Poslao: 19 Jun 2009 17:04
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- The Joker

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Dornier "LA-2000"
The United States is not the only nation to have invested in stealth airplane technology. The Low Observable site lists projects from the UK, Germany, Russia and China. This site will focus on the German projects, and is an attempt to collect whatever information is in the public domain (AFAIK, very little has been published about these projects).
In the 1980s, the German government ordered MBB to do some research into stealth technology. This resulted in the Lampyridae demonstrator.
A second project is even less well known: the Dornier LA 2000.
According to Doug Richardson's 1989 book "Stealth Warplanes", Dornier has done design work on a stealthy ground attack aircraft. Called LA-2000, it had a delta wing, "the pure shape of which was only marred by a raised section along the centerline. This incorporated the small canopy close to the apex of the delta. The two engines were located in a propulsion bay mounted under the wing. The inlet was between 1/4 and 1/3 of the way back from the nose". It had 2 turbofans with 25 kN thrust, feeding into a single twodimensional vectoring nozzle. It had an internal weapons bay of about 6 m^3. Drawings were published in a 1986 issue of Flight International (4014/15).
[Link mogu videti samo ulogovani korisnici]
[Link mogu videti samo ulogovani korisnici]
"Lampyridae"
From 1981 to 1987, Messerschmitt-Bölkow-Blohm's (MBB's) plant at Ottobrunn in Bavaria worked on a stealth aircraft, dubbed the Medium Range Missile Fighter or Lampyridae (Firefly), whose core design principle - deriving an efficient aerodynamic shape out of an arrangement of radar-deflecting flat panels or 'facets' - mirrored the technique employed on the then top secret F-117A.
The project was headed by Dr. Gerhard Loebert. MBB also developed a software package for RCS calculation, similar to Lockheed's 'Echo' RCS-calculation program. The Lampyridae was a pure research program: the airframes were built to test the shape, they were not meant to be complete, flyable aircraft.
The Germans spent 9 million D-mark (US$ 4.5 million) on the project. There are two prototypes. One was used for RCS measurements, the other for aerodynamics tests.
The aerodynamics testbed is an unpowered 3/4 scale model (length 12 m, span 6 m), which was 'flown' by a test pilot inside a 9.5 x 9.5 m2 wind tunnel of the Deutsch-Niederländischen Windkanal (German-Dutch-Wind-Tunnel) consortium. Before the tethered model was flown to speeds up to 225 km/h (120 kts) followed by a safe landing, the pilot trained several hours in a flight simulator.
The RCS-measurement model was built at full scale (length 16 m, span 8 m) in 1987, and it confirmed the predictions made with the software program, showing a lower RCS than even the F-117. Here is a 3-view drawing.
The project ended in 1987 when MBB had proved it could design a stealthy aircraft. The research has since been used in other aircraft designs (presumably the Eurofighter Typhoon, EADS MAKO and various weapons). According to some people, the Americans were responsible for ending the project.
The Lampyridae aerodynamics testbed is now located at the F-104 museum.
[Link mogu videti samo ulogovani korisnici]
[Link mogu videti samo ulogovani korisnici]
DASA "TDEFS"
The Daimler-Benz Aerospace designed a new project in
1997 for European combat aircraft,and its concept was
known as FTT (Flying Technology Platform).
Dasa leads push for European fighter demonstrator
DAIMLER-BENZ Aerospace (Dasa) is trying to pull together a European partnership to develop and build a technology demonstrator leading up to a pan-European combat aircraft. Dasa military aircraft division
president Aloysius Rauen says diat the company has been studying a
concept known as the Flying Technology Platform (FIT).
Programme sources say that the company hopes that the concept will lead to the construction of a piloted test vehicle incorporating
advanced technology developed by Dasa from other programmes.
Rauen says that the F I T builds on Stealth technology developed in
the last decade for the secret Lampyridae (Firefly) fighter concept,
and will include an advanced fly-by-wire "system and vectoredthrust
technology which has been developed from the German/US
X-31 programme. The project is also believed to incorporate radar-absorbent materials which are now underdevelopment
by Dasa, and already set to be incorporated in the Eurofighter
EF2000.
The EF2000 DA5 prototype is the first flying testbed for this technology. The demonstrator will also be used to explore the use of modular avionics. Rauen says talks are under way with potential European partners and the German Government to transform the programme, which began on a national basis, into an international effort.
FLIGHT INTERNATIONAL 25 June - 1 July 1997
[Link mogu videti samo ulogovani korisnici]
Za ovo ce me sigurno proterati iz Nemacke!
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Registruj se da bi učestvovao u diskusiji. Registrovanim korisnicima se NE prikazuju reklame unutar poruka.
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Poslao: 19 Jun 2009 17:55
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- mean_machine
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Odlican tekst.
Nemci ne mogu znati karakteristike premaza i materijala koriscenih na F-117. Oblik je samo jedna od promenjivih u jednacini.
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Poslao: 19 Jun 2009 18:15
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- Wisdomseeker

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Pa i Nemci imaju razvijenu industriju pa mogu sami da isprobavaju šta valja.
MBB nije firma za potcenjivanje.
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Poslao: 19 Jun 2009 19:17
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- The Joker

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mean_machine ::Odlican tekst.
Nemci ne mogu znati karakteristike premaza i materijala koriscenih na F-117. Oblik je samo jedna od promenjivih u jednacini.
Kad se setim svih onih stranih novinara '99 kako su "kruzili" i cepali od "nevidlivog" F 117 siguran sam da su neki bili i obavestajci...tako da i oni imaju primerak premaza...
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Poslao: 21 Jun 2009 11:21
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- sebab
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@The Joker
mislim da je reverse engineering prilicno precenjena kategorija. treba prvo testirati materijal, odnosno utvrditi o cemu se radi, debljini, najrazlicitijim karakteristikama. posle toga dolazi tezi deo, kako ga napraviti, pa kako ga naneti itd. dok se ceo taj posao odradi, ameri su otisli ne jedan, vec nekoliko koraka dalje. premazi za f22 i f35 su sigurno efikasniji nego oni na f117.
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Poslao: 21 Jun 2009 22:06
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- The Joker

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sebab ::@The Joker
mislim da je reverse engineering prilicno precenjena kategorija. treba prvo testirati materijal, odnosno utvrditi o cemu se radi, debljini, najrazlicitijim karakteristikama. posle toga dolazi tezi deo, kako ga napraviti, pa kako ga naneti itd. dok se ceo taj posao odradi, ameri su otisli ne jedan, vec nekoliko koraka dalje. premazi za f22 i f35 su sigurno efikasniji nego oni na f117.
Sto se tice dizajna zmaja mislim takodje da nije "previse" komplikovano jer relativno lako moze da se skine sa drugih letelica...ali opet treba tu dosta istrazivanja koji nagib daje najvecu refleksiju radarskih zraka.
Sto se tice premaza slazem se sa Wisdomseeker-om da Nemacka ima dovoljo kapaciteta da kreira svoj sopstveni premaz. Ja bih cak tvrdio da nemci mogu da naprave kvalitetnije letelice nego amerikanci...ukoliko bi imali slobodne ruke.
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Poslao: 21 Jun 2009 22:33
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- stegonosa

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Sam dizajn ako se misli na oblik se izracunava na osnovu prilicno konkretnih formula, a i Francuzi recimo poodavno imaju laboratorije za testiranje RCS. Setimo se modela Micubisija ATX u punoj velicini koji je upravo testiran u Francuskoj.
Sto se tice premaza sa F-117 pitanje je koliko su efikasni i da li imaju neku veliku ulogu, sam avion je izgleda napravljen od odredjenih materijala koji ne reflektuju radarsko zracenje, ali glavna stvar je bez sumnje oblik. Protiv radarski premazi su dugo razvijani i siguno da danas imaju veliku ulogu, pre svega sto se tice kokpita, lopatica motora i eventualno maskiranja radara (fora sa UV lampom).
F-117 nije imao radar, nije morao (a ni mogao) da leti brze od zvuka te mu je motor bio lepo skriven, a i kokpit nije bio bas pregledan zbog cudnog oblika itd. sto nije ni bilo bitno jer nije lovac...
F-117 je bez sumnje odavno prevazidjen, ali da je 99. znacajan broj delova zavrsio u laboratorijama sirom sveta ne treba uopste sumnjati. Kazu da je Rusima otisla elektronika. Ona svakako nije nista narocito, mi to danas znamo, ali u ono vreme kada je taj avion predstavljan kao najvece cudo na svetu sigurno je i njima znacilo da otkriju kako nije nikakva babaroga. Jedina vrlina tog aviona je bila radarska nevidljivost, kada je nestalo nje i taj avion je prevazidjen.
Danas je F-22 u svakom smislu respektabilan avion, cak i kada ne bi bilo stelta. Nemce danas ubija Eurofighter, tu je zarobljena ogromna kolicina novca koja bi se mogla uloziti za avion 5. generacije.
Nema postojanje aviona 5. generacije kod Nemaca preterano veze sa Amerikancima (odredjene ima ali ne presudne - zamislite koliko bi kostao taj avion razvijan sa tehnikom pocetka 80-ih - stotine miliona po komadu, kao i F-117), vec sa novcem koji je otisao drugde. Kada bi se Eurofihter prodavao dobro u inostranstvu, dobilo bi se dovoljno para za slican avion, ali ne pre nekih 10 godina od danas, ipak i Jurofajter treba malo da se naleti i da opravda svoje postojanje. Samo da sledeci put budu pametniji i udruze se sa Francuzima, tako da konacno imamo prelep, pouzdan, efikasan i znacajno jeftiniji avion.
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Poslao: 22 Jun 2009 13:09
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- mean_machine
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Premazi kod F-117 itekako su bitni. Sam podatak mu kisa smeta dovoljno govori koliko F-117 savisi od premaza.
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Poslao: 22 Jun 2009 15:34
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- stegonosa

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mean_machine ::Premazi kod F-117 itekako su bitni. Sam podatak mu kisa smeta dovoljno govori koliko F-117 savisi od premaza.
Vrlo moguce, ali ti premazi sigurno nisu ni izdaleka na istom tehnoloskom nivou kao danas. Sa druge strane, materijal od koga je napravljen mi ne deluje kao da voli kisu, bilo premaza ne bilo.
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Poslao: 22 Jun 2009 15:41
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- mean_machine
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stegonosa ::mean_machine ::Premazi kod F-117 itekako su bitni. Sam podatak mu kisa smeta dovoljno govori koliko F-117 savisi od premaza.
Vrlo moguce, ali ti premazi sigurno nisu ni izdaleka na istom tehnoloskom nivou kao danas. Sa druge strane, materijal od koga je napravljen mi ne deluje kao da voli kisu, bilo premaza ne bilo.
Mi ovde poredimo prve steltove. Da su Nemci zavrsili Svitca bilo bi to vrlo zanimljivo. Ja sam na netu procitao da je komisija USAF kojoj su Nemci predstavili svoj avion bila zapanjena (jer je slican sa F-117 koji je bio operativan ali strogo cuvana tajna) ali su izjavili da nisu zainteresovani i da smatraju takav koncept promasajem
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