Croyez-vous au programme JSF ?

Jusqu'au jour où les USA produiront des chasseurs hypersoniques.

bon, j'ai pas osé mettre mon post à la suite du jsf, je pensais que c'était hors sujet…Je te jure clansman que dans la vie en général, je suis moins pénible et il m'arrive même de comprendre vite…parfois…

Ok donc pour la vitesse max, je ne pensais pas que les chasseurs en général une fois armés ne dépassaient pas mach 1.5 ou 1.6

Dans le cadre d'interceptions cependant, il doit bien y avoir une utilité non ? si on pends le Mig 31 par exemple, sa capacité à atteindre Mach 3 a été un argument dissuasif face aux projets de bombardiers supersonique us et même au chasseurs non ?

Cette vitesse max de mach 1.5 ou1.6 est une vitesse max "absolue" ou relative à la vitesse max en configuration lisse ?

Dans le cadre d'interceptions cependant, il doit bien y avoir une utilité non ?

Ca en a une, dans ce cas, et sans doute à peu près dans ce seul cas d'ailleurs, mais à l'époque des missiles sol-air et air-air longue portée fiables, c'est dommage d'obérer les autres qualités d'un appareil pour le rendre simplement capable de dépasser Mach 2. C'est pas complètement inutile en soi, mais ça ne vaut pas les efforts exigés, pour une vitesse maximale qui ne sera peut-être jamais utilisée durant la carrière opérationnelle de l'appareil.
En outre, les grandes vitesses ne sont atteignables qu'à haute altitude. Même un MiG-31 ou un F-15 ne dépassera pas Mach 1,2 au ras du sol, par exemple.

ok, pigé!

Par là même, je comprends mieux pourquoi un F22 est "imprenable", je restais bloqué sur le dogfight.

En fait, ce qui compte réellement le plus, c'est de voir en premier, être vu en dernier ou ne pas être vu, les missiles actuels ne laissant que peu de chance au pilote même tiré à 40 km.

Aviation Week, un article amusant.

Within a year, Lockheed Martin’s Joint Strike Fighter team expects to make firm offers to its eight partner nations: the U.K., Italy, Australia, Canada, the Netherlands, Norway, Denmark and Turkey. In exchange for a commitment by all eight to aircraft numbers and delivery dates, they will get a firm price, several years before that would normally be possible under U.S. procurement rules.

The move is necessary because competitors are offering fixed prices, and because some partners need many of their aircraft from early production batches, which normally carry a high price.

Those commitments will be backed up by sanctions. “Partners who do not buy according to the program of record will cover the costs incurred by other partners,” says the Program Office director, Maj. Gen. Charles Davis.

Davis says the final price is the subject of intense discussions within the team, but numbers in the $58-63-million realm—flyaway prices in current dollars—have been mentioned. Given that total acquisition unit costs in export sales tend to be about twice the flyaway cost, this places the JSF unit cost close to that of Typhoon.

The partners should be clear about what they are getting for the money. At the inception of the JSF program, in 1995, then-project director George Muellner described the aircraft as “70% air-to-ground, 30% air-to-air.”

The F-35 is not optimized for air-to-air combat. JSF is neither fast nor agile enough to choose whether to shoot or scoot against an adversary like the Su-30. It either carries a maximum of four AIM-120 missiles—the capability is little publicized, although Davis confirms that it will be part of the systems development and demonstration program—or operates with compromised stealth. (A reduced-signature pylon for the outboard wing stations, designed to carry AIM-9X or Asraam missiles, is being developed.) Success in air combat depends on stealth, but although the F-35 should detect targets at long range before being detected, it will have to close to shorter distances to achieve an acceptable kill probability with the AIM-120C7, particularly against an agile target using jamming and decoys. The U.S. acknowledged this by developing the AIM-120D, designed to be compatible with new active electronically scanned array radars, but it will not be available for export in the foreseeable future.

Moreover, there is no longer any serious doubt that not all F-35s will be equal in stealth. Asked earlier this year to confirm that all would have the same signatures, George Standridge, Lockheed Martin’s vice president for business development, responded: “That is a matter for the U.S. government. I cannot and will not answer that question.”

The partner countries so far show signs of being able to live with the aircraft’s performance and the stealth capabilities they have been offered. The main exceptions are the U.K. and Italy, which will use the Typhoon as their primary air-to-air fighter.

Another major advantage of the JSF is the potential for spreading through-life upgrade and support costs over a large fleet of aircraft. This depends, however, on keeping numbers at their planned level, including 730 aircraft for partner nations, which means overcoming three obstacles.

The first is direct competition. Norway and Denmark are evaluating the JSF against other aircraft, mainly Saab’s Gripen Next Generation (NG). In May, the Netherlands government, under pressure from its Labor coalition partner, agreed to carry out a final assessment of other aircraft, including Gripen NG, Typhoon and Rafale, before making a commitment. Canada also intends to conduct a competition.

The second is budget concerns in the U.K. and Italy, where JSF procurement will be weighed against the final batch of Typhoon fighters unless money can be found for both types.

Third, U.S. numbers are shaky. Senior Air Force officers have stated that the service can afford only 48 JSFs per year rather than the 80 that the current program envisions, unless it gets more topline funding in the defense budget. The Navy and Marine Corps told the Government Accountability Office that they expect to buy 35 JSFs per year, versus 50 in the current plan. Davis says the JSF office “is waiting for the POM (program objective memorandum) process to see those numbers get adjusted.”

Technical risk is another factor. Later this year, the project office is expected to confirm a slip of 9-12 months in the completion of operational testing, with a consequent increase in development costs.

Davis minimizes its impact, saying it reflects the fact that early low-rate initial production (LRIP) batches have been reduced in size (12 aircraft on contract in 2008, for instance, versus 18 envisioned earlier), and observing that it is “at the discretion of the combatant commander” when to declare initial operational capability. Davis makes much of the flight of the first F-35B, on June 11, within the schedule planned in August 2006. “People said the program couldn’t make it, but this shows that we’re capable of performing to schedule.”

More important, though, is the Stovl (short takeoff and vertical landing) testing of the F-35B, which is, by Davis’s count, three months behind schedule. In the first quarter of 2009, the F-35B will start a series of 20 sorties at Fort Worth, Tex., in which the jet progressively slows down, leading to a slow landing. BF-1 will then be ferried to the Navy’s flight-test center at Patuxent River, Md., for tests leading to a vertical landing. The time­scale for that is not certain, but a vertical landing doesn’t look likely until well into the second quarter.

The U.K. has voiced concerns about vertical landings. Added to F-35B testing under a U.K. initiative is a new flight mode, shipboard rolling vertical landing (SRVL), in which the aircraft approaches the ship with about 60 kt. airspeed and 25 kt. wind-over-deck—the maximum design speed of the Royal Navy’s new carriers (see story, p. 51)—for a 35-kt. relative deck speed. Davis characterizes SRVL as a means to improve hot-day performance. The U.K. National Audit Office, in a November 2007 report, linked the move to SRVL to “weight challenges and propulsion integration issues.”

SRVL trials were carried out in May 2007, using the fly-by-wire Harrier operated by Qinetiq on the French carrier Charles de Gaulle. Challenges include the fact that the aircraft has to stop using wheelbrakes alone—37,000 lb. of aircraft at 35 kt. represents a lot of energy—on a deck that will likely be wet. A classic “bolter” will not be possible because power has to be reduced on touchdown to put the airplane’s weight on its wheels.

Vertical landing tests depend on the successful resolution of problems with the low-pressure turbine of the F135 engine, whose unusually large blades are designed to deliver power to the lift fan. A number of changes have been implemented, and tests continue to pin down the exact combination of circumstances where failures occur.

Two milestones are coming up: further analysis should lead to a limited clearance of the existing engine for inflight vectoring in October; and a modified, fully cleared engine should be ready to fly by late 2008.

The other main challenge in the JSF program will be ramping-up LRIP. Davis told an Aviation Week conference in early 2008 that he was “worried about getting the manufacturing lines down the learning curves.” Some problems stem from the weight-reduction redesign in 2004-05—the wing, for example, is harder than expected to assemble. These issues have to be sorted out by 2010: in 2011, production starts a steep acceleration, from 47 aircraft ordered in 2011 to 205 in 2014.

If the JSF program succeeds in locking up its international partners, the project could be within reach of its goal of an F-16-like, mid-four-digit production run and a near-monopoly of the fighter business outside Russia and China. The only other Western program with a long-term future will be whichever team wins India’s 126-aircraft order. But if JSF falls short of its goals—as almost every major military aircraft program has in the past 25 years—it will throw the re-equipment plans of a dozen air arms into disarray.

Pas mal, non ?

Ben en fait rien de vraiment nouveau pour nous, mais le simple fait qu'un journal américain, pourtant souvent chauvin, admette des choses aussi simples que:

*** Le F-35 coûtera finalement aussi cher qu'un Typhoon (et donc qu'un Rafale, puisqu'on est dans les mêmes fourchettes de prix)

*** Le F-35 n'a pas été conçu pour être agile

*** Toutes les versions de l'avion ne possèderont pas le même degré de furtivité

*** La version à atterrissage verticale est en retard

… ça, par contre, c'est assez nouveau, ouais.

En attendant, faut pas jouer à regarder le prix de l'engin en €…

58 à 63M $… (x2 pour le coût total = 116 à 126M $)
En € actuellement : 37,5 à 40,7M € (total : 75 à 81,4M €).

En Europe, ce truc ne sera peut-être pas très cher, et ça, ça fait mal aussi. Parce qu'ils oublient que le Typhoon aussi doit être calculé en $, et avec un fly away minimum de 63 M €…

Component Failures Impact F-35 Flight Testing

Y a t-il des infos supplémentaires sur l'éventuelle annulation de le réacteur General Electric/Rolls royce F-136?

Tuckson a écrit

Mijou a écrit

Y a t-il des infos supplémentaires sur l'éventuelle annulation de le réacteur General Electric/Rolls royce F-136?

GE Rolls-Royce fighter engine team completes F136 high-altitude tests
20 March 2008

first flight in the F-35 to follow in 2010

merci,
ça c'est ce qui est toujours prévu mais il parait (selon l'ami wiki) que la maison blanche serait favorable a son abandon alors que le congrès veut le garder pour faire pression sur les coûts et pour ne pas irriter les britanniques.

Qu'en est il advenu quand au refus des américains de donner un acces total aux britanniques aux codes sources du système d'arme? Et les transferts de technologie sont-ils effectifs? ICI et là.

Le R.Uni a atteint maintenant un point de non retour en ce qui concerne le F-35 (après la commande de PA STOVL ce qui limite leurs alternatives..au F-35) donc ils ne peuvent plus exercer de moyen de pression su Washington concernant un éventuel retrait du programme.

Dans le but de pouvoir revenir à bord d'un navire avec un avion plus lourd (près de 900kg), ou bien pour réduire les efforts sur les moteurs, le ministère de la défense met au point un système hybride d'atterrissage sur PA (SRVL) . En gros, atterrissage conventionnel, pas d'utilisation des brins d'arrêts mais uniquement des freins de l'appareil. Arrêt complet sur 90 à 150m. Le VLA (une aide à l'atterrissage) est développé également dans ce but.
Les essais avait été effectué avec un Harrier sur le CdG.
http://www.flightglobal.com/articles/2008/08/21/314976/uk-to-extend-rolling-carrier-landing-research-for-jsf.html

UK to extend rolling carrier landing research for JSF
By

The UK Ministry of Defence is continuing research to refine a hybrid shipboard rolling vertical landing (SRVL) technique, potentially to be employed as the primary recovery mode for Lockheed Martin F-35B Joint Strike Fighters operating from the Royal Navy's two Future Aircraft Carriers (CVF).

A programme of MoD-sponsored research work, including technical advice from the Defence Science and Technology Laboratory (Dstl), has already concluded that SRVL would offer a significant increase to the F-35B's payload "bring back", without any fundamental platform or safety issues. However, further investigations are planned to address a range of optimisation and integration issues, says Martin Rosa, JSF technical co-ordinator in the Dstl's air and weapon systems department.

STOVL F-35 JSF
© USAF

An SRVL involves a short take-off and vertical landing aircraft performing a "running landing" on to the carrier flightdeck, using air speed to provide wingborne lift to complement engine thrust. The touchdown position on an axial flightdeck is similar to that of a conventional carrier - about 45m (150ft) from the stern, but no arrestor gear is required, as the aircraft uses its brakes to come to a stop within a distance of 90-150m. The technique could allow an F-35B to recover with an extra 907kg (2,000lb) of weapons and fuel, or reduce propulsion system stress and increase engine life.

The Dstl began work to examine the feasibility of employing the SRVL manoeuvre in the late 1990s. Following a series of simulation-based studies, the MoD's investment approvals board in July 2006 endorsed the requirement as part of its F-35B-based Joint Combat Aircraft programme.

Speaking at the Royal Aeronautical Society's International Powered Lift conference in London in July, Rosa said SRVL studies have shown that "a way forward exists to achieving operationally useful increases in bring-back, compared to a vertical landing, on board CVF with an appropriate level of safety". But "uncertainties remain in terms of the scope of an operational clearance and the potential impact on the sortie generation rate for CVF".

Qinetiq used its VAAC Harrier testbed to perform representative land-based flight trials and a ship-based SRVL demonstration aboard the French navy's aircraft carrier Charles de Gaulle last year.

Rosa said past work has also identified a promising visual landing aids (VLA) concept optimised for SRVL and stabilised against deck motion. "We will continue to mature the SRVL-optimised VLA arrangements, look at the possible 'tuning' of the JSF flight-control laws, and further study the effect of SRVL on the CVF sortie generation rate," he said. The capability's full scope will be confirmed after flight trials from the 65,000t vessels, which are due to enter service in 2014 and 2016, respectively.

Other forthcoming work includes optimisation of the approach profile, agreement on the optimal post-touchdown technique, and mitigation for failure cases, such as a burst tyre on touchdown.

Je ne comprendrai jamais ces britanniques..
Pourquoi choisir le F-35 B??
Ils pouvaient bien choisir la version C et opter pour des PA CATOBAR ce qui élargirait la possiblité de coopération avec le France a 100% pour le PA (a l'époque..c'était avant la sortie du Livret blanc).

En plus le choix du design V/STOL interdit de facto d'embarquer l'E-2 hawkeye (l'œil de la flotte) . Du coup plus de couverture radar efficace , le groupe aérien est a moitié aveugle.

Personellement je trouve que la version C est la meilleure. Envergure augmentée , autonomie importante , capacités et souplesse opérationnelles beaucoup plus imortantes que la STOL version.

Tuckson a écrit

Faudrait les interroger ainsi que les Marines pour savoir pourquoi ils s'entêtent à vouloir du VTOL.

Parce qu'ils ont 10 bâtiments amphibies de 40 000 T (classes LHD wasp et Iwo jima) et qui ne peuvent embarquer que des hélicos et des VTOL. Et qu'une nouvelle classe de 50 000 T (toujours VTOL) devrait remplacer les Iwo jima a partir de 2011-2012.

A part ça ils peuvent toujours utiliser leurs hornets depuis les PA de la navy , mais ça ne les tente pas trop . Parce que les LHD américains bien qu'appartenant a la navy sont POUR les marines.

Bon je n'ai pas encore parcouru tout le topic mais connait on la signature radar du F-35 Je sait c'est beaucoup demander…
tout ce que je sait c'est qu'il est moins furtif que le F-22 mais serait il plus furtif qu'un rafale par exemple?

Bah déjà qu'on ne connait pas celle du Raptor , ni celle du rafale d'ailleurs. Alors pour celle du 35

Faudra attendre 2013-2015 quand plusieurs pays en seont dotés et là on pourra étudier sa signature radar.
Qui ça on?..aucune idée