HotshotWhat does the USN want? They aren’t as bullish on Adaptive engines as per a news story a while back. Supercruise? Do they want that? Not sure..9G’s..remains to be seen. 😉 At the moment the Navy is working hard at moving the UCLASS into FA-XX timelines 🙂
I don’t think the 9Gs will be that important, a decent maneuvrability should be enough with good off boresight missiles, but supercruise enables to run down enemy fighters and to escape faster. Anyways there will be a trade-off to make between the capabilities and the cost.
It is not sure the USAF and USN would agree completely on the specifications but they might be force to find a common ground. Usually there is more than one way to skin a cat. 🙂
HotshotAFAIK you’re right about the early model F-18Es & the APG-79 AESA radar, but the Raytheon RACR & NG SABR are adaptable for the F-18C/D, & Raytheon has also flight tested the APG-79(v)X, an APG-79 scaled down for the F-18C/D. If it fits the F-18C/D it should also fit the early model F-18Es. So there is a choice of AESA options for them.
If they field 15 F-35Cs per year, it would take 20 years or so to replace the F/A-18C/Ds. Ouch it doesn’t bode well. They have to find a way to ramp up the production more, but I sure as hell don’t know where they will find the extra money given all the other programs they have to fund.
I believe the problem with the first APG-79s is the cooling limitation, not sure. They might still be interested in upgrading these airframes with an AESA of one type or enother even if it costs more, because those super hornets won’t be replaced before a long time.
I also wonder if the US military should continue to keep the same fund allocations for the USN and the USAF, given the priority to counter China strategically. I would argue that Navy F-35Cs could be used from a ground base if necessary, but a very large fleet of F-35As wouldn’t be really useful against China. The F-35C is more versatile.
HotshotThat would be the logical way to do it..Its to a point where they are looking at getting airframe on deck..I doubt they can spare $20+ Billion in their RDT&E budget to develop a new fighter on their own..Even a new sixth generation fighter with F-35C’s avionics will cost a lot to design, and test..Its better to design a fighter with a realistic time-line of around 2035-2040 and in the meanwhile keep replacing the initial F-18E’F’s with F-35C’s and F-35C+ or an upgraded F-35C. The largest chunk of the investment in next-generation enabling technologies will come form the USAF’s budget so it would be best for the Navy to wait till the Air Force de-risks these. In the meantime, buy the F-18’s and F-35C’s..If they don’t do that, they’ll end up designing a sixth generation fighter without most of the low-maturity technologies that the USAF and the AF and Navy labs are working at getting to a higher maturity level..Things like Variable Cycle engines, directed energy weapons etc etc..
The USAF also would have a hard time developing a new fighter from scratch and fielding it in numbers with a good economy of scale. Making 2 variants would add a few billion but it would be relatively low risk. As long as there is no STOVL variant it should be relatively easy.
A modified F-35C as an quickly available F/A-XX could be an idea, but it is not sure it would be possible to do it. If they want a good supercruise and 9Gs they’d have to change the aerodynamics configuration. Not sure it’s feasable.
HotshotIt’s pure guesswork at this point which shortcomings it addresses, but if it does tackle those mentioned earlier, presumably by being smaller and lighter?
Edit: One of the features boasted on the main page are: “Lightweight and well balanced helmet.” Although, it’s a maker’s webpage so perhaps they claimed the same for the Gen2 🙂
It adresses problems of resolution, and latency, not the issue a rear visibility. To make a significant difference in that regard the helmet would have to be A LOT smaller, because of the head rest and the way the cockpit is designed. And even at that it is not sure it would be enough. This problem might be mitigated by using the DAS, IF the pilot can turn its head at will, but only partially. That’s the problem with fanboys, they cannot accept the idea that the plane can have any drawback, which can become unnerving.
HotshotThe number of ‘carriers’ debate is no longer in the hands of the USN. Its a congressional matter…The Navy has a lot on its plate between 2020 and 2040..Subs, railgun, lasers, new classes of ships and under-sea warfare technology through the third offset. The only way I see them buy less F-35C’s is if they get the UCLASS right, and that is a big IF because they haven’t really got a lot many clean sheet aircraft projects right recently. The FA-XX will put the same budget strain on them vis-a-vis the F-35 as the F-35 is putting vis-a-vis the F-18E/F, so they would most likely buy the F-35C, but more of them later when they have a choice between a 5th generation or an expensive 6th generation…The Super Hornet is at best at par, and at worst grossly outclassed by the threat in the 2020’s and 2030’s…a move to buy more of them NOW would mean more FA-XX’s earlier due the difference of capability between the Rhino of 2035 and a J-31 of 2035 etc etc..
If they want to replace the super hornet one for one they’ll have to be conservative. In the early 2030’s the F-35C will be relatively inexpensive ( mainly thanks to the economy of scale with the other variants ), so they might want to replace the first 135 super hornet block Is that can’t be upgraded easily with the AESA antenna from what I have read with F-35Cs. A 2030 F-35 would be largely superior to a non AESA super hornet. That could give them 5-10 more years to finish the development of the F/A-XX. With more F-35Cs available, the F/A-XX could be more focused on air to air. It would also come online at the same time as the USAF F-X so there could be more commonlity here, or even the F/A-XX could be a naval variant of the F-X.
HotshotI guess they won’t be redesigning the seat then as some people here suggested (not to mention the canopy redesign ideas 🙂 ).
Oups.. you just forgot to explain how the gen III helmet solves the problem…:stupid:
HotshotThe USN is adamant that it needs the same number of heavy carriers despite budget constraints and the fact that aircraft cost more and more. The heavy carriers are not even filled to their maximinun capacity. If they spent all the money corresponding to building and operating one new carrier on building more F-35s, they could afford a lot more of them to fill the 9-10 remaining carriers.
Also, does the Navy need as many heavy carriers when the Marine carriers can carry F-35Bs? The heavy and light carriers could complement each other well depending on the situation.
Hotshot
While the F-22A will surely get a life-extension (even though they may publicly say they haven’t decided or it wont for NOW) it will be a question of how many, and how economical would it be to sustain a smaller force. Anyways F-X will have to replace the F-15C’s and F-15E’s that get upgrades that should keep them good to go till the mid 30’s at least.
They’ve kept the tooling to work on the F-22 airframe so hopefully they won’t be too expensive to SLEP. But they’ll probably cost a lot to upgrade.
HotshotI bet the F-22s won’t even be replaced by the 6th gen fighter. They’ll keep them in service another 15-20 years like has happened with the F-15C. An F-22 in 2040 would be no slouch with upgrades coming from the F-35 or the 6th gen plane.
HotshotNo and No. A supercruising engine require other differences than thrust, and speed itself is not directly related to static thrust of the engine.
An PW-220 engined F-15E can supercruise at ~M1.03 at DI=0.
An PW-229 engined F-15E can supercriuse at ~M1.14 at DI=0.21% Thrust increase results in 11% speed increase, or 65 knots better speed, which has no tactical use whatsoever.
Anyway, no need to talk theory: Vmax Switch, heres what flight manual says about it:
And that is for just 4% increase in thrust.
Any idea about using such feature for cruising is nonsense -supercruise or not-. Use it and aircraft’s engines are in for a special maintenence to see if it cracked, warped bended or anything. If it is, engine is discarded and replaced with a new engine. In the best of circumstances, if pilot uses it 10 times for 6 minutes, engine goes for an overhaul. Its a very specific emergency feature, not for saving the pilot from missile or anything, but probably for intercepting supersonic strategic bombers in time.
PS: You are putting too much emphasis on supercruising. Any aircraft flying slower than transonic wavedrag (around M0.8) will be much more efficient. When you need fast, you have afterburners, So “supercruising” is ONLY useful for when you need to go fast for long flight ranges, not combat but penetration etc.
If you are in an F-22 which can go M1.7, it MAY have some use, as it would require some effort to catch it. However, its said 100nm supercruising cuts 600nm combat radius of F-22 to 450nm. Assuming done at M1.5 on average, thats less than 7 minutes on supersonic flight. And 100nm supersonic flight cuts 300nm flight range. Although altitude and flight conditions are unkown, that doesn’t sound impressive to me.
A MiG-29 9.12 going at MAX AB at 16000 meters has top speed of M2.3, and fuel flow rate of 5,5 kg/sec @M2.3. A MiG-29, needs 4,54 minutes or 1499 kg of fuel to fly 100 nm at M2.3 speed, and it will still have 1632 kg usable fuel left to cruise; with 2 AAMs, that makes ~494nm range. On a more realistic scenario, a MiG-29 armed with 6 AAMs and EFT, can fly at M1.5 @16k meters with 3,3 kg/sec fuel flow (assuming Full AB, probably less in reality). It takes 1577 kg fuel to do so, and leaves 2759 kg fuel for rest of the flight; with overly pessimistic 4 kg/Nm fuel consumption, that makes 689nm flight range; lets call it 300nm+ combat radius including take-off, combat, acceleration and landing.
F-22’s supercruise ability is good, but definately is not out of this world, and definately not a game changer; a MiG-29 flying Ground-Alert-Interceptor mission just 100 nm from its base will easily pursue and catch F-22 no matter how long it supercruises. And remember, MiG-29 is not exactly renowned for its range and combat persistance. I wish I had such detailed fuel consumption graphs for Su-27S, but I havent, but suffice it to say it has 184% more fuel to feed 50% higher thrust when compared MiG-29.
Well, if you’re in a 4gen plane for instance and you have to face modern fighters your chances or survival are like 50-50 at best, why would you care about the service life of your engine?
Also, the drag index would decrease significantly after the transsonic regime, so the fighter should be able to better maintain its speed. For sure it would need its reheat to go supersonic. It might still slow down with 10% extra mil thrust but not as much, the point is to stay in supersonic as much as possible just above the transsonic regime. It would be less likely to be detected by enemy IRSTs, and would also burn less fuel vs using its AB. The enemy radars can be jammed, but not the IRSTs so it might well help the fighter survive in BVR.
Also, you are comparing figures for the F-15E, but the E has a lot more cross-section so obviously a significantly worse drag index in transsonic than the C. I am pretty sure I read once that the F-15C had been tested at mach 1.3 supercruise with -229s in the early 90’s. The F-15C can also drop its centerline tank.
4th gen planes are old so at this point so are pretty expendable in a war, using these planes to their max would make sense if it increases their chances of success.
HotshotWhat … comparing a fighter to what a MiG21 was at its time would only be an high praise.
But when the 4th gens came online they needed 42% more thrust to try and keep up… seriously how much more thrust would an F-35 need to accelerate like a PAK-FA with its supercruising engines, probably something like 40% up to its top speed of mach 1.6. After that the F-35 is lost in the dust. how can people not be worried by such a large difference of performance? I bet real fighter pilots take that issue seriously, they sure hate their plane having a big disadvantage in one area or another.
HotshotIt’s not just heat but also rpm and cycles. RR RCo17 conway on the Victor 2000 hrs between overhauls . VC10 engine RCo43 many, many thousands of hours between overhauls due to the longer flights and less ‘playing’ with the throttles.
RR Adour Modular construction. Hot end was changed quite regularly
RR Spey 101 1000 hrs
RR Avon 302 600 hrs
RB 199 again modular, hot end changed regularly.
8000 hrs between overhauls? Very doubtful.Reheat is in general variable. Full bore and nothing else is like riding a turbo motorbike, fun but tricky………
Yeah I imagine lol… these engines are freaking monsters of power.
I did a search I found that:
http://www.network54.com/Forum/211833/thread/1176069334/F135+engine+breaks+records+in+turbine+inlet+temperature.
The F135-PW-100 engine used in the F-35 is currently the most powerful fighter turbofan in the world rated at 43,000 lbs in reheat and 28,000 lbs dry. Part of its exemplary performance comes from the exceptionally high temperatures at which its turbines are able to withstand. Thanks to advances in metallurgy and blade cooling measures, the turbine intake temperature of the F135 engine is 3600 degrees F (1982 deg C) about 20~25% than other fighter engines (<3000 degrees F). This increases power yield for any given compressor pressure ratio and/or fuel burned. Despite this increase in operating temperature, the F135 is being developed as a 6000 hours between overhaul powerplant 1.5 to 3x better than current engines.
Concerning the ‘Variable Area Vane Box Nozzle ‘ :
http://www.defense-aerospace.com/articles-view/release/3/100946/rr-delivers-first-production-liftsystem-for-f_35.html
The VAVBN is installed as one of the first items in the aircraft assembly sequence and, once installed, the VAVBN frame is never removed throughout the service life (8,000 flight hours).
Let’s hope the F135 finaly lives up to its promise. ( and not to its reputation… )
HotshotBut it will fly much less, at least in peace time, that will reduce the operational cost.
HotshotYeah pretty soon when the PAK-FA comes online the F-35 will be a modern day mig-21, it will need a setting with 42% more thrust to be on par… for block 4.2 maybe… 😀
HotshotSupercruise reduces IRST detection? Are you sure?
[ATTACH=CONFIG]239737[/ATTACH]
Supercruising versus using the AB at the same speed.
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