Trying to put myself in the position of the MoD re Harrier sale.
The only likely buyer is the USMC.
They offered us more than scrap.
They are going to an ally.

Did not the same situation exist in 1940 when we got those 50 destroyers off the Yanks?

and MoD is not in the business of speculating on the possible delays to the F-35B, especially as that would be betting against current policy.

Keeping it on the F-35B, I would now expect the US to be a bit more favourable towards us over it's future. It looks like that may have happened with Barak giving Dave a quiet word in his shell-like over current difficulties. They still seem to be keeping the Canadians in the dark over F-35 costs.

hval
 

I think the simple answer to all your questions is no. In the early days engine reilability was seen as vital to the future of jet VSTOL. Usually reliability gets better as you avoid complexity. In 1964 the Pegasus I flew had a 1 hour life with the nozzles deflected (25 hrs nozzles aft). Whenever it was pulled after the hour was up and went back for a strip overhaul there was always one blade missing in the hot end so the life allowance was hardly ultra-conservative. I don't know what thrust that engine would have produced at 50 deg C but I would guess about 8,000lb. Today's donk offers over 24,000 plus goodness knows what life - I lost interest once it passed 1000 hrs years ago.

There was continued development of the front end blade shapes and much more importantly big improvements to the hot end. In the end the Pegaus was FLAT RATED to 50deg C ambient. Or if you are not familiar with the significance of that in plain English it translates to the pilot only had RPM limits and could turn his back on JPT instead of checking that with evey third breath as was the case in earlier times.

With a powered lift aircraft you must control the thrust centre in the hover in the same way as the CG in normal flight. (sorry if I am teaching granny to suck eggs)

Not quite... The USAF retired the last bomber-version F-111 in July 1996, and the last EF-111 in May 1998.

The only other user in the world, Australia, retired theirs in December 2010.


So the USAF only used the F-111 for 30 years, and the RAAF used them for 37 years (delivered 1973).

Apologies Green Knight, I stand corrected.

JF - "Usually reliability gets better as you avoid complexity."

So true. Thank goodness that the F-35B is a nice, simple system with two propulsion units, a clutch, 90-degree 20MW reduction gears, four thrust nozzles, a blocker valve, a set of cascades and nine cover doors. :E

Actually, I tend to agree with Engines that making all this work is a miracle of engineering. I do worry that it will always be a bit of a bear from the maintenance aspect.

I read somewhere that one particular inspection hatch has 20 different screws, all of different lengths. Just to save weight
Can that make sense??? If its true, and typical, the possibility of a screw-up in maintenance must be considerable

Milo,

The aircraft with a hatch with 20 plus different lengths of screws is - Typhoon. That aircraft had an equally massive (but unreported) weight problem during development. Actually, most combat aircraft have a weight problem at some time. STOVL brings it into sharper focus as the weight vs. thrust equation is fairly black and white.

I can tell you that every panel on JSF was carefully looked at to get weight out, and the teams doing this had a lot of input from highly skilled and experienced maintainers.

The best solution from a maintenance aspect would be one size of fastener over the whole aircraft. Not practicable, so the next best choice is one size in one panel. If you can't bear that weight, things are more complicated and you end up trading fastener size and length - neither the best choice.

On one JSF panel I remember we ended up going for two different fastener sizes, far enough apart to make it harder to use the wrong tool. JSF has lots of panels (good for access) so lots of fastener issues to address.

As far as the multiplicity of nozzles, hatches and covers go, well that's what you get when you ask an LO supersonic aircraft to have a minimum flying speed of zero. I have to admit to getting ever so slightly miffed when people get sarcastic over that truth.

I suppose what I'm trying to put over is that the JSF team have done their level best to cover all the angles and meet the specs. The most onerous specs were in the areas of logistics and maintenance and they have spent a shedload of time and money to get to the best answers they can. They have also used highly talented people. Have they got everything just hunky dory? No. Have they done damn well? Hell, yes.

Best Regards as ever

Engines

Why Major Acquisition Programs Fail | AVIATION WEEK

The link takes you to an Aviation Week item from a few weeks back. Not a technical piece but easy reading, and I could certainly recognise the traits discussed in military programmes I have observed over many years. It isn't F35-specific and it's short on answers, but then so are we all. While finances stay tighter than a duck's posterior, it's very important we do things different next time. If we are awash with cash then you just keep spending it until it does what you said it would, but it's hard to see when those days might return. I see the USAF have also recently said their budget for F35A will not increase, so if the price goes up, the units purchased will come down.

It's part of F35's woes that it is facing unprecedented (in recent times) global financial headwinds. In other times, it might have raised much grumbling but the bills would have been paid. Equally, there seems to have been some very optimistic assumptions. Over-confidence in CAD for instance, that has delayed the programme to the point where it has been caught in a financial storm it might otherwise just have sneaked in front of and missed the worst.

I have no doubt that lots of people are now shedding blood sweat and tears - and then some more - to try and get it back on track. The cost is now out of the window and it's too late for it to be anything other than really ugly (not that it's the first military procurement to suffer from that). The acid tests now will be that the output matches or exceeds the input ie it meets the KPP's, and that it is still relevant when we get there. I wish the people charged with the responsibility for the first bit the luck to match their efforts. The second bit, I just wish all the users waiting for it all the luck in the world too.

Engines, nice post - as was your call to celebrate the uk engineering contribution to JSF earlier.

Was the typhoon panel you mention the avionics bay panel? Wasn't this also structural? Were the bolts captive?

"That's what you get when you ask an LO supersonic aircraft to have a minimum flying speed of zero."

Very true. I don't think anyone could have done much better, except perhaps the Macs design with a main-engine blocker and pop-out nozzles and a lift engine.

But nobody said in 1995: "Errrmmm... it's taken 30 years and the testing of all kinds of weird-looking aircraft to get where we can think of supersonic STOVL - and now we want LO as well?"

Or, quite possibly they did, and were told: "Don't bother your head about it, sonny, because it all has to do with stealth, and all you're cleared to know about that is Oooh-ee Oooh-ha-ha Ping Pang Walla Walla Wing Wang. Now :mad: off."

Aircraft carrier costs will be half what you think, US tells ministers - Telegraph

The septics are stepping in to the argument to tell us to stop messing around!

Well that changes everything!

if the US are willing to GUARANTEE the cost will only be £ 400 miilion its an easy decision (tho the rip-off merchants building the crarriers will have to find another way of charging squillions for their bottom line)

if the US are saying their best estimate is £ 400mm then I think we'd look at their own record of forecasting costs on the B-2, F-22 and F-35.....................

Referring to the spirilling cost of conversion a few days ago, Not_a_Boffin noted:

After today's revelation in the Telegraph, it looks like he may be correct and the programme office are finally stepping away from the "Conspiracy of Optimism" that has underpriced this, and many other projects, for the last few years.

This must surely silence the sceptics for now, let alone the septics.

Well, well, well. I wouldn't have put 'Spreadsheet Phil' down as a natural proponent of the Hokey Cokey. Perhaps he will give us a verse or two when he comes to make his announcement to the House Of Commons. Well done, Not_a_Boffin. Seems you got there before the USN did.

Meantime, Norway is gagging for F35 (helps if you have one of the few remaining strong economies in the West, underpinned by buckets of oil) Norway May Speed F-35 Buy | Defense News | defensenews.com, and Mr Kopp and Mr Sweetman, well-known F35 antagonists, would have it that the 'injuns' are already lying in wait in the rocks above the pass, armed with new bows and arrows and waiting for the coyboys to arrive. Fighters, Missiles For Countering Stealth | AVIATION WEEK

Aircraft carrier costs will be half what you think, US tells ministers - Telegraph

Another interesting development reported in the Telegraph. Who knows perhaps good ol' American common sense will prevail and prevent the UK Government from another supreme act of folly?!:}

FB:)

LF - Some wacky translation in that Noggy WP. Generally speaking, "speed" (v.) does not mean "delay by four to six years versus the program of record", to wit:

http://www.jsf.mil/downloads/documen...ate_4_2010.PDF (page 88)

The PSFD memo is old, of course, but there have been no official changes communicated to the US since then. This may explain why the Norwegian defense minister was characterized as "weasely" by US government people dealing with JSF (thank you Wikileaks).

The UK's "better pull a quick 360 and get the hell outta here" maneuver follows some interesting comings and goings - let's just say that there's more involved than USN pilots looking forward to exchanges on ships with more beverage options than Coke - and the Torygraph echoes the Standard's story cited a couple of pages back.

And may I echo the fact that Mr Boffin was right as usual. The horrors of SRVL may be avoided, and (for Mr Boffin) the even greater horrors consequent on the adoption of SRVL as routine procedure, on account of rash commitments made on these pages by said Boffin, recede into the dark corners of nightmare.

Don't shoot the messenger
 

Somebody told me that mixed up in this whole sorry B/C story is that the power supplies of the boat will have to be changed (whichever type of cat) and there is some concern about the modest top speed of the class as well.

If the power supplies do have to be replaced, does that not negate the argument, put forward by the manufacturers, that the ships are easily convertible into one configuration or another? I should think, getting power supplies out of a ship, once it's already been built, is a potentially prohibitive operation...though I have absolutely no clue what I'm talking about here.

Yes, sorry about the 'wacky' language LO. I got a bit carried away by a beautiful spring morning and I have now had my medication. Anyway, Lockheed Martin started it by calling the F35 'Lightning'.

I am now totally confused as to what is or is not going to be announced, if anything, about carriers, cats, Bs or Cs.

• The cost of a catapult is prohibitive... or not
• The B is cheaper....or not
• The US is going to cancel the B...or not
• The QEC engines can take it....or not
• We can afford it - well that's not or not either way
• We are going to buy the more capable C...or not.

It's all getting so muddled that I am almost resigned to waiting to hear what Phil has to say...or not.

The other angle of this is La France - and the cooperation Treaty we signed with them last year on matters naval and nuclear. If we go back to Dave-B (and pls God, make this stupid idea stop) then La France is rather stuff-ed whenever Port-Avion CdG needs to be fixed.

So according to the last rumor I heard, Dave is getting it from Barack and from Sarko: Dude, don't do the stupid thing....!

S41

Mr Boffin says that there enough volts to do the job. It needs software changes and cables. And a bloody great plug.

What of it, if you don't mind me asking?

Quote:
Lockheed Martin started it by calling the F35 'Lightning'.
WW,

Simply that I associate 'Lightning' with something that arrives very, very quickly. F35 is, at a guess, 10 years away, maybe more, and some versions it seems may never arrive at all.

from all I've heard and saw this catapult is essentially nothing more than an, albeit complex, linear electromotor not unlike the system used for a MAGLEV.
Therefor it is not without logic to think that it will draw its power for each shot from a buffer aka a set of capacitors, this would not require an overwhelmingly large dimentioned powercable from the generator to the capacitors, it'll probably have ample of loadtime (30-45 sec) to prepare for the next shot.
Therefor high peakpower from the generator is probably not required even with 2 (and in the case of the US NAVY 4) CAT's in constant use at its highest possible rate.

AKAIK the US NAVY CVN's must be able to launch 4 planes every 90 seconds at the least, but probably don't better 4 every minute which gives about 1 minute between every launch per CAT.

The current configuration is a bit more steampunk. The juice spins up a bank of seriously big-a55 motor-flywheel-generators which store energy kinetically. Throw switch, dump energy rapidly into cat. SHAZAM! Capacitors are under study, not ready for Ford or PoW.

As for the name Lightning - it reminds me of the scene in To The Manor Born where DeVere tells Audrey (Penelope Keith) that his new horse is named Fearless, and she responds:

"He's a coward. Horses are always named for the opposite of what they actually are. If you ever find a horse called Utter Rubbish, buy it."

Ms Keith was superb in The Good Life, too, but was always upstaged by the dynamic phenomena occurring in Felicity Kendal's shirts.

Mmmmmm, Felicity Kendall........

Right - back to electrickery. The link below gives the details on the EMALS system.

Electromagnetic Aircraft Launch System (EMALS)

The main difference twixt the CVN78 fit and the QEC fit is that for CVN, you have a power generation grid that is separate from the propulsion system, ie the kettle generates electrical power via turbo-generators, but the main propulsion system is geared steam turbines. On QEC, the main engines (two Trent GTAs and 4 Wartsila diesels) generate electrickery (about 110MW) that powers both the ships propulsion system (four 20MW electric motors, scaled up from the T45 plant) and the ships service load. The only difference I can think of is that CVN probably distributes electrical power at 450V AC 60hz, which is what the "Prime Power Interface" will see, whereas QEC distributes shipwide at 11kV AC, but steps down to 440V 60hz for zonal power supplies.

I'm far from being an expert in electrickery, but would have thought that the PPI shouldn't be too difficult to modify to accept 440V. As noted previously, there will have to be work done on the QEC power management system, but it should only be accepting another pair of loads (cat 1 and cat 2) of some small MW. That will cause some balancing issues but nothing that shouldn't be possible to overcome.

As far as "convertible" goes, there appears to be a bit of a misunderstanding. The meaning of the term was always that if during the design, build or service life of QEC, the STOVL option became a non-starter or was superseded by a CTOL aircraft or UCAV, then the design of teh ship was such that cats n' traps could be accommodated. What this actually means is that there is enough space to accommodate cats, recovery deck and safe parking areas, there is enough spare volume in the gallery deck to fit cats n traps of whatever flavour and that there is sufficient weight provision in the stability and structural calculations. It was never intended that you could just plug and play - what it meant was that the ship was essentially capable of conversion without starting again.

IMO opinion the limited speed of QEC (which was one of the early performance trades) might have an impact, but not due to EMALS, more an operational issue when trying to recover aircraft with light winds from astern on the MLA. That basically means you have to turn away from your desired course and work up to a fair speed to have sufficient wind over deck for the cabs to land. You pays your money and takes your choice, it's a minor PITA, rather than a real showstopper.

About the EMALS, I was just attempting a best guess how it is set up,
Capacitorbanks or flywheel as a buffer, it doesn't really matter I guess but still,
thx for clearing things up.

BTW, I'm certain that I've read somewhere ,over here or on the keypublishing
forums or somewhere else, that the speed of the carrier is supposed to be a lot less important for the use of the EMALS-CAT, even the heaviest planes at MTOW can take off with 0 wind over deck.
The more gradual acceleration and higher total power is supposed to make the EMALS superior in those regards vs the old C11 and C13 steam cat.

ALso the speed for landing is high enough for CDG to work with all its planes, also only 28-ish knots and that is even smaller than the future UK CVF.

just a follow up question.

All this made me wonder, why doesn't the RN opt for a Nuclear propulsion
for their carriers?
Sure it must be a little more expensive to install (200 million $ per reactor acc. to US NAVY) but so is fuel I would guess, also it would have gotten rid of the exhaust, made for a better smalller island , and limitless 20 year full speed, I would think?

Not that it would need to be a British design, but an American of the shelf reactor like the new A1B on the CVN78 would have done the job , no?
+150000HP is about what you get now with the complex setup of no less than 6 powersources, all of different size and even different fueltypes (GAS and diesel).

https://netfiles.uiuc.edu/mragheb/ww...Propulsion.pdf


Or is this just a dumb question on my behalf ?

It seems to me JSF is flawed by trying to be too many things-

Replacing F-111s for the RAAF at one end of the spectrum to Harriers and A-10s at the other. oh, by the way, can you also make it to be the second best fighter around (after F-22) for the next 30 years. I'm half surprised it was not pencilled in for tac airlift too.

It seems to me the B model should have been a seperate machine - a Harrier 3? Perhaps then we would have two winning machines on the verge of entering service.

Can anyone enlighten me what plans were afoot for a next generation Harrier before it got swallowed up into JSF?

I would also be interested to know - was differential vectoring of thrust ever tested on a Harrier? By that I mean keeping the aft exhausts pointing backwards and rotating the front ones down (slightly). I always thought it would give a massive boost to turning performance - although at the cost of another button to switch between 2 and 4 nozzle vectoring.

The carrier speed doesn't affect EMALS which is indeed a zero wod system. Nor does it prevent recovery. Low speed just adds a level of operational embuggerance in certain scenarios , that's all.

As for a kettle powered ship, you have to realise that the decision was taken in the mid-90s, when all of a sudden the decommissioning costs of nuclear ships began to look scary (see the sixteen or so old subs we still have floating in Rosyth & Devonport). The lack of somewhere to store the waste at end of life and the high costs basically killed it without much in way of detailed study.

Given the current debate about PWR3 and UK reactor design capability, a few years later might have brought a different conclusion. Difficult to say really.

Wasn't the F-22 going to be the Lightning II as well, until someone thought that Raptor sounded cooler?

At appx £200m an aircraft ,with Spitfires /Seafires on the market at £2m each,I think it would be much better if this F-35 was ditched and we bought some quality aircraft instead....Much better for the anoraks,sound better,look better,quantity over perhaps quality;;; As the USAF blame the pilot for the loss of an F-22,because of a design failure,what will happen when someone ditches one of these `wonderful`5th generation warbirds..... What a `waste of space`; who are we presumed to be going up against anyway..? China..? NKorea..? bunch of Somali pirates ?

Fascinating thread-thanks all.


Now that does beg the question, did anyone presume in say, 1980 that a war with Argentina would be on the cards within a couple of years?

With regards to the nuclear propulsion; the only conclusion that I can come to, is that non-nuclear propulsion looked good for short term finances for both its construction years and the years following the end of its service life...the labour government was all about making the numbers look good, even if the underlying truth wasn't good!

Windspeed, a question.

The F35C doens't need any windspeed to get launched at MTOW with the new EMALS, that much seems to be clear now.
What about the F35B, could that lift off with a skijump at MTOW but without
windspeed over deck ?

The non-nuclear decision predated the election of the Smiling Menace and his mate the Financial Genius, believe it or not, when the ship was called CV(R). Yes, the gestation has been that long!

As for whether the B will do MTOW with zero WoD/ski-jump, I don't know. ISTR the requirement may have been for that, but don't know whether that stuck. Engines will probably know, but not sure whether it's releasable or not.

kbrockman
 

Windspeed over deck is a landing problem for a trap. Too little and you have the hook out or break the wires.

too little wind on landing
 

That's how I figured it would be, I was specifically talking about the
take-off fase.
However, your remark got me thinking, would the 25 knot speed of the new CVF's be to little, to slow ?

As far as I know, the French carrier sails at max 27 knts and it seems to do ok, also with E2 , C2 and the heavy superhornets, no?
Also don't the Naval aviators usually also practise landing on a simulated
portion of dedicated airfields that have a Carrier deck layout incl complete Arrestor wire systems ?
They don't move forward and therefor don't have an extra windcomponent, granted the planes are probably at or close to minimum weight when landing meaning lower app speed and lower stress on the frame , but still ?

Somewhere in Russia;
http://www.9abc.net/wp-content/uploa...1/8/2922-1.jpg

It's the NITKA facility in the Ukraine actually, and they are rumoured to be about to rent it out to the Chinese and/or the Indians in the near future as well as the Russians!

As to the CVF speed, officially 25+ knots. The 'plus' bit is telling to me. The RN has a track record of understating the top speed of it's warships, for years the Invincibles were quoted as being capable of 28 knots, but in the last decade the figure seems to have been revised to 30 knots... I iwould personally be surprised if the CVFs could only do 25 nots in service, but it should also be remembered that Wind-Over-Deck is normally composed of ship speed and local wind, hence the order to 'turn the ship into the wind' before flying operations commence. Nil wind conditions certainly are a factor, but by no means the norm for carrier ops.