F-35 Joint Strike Fighter

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nego, mislim se nesto..

posto navodno B i C verzije imaju problem, a A nema.

Dal je to zbog razlika u koriscenju?

A se koristi na kopnu a B i C uglavnom na moru. Da nije problem u vremenskim razlikama, koroziji, velikoj kolicini soli itd, sto itekako utice na avione koji su na moru?

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^I mene zanima taj podatak. Ubeđen sam da USAF prihvata taj stepen oštećenja jer može da ih brzo servisira. NAVY i USMC su mesecima na misijama a nemaju logistiku USAF-a. Njima bi tako oštećeni avioni bili neoperativni do povratka u bazu.

• 3Ovo se svidja korisnicima: MB120mm, lacko, Mixelotti
  
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Morska so je ubica tehnike.

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Predstavnik mornarice adm Winter je napomenuo ono što je Yrraf rekao, u slučaju opasnosti naravno da je pilotu dozvoljeno da ide i preko propisanih limita letenja (kojeg uzgred imaju i drugi avioni mornarice, kao i brodovi), ali tu je opasnost da se taj sistem ošteti i da mu se osnovne karakteristike dovode u pitanje pre svega se misli na steltnost. Limiti se postavljaju radi održavanja idealnih karakteristika kako bi sistem izdržao dok je na moru gde su mogućnosti opravke limitirani.
Mada oni su napomenuli da se to desilo samo na B, i C modelima i to prilikom testiranja u krajnjim i ekstremnim uslovima letenja. I da su kasnije pokušali da simuliraju te iste uslove ali da nisu uspeli. Ali limiti su ostali , premaz je promenjem od Lota 8.




Citat:Winter acknowledged that the deficiency could keep the Navy from accomplishing its supersonic intercept mission — as the documents charge — if similar issues were being experienced more widely across the F-35C inventory.

“If you had that performance on all of your fleet, then you would have a problem. That’s not the case,” he said.

“We have put into place what we believe are the appropriate technical fix to ensure that our F-35Cs have the full envelope and capability to do the high-speed mission, if needed. That’s where we are. Right now, our United States Navy and Marine Corps flying the sea agree with that,” he said.

The new coating, which was introduced in Lot 8, allows the jet to withstand hotter temperatures caused by the afterburner, the documents stated. Winter characterized the material as able to withstand “what we call the thermal shock wave,” but declined to specify how the coating works or how much protection it provides.

Bryan Clark, previously a top aide to former Chief of Naval Operations Adm. Jonathan Greenert and now an analyst with the Center for Strategic and Budgetary Assessments, likened the limitation on the afterburner to similar restrictions on submarine and ship operations.

“I think the operational impact is not huge, since it only applies during a small fraction of the jet’s operational profile. In subs and ships, we have a ‘safe operating envelope’ that defines where the platform is engineered to operate reliably for a long time. We can operate outside the safe operating envelope for a short time, but there are risks to doing so. The operator or commander needs to balance those risks against the benefits," he said.

“That is similar to this situation," he added. "The pilot can be on afterburner as long as needed to evade a threat but has to know the risk of structural damage increases. The pilot can balance that against the risk of getting shot down because he or she didn’t evade fast enough.”

The most important piece will be how well trained the pilot is on the aircraft, he continued.

“As a submariner, I knew the risks of being outside the safe operating envelope and how those risks increased over time and would impact ship performance.”



However, a naval aviator currently in service said the afterburner problem may not be that troubling to pilots, who must frequently work around a jet’s limitations. The key, he said, is understanding how often the issue occurs.

"I think you'd do well to go back and look at all the times they used the afterburner and that didn't happen," he said. "We're talking about tens of thousands of sorties at this point that this aircraft has flown."

Other aircraft that the Navy operates also have afterburner limits, he explained.

“I think that number needs context,” he said. "It looks scary on its own, but [the Super Hornet] has afterburner limits. They’re not that restrictive, but they have them. The aircraft has an afterburner, you want it to work.

“But I would want to get context for that number: Does this represent 0.002 percent of all sorties? If that’s the case, I don’t give a sh--, and I’ll probably have 15 other things fail before that."

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Pa to znaci da je max brzina kod F-35 ustvari nesto ala Vmax kod prethodne generacije.

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I opet... F-35 VS F-15X sinergija ili politika...

[Link mogu videti samo ulogovani korisnici]

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Napisano: 01 Maj 2020 11:13

U suštini njihova najveća greška i ono čime su osakatili NAVY jeste nedostatak klasičnog lovca penzionisanje F-14, a da nisi išli sa varijantom F-22 za mornaricu, time bi imali dve univerzalne platforme za sve rodove pošto marincima klasičan lovac i nije bio potreban. Al šta je tu je imaju to što imaju i moraju izvući maksimum iz toga što imaju. A sve je politika pola novinskih članaka i podataka dostupnih samo njima kako vole da se izražavaju novinari su plod sukoba lobija u SAD.

Mean

Prema izjavama onog admirala i predstavnika lokida jeste.

Dopuna: 01 Maj 2020 11:29

Evo malo o limitima za F-15

For peacetime flying purposes the F-100 PW 100 was limited to 98% of its useable power. In case of emergency you flipped the Vmax switch and that dumped extra fuel into the engine giving it full 100% power. De-rating the engine meant longer time between servicing. From what I recall, if you used Vmax for less than 30 seconds or so, then the engine stayed with the airplane and it was noted in the forms. It seems like there was an overall 30 second limit before the engine had to be borescoped and checked for damage. The system is similar in concept to the "gate" on WW II piston power fighters. essentially war emergency power.
Now a caveat, I am a crew chief, not an engine troop, so I may be wrong in the details-but I am pretty sure that is essentially what I have been told over the years by the engine guys. The switch is still in the cockpit, but I am not even sure if it has a role to play with the -220 and -229 engines.

Dopuna: 01 Maj 2020 11:30

Naravno on kaze da limiti ostaju i za nove motore iako su move verzije izgubile Vmax

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@ Leonardo

1.6 Mah je ograničenje F-16 pod kojim uslovima? Voleo bi da procitam vise o tome ako imate link.
Ipak 1.6 Mah je dosta veća brzina od ograničenja koje su kao rešenje oficijalno stavili na F-35. Inače Mah 1.6 je apsolutna maksimalna brzina F-35 na papiru koju zbog štete po zmaja izgleda neće nikad videti.
Sa 1.6M možeš raditi air policing u većini slučajeva, a znamo da u kritičnim situacijama F-16 može da ide i do bar 2.0 Maha. Naravno bez podvesnih reservoara i bombi. Par raketa sigurno, a možda i više.

Ja ne verujem da glavni problem ovog ograničenja F-35 leži u oštećenju stelt farbe. Problem mora da leźi u vibracijama i fizičkom stresu. Inače nikad ne bi bio klasifikovan kao Kategorija 1 problem.

Kad kažete da će F-35 da ih nadmaši. Nisam siguran u kom smislu mislite :-) U ograničenjima?
U brzini sigurno neće. Da li je bolji avion u budućim misijama od F-16 ? Sigurno jeste. Te misije će doduše biti veoma specifične.

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Za F-16 je ranije bio podatak da moze 2M sa dve rakete na vrhovima krila, e sad varijante sa ledjnim rezervoarima imaju veci aerodinamicki otpor pa je max brzina mozda niza.

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@ Milos1977

Samo bez persiranja.

Te cifre su uvek diskutabilne i pitanje je pod koji uslovima. Sumnjam da se ikad i jedan operativan terao preko mah 1.8 gde je upravo to bilo prvobitno ograničenje, a da su odavno ograničeni na 1.6 (eto možda grešim pa je prava cifra 1.8 ). Suštinski je to sve nebitno za njegovu upotrebu. Mislim da je u pitanju usisnik koji ne može da obezbedi adekvatno strujanje vazduha na toj brzini kako je zahtev bio što jednostavnije rešenje. Treba kopati. Davno je to bilo ovde na forumu.

Recimo kod F-15 sa CFT ograničenje je mah 1.4. Takođe F-15 bez CFT nikad nije prešao brzinu od 1.4 u misijama, koliko sam ja upućen. Pri čemu je daleko važnije vreme za koje avion ubrza sa 0.8 na 1.2, e tu je F-35 slab u odnosu na prethodnu generaciju.