Cola1973But 🙂 F-22s are using C-7s so we can’t ACCURATELY assume anything – which is our point!
Agreed, but how can one go and talk around (and present himself as a USAF pilot), that he can engage 4 enemy aircraft and flyaway and he doesn’t even know what his missile can do and what aircraft will he go against and in which conditions?
Cola1973I DIDN’T CLAIM ANYTHING.
I JUST GAVE AN ALTERNATIVE POINT OF VIEW ON THE SAME DATA, THAT HAVE BEEN REPEATED OVER AND OVER AGAIN, AS AN “UNDISPUTABLE” PROVE OF F22’S SUPREMACY.
Am I going to have to start writing disclaimers, here?
Cola1973But there’s no basis for assuming that every extra missile that was fired was a miss. It’s not uncommon to ripple fire missiles at a target to achieve a higher pK, and if both missiles were fired within the proper launch envelope, there’s a reasonably high chance that either missile could’ve achieved the kill on its own. This being the case, it’s not unreasonable to conclude that the actual performance of the missiles was greater than simply the number of targets that were killed.
Agreed, but Pk isn’t an assumption. This is just an amalgam of the results of actual combat firing. So, the US air forces fired, let’s say, 537 AIM-120As. Of that number about 333 scored a kill (not hit, although I’d expect US sort this out).
For the sake of the argument let’s put AIM-120A, or whatever missile this Pk is addressed to.
Now, let’s make that F22 engage 4xMig-23, in BVR. With a Pk of 0.62, the chances are that of the 6 launched AMRAAMs, 3.72 will score a kill (not hit). This means 3 destroyed and 1 “wounded”, Mig-23s. After that, the F22 must engage visually, if it wants to destroy the 4th target. It may well happen that all 4 AMRAAMs score a kill and F22 just flies away. OTOH, none of first 4 AMRAAMs may not score a kill and in this case, F22 is on 2*AMRAAM and 2*Sidewinder, for a WVR fight.
Cola1973Again what you said was:
That range being 30Km – the F-22 becomes visible – is what you said. Now no one doubts that certain sensors will almost certainly pick the F-22 up at that range – but what you said was the F-22 becomes visible at 30km. To which I replied:Not to mention the fact that he knows the F-22 becomes visible on radar at 30km – universally.. The point being you can’t generalise – especially since we were refering to 4 enemy fighters – likely F-15s which have X band radars and don’t have IRST. There is a lot of US literature saying the F-22s often merge WVR without being detected by F-15s/F-16s – so again I was picking holes in your rant.
Your remark is just another input. Where did I say universally? That’s your interpretation and I certainly didn’t mean that. For example, it’s pretty obvious that the older F5 with it’s small radar, won’t see F22 on 30 km. I though it’s pointless to emphasize that, but it seems I was wrong…
Nothing there claiming you were restricting the conversation to how well the F-22s radar copes…….
To which I replied that there was a lot of USAF literature stating that ground hugging tactics from 500ft low have had no real success against the F-22. I even linked you to an article that stated it clearly – one you didn’t care to read lol. Well I will post the quote for you your highness :)…
There was an article (High Rider) EF being able to lock onto F22 at surprisingly long range, but I don’t go around quoting it.
When I spoke of ground hugging, I meant beam riding, because else is pretty much useless.
Again, that’s obvious too…
So in your effort to undermine the F-22, you twist your own words – say you were only talking about radars – say how its a big hinderance to the F-22.
Well, F22 has radar only, doesn’t it? And it needs to look/shoot down most of the time, doesn’t it?
Mate, this is not your area, clearly. Now I’m gonna attempt to explain it to you one more time… I might not be the best teacher but here goes. What you are looking at is not a transonic drag peak… Drag COLA is a force, measured in NEWTONS. What you are looking at is the transonic coefficient of drag peak – shown against Mach No. Now I corrected you earlier in the thread where you said that an aircraft has higher drag in the transonic region – that is false, wrong and incorrect! In general they have LOWER DRAG, but a HIGHER COEFFICIENT OF DRAG in the transonic region – and thats what you see in that graph you posted. MY curve although a shabby 2 second job shows you what happens to the DRAG – the actual force experienced. WHY is this the case, you ask? Its because Drag = 0.5*local air density*velocity of the aircraft*velocity of the aircraft*drag area*Coefficient of drag. Therefore while the Cd is higher at Mach 1 than it is at say Mach 1.4 – the aircrafts velocity is higher at Mach 1.4 and velocity its the dominant expression in the drag function as its not linear like the Cd but rather a 2nd order expression – or an expression that is raised to the power of 2! Thus in general for aircraft the actual drag in force vs mach relation looks like the graph I posted in my previous post! Remember Cd is non-dimensional and is not the same as drag – and drag is not the sum of Cd’s.
Agreed and this is the first thing you wrote that makes sense. Mistake on my part, although merely semantic one. Cd (gross, total, or whatever) is often referenced as just “drag”, meaning sum of coeffs.
>>I never said, or implied that you are a little $hit and even personally, I don’t think so.<<
After I make a review of your posts, can’t help but remember a guy from Alan Ford (think it was a ZOO Symphony episode), that works for an electric company and goes around and cuts electric current cables of those who didn’t pay the electricity bill. So, one day he arrives to Alan Ford and cuts his candle in half, because there’s no more cables to cut. 😀
Cola1973Yes, I did asume the other 38 missiles will miss, but I may have also assume the original 62 miss. But I didn’t speak of HIT probability (Ph), but KILL probability(Pk), because I don’t have a figure for a Ph. Sure, its possible and probably has happened, that the two missiles scored a hit on the same target. This is one of the reasons, why modern fighers feature datalink.
Anyway, I agree, that 7M is a good missile, which faired well in combat. The combat service is what makes it good, though. Not laboratory predictions.
So does the baptism of fire awaits all new models, regardless of amount of predicting and simulating and such.
Sure the F22 has theoretical advantage, but against what and whom and that remains to be seen.
Cola1973Just out of curiosity, what would you think the pK of an AIM-9B vs. an AIM-9X might be, or an AIM-7B vs. and AIM-7M? Do you think you can draw a corrolation between the earliest model, and one that’s had numerous improvements? You still didn’t address the fact that the 62/100 number didn’t necessarily reflect the number of missiles that came within the lethal radius of their target.
Ok, I’m not inventing a hot water here. I’m using data cleared by USAF and I don’t know how did they count the AMRAAM’s Pk and I doubt anyone here does.
So, if they’re wrong, I’m wrong too and I never said otherwise. But that’s also the point, since I don’t try to speculate on known data (which may well turn to be different eventually).
But if you ask my guess, I’d say that today’s AMRAAMs have better Kp against Mig-21s than AIM-7. If that’s the case with new fighters, I couldn’t tell, but I’m pretty sure the opposition doesn’t fly Mig-21 (mostly) today. Moreover, I merely point out the possibility that that the AMRAAM C-777 can miss and probably will, as has A,B and C before. Just because you don’t recognize some parameter, doesn’t mean that it doesn’t exists.
There has been a discussion in that direction, earlier in the Mig-31 thread. So, there was news from US (from late 90s or so), that the US fighters fired 6 or so missiles at the Iraqis fighters (AMRAAM, Phoenix and Sparrow), in the no-fly zone and none of them hit!
Still, the Iraqis turned the tails and ran away, enabling US to claim mission kills. However, NONE of the missiles scored a hit. So what does that tell you about Pk?…just a bad luck, or something more?
Although F22 has some doubtless advantages, it has shortcomings as well and in this case, a weapon compatible with its mission profile. Now, I don’t say AMRAAM is a POS (it’s maybe the finest MRM in service), but it doesn’t exploit F22’s potential to the maximum.
However, if USAF, doesn’t find it necessary to upgrade F22 with a new weapon of longer (AGP-77’s) range, then it’s possible that there’s no need to do so, because F22 doesn’t have such superior characteristics in the first place.
That’s, however, more of a speculation, but bears a certain degree of merit.
Cola1973mod delete this, plz
Cola1973With regard to your comments about the USAF giving pk results for the AMRAAM C-7 please link me too them being 62%.
I wasn’t talking about any specific weapon, but AMRAAM in general, since it has been the only figure given. I don’t care about C7 or C77 or C777.
Modern missile, modern ECM, got it? And where did the C7 actually experienced combat firing?
“Ah sorry, I forgot. “It won’t let me put my weapons on it”, right?” I now understand I’m not dealing with anyone worth arguing with lol – aka a fanboy – what kind of retort is that….
Heard that one before. What model am I fanboy of, btw?
It’s a kind of rhetoric that assumes that F22 is radar visible at 30km. Well, I may be wrong and F22 could have been actually detected in um wavelength (go figure, which sensor you need to use for that), sooner than on cm wavelength, but then hats off for F22’s LO features. 😀
Again, I never claimed that being the case, but just pointed that out as a possibility.
“Care to post a link to an article that explains how did the APG-77 solved Doppler screening? Really, I’m rather curious to read it.” Don’t be so one-dimensionally ignorant… there are many ways to skin a cat and get a firing solution but I don’t care to speculate with someone who will make the whole process more tedious than it needs to be – I’ve done it with people in the know. But in short read this article before I lose my patience with you futher…. http://www.f22-raptor.com/media/documents/aviation_week_010807.pdf – It directly refutes your 500ft claim.
Didn’t have time to read it, but looking forward to learn how did the F22 solved the Doppler shift.
I agree, there’s more than one way to skin the cat, but I’ve been talking about this particular one, so don’t go around, talking about things that I didn’t say, or assume you know what I think and know.
It’s just plain obvious you have a grudge with me (being LmRaptor after all and i don’t blame you), but this is no excuse for twisting someones words and pulling unrelated stuff into the discussion. I balanced my words carefully and if you want to conduct a meaningful conversation, I’d suggest you do the same.
Your claim that you experience higher drag in the transonic realm of flight than above it is complete bol.locks – I will repeat – you experience greater drag above the transonic regime and if you want proof – go and do some research.
I study Aerospace Engineering – I do this stuff day in and day out – and I’ve just written a bunch of exams and done a load of reports based on this in a Mach 1.8 supersonic wind tunnel as part of my degree. For simplicity D=0.5*p*(V^2)*S*Cd and while the Cd(which is linear) does indeed rise more so in the transonic regime – as I said – so does the velocity which isn’t linear in its relation to the drag equation and as a result a standard supersonic drag graph vs mach looks like this.
http://yfrog.com/20draggraphp
…”I study Aerospace Engineering”…sad…(sorry, but couldn’t help myself :D)…
http://www.centennialofflight.gov/essay/Theories_of_Flight/Transonic_Flow/TH19G5.htm
Pretty, straightforward…
And there’s an attachment. You should be able to see transsonic drag peak, translated into flight envelope curve…
As for your Yfrog curve, I generally have no objections about it, but…it managed to omit a slight (depending on aircraft) flattening part of the curve in the transonic region and that would be a transonic drag peak.
Oh and what you’ve written in your previous post displays nothing but ignorance and a very simplistic understanding of the topics at hand – wiki only goes so far 🙂 – so if you don’t understand why your wrong – I’m sorry but I don’t have time to correct you.
Also don’t mind me when you rant with your fanboyesq anti F-22 feelings – I don’t care – but when you start talking nonsense – if I have time – never fear – I will correct you.
I don’t have a sentiment pro or against F22 or you. I do have one for stupidity, though.
But seriously correct me if I’m wrong. I don’t have any objections about that and I’m no egomaniac, since I didn’t put my background, as an argument.
However, first make sure that what you’re saying goes along with the facts.
Cola1973It would depend on how much time the missile spends at low altitude, to how much effect on the performance there’ll be. If the missile stays high for the majority of the flight before diving, then the drag issue won’t be as extreme as a 30 percent reduction in range.
Agreed. The thing is, its range is still being rather reduced compared to maximal.
Also note, French Matra’s SUPER530.
I’m using this example because the missile had good snap up and snap down capability. So, SUPER530 flew a square envelope, meaning it has been programmed to reach the height first, in case of higher altitude intercept and azimuth later. In snap down capacity, it didn’t flew exactly the same square envelope, but the missile did try to reach look-up target aspect as soon as the range made it possible.
I’m not sure about new models, but the notion of AA missile hitting a target from above (ALARM like flight profile) wasn’t used in the past.
Cola1973Additionally I find it amusing that he understands the technical intricacies of US DACT or how he is an authority on what makes the F-22 superior or not – despite not really understanding the particular ROE.
Glad to amuse you. 😀
The Hornet’s kill against the F22, came from below the deck and has been commented as irregular (and if I misunderstood, I apologize)…
Additionally I love how he gives an AMRAAM a pk thats based on a different variant of the missile.
I didn’t give anything. USAF/DoD did…
Not to mention the fact that he knows the F-22 becomes visible on radar at 30km – universally.
Ah sorry, I forgot. “It won’t let me put my weapons on it”, right? 😀
Its a pitty he doesn’t realise that a lot of literature written on anti-VLO tactics adopted by F-16s and F-15s have shown pilots using ground hugging tactics have failed almost as miserably as those using different tactics.
Care to post a link to an article that explains how did the APG-77 solved Doppler screening? Really, I’m rather curious to read it.
Now I can understand being impartial – which is what I expect – but the poor chap has a chip on his shoulder – probably from digesting to much F-22 fanboy nonsense.
…Well, I don’t want to patronize you, but you’re the guy that claims, the drag gets lesser, while drag coefficient gets higher.
Ok, English isn’t my native tongue, but as far as the available English literature goes, drag figure is a sum of all drag coefficients. Now, it seems to me you are the one that has problems, with grasping even simple things, let alone a stealth fighter concept…
Finally, my intention wasn’t to discredit USAF’s fighter and I apologize if I did. All I wanted is to point out some universal shortcomings of today’s technology (and F22’s too), that has often been omitted from official press releases, or interpreted in a biased way.
All those figures can be interpreted differently, but more importantly, they can be USED differently.
So, LmRaptor I agree. I am ranting, because the people who need to know these things, already know them and use that knowledge, no matter what I say…
Cola1973If the missile is lofted and just decends during the terminal phase I see no reason why the range would reduce by 30%. While air density is higher at low heights increasing drag, lift is also better at that altitudes and it should be easier for a missile to maintain energy while decending than keeping in level flight or even climbing to the target.
Missile doesn’t have wings and it relies on body lift. I don’t think you appreciate enough the change in pressure (density), as it can affect drag performance in a quite sever manner. AMRAAM, f.e., has a top speed of M4. However, that speed occurs at motor burnout and from that point on AMRAAM glides. Although the exact data for AMRAAM are classified, the available data suggest that average speed on a high-high launch profile at maximum range, is about M2-2.5 and that’s significantly lower than top speed.
Now, as I said, the speed rises with the square of (form) drag. That means that the AMRAAM will go M4 for a brief period of time, but the speed will exponentially bleed off, until the performance curve takes less steep direction and that wold be around M2.
So, the missile will fly M4 for 2 seconds, but will fly M2 for 15 seconds (these aren’t actual numbers, but I’m just making a point of non-linear speed drop off).
AMRAAM is, unlike a Phoenix, a light missile for its size and has less inertial potency. This means it looses speed more rapidly in high pressure environment, so even if you preprogram it to have high ballistic trajectory, it won’t achieve results comparable to Phoenix.
Many discussions and articles have been written on this topic and a general consensus is that the missile’s range can drop to as low as 1/3 at lower levels. True enough, high speed and height would give better chances to score a hit, always and may not reduce it’s range to 1/3 exactly, but more towards 1/2 or something, but I don’t want to speculate on actual model’s performance.
The thing is, the difference between tropopause and S.L. is quite severe. Just check the difference in speed for aircraft and those have wings to support them.
Cola1973“I was able to kill all adversaries and accomplish the mission outnumbered 4 to 1. There is no current fielded jet that could accomplish this feat today.”
This is a common statement that has been used to “prove” F22’s superiority, but is untrue.
In reality, the pilot that issued this statement hasn’t killed anyone.
What he did is, he put a tracking beam on targets long enough for APG-77 to calculate intercept vectors and launch missiles. It doesn’t even say if the pilot lingered long enough to provide mid-course vector update, during imaginary AMRAAM’s flight, or leaved immediately after the launch.
It also doesn’t say if the pilot used common kill probability coefficient (Pk=0.62) for AMRAAM, or not.
With Pk=0.62 which has been derived from actual combat experience against technologically austere enemy (Iraq, Yougoslavia), the AMRAAM scored 62 hits in 100 launches ratio. Keep in mind that Iraqis f.e., didn’t have ECMs and overall EW suite to counter US air assault, so the missiles had relatively easy job.
Then, there’s the issue of the flight level being limited for safety reasons, effectively cutting off, the most effective weapon against LO, the ground hugging. That goes for either offensive (ambush), or defensive (ride the beam and hide in the clutter) tactics. Turbofans spend less fuel in low level flight than F119.
Although, the SC has been advertised as a way to go in missile’s envelope terms (and it is), one has to remember that this works best for the comparable flight levels, only. So, if F22 at M1.5 launches an AMRAAM, it’ll have significantly increased range against a 40,000ft flying target, indeed. However, if the same F22 launches against a target at 500ft, the range could get reduced to as much as 1/3, meaning a 100km figure would go down to 30km figure. At that range F22 becomes visible and it complicates escape window (and survivability) exponentially and then there are still 4 enemies, to solve.
Now, all of this goes for other aircraft as well (and this is just something from the top of my head), but I just wanted to point out the complexity of flight, let alone combat dynamics, which makes statements like this sound like a scenario for some computer game.
Cola1973The F119 can supercruise for ~5 minutes at M 1.82 for a maximim distance of ~100 miles (161 kilometers) on internal fuel before it hits bingo fuel state.
Let’s assume the F22 uses 15% of its fuel as a reserve (not combat, but regular flight reserve) and the rest can be spent and that brings us to 7000kg of expendable fuel.
Now, if F22 could do what you’re saying (M1.82 for 100 miles), that would mean it burns about 80 kg/nm, while doing that. As far as it has been known, F22 burns ~21kg/nm at M1.5 at lower tropopause layer.
Although, it’s true that form drag rises exponentially with the speed, I must say that it’s highly improbable (about 99.9% :D) that it actually rises so much that the engines require 4 times more fuel than while on M1.5. Moreover, if you look closely, you’ll see that such SFC would probably choke the engine, since I doubt the F119 has the ability to burn such amount of fuel in its burning chambers alone.
I don’t think the F119 burns 80kg/nm, even in its AB range.
Cola1973F119 – incorporated BLISKS, Hollow fan blades, counter-rotating spools, two stage combustors and 2D TVC – with an exceptional TWR – seeing as its dry weight including the heavy TVC nozzle is only 3900lb.
http://www.mtu.de/de/technologies/engineering_news/production/bayer_bliskfertigung.pdf
http://www.mtu.de/en/technologies/engineering_news/development/24812Advanced_Compressor_Technology.pdf
http://www.janes.com/articles/Janes-Aero-Engines/Pratt–Whitney-F119-Germany.html
Check who did it…:D
Cola1973…oh yes and the vectoring nozzle has been constructed, tested and overall solved by British RR and German MTU, back in 1966, for RB153 engine. So obviously, some people can overcome problems and make a step forward…I wonder what did actually PW’s engineers invent on F119, or we’re going to get another lecture about heroic efforts of epic proportions…
Sign In
