F-35 Lightning II

Uusin GAO raportti, 43 sivua.
http://gao.gov/products/GAO-15-364


"Instability in the development program is likely to continue with more complex and demanding development testing still to go. As the program continues to discover problems in development and testing, it also faces a significant challenge to improve the reliability of the engine. Program data show that the reliability of the engine is very poor..."

"DOD still plans to increase procurement rates by nearly threefold over the next 5 years. This same highly concurrent strategy has already proven to have negatively impacted the program. According to program reports, $1.7 billion could be incurred in costs associated with retrofits to already delivered aircraft. This cost will likely increase, as more aircraft are purchased and delivered before development ends."

Prototyyppien taloudellisesti järjetön laajamittainen sarjavalmistus jatkuu.

"According to program reports, $1.7 billion could be incurred in costs associated with retrofits to already delivered aircraft. This cost will likely increase, as more aircraft are purchased and delivered before development ends"

"As of January 2015, 56 percent of the Block 2B functionality had been verified by program officials"

"In response to the challenges faced in 2014, program officials reprioritized test resources and aircraft capabilities, deferred or eliminated test points, and ultimately delayed completion of some developmental test activities. Personnel and facilities that had been dedicated to developing and testing Block 3i and Block 3F software blocks required by the Air Force and the Navy to field initial operational capabilities in 2016 and 2018 respectively were reassigned to focus on delivering Block 2B to support the Marine Corps initial operational capability in 2015. In addition, program officials eliminated over 1,500 test points from the overall Block 2B developmental test plan, and deferred some Block 2B capabilities."

"Pratt & Whitney has identified a number of design changes that officials believe will improve the engines reliability and is in the process of incorporating some of those changes into the engine design, production, and retrofitted to already built aircraft; however, other design changes that Pratt & Whitney officials believe are needed, such as changes to engine hoses and sensors, are not currently funded."

"Officials from the Office of Secretary of Defense have stated that the current sustainment strategy is not affordable."

USA:lla ei ole varaa hankkia ja ylläpitää suunniteltua määrää F-35 hävittäjiä, tämä tulee väistämättä johtamaan muutoksiin hankintamäärissä.
 
Viimeksi muokattu:
Ensimmäinen Norjalle valmistuva F-35A on päässyt jo jaloilleen:

am-1-wow-news__main.jpg
 
Tässä hyvä postaus toiselta foorumilta:

quote:

stealth technology represents a false promise of invulnerability

No, it never did - and the only people who claimed that were misguided. What stealth provides is increased difficulty of detection.

quote:

also i did not know until now, that the soviet union "helped" stealth in the USA: Pyotr Ufimtsev's famous work "method of edge waves in the physical theory of diffraction" from 1964 was later translated and studied by US scientists

Notable for the 30 year gap in adoption by the Soviets/Russians. They didn't really realize what they had until the US found it first (very much like the Japanese and the Yagi antenna), and they certiantly didn't have the computer power to leverage it. Furthermore, the techniques for CFEA have evolved substantially since then, as indicated by the more sophisticated shaping of the B-2, F-22, and F-35 that isn't easily modeled within Ufimtsev's framework.

quote:


stealth is not invincible... many AESA sensors can detect VLO aircraft and missiles now.

Any radar can, at sufficiently small range. AESA is not a requirement. Stealth is a physically motivated technology, reducing signal to noise for all systems at all ranges under any condition. This means that a non-stealth aircraft will always be detected before a stealth one.

Now, for the F-35 comment:

First, I want to note that whale.to is about the least reputable source that it is humanly possible to exist (IIRC, they're one of the sources of the hollow earth idea), so I will instead discuss the presentation that you linked instead.

The claim you're trying to substantiate with this source is:
quote:

IMHO the f-35 is toast. anti-stealth tech will neutralize stealth up to zero.

I will take this to mean that you believe that the F-35 will be equivalently detectable to an F-16 with respect to a combination of counter stealth technologies. Let's evaluate this claim.

For the purposes of having numbers about RCS that exist, we will be considering both aircraft in a clean loadout, which on the F-16 is 2xAIM-9, and on the F-35 is 2xAMRAAM + whatever is internal. Any additional load on the F-16 will dramatically increase RCS, though how much is difficult to estimate without detailed information. Already, the F-35 has a substantial weaponry edge for this given level of detectability.

From your presentation, the F-16 has a frontal RCS of 1.2m^2, and the F-35 has a frontal RCS of .005m^2. This applies to all forms of radar, however shaping becomes less important and paint materials become more important as wavelength get longer (and frequencies get lower). This has a number of crucial benefits, as the presentation mentions and are easily seen on slide 12. The F-35 has a dBsm of about -35, all the way to the left of the graph, and the F-16 has a dBsm of about 2, most of the way to the right of the graph. As such, the F-35 would be detected by L-band (the lowest deployed) at ~60 km, compared to the F-16 at 300km. This isn't looking good for the F-16.

The next relevant slide is page 21, which quotes an image from Kopp's laughable analysis of the F-35's shaping from about 3 pictures of it. If you want to see what this should look like, see his computational analysis of the PAK-FA, and compare the quality of the methodologies. This figure and all the figures derived from it are highly suspect, as such, and don't warrant discussion.

Now, multistatic radar. There are problems with the technology that aren't mentioned a lot, most notably the fact that reduced RCS and RAM features mean that the secondary return is alsoreduced. Additionally, the technology is untried on long wavelength transmissions, with the majority of systems (such as Silent Sentinel) working on cellphone signals in the Ghz range.

ESM is easily countered by a combination of LPI and EMCON - techniques that are becoming steadily more common among air forces. The F-35 won't go flying around banging away with it's radar on 24/7.

Low frequency radar is really the only major concern, as demonstrated by the major interest in the technology. However, as demonstrated by the chart in the presentation, stealth platforms are harder to detect with this radar, and always will by (physics, again). The lower frequency simply pushes the range out from 10 miles to 50 - and they cost enough that at 50 mile separation you can't buy enough of them to surveil a large enough area.

OTH radar is both really uncommon - only the Australians have a good one - and really inaccurate and imprecise. Knowing that there's a contact 500nmi out doesn't help much when the AOI is 50km on a side and you have no information at all about type.

IRST. The problem here is that you're looking through a really tiny straw at a really big sky - it's like trying to find an ant at your feet, given a drinking straw to look for. The systems work great for identification once the target is acquired, but until that point you're squat out of luck. Furthermore, the F-35 likely has a substantially reduced IR signature thanks to novel internal cooling solutions (which, incidentally, cause the fuel temperature restrictions), and a new IR-reducing engine nozzle. These systems provide the F-35 with an IR signature equal to or smaller than the competition - and remember that the F-35 has a bleeding-edge IRST system of its own. Furthermore, western IRST systems are far ahead of the Russian technology, with IIR missiles widely deployed and targeting pods existing at all. The experience of western pilots in IRST equipped Soviet aircraft is that the IRST systems in those aircraft are not tactically relevant.

Note that the dogfight between the Rafale and F-22 was both (a) a dogfight, where stealth is at its least useful, and (b) relying on French figures.

Stealth is not a panacea - but signature reduction technology is important to the modern battlefield, and you've presented no evidence whatsoever that this technology is 100% outmoded the way you claim. The F-35 is the result of a lot of work - work that the Russians and Chinese clearly value or else they wouldn't be developing the PAK-FA and J-20 with similar ideas.
 
Sardaukar kirjoitti:
Tässä hyvä postaus toiselta foorumilta:

quote:

stealth technology represents a false promise of invulnerability

No, it never did - and the only people who claimed that were misguided. What stealth provides is increased difficulty of detection.

quote:

also i did not know until now, that the soviet union "helped" stealth in the USA: Pyotr Ufimtsev's famous work "method of edge waves in the physical theory of diffraction" from 1964 was later translated and studied by US scientists

Notable for the 30 year gap in adoption by the Soviets/Russians. They didn't really realize what they had until the US found it first (very much like the Japanese and the Yagi antenna), and they certiantly didn't have the computer power to leverage it. Furthermore, the techniques for CFEA have evolved substantially since then, as indicated by the more sophisticated shaping of the B-2, F-22, and F-35 that isn't easily modeled within Ufimtsev's framework.

quote:


stealth is not invincible... many AESA sensors can detect VLO aircraft and missiles now.

Any radar can, at sufficiently small range. AESA is not a requirement. Stealth is a physically motivated technology, reducing signal to noise for all systems at all ranges under any condition. This means that a non-stealth aircraft will always be detected before a stealth one.

Now, for the F-35 comment:

First, I want to note that whale.to is about the least reputable source that it is humanly possible to exist (IIRC, they're one of the sources of the hollow earth idea), so I will instead discuss the presentation that you linked instead.

The claim you're trying to substantiate with this source is:
quote:

IMHO the f-35 is toast. anti-stealth tech will neutralize stealth up to zero.

I will take this to mean that you believe that the F-35 will be equivalently detectable to an F-16 with respect to a combination of counter stealth technologies. Let's evaluate this claim.

For the purposes of having numbers about RCS that exist, we will be considering both aircraft in a clean loadout, which on the F-16 is 2xAIM-9, and on the F-35 is 2xAMRAAM + whatever is internal. Any additional load on the F-16 will dramatically increase RCS, though how much is difficult to estimate without detailed information. Already, the F-35 has a substantial weaponry edge for this given level of detectability.

From your presentation, the F-16 has a frontal RCS of 1.2m^2, and the F-35 has a frontal RCS of .005m^2. This applies to all forms of radar, however shaping becomes less important and paint materials become more important as wavelength get longer (and frequencies get lower). This has a number of crucial benefits, as the presentation mentions and are easily seen on slide 12. The F-35 has a dBsm of about -35, all the way to the left of the graph, and the F-16 has a dBsm of about 2, most of the way to the right of the graph. As such, the F-35 would be detected by L-band (the lowest deployed) at ~60 km, compared to the F-16 at 300km. This isn't looking good for the F-16.

The next relevant slide is page 21, which quotes an image from Kopp's laughable analysis of the F-35's shaping from about 3 pictures of it. If you want to see what this should look like, see his computational analysis of the PAK-FA, and compare the quality of the methodologies. This figure and all the figures derived from it are highly suspect, as such, and don't warrant discussion.

Now, multistatic radar. There are problems with the technology that aren't mentioned a lot, most notably the fact that reduced RCS and RAM features mean that the secondary return is alsoreduced. Additionally, the technology is untried on long wavelength transmissions, with the majority of systems (such as Silent Sentinel) working on cellphone signals in the Ghz range.

ESM is easily countered by a combination of LPI and EMCON - techniques that are becoming steadily more common among air forces. The F-35 won't go flying around banging away with it's radar on 24/7.

Low frequency radar is really the only major concern, as demonstrated by the major interest in the technology. However, as demonstrated by the chart in the presentation, stealth platforms are harder to detect with this radar, and always will by (physics, again). The lower frequency simply pushes the range out from 10 miles to 50 - and they cost enough that at 50 mile separation you can't buy enough of them to surveil a large enough area.

OTH radar is both really uncommon - only the Australians have a good one - and really inaccurate and imprecise. Knowing that there's a contact 500nmi out doesn't help much when the AOI is 50km on a side and you have no information at all about type.

IRST. The problem here is that you're looking through a really tiny straw at a really big sky - it's like trying to find an ant at your feet, given a drinking straw to look for. The systems work great for identification once the target is acquired, but until that point you're squat out of luck. Furthermore, the F-35 likely has a substantially reduced IR signature thanks to novel internal cooling solutions (which, incidentally, cause the fuel temperature restrictions), and a new IR-reducing engine nozzle. These systems provide the F-35 with an IR signature equal to or smaller than the competition - and remember that the F-35 has a bleeding-edge IRST system of its own. Furthermore, western IRST systems are far ahead of the Russian technology, with IIR missiles widely deployed and targeting pods existing at all. The experience of western pilots in IRST equipped Soviet aircraft is that the IRST systems in those aircraft are not tactically relevant.

Note that the dogfight between the Rafale and F-22 was both (a) a dogfight, where stealth is at its least useful, and (b) relying on French figures.

Stealth is not a panacea - but signature reduction technology is important to the modern battlefield, and you've presented no evidence whatsoever that this technology is 100% outmoded the way you claim. The F-35 is the result of a lot of work - work that the Russians and Chinese clearly value or else they wouldn't be developing the PAK-FA and J-20 with similar ideas.
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Vaikka tämä vastaväittäjä onkin paremmin perillä asioista kuin hlö jolle hän vastaa, niin hänenkin väitteissään on virheitä - hän ei tunnu tietävän eroa IRSTin ja FLIRin välillä, myös väite että LPI-tekniikat päihittävät ESM:n "helposti" on äärettömän kyseenalainen. Oman näkemykseni mukaan juuri sensorifuusio tulee vähentämään häiveteknologian etuja kun pystytään esimerkiksi yhdistämään ESM:n ja tutkan havaintoja samasta kohteesta.

Carlo Koppin näkemykset F-35:stä nyt ovat mitä ovat, mutta häivetekniikoista hän kuitenkin tietää enemmän kuin oikeastaan kukaan muu länsimainen ilmailutoimittaja joten hänen juttujaan ei niiltä osin kannata ohittaa olankohautuksella.
 
fulcrum kirjoitti:
Vaikka tämä vastaväittäjä onkin paremmin perillä asioista kuin hlö jolle hän vastaa, niin hänenkin väitteissään on virheitä - hän ei tunnu tietävän eroa IRSTin ja FLIRin välillä, myös väite että LPI-tekniikat päihittävät ESM:n "helposti" on äärettömän kyseenalainen. Oman näkemykseni mukaan juuri sensorifuusio tulee vähentämään häiveteknologian etuja kun pystytään esimerkiksi yhdistämään ESM:n ja tutkan havaintoja samasta kohteesta.

Carlo Koppin näkemykset F-35:stä nyt ovat mitä ovat, mutta häivetekniikoista hän kuitenkin tietää enemmän kuin oikeastaan kukaan muu länsimainen ilmailutoimittaja joten hänen juttujaan ei niiltä osin kannata ohittaa olankohautuksella.
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Kuten tuossa sanottiin, LPI ja EMCON auttavat ESM:n voittamisessa. Eli jos ei suuremmin lähetä mitään, niin on vaikea havaita. Eihän tuossa edes mainita FLIR-juttuja, vaikka esim. Sniper Pod on ehken sinnepäin, mutta kuitenkin toimii myös IRST:n kaltaisena ilmamaalejakin vastaan. Länsimainen IRST- ja FLIR-tekniikka on todellakin ison harppauksen edellä venäläistä.

Olen tuon postauksen kirjoittajan kanssa samaa mieltä. Eihän stealth ole mikään maatamullistava asia, mutta hupaisaa, miten jotkut ajattelevat ettei sille ole tarvetta ja kone sen vuoksi olisi jotenkin huonompi. :D Carlo Koppin "asiantuntemuksesta" nyt voidaan olla montaa mieltä. Tietysti venäläisten artikkeleja papukaijamaisesti toistamalla voi saada "asiantuntijankin" leiman... :P
 
Sardaukar kirjoitti:
Kuten tuossa sanottiin, LPI ja EMCON auttavat ESM:n voittamisessa. Eli jos ei suuremmin lähetä mitään, niin on vaikea havaita. Eihän tuossa edes mainita FLIR-juttuja, vaikka esim. Sniper Pod on ehken sinnepäin, mutta kuitenkin toimii myös IRST:n kaltaisena ilmamaalejakin vastaan. Länsimainen IRST- ja FLIR-tekniikka on todellakin ison harppauksen edellä venäläistä.

Olen tuon postauksen kirjoittajan kanssa samaa mieltä. Eihän stealth ole mikään maatamullistava asia, mutta hupaisaa, miten jotkut ajattelevat ettei sille ole tarvetta ja kone sen vuoksi olisi jotenkin huonompi. :D Carlo Koppin "asiantuntemuksesta" nyt voidaan olla montaa mieltä. Tietysti venäläisten artikkeleja papukaijamaisesti toistamalla voi saada "asiantuntijankin" leiman... :p
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Ei kai kukaan ajattele että stealhille ei olisi tarvetta ja että se tekisi koneesta jotenkin huonomman. Lähinnä varmaan on ajatuksena se että kone kanta ei supistuisi ylilento ilmavoimiksi ja niillä vehkeillä olisi varaa lentää muutoinkin kuin simulaattorissa... Se on oma kysymyksensä että mikä painoarvo stealhille annetaan. Jos se on lähtökohtaisesti "must have" ominaisuus niin silloinhan voidaan valinta tehdä ilman kummempia valintoja koska kilpailua ei ole, ainakaan silloin kun suomi valintoja tekee eikä ainakaan sellaisia vaihtoehtoja joihin olemassa oleva aseistus sopisi... Jos taas stealth on pelkkä lisä arvo niin silloinhan vaihtoehtoja on enemmän. Taktiikalla on kuitenkin myös suuri merkitys joka voi antaa anteeksi sen stealthin puuttumisen.
 
Government Accountability Office on sitä mieltä ettei ilmavoimilla (ja laivastolla ja merijalkaväellä) ole varaa F-35:n
Raportti
Sen ostaminen maksaa liikaa
Sen operoiminen maksaa liikaa
Lukekaa pojat huviksenne Appendix I, kyyti on kylmää.

It is unlikely the program will be able to sustain such a high level of annual funding and if required funding levels are not reached, the program’s procurement plan
may not be affordable
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Kiinnostaisi vähän tarkemmin ymmärtää F-35 Stealth, ja nimenomaan Suomen näkökulmasta.

1. On ollut huhuja, että vientiversiot eivät ole yhtä Stealth kuin jenkkien omat. Onko tähän luotettavaa faktaa puolesta tai vastaan?

2. Miten paljon Stealth hankaloittaa ja vaikeuttaa huoltoa ja ylläpitoa?

Tässä pari linkkiä jälkimmäiseen teemaan liittyen.

http://articles.sae.org/7072/

To meet the F-35 Joint Strike Fighter’s strict radar cross-section and weight requirements, stealth coatings must be applied to extremely precise thickness tolerances.

Along with optimization of CDS parameters and robot programming, the hardware innovations resulted in much better coating coverage performance vs. the hand-spray approach. In four samples, the percentage of inspection points that were within tolerance for robotic spray ranged from 75 to 85%; for hand spray, the range was from 0 to 42%. Regarding thickness range (max-min), robotic spray realized decreases of 70 to 90% over hand spray.

http://flightlines.airforcetimes.com/2015/03/10/new-tool-checks-f-35-paint-for-damages-in-minutes/

“For one particular application, it can image a portion of the aircraft in about 15 minutes; vs. two to three hours that it would have taken the system that we currently use to collect the same information,” Calzada said.


--> Pelkkä silmätarkastus ei riitä Stealthin verifiointiin?
--> Edes huolellinen ihmisen tekemä spray-paikkaus ei välttämättä toimi?
 
Mustaruuti kirjoitti:
Kiinnostaisi vähän tarkemmin ymmärtää F-35 Stealth, ja nimenomaan Suomen näkökulmasta.

1. On ollut huhuja, että vientiversiot eivät ole yhtä Stealth kuin jenkkien omat. Onko tähän luotettavaa faktaa puolesta tai vastaan?

2. Miten paljon Stealth hankaloittaa ja vaikeuttaa huoltoa ja ylläpitoa?

Tässä pari linkkiä jälkimmäiseen teemaan liittyen.

http://articles.sae.org/7072/

To meet the F-35 Joint Strike Fighter’s strict radar cross-section and weight requirements, stealth coatings must be applied to extremely precise thickness tolerances.

Along with optimization of CDS parameters and robot programming, the hardware innovations resulted in much better coating coverage performance vs. the hand-spray approach. In four samples, the percentage of inspection points that were within tolerance for robotic spray ranged from 75 to 85%; for hand spray, the range was from 0 to 42%. Regarding thickness range (max-min), robotic spray realized decreases of 70 to 90% over hand spray.

http://flightlines.airforcetimes.com/2015/03/10/new-tool-checks-f-35-paint-for-damages-in-minutes/

“For one particular application, it can image a portion of the aircraft in about 15 minutes; vs. two to three hours that it would have taken the system that we currently use to collect the same information,” Calzada said.


--> Pelkkä silmätarkastus ei riitä Stealthin verifiointiin?
--> Edes huolellinen ihmisen tekemä spray-paikkaus ei välttämättä toimi?
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1. En ole Kuullut
2. Gripen ng:n lentotunti maksaa $4700 ja F-35A:n $32000. Joten tuo kertoo jo jotain.
 
Häivepinnoitteet ja niiden huolto ovat kyllä kiinnostavia asioita. Jonkun verran (ruisku)maalauksenkin parissa puuhastelleena olen sitä mieltä, että robotilla saadaan tasalaatuisempi tulos, etenkin jos kyseessä on erikoispinnoite. Jos paikkamaalausta tehdään koneeseen ilman osien irroittelua ja purkamista, täytyy maalausrobotin olla melkoinen häkkyrä. Se vielä mietityttää, vaatiiko pinnoite erikoisolosuhteet maalaamisen ja kuivatuksen ajaksi?

Häivepinnoitteissa on tapahtunut kehitystä käyttöystävällisempään suuntaan ja nykytilanne ei välttämättä ole se viimeinen sana.

Koskahan koneisiin saataisiin se näkymättömyysnanoputkimateriaali (vai mikä se nyt olikaan) pinnoitteeksi? WVR -kahinassa heikosti tai ei juuri lainkaan näkyvä hävittäjä voisi olla eto peli, joskin vaaransa siinäkin on.
 
Tuo pinnoite käsittääkseni vaatii tehdas tasoisen huollon eli ei liene kentällä tai suomessa tehtävä huolto. Villi veikkaus on että jenkit tuskin antavat tuota stealth pinnoitetta vietäväksi "kotiin"
 
Eiköhän se pinnoite ole lisänä. Itse rungon materiaali on se varsinainen havaittavuutta pienentävä tekijä.
 
RPG83 kirjoitti:
Kanadalaisilta on tullut tällaista palautetta. Jotakin aiheesta tästä linkistä: http://defence.pk/threads/exported-downgraded-f-35-has-beach-ball-size-rcs-of-0-15-m2.206023/
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Jep.

In an unclassified illustration of a stealth analysis, the F-35 had an approx. 95% improvement over 1st to 4th generation fighters - meaning a much smaller radar signature.
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F-35 has a 95% RCS reduction over 4th-gen jets according to Julian Fantino, the vice defense minister of Canada. Going by the standard RCS of a generic 4th gen fighter used by radar vendors (5 m2), that would be 0.25 m2. If he was going by CF-18's RCS of 3 m2, then it would be 0.15 m2."

Ja.

http://en.wikipedia.org/wiki/Lockheed_Martin_F-35_Lightning_II

Considerable criticism followed in the wake of U.S. Ambassador Tom Schieffer's confirmation to the Joint Standing Committee on Foreign Affairs (JSCFADT) on 21 June 2004: "With regard to the stealth technology, the airplane that Australia will get will be the stealthiest airplane that anybody outside the United States can acquire. We have given assurances to Australia that we will give you the absolute maximum that we can with regard to that technology. Having said that, the airplane will not be exactly the same airplane as the United States will have. But it will be a stealth fighter; it will have stealth capabilities; and it will be at the highest level that anyone in the world has outside the United States."[149][150] Lockheed Martin's Tom Burbage stated in a 2006 article that export of key technologies such as stealth would be limited by U.S. national disclosure policy.[151] A Jane's article in 2004 gave a hint that US$1B, spent on several contracts, may provide for a less stealthy F-35 export configuration.[152]

Jos nuo pitävät paikkansa, F-35 stealth ei käytännössä ole enää hirveän paljon parempi kuin esim. Gripen NG:llä ja Superhornetilla tai Pakfalla? (Pakfasta ei taida olla kyllä ihan kovin luotettavia arvioita?) Suurempi ero muodostuu ehkä ulkoisesta aseistuksesta?
 
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