Supersonic stealth jumpjet passes hover thrust test The F-35B supersonic stealth jumpjet which will replace the famous Harrier in the British and US forces has successfully completed "hover pit" testing, according to lead maker Lockheed. The company says that the plane is able to generate 550 pounds more vertical thrust than was required. The F-35B in hover pit trials at Fort …
Fans in wings hasn't been part of this project for at least a decade, if they ever were. Sure you aren't getting mixed up with the V-22 Osprey?
One reason the RN favours STOVL aircraft for carriers is that you can operate them in much rougher seas, because you can cope with much more ship motion. The USN does a lot of its training off Florida and California while the RN trains north of Scotland. STOVL landing are also easier for the pilot to carry out, so there's much less requirement for continual practice. It means you can deploy a naval squadron to do something from land, and not have to have an expensive re-certification process for carrier landings later.
If we're going to have carriers, this does look like about the best way, provided they can create a decent airborne radar system. Can we afford them? We'll, I'd cut ID cards, the NHS Spine and the super-database of all phone calls, e-mail and web sessions first, but that might not be enough.
if a pilot takes off from a carrier and for some reason has to land quickly thereafter, he has to dump his fuel and (expensive) armament in the ocean before he can land? Sounds like a good idea if you're the guy selling armament, but to us taxpayers, not so much. Who thought-up this idea? Haliburton?
So, this generates 1% more thrust than it needs. Er, and they expect people to fly in it?
Anyway, how much is jet engine performance affected by atmospheric conditions such as altitude, air temp and humiidity? If you only have 1% spare in test conditions, how much will you have spare in the tropics?
Tim#3
Pirate Dave, I do agree with what your saying but if every permutation of a mission going wrong was thought of then nothing would ever get built.
And I believe they could do a trickier but still possible rolling landing with the ship and the plane moving forwards. Its bloomin' hard to do but if anyone can our guys can!
This is good news for the project and hopefully it will be delivered on time....actually hopefully its late so it will be able to tie in with the carrier project which will be (if it isn't already) late.
Us here in Blighty have a V/STOL aircraft for the last 40ish years. It's proven tech, why don't we spend our development GBPs on turning this is to an improved aircraft, installing computers to make it easier to fly, improved warfare capability, etc, instead of relying on a American concept that'll only work off a carrier on a cool day in the Doldrums?
Traditional carrier based aircraft also do this if they encounter a problem just after take off - the arrester equipment is generally not designed to catch a plane full of weapons & fuel. Also the last thing you want landing is a faulty flying object full of somewhat flammable liquid and lots of things that go bang
The original tests made using a grated pit essential because landing on a solid surface caused the engine to ingest superheated exhaust gas which reduces thrust while causing the engine to backfire or worse yet implode....just a little something they forgot to mention.
So imagine wanting to land but first you have to find the grated pit, then hover and pinpoint land while at the same time being shot at.
I'm sorry, but that's just worthless! Sure, it looks impressive to the press and the gaggles of aviation buffs, but when you get down to it, how's the damn thing going to react when you try to put it down on a regular road or in a field? This thing is still a turd. It's biggest flaw is the central "fan". If it's sensitive to hot exhaust or debris then I see this as nothing more than a waste of money for everybody who buys some.
Surely they mean "As Much As"* or "Upto"* 500lb more thrust.
*On a good day, cold air, no following wind, and only if bought in quantities of 50 or more. Please ask your dealer for more information - just before you land. Warranty applies in the US only. Fuc*k the rest of the, er, er, wazzit called now - world?
In case anyone has wandered in off the street and doesn't know the real reason behind the lack of rubber on those wheels, it's this - it's so they can tie the sodding thing down properly. Nothing quite so embarrassing as having your nice new shiny STOVL WhizJet disappearing rapidly skywards as the frantic testpiglet screams blue murder at the Avgas-addled Groundies who forgot to secure him properly...
The main excuse for buying the JSF instead of further Harrier development seems to be that the JSF is "stealthy" and that Harrier is not - nothing to do with improving things for the aircrew or groundcrew. GR5s had an auto-handling system on them when first introduced - it was one of the things Brutish Waste-O'Space was so proud of at the time. And if they'd been allowed to let Rolls Royce carry on developing the Pegasus as they wanted to instead of trying to con the RAF and RN into buying into the JSF project then we wouldn't be looking at the wrong end of yet another MoD procurement plan going from a flyaway cost of "almost peanuts" to something resembling the next Zimbabwean banknote denomination...
Mine's the one with "GR5 Pilots Do It Both Ways" and "We designed it - they f**ked it up!" badges...
AC@12:40
I thought in the original prototype the vertical thrust was from fans in the wings?
You appear to have slipped about 4 decades. That would be the Ryan "Vertifan."
Peter Gant
"this future point ONLY VTOL aircraft and helicopters will be able to use the carriers."
IIRC all current UK carrier operations are done with Harriers (VSTOL) or helicopters already.
i believe we managed to clear that Debt off around 2001 or so.
but then the USA got more than just a few thousand tonns of gold (and everything including the kitchen sink.)
they also got cartblanch veto (outright theft of patents) control on all patents issued in the UK: the precursosr to transistor technology, the jet engine, the RAMJET Hypersonic jet aircraft, the supersonic capable tailfin, all the biochemical warefare tech the uk had, all uk nuclear techology, free reine to impose anything they liked on the UK population.
in return we got shafted, bancrupted (several times), dragged into a number of very nasty wars that we should not have been involved in, MTV (probably the most socially damaging thing that could be imposed on any society, barring DALLAS, 90210, desperate houswives, (c)RAP, GI's)
We now have a society that is fragmented, ghettoised, with hostile ethnic factions with extremist views and agendas, all thanks to the liberal american ethos having been stuffed down our throats till the ~$%& hits the fan and serious disturbances and social upheaval takes place.
ME!, i'd rather live in the USSR, its probably safer there than the US or UK anyday....
oh here's me coat, im off........
Actually, Britain finished paying for WWII two years ago
http://news.bbc.co.uk/1/hi/magazine/4757181.stm
However, Britain still owes the U.S. for WWI, and is in turn owed an even larger sum by other countries (presumably within the Empire) that it loaned money for the Great War.
Tony.
"all current UK carrier operations are done with Harriers (VSTOL) or helicopters" or from the deck of a RN ship looking on at the US carriers steaming alongside us? Somehow carrierborne aviation has never been gotten right over here... from the early lead with HMS Argus, through the highly advanced HMS Ark Royal in the 1930s, to the modern era (the Invincible class design could have been sold internationally instead of those ships that all resemble the Principe Asturias of the Spanish fleet - imagine the extra dosh of having the shipyards churning out a half dozen of those to friendly nations over the last two decades, with extra cash from selling Harriers and maintaining them). About the only true success story was recognising the Fleet Air Arm of the 30s/40s was pants and putting steel decks on the Illustrious and Formidable class carriers for WW2 so the ships could survive.
PS. Fans in the wings? Dirge the Decepticon!!
From what I understood these planes were extremely cost effective, which is the primary reason the US is going to try scrapping plans to buy more F-22s. Instead they know they can buy a shit load of F35s, which may not be quite as good as the F-22, but still well ahead of most competitors.
The only question I have is does this mean the end of the Eurofighter? It should. If we're getting planes that are just as good and cost significantly less for the Navy, then surely we should be doing the same thing for the Air Force.
I seem to remember that the main reason there was so much negative press over the F-35 was that it could put it's competitors out of business, at least it would if governments had any sort of realism when it came to defense spending.
So they cooked up fake stories about what it couldn't do before it had even made an appearance as a prototype. For some reason military buffs bought into this, despite the obvious bias of the sources.
Never mind, I'm sure the Eurofighter will continue to arrive in tranches and the F-22 will survive. Politicians with lobbyists and campaign contributors to protect won't let either project disappear any time soon.
To be honest I thought Lockmart would find a way to kill this variant. After all with Uncle Sam having a carrier fleet with runways they could play the why bother card. Of course that would screw the UK (rather like cancelling the TSR2 on the promise of the UK version F111). They have actually got it working. I'm guessing this has more to do with the clout of the USMC than Mr Broon however.
And regarding the fact that vertical thrust is *only* 500lb greater than full load.
So what. Unlike physics book questions the vehicle's mass is continually falling as it burns off fuel. You'd have to throttle *down* to maintain height. Now the *real* question for UK aviators is can it hover in the sort of conditions where the Harrier has to ditch weapons to land.
Yes a redesigned Harrier would have been great. But it would have needed a *very* substantial re-design. Whipping off a wing and most of the body to get the engine is completely unacceptable in a modern design. An aircraft that only flies at full spec over Western Europe if your planning to operate globally is not a good idea either.
So a good start. But we'll see what happens.
IIRC the RN also invented the steam catapult. I still find it surprising that the Harrier (bit like the Buccaneer before it) did not seem to sell abroad. 1st rate engineering (given the budget and schedule) with 3rd rate marketing. I suspect that the decision to have no radar option at all until the Navy Blue Vixen unit (no idea how well this actually works) probably did not help. Some times its better to give the customer what they want, regardless of wheather they will actually use it.
I think you missed the point...
The article is about Lockheed rolling out the fanfares and dancing girls for something that their poor cousins in merry ol' England did yonks ago (even with bad teeth and funny accents).
Supersonic? Stealth? Pah, mere distractions. In the end it all comes down to the nut behind the joystick and I'd rather have our nuts any day, whatever they're flying.
F35? I remain unimpressed. To quote Vader, "Don't be too proud of this technological terror you've constructed"
@Pirate Dave:
> if a pilot takes off from a carrier and for some reason has to land quickly
> thereafter, he has to dump his fuel and (expensive) armament in the
> ocean before he can land?
In an emergency you ALWAYS dump fuel and armament, even on a conventional carrier.
The only emergency where you do not dump the armament is when your bombs got armed before you drop them, in which case whatever harsh you do would detonate them: landing on a carrier, dumping the bombs, ejecting. The only thing you can do is a soft landing on a land base, then wait for the EOD.
The problem with the Harriers is that in hot weather they do not have the power to land vertically with unexpended armaments.
Now, the question is: I have never heard about the Italian Navy dumping AMRAAMs when landing on the Garibaldi. Neither about the Marines doing the same. What is the problem with British Harriers?
The hover pit is to simulate hovering in free air - it's not what they will actually be landing on. The 1% excess is what the engine produces over and above a performance requirement - it isn't a 1% margin for normal operations.
Also, as Lewis reported back in mid-Feb, the intention will be for the F35B to use a short rolling vertical landing as a standard procedure for the RN carriers as it will allow it to land with more stores.
As for other comments about spending money on improving Harrier instead, well that happens anyway. Doesn't mean we shouldn't also be thinking about replacing them with something faster, stealthier, and newer; there's only so much you can do with a 40 year old airframe that will be closer to 50 years old when the F35 enters service! There's still plenty of Brit know-how going into the F35 - Lockheed may be the lead, but BAE Systems are still a major partner. On a project this big (the largest military aircraft project ever), you get plenty of economies of scale, and therefore more bang for yer buck.
Oh and the lift fan is actually a pretty effective means of delivering a STOVL capability while maintaining decent conventional performance. When you have a highly specialist engine as you have with the Pegasus in the Harrier you sacrifice a lot of wingborne performance due to the arduous path the jet exhaust takes through the nozzles. The beauty of the lift fan method is that when it isn't required the jet operates pretty much as a conventional one and hence allows the jet to get much closer to conventional aircraft performance. The F35 jet obviously has considerable specialisation due to the rotating rear nozzle, but in conventional mode it is much closer to a conventional jet than a Pegasus. Yes there is a fair amount of "wasted space" when in conventional mode as the lift fan is just dead weight, but when you consider the other options it actually ends up being one of the more efficient solutions. The main issue is sorting out the gearing so the jet can cope with a huge great fan suddenly needing to be spun up mid flight.
"Anyway, how much is jet engine performance affected by atmospheric conditions such as altitude, air temp and humiidity? "
Well, there may be some small variances due to tides, but I'm pretty sure that sea level + deck height will be near enough the same all over the world, so I guess the effect of altitude on engine performance can safely be forgotten about. Unless of course, sea levels rise significantly over the next 50 years that this thing might be in service for. But no-one's made any suggestion of something like that happening have they?
You sir / madam or thing get the Laugh of the Week award.
My grandad (worked for Martin Baker in the 40's and 50's and had so many stories of what went on when testing aircraft, seats, canopies and when investigating what had gone wrong when there were accidents) would have loved "test piglets".
Though he had a lot of respect for those who went up to check aircraft out for the first time. Slight dearth of computer sims in those days....
"Anyway, how much is jet engine performance affected by atmospheric conditions such as altitude, air temp and humidity"
Quite a lot.
Jet engine performance varies depending on the *mass* of air it sucks in and how much energy it adds to the flow coming out of the back. NB temp in this case is measured on Kelvin or Rankine scale. 25c to 50c does not half the mass flow by doubling the temp. Its more like 8%.
Engine inlets have a maximum *volume* of air they can take in at any one time.
Warm air is less dense than cooler air. So either you put more energy in and accept higher fuel consumption or accept less thrust at higher ambient air temperature.
But VTOL aircraft are a special case. Most aircraft have engine thrust roughly 1/3 of their mass. Very few aircraft come close to achieving vertical climb (F15 and BAe Lighting IIRC). But F35b and Harrier do so in *ground* effect where they are also ingesting recirculating hot exhaust into the inlets. So average temp of inlet air is higher than surrounding (which might be pretty hot anyway) giving a performance hit just when you don't want it. What works fine on the East German border (when there was an East German border) is a different ball game in Iraqistan.
And dealing with that problem is one of the things that makes VTOL tricky to get right.
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