People, you are writting “War & Peace”…of Tolstoy again…
Numbers ???
Allowed angle of attack, corner velocity, altitude loss in split-S ????
Anything not inline with conservative manuals ???
I saw it only in that book on eBay and Google books:
http://http://cgi.ebay.com/Fighter-Performance-in-Practice-Phantom-versus-MIG-21_W0QQitemZ290420475752QQcategoryZ2228QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DDLSL%252BSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%252BDDSIC%26otn%3D20%26po%3D%26ps%3D63%26clkid%3D9015911580207100985
I have heard that according to manual, it is not recommended to exceed 17 deg true alpha ?
It would be nice to see similar books about other hi-perf a/c
Agility consists of maneuverability and controllability. Maneuverability is the abilty to change speed and direction of flight path (velocity vector). Speed is changed thru dynamic thrust, drag and weight ratios. Direction is changed instantaneously thru high lift to weight ratio (min speed and corner velocity are good indicators) and in long term with thrust and drag at lift terms added.
Controllability is the ability to change aircraft attitude and thrust. It is essentialy nose pointing and engine spool-up time. Good pointing indicators are ability to acheive high alpha and aileron and rudder departure parameters.
MiG-21 maneuverability is best described in book:
Thank you “haavarla” !
Nowadays kids can collect more official performance graphs than Intelligence Agencies. Maybe latter are not more interested in these things, but in putting puppet governments with latter consequences (benefit to few, damage to all).
Merry Christmas and Happy New Year to Aviation enthusiasts !
Thanks! Did he say where the exam was from? RTU? FWS?
He didn’t. We do not pay attention to particular parts of air forces, only if it is obvious.
I can only say that I consider AF most professional and open af. Israelis may be even more but they do not release even a photo without photoshop and army of security officers behind.
I agree that the info on that chart is misleading. My data (manufacturer flight test and USAF EM info) doesn’t agree with it. Not knowing where that chart came from, I have serious doubt about how ‘famous’ it is!! 🙂
My colleague sent me some graphs from USAF exams:
It is about reading data properly as someone did prove to be unable some way already, when selected raw data do just show one side of a coin only in a misleading way by questionaable intentions more than ones. In the MiG-15/F-86 case all relevant details are available to make up a balanced mind about that and a classic in the best sense about jet fighter maneuverability comparison. 😉
Once, when I went to our library, officer in charge told me that he would also like to see some our F-86 manuals, but he is not allowed. I told him that it can be found on internet openly on Force’s “fan” site! So much about confidentiality.
When country was in war, me and colleagues laughed at statements (about shot-downs) what our spokesman told. Latter we laughed even more when we heard what other side succeeded. So much about fairy tales about kill-ratios. I learned “not to believe eyes but tactile senses”.
I will stay polite. The F-16 did start that turn at Mach 1,2 and 6 Gs , when slowing down but keeping the height. When looking into such graphs you have to be able to read that properly. 😎
You are really tough. One can learn more from you guys than by attending flight academy. Our professor, although working for NASA could not answer none of our questions. And you, Sens gave closer explanation than author of that graph. I would enjoy if I was good in arguing. My colleague told me that curve depicts turns at Ps=0 i.e. sustained turns. As I said that is unrealistically high, while instantaneous turns would be too low. In decelerating turn, time function should figure and a/c should start from the same point.
More than often raw-data are misleading in general, when it does come to fighters and the practical behavior from that. The MiG-15 and MiG-15bis are famous examples about that, when that offered higher absolute numbers compared to the F-86s and did suffer despite that.
The turning data of that are available for years, but the raw data from that will not tell the full story. 😉
You, like gentleman before are wright.
MiG-15 didn’t have all-flying tail nor irreversible hydro-controls with all consequences from that (I think that F-86’s successor in UK also didn’t have flying tail).
But let the readers (us) judge pro and contra of all that equipment and performance, by releasing data for a/c 60 years old. Otherwise, one should better spend time working-out or reading classics.
The enthusiasts I was referring to are the folks who come here to get information. Those of us who provide that information have a responsibility to be correct. Sometimes, it seems to me that what I see is someone trying to score points over someone else by posting irrelevancies from un-named sources…that some people seem more interested in proving someone else wrong than in providing info for the other posters.
I agree that the info on that chart is misleading. My data (manufacturer flight test and USAF EM info) doesn’t agree with it. Not knowing where that chart came from, I have serious doubt about how ‘famous’ it is!! 🙂
I do not doubt honesty of individuals in any Air Force, also care (by someone upper) for information not to leak must be appreciated. But I have sympathy for all fans and enthusiasts who waist time and energy (and money) reading a/c articles and books.
I will ask some colleague to give me origin of these graphs and I’ll attach it, but I do not doubt it is USAF as is Foreign Tech Div origin of another.
You are guessing to stay polite. To avoid further misunderstandings here are the scans about that.
Graphic 1 is in metric and it is about the turning radius in km at 11 km height over a speed range (~ Mach 0,25 till ~ Mach 1,6) and the resulting G-loads and turning-rates in °/sThe main purpose was to show the superiority of the than new F-16!
By the second scan the Ps = 0 is of intrest, because it does show the value available and in need for a constant G-load of 3 or in short, the F-4 has not enough thrust available to pull a constant 3 Gs above 11 km height or the speed/height does drop! Compared to the MiG-21 the F-4 has a higher kinetic-energy and installed thrust to deal with, when the lower wing-load does give the MiG-21 the advantage in better lift at lower speeds and high-up.
The issue is fictional and misleading graphs or simple data that is circulating in open literature or internet !
I apology if I have ‘last intentions’.
Famous German precision…in that first your graph, they give credit to F-16 – more than 6 g sustained at 11 km altitude, where in reality it can’t hold 3 g !
Second depicts you said, SEP at 3g. No a/c today or in future have that SEP of 300 m/s at very low altitude. Most modern has somewhat higher SEP at 1g ! And F-4′ SEP is not 300 at 3g, but somewhat above 200 m/s at 1g !
That is what I’m talking about.
If someone wants to give us some clue of a/c capabilities, let them give correct one. Don’t release current a/c abilities, because one can forward it to Al Khaida or competitions, but ’40s or ’50s graphs will do no harm.
Yes…when we are trying to present information to enthusiasts, it doesn’t help when questionable data is used.
I agree, the info is confusing…depending on what F-4 version is being shown, the sustained values are going to depend on the altitude…and I don’t see altitude on this chart.
What famous USAF diagram?
Surely Air Forces are aware that there are other side’s ‘enthusiasts’ as well. That’s the reason. But when a/c is no longer operational (sustained turns of F-86/100/14…) there are also reasons not to release data?
I do not value these diagrams, that’s why I do not keep record of their exact origin. As I say, model a/c is not important if there are cardinal discrepancies. Like that on that first graph, as I mentioned (4.5 g subsonic, 5.5 supersonic). Subsonic G suggests altitude of about 15 Kft.
In second graph slatted F-4E figures, since it is main F-4E (since ’72.).
Last graph is ‘famous’ US diagram depicting SEP difference of early models 21/F-4. Allowed speeds suggests it. I saw it countless times from various articles on paper and from USAF electronic classrooms. Individuals does not fools around with that. At first it looks very serious, but not enough.
Where did you see that?
The first graphic is around the turning radius only?!
In the forth the Ps= x m/s is shown. It has two max values for the F-4.
The first is around Mach 0,9 below 5 km height and is the subsonic one, when the second is around Mach 1,5 to Mach 2 at heights between 7 and 11 km and the supersonic one. There is nothing wrong about that.
I hope I’m not subjective about these planes. We were operators of both Euro/US and Eastern planes. All had good and bad points.
In the first graph ‘g’ can be seen at left side of curved lines. It looks like the altitude is about 15 Kft, but F-4 figures for sub and supersonic speeds (4.5 and 5.5) tells that it is impossible, no matter the variant.
Other graph depicts SEP differential – who is better and where. Obvious sign of less seriousness is that from, say 40-55 Kft altitude/Mach 1.6-2.0 F-4 (no matter which variant) has more SEP (+) 50 to 150 fps, in the part of envelope where MiG’s engine and drag excels.