ErkokiteHi. Do you have any hard facts that you can bring to us to back up this claim that the F-22 has more drag than the F-15 does. It’s that in my opinion its an odd claim to make.
Well, believe it or not, it’s not that odd. Making an aircraft stealthy requires that you make sacrifices elsewhere. For example, the rule of planform alignment adds constraints and means you have fewer angles available to use for optimization. Of course, the F-22 flies clean, so it has that advantage. Just because it is newer, doesn’t mean it is better in every way.
When designing an aircraft, you optimize about a certain design point- you don’t get performance for free. For the F-22, stealth was a major design factor. For the F-15, aerodynamic performance was a major design factor, whereas stealth was not.
ErkokiteI realise that you and alot of others here object to the facts that pcfem posts here but it would be nice if you hold back the nasty slurs toward him.
Some of us do infact appreciate his efforts to debunk the trash talk and dishonest garbage that frequently gets posted here surrounding the F-35.
Pfff… Pfcem is in love with the F-35 and always has been, and even though he’s well within his rights to do so, very few people on this forum still take him seriously as an objective source of information on the F-35. The fact of the matter is the F-35 is so over budget that it triggered a Nunn-McCurdy breach (that’s an objective fact). When was it supposed to reach IOC anyway? 2011? 2013? 2016? Who knows? And I think I trust the GAO more than some fanboys on a fighter aircraft forum.
Erkokiteactually, a simple way to compare the two would be to give them the same amount of thrust and see what it gives (talking airframes as such).
if the F-22 is more efficient aerodynamically (less draggy), it should be ahead..
the f-15, with PW F100-220 turbofans, in full Ab has about 22t of thrust overall
http://en.wikipedia.org/wiki/F-15_Eagle
the f-22 has about 21t of thrust dry.
http://en.wikipedia.org/wiki/F-22_Raptor
from there on, it’s quite simple: the F-22 at max military power and the F-15 at max AB thrust generate the more or less the same thrust (less than 5% difference).
The F-22 goes up to something like M1.8 in such conditions. The F-15 reaches around M2.5.
from these numbers it seems quite obvious that the f-15 aircrame generates less drag at supersonic speeds
Ah, but you are forgetting- the F-15 has variable geometry inlets, which helps it reach a higher speed and also isn’t constrained by RAM coating heating.
Really, the only way to be sure would be to do either wind tunnel testing or CFD.
ErkokiteWhy the insults? didn’t you just lecture me on maturity?
There are 2 different stories on the net about what happened in UAE.
The one I read says the F-22 Killed the Rafale without even using its radar.
Its odd how that’s supposed to be a straw man argument and I am supposedly willfully ignorant on the subject, but I have posted you links from credible sources with factual information and you still continue on the same line of reasoning. You cant even grasp the concept or PLURAL ( weapon types launched from the F-35) and singular ( the AMRAAM)
I apologize I am a spirited debater and don’t easily lay down in an argument.
( the always wanting to win American you stereotyped earlier)
Either way ratcheting up your rhetoric wont do do you good here.
You must have mixed me up with someone else. That was my first post on this thread. I really have no idea what you are talking about. I apologize for the insults, but my patience wears thin after correcting you about this very thing in another thread. As for the F-22 kill of the Rafale, yes, the F-22 did achieve a passive kill of a Rafale. However, this was outside any planned DACT. The Rafale was not flying against the F-22 in this exercise- both aircraft happened to be in the same area, but were not engaged in any simulated combat against each other. The Rafale would not have had any countermeasures engaged and would not have been flying silently as it would in a BVR engagement with an F-22. This would have been done outside of RoE, as there was no planned DACT between the F-22 and Rafale besides WVR. If you want more info, please see the following thread:
http://forum.keypublishing.co.uk/showthread.php?t=98076
Anyways, this is the wrong place to discuss this, so I’ll let this rest.
ErkokiteJust like the F-22s advantages were mitigated in the UAE exercises right?
When the Rafale used its Aesa, supercruise, active cancellation, and spectra to counter the Raptor in BVR? Ohhh waiit….
There was no BVR DACT between the Rafale and the F-22 during the UAE exercises. Nor were SPECTRA or APG-77 even used in the DACT that did take place. DACT was purely WVR and the F-22 only scored a single kill on the Rafale (out of 6 encounters). This is the second time I’ve had to tell you this, and the fact that you don’t seem to grasp this, despite it being very old news that has been discussed to death, either suggests that you are trolling or willfully ignorant. Please stop bringing up this strawman. To your credit, though, you finally figured out how to spell “Rafale.”
ErkokiteAll these comparisons with the current generations of fighters to the F-35 — are always fun, but how relevant are they?
The main challenges the F-35 will face will be from SAMs not 4.gen fighters.
And the second biggest challenge will be from other 5. gen fighters.
AFAIK, most “professionals” seem to be quite happy with it’s technical capabilites (although I believe DJCross once said that he would have liked a longer range on internal fuel).
The main critisism in the media recently seems to have been focusing on project management, delays, and how that could affect the price and the fighter gap, not on the capabilities.
The Eurocanards are fantastic fighters, however I think we need to accept that they are not VLO; This reduces survivability when faced with advanced SAMs, and also when meeting 5. gen jets like e.g. the PAK FA or the J-12.
However in most other scenarios they will still do fine, and for many years to come.
It’s a pity Europe did not launch their 4.5 gen fighters a bit earlier and then moved on to a 5. gen — some competition would have been good, both for European companies and for LM. Now it looks like it will become an LM monopoly in the future, in the “Western world”.
It is not all too late of course; Perhaps Japan or S Korea will decide to move forward with a 5. gen. Could be very interesting if that happened…!
Unfortunately it seems that Germany has decided it does not need a 5. gen — German engineers are excellent and it could have been great for us enthusiasts to see what they could have produced, if given the chance by their politicians. Alas not likely to happen. Perhaps France will launch a 5. gen initiative, perhaps together with UAE and/or Brazil?
We will see. I don’t think the F-35 will have a huge advantage over advanced versions of the Eurocanards. It will be stealthier, sure, but if you have very good datalinking, ECM and passive detection capability, this disadvantage will be mitigated I think. Can’t make generalizations though- it will probably depend on the situation, i.e. AWACS/UAV support, atmospheric conditions, the angle and altitude difference between the approaching fighters, etc… Maybe I will be right or maybe I’ll be wrong- only time will tell.
Also, IF (and this is a really big if) the Rafale does get true active cancellation, then I think it could technically be considered a 5th generation fighter- AESA radar, supercruise, stealth, passive detection and categorization, passive MAWS/MLWS. However, it’s debatable.
Saab seems to be moving ahead on 5th gen studies. So we will have to wait and see what comes out of Sweden in the next 10 years.
The UK has already bought the F-35 of course, so I don’t see them forking out money for an entirely domestic 5th generation program- really the F-35 could already be considered fairly domestic for them, as they participated heavily in its development.
ErkokiteYou are really funny:D J-10 > J-11B > Su-35 ??? Did you mean Su-35 or Su-25?
I think he was joking. He was attributing these rankings to Chinese fanboys. We all know the J-11B and J-10 are no match for the Su-35. 😀
ErkokiteLow pressure compressor stage KND-924-3 destined for Salyut’s AL-31F-M3 delivering 15T+ thrust:…….
That’s quite a complex blade geometry. Thanks for the picture.
In any event, even if the inlet goes straight through, this is not the end of the world, as RAM coated fan blades, like those on the Su-35, reduce RCS considerably, and blockers can also be used- they were good enough for the X-32, so I see no issue with PAK-FA.
ErkokiteYou are misunderstanding facts, first the Kfir has a turn rate like this, ITS of 18deg/s, STR of 9.6 deg/s, both the F-16 and F-15 have better sustained and Instantaneous turn rates even the Harrier AV-8B has better ITR and STR
The same will happen with the Viggen it is less capable than even the F-15 and Harrier and much less capable than even the MiG-29.
It is not that delta canards have high ITRs but that they do not have good STR because they bleed energy fast, that is the reason they use canards and relaxed stability to increase sustained turn rates.If you read aircraft history you will know that each generation has increased thrust and thrust to weight ratio.
The Eurofighter, Rafale and even the Gripen have done it, the MiG-29 and SU-27 have done it too.However deltas with canards have less supersonic trim and this allows for more compact designs since you can pack more lift in a given design because the control surface is ahead of the center of gravity and with relaxed agility well that will make for good fighters
What the americans did in the F-22 is pack two very powerful engines and give it a huge wing in a very aerodynamicaly clean airframe.
This has given them the ability to give it really high ITR and STR, now TVC is important but its agility is not 100% product of TVC.The F-22 and Su-30MKI once they use TVC they slow down, they do Cobras or Kulbits or BElls but the name for the Cobra is in reality dynamic disaceleration what the Cobra is doing to a Su-27 is slow it down, an F-15 can even shot down an unexperienced Su-30MKI pilot just by the way it sinks in the air once its uses supermaneouvrabity.
However the F-22 has a turn rate of 28 deg/s and it is not because of TVC it is because it has excess power it can even supercruise at military power, consider then if it won`t have an excellent turn rate just without TVC,
you take like a bible that canards are the only element to make a fighter agile but it is not it is simple lift and thrust.
If the F-22 uses TVC it will do bells, cobras, kulbits, etc etc but ist turn rate is the result of pure thrust and lift
The Kfir was a stable design and had unmoving canards.
ErkokiteLook blue who does what better?
1. The F-35 has better weapons and better access to Gps ( The Euro Gps isnt fully ready yet and gps could be cutt off from France is in a dispute).
2. The F-35 has better and newer sensors with Aesa, put of the box 360 degree Irst
3. The F-35 has a better fuel fraction and higher thrust to weight. you have to strap tanks all over a squall To do what a F-35 does clean.
4. Is a full all aspect stealth aircraft out of the box! it can fulfill the F-117s mission from the start, it can go into down town bagdad, Moscow, bejing, paris, or anyother heavily defended airspace on earth and deliver weapons on target. Im not adressing just the range of the target here. talking about the ability to prosecute even if it gets there!
5. It will slaughter anything short of a T-50 or F-22 In BVR combat. You gambled that The rafael sensors would save you from the F-22 in an exercise and learned a horrible lesson in the UAE. Now your makign the same gamble that the Raf will make it to a merge.
6. If you merge with it you had better hope that what ever version your fighting Wont have Aim9-x with Hobs ability. then its either your dead or mutual kill.
7. Better comm network, better SA, better, automatic main soft ware.
Please tell me 1 thing that the French Rafael does better than a F-35 besides turn slighty tighter, or go slightly faster? It goes mach 2 but I dont see you flying around with Ab on at all times. I suppose its faster than a Raptor also?
The first point about GPS is kinda ridiculous. Really if it comes down to it, I’m sure GLONASS could also be integrated very easily. Galileo will be ready in due season as well. Perhaps even before the F-35 enters operation.
The Rafale actually has a higher thrust/weight (as far as wet thrust at sea level/loaded weight). Shortly it will also receive 360 degree IR coverage via the DDM-NG as well as an AESA radar. OSF-IR will also provide long range coverage in the frontal sector. The IRST on the F-35 is mounted on the bottom of the aircraft and is primarily optimized for the strike role, whereas that of the Rafale is mounted on top of the aircraft and is intended for air to air. The Rafale is also offered with a helmet mounted display, although AdA has not ordered it.
“You gambled that The rafael sensors would save you from the F-22 in an exercise and learned a horrible lesson in the UAE.”
SPECTRA was not engaged in the UAE exercises against the F-22. DACT between the F-22 and Rafale was WVR. And the Rafale performed quite well.
I think you greatly overestimate the stealthiness of the F-35. There are likely a number of systems out there that are likely capable of detecting the F-22 and F-35. Long wave over the horizon radars like France’s NOSTRADAMUS and Australia’s early warning radar network are rumored to detect these aircraft. The SMART-L radar is also rumored to have detected the F-22 at long range. The F-117 has already proven to be detectable by unsophisticated long wave radars- likely part of the reason for its retirement. Boeing’s Silent Sentry system is capable of detecting “holes” in RF radiation. There is a similar system in France, but I do not remember its name.
Engine Nozzle
The F-35 is powered by a single Pratt & Whitney F135 engine that produces approximately 40,000 pounds of thrust in afterburner. The thrust makes the Lightning II the most powerful single-engine fighter ever built. To reduce cost, the nozzles of engines flown on the first aircraft do not have the low-observable characteristics that will be found on engines for subsequent aircraft. The geometry of the swiveling nozzle associated with the short takeoff/vertical landing version requires slightly shortened tail feathers.
Great. It’s also just a single engine on a rather heavy aircraft. Thrust/weight is nothing special in comparison to other current fighters.
GS.org also calls the F-35 all aspect
I’d like to see some more sources. Even the F-22 is not considered, “all-aspect” from what I understand. Aircraft like the X-47b are all aspect.
Also, it’s “Rafale,” not “Rafael.” Rafael is an Israeli arms manufacturer.
ErkokiteLPI is Low Probability of Intercept; basically ‘stealthy radar’. Just like stealth on the aircraft itself (due to shaping, RAM, etc.) makes it have a low probability of intercept on radar, but of course the closer you get, the easier it’ll be to detect. It’s not invisibility from radar, only stealth – a major reduction in the effectiveness of your enemy’s radar range.
I’m sure Lockheed Martin has tested this themselves, most likely putting two F-22’s up against each other with both AESA radars on full blast, seeing who can spot who first, and how long it took from the time they turned them on; also probably tested them against other powerful radar systems on the ground and air (including powerful AWACS).
I’m sure the USAF has seen and has done the same.
They will know the effectiveness of their systems and learn to use their strengths and thus help cover the weaknesses.
Do people not think of this before posting? 😉
Yes, everyone here is well aware of what LPI is. Hell, I’m sure there are posters that could delve into detailed phase shift keying algorithms, chirplet transforms, pulse compression, etc… LPI is not exclusive to the US and is a well understood radar technology. It’s also not invisible. Just significantly less easy to detect. Why do you think that when the Rafale and the F-22 flew DACT against each other a few months back, it was all WVR, with neither the APG-77 nor SPECTRA engaged? Because the USAF didn’t want to give the French anything to chew on using SPECTRA’s SIGINT capabilities and likewise the French did not want to expose whether or not the APG-77 was detectable by SPECTRA.
If that’s what you want to believe in order to feel better at night when you go to sleep, then so be it. lol! That means Zimbabwe, Egypt, Croatia, North Korea, etc. etc. all have cmparable radar systems and avionics compared to the U.S., Russia, European companies, etc. therefore? Hehe! I don’t think so.
Stop kidding yourself, bud. It’s not that easy to make world class avionics.
The countries you named largely don’t have the intellectual and human capital to design advanced systems like fighter aircraft, or if they do, they lack the financial capital to implement them. The F-22, at best, uses chips that are commercially available at the time of design freeze. In 2004, when the CPU’s were upgraded to PowerPC’s from the i960mx (a 20+ year old chip), the G5 CPU was at the top end of the PowerPC CPU family. This chip is dated now.
They don’t design new CPU’s for a new fighter aircraft. They buy mil-spec versions of commercial CPU’s from any number of manufacturers.
Undoubtedly there are also custom, ASIC chips, but these are likely still manufactured by processes which are dated in the commercial world (in both the USA and the rest of the world)- certainly nothing that wouldn’t be easily available in Russia, Europe and Asia from any major manufacturer. But who cares? The chips do what they are supposed to. Fighter jets don’t “refresh” every 6-18 months with new manufacturing processes in the same way that microprocessors do. When commercial industry switches from 90 nm to 65 nm to 45 nm, they don’t go out and re-fab and reinstall the chips in the F-22 to keep pace. There’s no reason to.
A bigger concern for Russia is the availability of X-band MMIC technology. Fortunately, they seemed to have figured this out on their own, and in any event, nowadays the technology is available commercially from Europe and Asia as well.
Really, don’t kid yourself. The technology to do these things is available outside the US from a large number of manufacturers.
ErkokiteWould it be possible to make canards from a radar-transparent material, with only the actuator at the joint being potentially reflective?
Yes, quite possible. Kevlar and fiberglass are transparent to radar waves, whereas CFRP and metals are not. People often forget that the visible shape is not entirely indicative of the stealthiness of an aircraft- it depends on material properties and internal structure as well. Of course, generally you would want to ensure that your external surface is not transparent as you don’t want radio waves bouncing around your internal structure (plus it would be an absolute pain to model the rcs and optimize due to these effects).
You could probably have a single transparent vertical tail and two high mounted canards, and assuming you found a way to hide the actuator, this probably would not be a huge issue.
ErkokiteYou can actually purchase RAM coatings and pyramidal absorbers from companies like ARC, CFoam, and Hitek. It’s not super-secret, deep black, wonder-technology.
ErkokiteIHI makes parts for several major engines, & manufactures some under licence. It has participated in the development of a couple of widely-sold commercial jet engines. It has also built its own jet engines, though so far relatively small ones. The Japanese T-4 trainer has an indigenous engine.
I’m sure they can build an engine for the Shinshin. The question is, how long will it take?
I’ve no doubt they could build an excellent engine. The XF5-1 has already been built and runs.
Some pictures here:
But of course, there is more to building an engine than simply getting it to run- there is optimization of the FADEC system, and other components, meeting targets for thrust, weight, MTBO, etc… So we’ll see, but it’s certainly getting there. Should be nice to have another manufacturer of military turbofans, but unfortunately Japan isn’t too keen on exporting hardware.
ErkokiteThis announcement is only about a development/test engine, not a final production engine.
In other words, exactly like development engine used for the in-development Tejas, or Rafale and most other planes. Nobody buys an in-development engine for use as a test engine while the final engine itself is being developed, that would defeat the whole point. Price is really secondary if you know Japan, and as a test engine it will not be procured in large amounts anyways.The question is really what is Japan trying to do with this project as a whole as well as the engine specifically.
Clearly it would be cheaper and have as good or better performance if they partnered with an existing engine builder to develop a next-gen design or advanced version of current engine, and if that’s the case the question is if they are looking to find a test-engine provider who would also partner with them in this regard. If they’re going to the trouble to develop their own engine from scratch, I don’t see why they don’t aim for a F136-class engine, but perhaps Pratt/ GE+RR may not be willing to transfer enough tech. Then again, if they are developing their own from scratch the idea of 2 engine redundancy might be re-assuring.
Well, the ATD-X is a twin-engined aircraft, which makes sense given Japan’s small amount of land and large amount of water. So the F136 would be overkill and too large for the task. It is probably also easier to design an engine in the F404 class rather than the F136 class, especially since Japan has less experience designing military turbofans than the major western manufacturers (though we know Japanese engineering has an excellent reputation). So my thoughts, but we’ll see how it pans out.
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