1. Mikä ongelma tämä on? F-35:n korvaamista konetyypeistä suurilukuisin on myös yksimoottorinen F-16. Yksimoottorisuus oli mukana kaikissa näissä eri ohjelmissa (STOVL tai ei) joista sittemmin muodostui JSF-ohjelma, tavoitteena niissä kun oli koneen pienehkö koko ja edullisuus.
Ei tuo ainakaan STOVL-varustuksesta johdu. Ne kun eivät koneen mahdollista pulleutta lisää. Enkä muutenkaan ole samaa mieltä siitä että tuo olisi poikkipinta-alaltaan liian suuri. Tottakai Stealth-ominaisuudet ja tarve kantaa asekuorma ja suuri polttoainelasti sisäisesti vaikuttaa koneen kokoon, mutta vastaavasti vähentävät aika lailla tutkavasteen lisäksi myös reaalisesti ilmanvastusta koska aseita, sensoreita ja lisäpolttoainesäiliöitä ei tarvitse kantaa ulkoisesti.
2. Tämä nyt on ihan huuhaata.
1. Esim. tuosta.
http://foxtrotalpha.jalopnik.com/7-things-the-marines-have-to-do-to-make-the-f-35b-worth-1560672069
The short takeoff and vertical landing optimized F-35B is so capable because its close relatives, the USAF's conventional runway operated F-35A and the Navy's catapult and arresting gear ("cat and trap") configured F-35C, paid a huge price aerodynamically and conceptually in order to include the short takeoff and vertical landing (STOVL) requirement into the Joint Strike Fighter's basic design.
In the name of commonality, the F-35B, with its huge box-like central lift fan, along with its complex drivetrain and downward swiveling exhaust nozzle, basically handicapped the aerodynamics, and in essence the very concept, of its more conventional Navy and Air Force brethren. In other words, some would say that the F-35 was built as a STOVL aircraft first, and then adapted to a standard and carrier fighter second, instead of the other way around.
The F-35B design demand of lifting twenty plus tons, near vertically, on a pillar of thrust, are simply so consuming that they compromised the potential performance, and to some degree the cost, of the other two more traditional, less "engineering challenged" F-35 variants. Oddly enough, the Marine's F-35B order only represents about 14% of the DoD's total F-35 buy, yet the other 86% of aircraft will handicapped by the F-35B's unique design requirements. When the JSF's baseline design was finally locked, the aircraft was left with a massive fuselage cross-section, as well as a single engine with a huge circumference. This, along with many other STOVL related design results, gave the more numerous A and C versions of the jet an airframe that is far less than optimal given their basic sub-design's goals. This conceptual strategy, known as "commonality," was supposed to save money and speed the aircraft's delivery to the front lines when compared with building two or even three separate primary designs that share avionics subsystems. This "strategy," one that many predicted was more of a sales ploy than a relevant procurement and design concept, has
now been proven to be far less than ideal, and its benefits borders on nil in actuality.
2. Täyttä huuhaata?
1.
https://medium.com/war-is-boring/fd...th-the-worlds-worst-new-warplane-5c95d45f86a5
Many of the JSF’s problems converged in 2004, when Lockheed was forced to admit that the Marines’ F-35B variant was greatly
overweight, owing in part to the addition of the lift fan. Ironically, the fan and other vertical-launch gear threatened to make the new plane too heavy to take off vertically.
“The short takeoff/vertical landing variant would
need to lose as much as 3,000 pounds to meet performance requirements,” Lockheed manager Robert Elrod
revealed in an annual report. Panicked, Lockheed poured more people, time and money (billed to the government) into a redesign effort that eventually
shaved off much of the extra weight — basically by removing safety gear and making fuselage parts thinner and less tough.
O’Bryan said the weight reduction ultimately benefited all three F-35 variants. But the redesigned JSF, while somewhat lighter and more maneuverable, is also
less durable and less safe to fly. In particular, the elimination of 11 pounds’ worth of valves and fuses made the JSF 25-percent more likely to destroyed when struck by enemy fire , according to Pentagon analysis.
2.
Kone ja sen moottori taipuu liikehtiessä G-voimilla enemmän kuin oli kuviteltu ja se aiheutti sen moottorituhon. Olisiko rakenteiden kevennyksillä ollut vaikutusta?
3.
Koneessa on murtumia
http://www.thedailybeast.com/articles/2015/03/25/stealth-jet-s-slow-half-blind-debut.html
Meanwhile, Bogdan told reporters that the
F-35B’s structure is showing a tendency to crack. It’s a problem that stems from earlier efforts to reduce the jet’s weight. Because the program switched from extremely strong titanium parts to aluminum to save weight, problems are showing up.
4. Koneesta on poistettu turva-venttiileitä
http://www.bloomberg.com/news/artic...ed-f-35-should-get-safety-valve-official-says
The two-pound valve system was part of 43 pounds (20 kilograms) of equipment removed in 2008 to save weight on the F-35, the Pentagon’s most expensive weapons program. The valve is intended to shut off the flow of a flammable liquid used to cool avionics.
Computer analysis of the pared-down F-35 design last year determined that the aircraft’s
vulnerability to fires ignited by enemy bullets or missile fragments
increased 25 percent from an assessment before the equipment’s removal, according to data from the Pentagon’s weapons-testing office.
5. Haastavien lähtökohtien ja tehtyjen heikennysten seurauksena kone todettiin testeissä hyvin riskialttiiksi vuodoille ja tulipaloille
http://www.news.com.au/technology/i...ity-combat-risks/story-fnpjxnlk-1227269104114
LIVE FIRE DANGER
The Operational Test and Evaluation has found the F-35’s unusual fuel containment system was a risk of “catastrophic fire” — despite recent redesigns intended to address the issue.
Live fire tests “demonstrated the expected cascading damage vulnerability to fuel ingestion, fuel and hydraulic fire, and hydraulic ram events,” the report says.
Dumped fuel also had a tendency to collect in the aircraft’s structure, creating a fire hazard. The F-35’s unique 270 volt power system added to the likelihood of sparks from faulty maintenance or minor combat damage, the report says.
Lack of protection from electrical storms —
believed omitted due to weight concerns — means pilots are instructed not to fly closer than 30kms to approach weather systems.
Arpapeliä sehän loppujen lopuksi on. Kynnystä se kivasti nostaa (60) F 35.