Cola1973How does “slight buffet remains constant from twenty-six degrees to about forty degrees AOA, where it decreases” limit the F-22’s AoA?
Well pfcem, you should know that, being an “expert”, right? 😉
So, why don’t you explain us why this buffeting occurs and what actually happens at 40°+ AoA when buffet fades away…
Cheers, Cola
Cola1973I agree, there have been very few Typhoon displays where you could really believe that the plane was being pushed, and the early displays flown by Keith Hartley or Craig Penrice seem to show off more of the planes high alpha performance than any of the displays seen since, but out of the RAF displays some of those flown by Jim Walls in 2007, including the display at Southport you mentioned, have been the most impressive IMO, he seemed to really know how to chuck the plane about. 😀
I seem to remember reading before somewhere that the limit was 8g before the phase 5 FCS, although I’ve also heard in one RAF display the transit pilot/commentator mention that the Typhoon flying the display was limited to ‘90% flight capability’, only to point out that plane was pulling 9G later in the same display. 😉
Anyway, I did a bit detective work, and it seems that none of the aircraft used for the RAF displays so far have even been Block 5 standard, and that includes the two displays flown so far this year at Southend and Duxford. I’m almost 100% on that, but maybe somebody here can confirm whether that’s actually the case ?
This is definitely a Block 5 Typhoon though –
http://www.youtube.com/watch?v=LMiWPj4DzP0
The aircraft is 30+41 GS027/134, one of the Block 5 Luftwaffe aircraft that ended up with Austria. It’s not a display unfortunately, the plane is fresh from the factory (still in primer) just being taken for a quick spin around the block. 😀 Starts off a bit slow, but gets interesting after the 2.15 mark.
That’s some heavy g manoeuvring indeed, especially those “over the top” scissors and with centerline tank too. Just check the sound pitch rising due the g loading…
Nice clip, thx.
However, this still isn’t the limit (no tip’s and fuselage’s vortexes yet, just wing’s), let alone “beyond the curve”…However, the most impressive is how slowly EF looses energy (something atypical for delta in manoeuvre), so I guess the pilot uses DFC excessively (apart from not pushing the airframe to the limit). Anyway, it’s far beyond any classic configuration.
Btw, I have a clip in which DA(dunno number) rolls 360° in about 1 sec!, so check EF entry at the end of the film (8:13) 🙂 The film is from YouTube, but is no longer hosted there.
http://www.2shared.com/file/6007628/ed8fa4a6/GermanArmedForces.html
Cheers, Cola
Cola1973I just read this statement by Paul Metz:
http://www.codeonemagazine.com/archives/2000/articles/oct_00/f-22/f22_1.html
Obligatory, thx for the link.
I’ll just quote “The slight buffet remains constant from twenty-six degrees to about forty degrees AOA, where it decreases.“
Well, so much about unlimited AoA for Raptor 😀
Cheers, Cola
Cola1973I think you got it all covered up…
Am I leaving any possible scenario out? Could the North have any other means of delivering its bombs?
Well, maybe by mail, but I’m not sure whether DHL delivers nulear parcels 😀
Cheers, Cola
Cola1973The specifications of the F-22A.
Very intersting…Care to share a link. I’d like to take a peek myself. Thx
Cheers, Cola
Cola1973What was the task of that MiG-25? Bought for millions and every flight hour of that did consume thousands of Dollars too!
To hurt the US taxpayer, before that AAMs riched their intended life-time?
Yes well, but I’m sure you can appreciate a tactical point of this…
Cheers, Cola
Cola1973There’s one misconception regarding missiles and their abilities. The general assumption is that big missile is for knocking down large targets (like bombers and such) and it’s wrong.
Now, big missiles are big mainly because they have long range.
So, in order to achieve long range a missile needs stronger engine and more fuel. From kinematic point of view, larger mass has greater inertia which is also desirable for a projectile which glides (non-ramjet) most of its flight time. Further, long range missile needs large warhead, not because it needs 50kg wh to knock down B52 (10kg or even less, is enough), but because it has been guided by longer wavelength radar and therefore the probability of non-direct hit is higher than with WVR missiles. So, larger warhead has larger lethal range.
One other thing is important and often overlooked. True, the missile can be outmanoeuvred, but only when the pilot knows its exact position and TTI and even then the timing is crucial and generally too complicated for a human to execute it in a regular basis. After all, missiles are all but invisible in the sky and that’s especially true for coasting missiles, which after engine burnout leave no visible trail (its no accident AMRAAM has smokeless engine).
To conclude, the greater the difference in speed between projectile and its target, the less manoeuvrable projectile is required to be, to score a hit (f.e. bullet against human, or hypersonic (check recent German experiments in this area) missiles against today’s aircraft). This is why the plane is required to pull g (function of SPEED and rate of turn) in order to outmaneouvre a missile. Although the fighter may have better turn rate at speeds below “corner velocity”, its speed simply isn’t good enough to move it out of danger.
Cheers, Cola
Cola1973In case of the F-22 the excess thrust requirement resulted in the capability of achieving more than Mach 2. It is like cars that in order to quickly accelerate to 200 km/h have enough power to achieve 270 km/h, still are limited to 240 km/h.
Check my link from post #43, page 63. If that’s true your story goes down the drain.
Cheers, Cola
Cola1973In service is a question of someone ordering them. The R-33S is already 200+ KM range, which is very high.
They are huge, but that does not matter. They have massive warheads and high kinetic performence. They have been rated for 12G targets.
The NEZ might not be 400KM, but it’s a hell of a lot higher than medium range AAMs.
The ranges, again, are still higher than medium range AAMs, which is what counts.
Agreed…Tomcat+Phoenix combo wasn’t withdraw because it was incompetent, but because it was too expensive. I’m sure USN would like to see their F14D still on its decks, if they had enough founds.
Cheers, Cola
Cola1973I really doubt the Mig is outrunning an F-15 at low level. They can not even go above mach 1 at low level and in general are terrible low level performers. The engines and plane were designed for high altitude high speed interception.
Well, I can’t make a claim on that, but I have paraphrased actual F-15 pilots that claimed to be outruned by Mig25…I mean, it was all over the news…
I didn’t mean it is as aerodynamically efficient, but it’s TVC makes it as agile.
Hm…now we come into tricky area. USAF have a certain definition of agility. Forgot where I red it, but if I find it again, I’ll post a link…Anyway, to paraphrase;The agility has been defined as the ability of the plane to sustain transitions though lateral plane, while being g loaded in longitudinal plane.
In plain English, it’s “Barrel Roll” manoeuvre. Now, I’m not sure, but some reports indicate nozzles on F22 to being slaved together and if that’s true, there’s no TVC help in roll.
So far, I’ve seen F22 manoeuvring in one plane only, either lateral or longitudinal, but not combined and pilot makes a brief control leveling between changing planes, even in quick transitions. So, to classify as agile (I didn’t invent this term and I find it stupid, but USAF insists on such formalities), F22 should exhibit, at least two plane rotation.
Finally, don’t forget DFC, which is beyond Raptor’s domain…
Btw, check this link which, I believe is more important: http://www.cdi.org/pdfs/Stevenson%20F-22%20Brief.pdf and I’m sure you’ll see that the guy has point on more than one issue 😉 The guy that wrote this was a TopGun Journal editor for years and had contact with TopGun instructors.
Cheers, Cola
Cola1973Now, as far as the Raptor goes, all I have to say is…it could have been even more capable…I’ve got a book from ’84 with some 20 pages full of ATF design proposals and you should have seen those. You can’t tell which is more creative or revolutionary and in the end US chooses the 1970s layout…bah…
Finally, don’t compare F22’s layout with Eurocanards, as those are two different designs and although F-22 is a high performer, it has limits which can’t be overcome.
Cheers, Cola
Cola1973Quite right, but MiG-31 uses speed instead of “stealth” to come within NEZ for a given target, by giving the missile a jump-start, which for all practical purposes has the same effect.
F-22 does both however, and that’s what makes it so deadly.
On top of that, it has the high speed/altitude agility of a delta canard while retaining low speed/altitude agility of a conventional a/c! so at least in that respect, it is a masterpiece of engineering.
I would also not dismiss russian missile design, more often then not they are world leading, tho my impression is they twist and exaggerate numbers even more then western designers.
True. Both speed and stealth are two (of more than just two) possible approaches in solving the problem of achieving a firing solution.
Having both speed and stealth, like F-22 has, is most certainly advantage above having just one of those two and there is no question about that.
However, it’s not essential (the ONLY way) as US (and it’s forum trolls :D) are permanently trying to present. Obviously this is because US heavily invested in stealth and seeks investment return through F35 and if the world would go other way in aerial doctrine warfare, US economy would suffer.
Here’s an example from pre March 2003. At one point, newspaper reported multiple missile launch against Iraqi aircraft, by USN and USAF F-14, F-18 and F-15, of which NONE hit the target, but the mission was successful (due mission kills). I don’t remember it being confirmed, but unofficially, teens fired 2 Phoenixes, 3 AMRAAMs and 1 or 2 Sparrows at Iraqi fighters, which were provoking (testing) American response time, readiness, etc…So, the trick was, as soon as Americans fired their missiles, the Iraqis turned tails and ran away…conditions; no stealth, basic GCI, no onboard ECM, etc…and yet all Iraqis came back.
Moreover, the only aircraft to score a kill against US aircraft in 2003, was not Mig-29, or some other hot-rod Russian dogfighter, but “old bucket” Mig25!
Yes, Mig25 can’t pull more than 5g and has a turn radius of 10km, but has still performances which were obviously good enough to allow it to burn through US ECM screen and reach firing solution and score a hit.
F15 pilots reported Mig25 have been causing problems, even at low level and more than ones F-15 got outruned by Mig25, just above sand dunes.
So, I think Mig31 has its role in today’s warfare and if used correctly it may prove surprisingly efficient (even more than today’s analysts predict). More modern avionics and improved engines and weapons will most certainly tip ratio even further into its favor.
Cheers, Cola
Cola1973To follow a fighter doing 8 G at 800 km/h, the three times faster AAM has to pull six times the G. Simple physics. That is a 48 G capability at 2400 km/h. When limited to 12 G at 2400 km/h, the related target has do not more than 2 Gs, when that is something even bombers and transports can match. 😎
True, although I’m not sure whether 12 g is an actual limit for R33. It seems low for an all solid-state electronics system. Any reliable data on that?
Anyway, in order to evade such a missile, the pilot must know the exact moment when to turn! Now, this sounds much easier than it actually is and that’s missiles best chance of success. The window for defensive turn against such a missile, in reality, is a few seconds at best.
Further, although there’s no reliable data, it may well prove fatal to assume the Russians (or not just Russians) didn’t improve their guiding algorithms. It’s really difficult to expect they still use basic proportional guiding from 50 years ago and so “over the nose” missile’s energy depleting turning, may prove useless (or less useful at best).
Hahaha. No need to tell them. They already know. They did not invest further into modernizing or replacing the AIM-54 Phoenix because the only USNavy aircraft (F-14) capable to carry it was going to be phased out. They prefered the more versatile and lighter AMRAAM. There are both pluses and minuses in that decision.
In RuAF and for varous reasons, they still like the long range AAM, and are still investing in such missiles (R-37 and KS-172).
There is a whole new series of Russian AAMs in development (maybe they will reveal some of them during the MAKS-2009 show this August). One of those AAMs is a long range one. Unlike the Soviets, the Russians don’t have the cash to invest into an AAM that can’t shoot down maneuvering targets.
Hm…I’d look at that as a matter of doctrine and economics…
Simple mathematics shows following: F22 and F35, are theoretically more cost/efficient than other non-stealth aircraft.
This is so because, in theory again, stealth aircraft can come closer and deploy “dumb” weapons (less expensive) as opposed to non-stealth which must stay outside AA systems range and deploy long-ranged (more expensive) weapons.
So, in theory again, today’s Raptor+AMRAAM can match F-14+Phoenix, by being able to come within launch envelope using stealth.
It’s seems that initial procurement cost for stealth aircraft has been offset by their ability to deploy less sophisticated (and therefore expensive) weapons.
Consequently, stealth aircraft have been tailored for wartime use and their cost/effectiveness ratio “sinks through the floor” in peace.
Cheers, Cola
Cola1973True again, BUT it’s difficult to expect for a non-ramjet (or even ramjet) missile to maintain nominal speed at the edge of its envelope, so it may well cool down by the time it reaches engagement zone.
However, if that fails you can always go with dual guiding (as echonine said), with low sensitivity (low-IR band) thermal resilient IR seeker for general tracking and then combine with laser for terminal run.
I mean all these things have already been constructed. It’s a matter of application and tuning…
Cheers, Cola
Cola1973ROFL, man.
I guess Norbert Biehler is a “waiter” with the highest paycheck in the world. 😀
Anyhow, I think dropping sausages on “unsuspecting wedding” is much healthier than dropping Mk84s.
Cheers, Cola
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