-35 for stealth

http://www.navy.mi.th/nrdo/jane/dev_...tionJuly48.pdf [link no longer available]

"...In addition to machining advances that allow LM to achieve high manufacturing tolerances, advances have also been made in the composition of the radar-absorbent structure (RAS) of the aircraft. This Linhart said, is "complete-ly different" from earlier RAS materials in the way it is resistant to chipping, even in the face of bird-strikes...."
_____________________

New Stealth Concept Could Affect JSF Cost By Amy Butler - May 17, 2010

http://www.aviationweek.com/aw/gener...hannel=defense [Link no work now]

"FORT WORTH — As the debate rages about Joint Strike Fighter life-cycle cost, Lockheed Martin officials are raising a previously unheard point to bolster their low-price claims — a new low-observability (LO) substance called fiber mat. Lockheed officials avoided the need to use stealthy appliqués and coatings by curing the substance into the composite skin of the aircraft, according to Tom Burbage, executive vice president of F-35 program integration for the company. It “makes this airplane extremely rugged. You literally have to damage the airplane to reduce the signature,” he said in an interview with AVIATION WEEK. This top-fiber mat surface takes the place of metallic paint that was used on earlier stealthy aircraft designs.

The composite skin of the F-35 actually contains this layer of fiber mat, and it can help carry structural loads in the aircraft, Burbage adds. The F-35 is about 42% composite by weight, Burbage says, compared to the F-22 at 22% and the F-16 at 2%. Lockheed Martin declined to provide further details on fiber mat because they are classified...."
________________

Lockheed Gives a Peek at New JSF Stealth Material Concept by Amy Butler May/17/2010

Blogs [Link no work now]

"It is called "fiber mat," and Tom Burbage, executive vice president of F-35 program integration for Lockheed Martin says it is "the single, biggest technological breakthrough we've had on this program." He says that a new process to blend stealth qualities into composite material avoided the need for stealthy appliqués and coatings. Using a new process, Lockheed officials are curing the stealthy, fiber mat substance into the composite skin of the aircraft, according to Burbage. It “makes this airplane extremely rugged. You literally have to damage the airplane to reduce the signature,” he said in an interview with Aviation Week in Fort Worth. This top-fiber mat surface takes the place of metallic paint that was used on earlier stealthy aircraft designs. The composite skin of the F-35 actually contains this layer of fiber mat, and it can help carry structural loads in the aircraft, Burbage adds. Lockheed Martin declined to provide further details on fiber mat because they are classified. But the disclosure of this new substance comes at a time when Lockheed Martin offic-ials are arguing that maintenance costs for the F-35 will be lower than anticipated by operators...."
___________________

The F-35 Low Observability’s Lifelong Sustainability: A Revolutionary Asset for 21st Century Combat Aviation

The F-35 Low Observability’s Lifelong Sustainability: A Revolutionary Asset for 21st Century Combat Aviation | SLDInfo
_____________________________

Graphic of F-35 damage/repair from:

https://www.box.com/shared/3uo7o5qt25e2x6ylc294

navyleague2008PDF.pdf (3.2Mb)

CLICK Thumbnail for large version: http://i98.photobucket.com/albums/l2...e2008brief.gif
_________________

Permanent download sites for RAN FAA A4G Skyhawk / Fixed Wing / Helo FREE Material here:

https://drive.google.com/?authuser=0...DhIQ0szeVJFY0U
OR
https://skydrive.live.com/?cid=cbcd6...6&sa=822839791

that come with a zero cost guarantee?

I think Glad Rag was referring to how long the LO characteristics, even if maintained to the 'as designed' state, would remain relevant.

The LO characteristics are reasonably fixed but the threat continues to evolve. We are already seeing tracking and targeting systems switch to different parts of the EM spectrum and multi-spectral systems with digital processing is rapidly becoming the norm. One of the great gambles with LO aircraft is judging how long it remains relevant - 10 years? 20 years? Anyone want to go higher?

Of course with JSF the obsolescence clock started ticking some time ago and this clock pays no respect to IOC slips.

Thank you to SpazSinbad [!] for those intriguing insights.

Indeed, getting the "meat" of the RCS reduction into the structure of the airframe is, once you step back, a no brainer really, it HAD to be done.:D

However I go back to my original précis. Once the RCS element of overall LO reduction is overcome we are left with what?





One thing that has become more relevant to this western guy [me] with increasing years, is the arrogance of our mindsets to the capabilities of the East.

There are quite literally many millions of bright intellects that are being moulded and trained, given the resources, it will be only a matter of time before technological parity in even the most advanced disciplines are reached.

Look at graphene and who has the highest patents recorded for it's use.

BBC News - Graphene: Patent surge reveals global race

To surmise, IMO, overall, the F35 is 7 years late, 20 years behind in performance and may well lose it's radar stealth cover <10 years, overall, a pretty poor investment.

Unfortunately.

Fueldraulics
 

Didn't the RR Speys in RAF/RN F-4s use 'fueldraulics' to power the nozzle actuators?

-RP

Spaz - Minimal maintenance LO is clearly a laudable goal. Indeed, if you didn't have dramatic improvements in that area, you might as well reassign the F-35B/C to 309AMARG right now and save a few pennies, because no previous LO design would be maintainable through a cruise without installing a very large, climate-controlled facility on the boat.

On the other hand, Mr O'Bryan's statement that the F-35's LO is better than anything except the F-22 has raised eyebrows here and there.

By the way: Interesting, n'est-ce quoi, that O'B considers that it is safe and noncontroversial to imply that the F-22's RCS is lower than that of JSF. Security-wise, that surely means that it is considered obvious, and indeed it is. But when Air Power Australia reached this conclusion the fans had a meltdown.

The "built into the skin" piece of the LO system, by the way, is a conductive element. There is a sprayed coating on top of that, which is described as resembling the anti-erosion polyurethanes used on helo rotor blades. It had better last a long time because it sounds like it would be a real :mad: to remove and replace.

One thing that has become more relevant to this western guy [me] with increasing years, is the arrogance of our mindsets to the capabilities of the East.

I've always thought that the most effective way of spending a tiny portion of your western military budgets would be to train 20% of your mid-ranking officers in Mandarin Chinese then send them off on a three month backpacking trip around China and SE Asia.

Have them walk around with their eyes open. Encourage them to speak with the people they meet. Then see how many return confident that the west still retains a qualitative advantage in most fields.

F-35 Cancelled, then what?

Hmmm, perhaps the Chinese would welcome new partners on Snowy Owl?

"Security-wise, that surely means that it is considered obvious, and indeed it is. "

Never mind obvious, didn't the USAF specify the difference?

Warplanes: F-22 Stealth Ability Revealed by USAF

I seem to remember they relaxed the F-35 requirement even further, to a beach ball sized RCS and started using the term Low Observability instead of Stealth.

More problems.

Lightning will ground F35 fighter jet known as the Lightning II

Low Observability Compromised
 

LO was compromised by theft of the drawings by the Chinese. There are a number of things that can be done to negate theft of drawings and documents, but possibly not enough to prevent negation of low observable design through the theft.

'Interesting' cost figures in that article. Hopelessly optimistic or hopelessly out of date?

Both, its from 2005. But I guess it was just under the price of a F-18 at the time, inflation, eh..


It won't lose anything, it will always be more difficult to detect and track. Why make it easy?

On topic, if the F-35 is canceled we can start another development that will be massively over budget, late and fail to meet expectation, while fighting with aircraft designed 60 years ago.

I find it impossible to believe that the defense industry will suddenly discover a method of developing new weapons on time and on budget, so its pointless to dwell on it.

Peter we,

Unless companies invest in technologies at their own cost and not as part of a project being paid for by a government. Rarely happens these day. R & D does pay for itself; it may take a while; but it does pay for itself.

When I write developing technologies, I do not mean developing a complete aircraft, just the packages involved. An example might be engines to be used for vertical take off, or a rather posh helmet that does everything. Off course there will be a requirement for integration in to a complete package int he future, but at least the basic technology should be there.

I totally agree, but a 25 year development cycle? How long is its replacement going to take to develop...half a century?

Probably just in time to use the last drops of oil :E

Makes the mere 102 days period from contract signing to prototype roll-out of the NA-73X (what was to become the P-51 Mustang) seem frankly astonishing - even for 1940.

Two points.

1. The short term option is more F/A-18E/F/G and F-16/F-15 with the updates offered at low/no cost.

2. The next generation is essential to keep the design teams together, even of not put into mass production. In fact a strong recommendation is to keep designing prototypes and buying 1-2 Sqns of each for exactly that purposes, so the skill is there when you need it.

The USN has already started on the next generation.

That whole RVL is just so....yesterday..

It will be ten years late, cost 500Milllion each and be below specification.

Probably best to cancel now and look at its replacement, which will be a disaster too.

The F-35 is the best the USA/UK can do at this time, it isn't going to be any better next time.

Beat this, less than 90 days

Heinkel He 162 - Wikipedia, the free encyclopedia