F-35 News

[GDA_Fear]

Desculpem minha ignorância, são dois motores (duas fontes autônomas de energia) ou apenas um motor que gira uma hélice na parte da frente da aeronave através da tomada de força?

se eu entendi bem aquela tomada de força alimenta o motor.

[soultrain]

Parecido, aquele eixo alimenta não um motor mas uma fan, patente comprada da Yakovlev Design Bureau.

[soultrain]

Trillion-Dollar Jet Has Thirteen Expensive New Flaws

The most expensive weapons program in U.S. history is about to get a lot pricier.

The F-35 Joint Strike Fighter, meant to replace nearly every tactical warplane in the Air Force, Navy and Marine Corps, was already expected to cost $1 trillion dollars for development, production and maintenance over the next 50 years. Now that cost is expected to grow, owing to 13 different design flaws uncovered in the last two months by a hush-hush panel of five Pentagon experts. It could cost up to a billion dollars to fix the flaws on copies of the jet already in production, to say nothing of those yet to come.

In addition to costing more, the stealthy F-35 could take longer to complete testing. That could delay the stealthy jet’s combat debut to sometime after 2018 — seven years later than originally planned. And all this comes as the Pentagon braces for big cuts to its budget while trying to save cherished but costly programs like the Joint Strike Fighter.

Frank Kendall, the Pentagon’s top weapons-buyer, convened the so-called “Quick Look Review” panel in October. Its report — 55 pages of dense technical jargon and intricate charts — was leaked this weekend. Kendall and company found a laundry list of flaws with the F-35, including a poorly placed tail hook, lagging sensors, a buggy electrical system and structural cracks.

Some of the problems — the electrical bugs, for instance — were becoming clear before the Quick Look Review; others are brand-new. The panelists describe them all in detail and, for the first time, connect them to the program’s underlying management problems. Most ominously, the report mentions — but does not describe — a “classified” deficiency. “Dollars to doughnuts it has something to do with stealth,” aviation guru Bill Sweetman wrote. In other words, the F-35 might not be as invisible to radar as prime contractor Lockheed Martin said it would be.

The JSF’s problems are exacerbated by a production plan that Vice Adm. David Venlet, the government program manager, admitted two weeks ago represents “a miscalculation.” Known as “concurrency,” the plan allows Lockheed to mass-produce jets — potentially hundreds of them — while testing is still underway. It’s a way of ensuring the military gets combat-ready jets as soon as possible, while also helping Lockheed to maximize its profits. That’s the theory, at least.

“Concurrency is present to some degree in virtually all DoD programs, though not to the extent that it is on the F-35,” the Quick Look panelists wrote. The Pentagon assumed it could get away with a high degree of concurrency owing to new computer simulations meant to take the guesswork out of testing. “The Department had a reasonable basis to be optimistic,” the panelists wrote.

But that optimism proved unfounded. “This assessment shows that the F-35 program has discovered and is continuing to discover issues at a rate more typical of early design experience on previous aircraft development programs,” the panelists explained. Testing uncovered problems the computers did not predict, resulting in 725 design changes while new jets were rolling off the factory floor in Fort Worth, Texas.

And every change takes time and costs money. To pay for the fixes, this year the Pentagon cut its F-35 order from 42 to 30. Next year’s order dropped from 35 to 30. “It’s basically sucked the wind out of our lungs with the burden, the financial burden,” Venlet said.

News of more costs and delays could not have come at a worse time for the Joint Strike Fighter. The program has already been restructured twice since 2010, each time getting stretched out and more expensive. In January, then-Secretary of Defense Robert Gates put the Marines’ overweight F-35B variant, which is designed to take off and land vertically, on probation. If Lockheed couldn’t fix the jump jet within two years, “it should be cancelled,” Gates advised.

Tasting blood in the water, Boeing — America’s other fighter-plane manufacturer — dusted off plans for improved F-15s and F-18s to sell to the Pentagon, should the F-35 fail. Deep cuts to the defense budget certainly aren’t helping the F-35's case.

Humbled, Lockheed agreed to share some of the cost of design changes, instead of simply billing the government. The aerospace giant copped to its past problems with the F-35 and promised better performance. “There will not be another re-baseline of this program. We understand that,” Lockheed CEO Robert Stevens said in May.

But another “rebaselining,” or restructuring, is likely in the wake of the Quick Look Review. F-35 testing and production should be less concurrent and more “event-based,” the panelists advised. In other words, the program should worry less about meeting hard deadlines and more about getting the jet’s design right. It’ll be ready when it’s ready. Major production must wait, even if that means older warplanes — the planes the F-35 is supposed to replace — must stay on the front line longer.

Needless to say, that’s got some members of Congress up in arms. “It is at this exact moment that the excessive overlap between development and production that was originally structured into the JSF program … is now coming home to roost,” said Sen. John McCain, an Arizona Republican and the ranking member of the Senate Armed Services Committee. “If things do not improve — quickly — taxpayers and the warfighter will insist that all options will be on the table. And they should be. We cannot continue on this path.”
http://www.wired.com/dangerroom/2011/12 ... -13-flaws/

Resumo:

The Helmet mounted display system does not work properly.
The fuel dump subsystem poses a fire hazard.
The Integrated Power Package is unreliable and difficult to service.
The F-35C's arresting hook does not work.
There are classified "survivability issues", which have been speculated to be about stealth.
The wing buffet is worse than previously reported.
The airframe is unlikely to last through the required lifespan.
The flight test program has yet to explore the most challenging areas.
The software development is behind schedule.
The aircraft is in danger of going overweight or, for the F-35B, too nose-heavy for VTOL operations.
There are multiple thermal management problems. The air conditioner fails to keep the pilot and controls cool enough, the roll posts on the F-35B overheat, and using the afterburner damages the aircraft.
The automated logistics system does not work properly.
And the lightning protection on the F-35 Lightning II is uncertified, with areas of concern.

[Andre Correa]

O que encontrei foi isso:

Shaft Driven Lift Fan (SDLF)
Lockheed Martin developed the idea for a Short Take-Off Vertical Landing (STOVL) lift system that uses a vertically oriented Shaft Driven Lift Fan (SDLF). A two-stage low-pressure turbine on the engine provides the horsepower necessary to power the Rolls-Royce designed Lift Fan. The Lift Fan generates a column of cool air that provides nearly 20,000 pounds of lifting power using variable inlet guide vanes to modulate the airflow, along with an equivalent amount of thrust from the downward vectored rear exhaust to lift the aircraft. The Lift Fan utilizes a clutch that engages the shaft drive system for STOVL operations. Because the lift fan extracts power from the engine, exhaust temperatures are reduced by about 200 degrees compared to traditional STOVL systems.

The SDLF concept was successfully demonstrated through a Large Scale Powered Model (LSPM) in 1995-96 and during the flight-testing of the X-35B during the summer of 2001. The Lift Fan, a patented Lockheed Martin concept, was developed and produced by Rolls-Royce Corp. in Indianapolis, Indiana and in Bristol, England.

Fonte

Nessa imagem deixa a mostra que o eixo da turbina está ligada a Lift Fan:



E mais essa:



E aqui um Cutaway, em altíssima resolução, de todo sistema de motores e fan do F-35B:



Aqui outra informação:

Weighing less than 100lb and spinning at 8,000rpm as it transmits almost 29.000shp from the engine to the lift fan, the driveshaft met the orginal specification but had to be redesigned because of greater than predicted variations in length caused by airframe and engine build tolerances, thermal and pressure growth and maneuver deflection.



A redesigned driveshaft with a more-flexible bellows coupling will be fitted to production aircraft beginning early in 2014. Driveshafts in aircraft already produced, including the test jets, are being fitted with tailored shims, or steel spacers, to ensure they can accommodate the length variations in operation.

Fonte

Essa imagem, fora do assunto, mostra a comunalidade entre cada versão, expressada em %:

[PRick]

Que gerenciamento de projeto desastroso, como podem fazer tanta besteira junta? Parece que não aprenderam nada com o F-18E, estão repetindo tudo de novo com o F-35, a diferença parece ser que o projeto do caça não é ruim. Mas o resto está demonstrando que a cultura industrial dos EUA acabou.

[]´s

[Túlio]

O que coloca a Inglaterra no colo da França - ou abre mão em definitivo de ter NAes...

[Andre Correa]

Vão operar o CTOL, que é mais simples... é apenas mais um caça dentre os vários já navalizados ou construídos para tal, pois o problema mesmo está sentado no colo da USMC, eles sim vão ter ainda muita dor de cabeça com esse F-35B... Eu acho que o mesmo terá, em toda sua vida útil, apenas um usuário, que serão mesmo os Marines... Já a versão C poderá ser usada por qualquer um que deseje um caça navalizado 5G.

[soultrain]

O texto e o relatório, não são sobre o F-35B, são sobre todas as variantes.

[Andre Correa]

Diagrama da sequência de produção do modelo F-35C:

[pauloguita]

Que gerenciamento de projeto desastroso, como podem fazer tanta besteira junta? Parece que não aprenderam nada com o F-18E, estão repetindo tudo de novo com o F-35, a diferença parece ser que o projeto do caça não é ruim. Mas o resto está demonstrando que a cultura industrial dos EUA acabou.

[]´s

É Prick, realmente não aprenderam nada. Interessante nos americanos, é que eles conseguem fazer tijolo voar e ainda vendem centenas deles.
O F35 vai ser a mesma merda do F18, e vai vender mais ainda.
Mas não esquenta não, porque os paises que compram estes caças americanos, so os compra porque não vivem ameaça de guerra, então sabem que não serão usados em combate. Mas se o bicho pegar de verdade, ai sim tem que ser o rafale, pois so ele tem o sistema SPECTRAMAN. simplesmente invencivel.
Feliz ano novo.

[Hader]

É, não adianta nada... Ser educado virou sinônimo de fraco? Ser inteligente nas respostas foi proibido? A única forma de dar vazão a não concordância é ser grosseiro e deselegante? Parece que sim... Vamos longe assim. Falo isso de modo geral.

Editado para ficar mais claro e menos genérico.

O FDB é feito por nós, os usuários. Cabe a nós parar com certos comportamentos agressivos e jocosos que não levam a lugar algum. Acho que é hora de todos nós olharmos o espelho e buscar uma reflexão.

[]'s

[kekosam]

Se o F35 fosse um projeto tão desastroso assim, le ja teria sido cancelado. assim como centenas de projetos foram cancelados na história da aviação americana.

Acredito, Sunté, que agora o problema é, diferentemente de outros tempos, Time and Money. Time para desenvolver outro projeto sem ficar na berlinda do poderio militar e Money que já foi gasto no projeto F-35 (e que não foi pouco).

[FoxTroop]

Este projecto (F-35) é uma amostra do que espera muitas nações por este mundo se os USA conseguirem levar a sua avante e privarem a Europa da sua industria aeronáutica militar de ponta. Muita nação por este mundo vai passar a subsidiar ad aeterno uma LM ou Boeing da vida. Ou então vai ter de comprar russo, mas manuais em cirílico e painéis de cor duvidosa é coisa complicada, a não ser que façam com o "J" que passou uma tarde a converter os nomes de todos os camaradas do PLT para cirílico de modo a saber que PECTOPAH é restaurante e não passar vergonhas. Ou então o Ching Ling, mas se cirílico já faz dor de cabeça.......

[Túlio]

Que gerenciamento de projeto desastroso, como podem fazer tanta besteira junta? Parece que não aprenderam nada com o F-18E, estão repetindo tudo de novo com o F-35, a diferença parece ser que o projeto do caça não é ruim. Mas o resto está demonstrando que a cultura industrial dos EUA acabou.

[]´s

É Prick, realmente não aprenderam nada. Interessante nos americanos, é que eles conseguem fazer tijolo voar e ainda vendem centenas deles.
O F35 vai ser a mesma merda do F18, e vai vender mais ainda.
Mas não esquenta não, porque os paises que compram estes caças americanos, so os compra porque não vivem ameaça de guerra, então sabem que não serão usados em combate. Mas se o bicho pegar de verdade, ai sim tem que ser o rafale, pois so ele tem o sistema SPECTRAMAN. simplesmente invencivel.
Feliz ano novo.

É sugerido que moderes teu linguajar, Paulo. O colega PRICK expressou sua opinião, à qual tem pleno direito, poderias muito bem ter expressado a tua, ao invés de partir para a mera agressão.

Assim, recebes uma merecida ADVERTÊNCIA.

[Penguin]

O que coloca a Inglaterra no colo da França - ou abre mão em definitivo de ter NAes...

Como anglo-saxões que são e aliados de primeira hora, mais provável que eles caiam no colo do Tio Sam...



UK SDSR One Year On – Has The Dust Finally Settled?
Tim Cox ponders the state of the UK’s defence plan one year after the Strategic Defence and Security Review and argues that the Royal Navy should ditch F-35 and look for an alternative – the Super Hornet perhaps?