AndraxxusWell, that explains why the KPPs were relaxed twice instead of a redesign..
They are still higher than F-16’s performance.
The MiG-29 might be the light component of the Russian Hi-Lo mix but it definitely ain’t a light aircraft.
Light is relative. F-18C is also 10,4 tons. Is that a heavy aircraft too? Or F-14D weigh 19,9 tons. Suddenly F-15C is a light aircraft? You wouldn’t have a problem putting F-14D, and F-15C in same weigh class, despite 50% or 6,6 tons weight difference.
What matters is why MiG-29, F-18 and F-16 are designed for. They are designed as cheaper and smaller alternatives to Su-27, F-14 and F-15 respectively. And F-35 is designed as a cheaper alternative to F-22. Is it not cheaper, and smaller? IT IS. Then comparing them in weight with respect to legacy aircraft is just stupid.
Mirage 2000 with 7,5t empty or JAS39 with 6,8t empty, THAT is a light aircraft.
Light is relative, a MiG-15 is 3,3 tons. Those aircraft are few times heavier than those.
An F-16 was definitely less complex than an F-4. Especially the A version.
I was referring to F-4 -> F-15 and F-5 -> F-16 upgrades. In any case, complexity is directly proportional to capability and F-16A was not more capable than F-4E. Even for such comparison, F-16 adds much advanced radar and avionics, MFDs, flyby wire, LE flaps, and a more complex engine in place of two simpler engines. I wouldn’t say “definately” less complex. Maybe, maybe not.
If the air forces in question have originally subscribed to a light and affordable fighter, then yes, it is the F-35’s fault.
light and affordable fighter relative to F-22, and they are getting it.
About passive detection :
RWR : ( even if we discount LPI)
+1. except
2) in many vs many engagement, RWR can be used to geolocate enemy’s aircraft by triangulate between multiple aircraft using data link, however in many vs many engagement, enemy can also data link their aircraft and only let 1 fighter radiating, thus rely on RWR in this situation would actually be very terrible since pilot may think there is only lone enemy fighter on the sky while there are actually many.
While RWR on multiple aircraft -in theory- can be used to triangulate target’s location, this is insufficent to attack it as it doesn’t provide vector data. Maybe a HOJ like launch would be possible, but without loft trajectory that would cut range drastically.
And there is a second part to that discussion. How a missile is expected to attack its target?
ARH? Most ARH seekers acquire their targets at 10-15 km range. That is for normal aircraft with ~ 3-5 m2 RCS. Droping RCS 100 times (to 0,05) will reduce this range to 3,1 to 4,7 km. Potentially more if RCS reduction is greater. A Typhoon will blind fire a missile, then missile will reach within 4 km of maneuvering target without any command guidance?
Anti-Radiation? Such thing doesn’t exist for A-A missiles, and won’t due to space constraints and the need of specialized equipment for this task.
With only variable turning radar on or off,
1- If F-35 radiates, Rafale/Grippen/Typhoon will be aware of its presence, but without any means of attacking back, they withdraw or die.
2- If Rafale/Grippen/Typhoon radiates, F-35 will be aware of their presence, turn its radar on to attack, everything follows #1
3- They both don’t radiate, F-35 dies stupidly because EOTS more like an internal Sniper XR and is less suited to A-A roles than PIRATE etc.
That doesn’t mean non-stealthy aircraft are completely defensless againist F-35, but its not simple as that. For example flying very low and fast non-VLO aircraft can mitigate stealth advantage to a degree because;
1- Even the most modern radar will operate reduced effectiveness againist ground clutter, and in theory low power modes will be affected more. However slight the difference maybe, it will delay detection/tracking range and make tracking unreliable when aircraft moves in and out of radar shadows of ground objects. It will also put F-35, in unobstructed view againist clear sky, and provide slightly higher FOV to increase detection range.
2- When BVR missiles are fired to very low flying objects, they have very short range, even if they are fired from higher altitude; ~20 km head on range for AIM-120B, againist non-maneuvering target for example. This will force stealth aircraft into IRST range, and missiles like MICA-IR and R-27TE can be used quite effectively.
3-Low flying aircraft can turn very well due to increased lift, and turbofan engines are at their peak power to regain energy after hard turns. As missiles are too fast, they are already G limited to benefit from increased lift, and increased drag at low altitude will heavily degrade their terminal Pk. So evasion of missiles (by maneuvering) at low altitude is easier than that of high altitude.
Andraxxus1. As we have learned, the F-35 obviously is not maneuverable enough for an F-16 replacement, not even one carrying two wet tanks.
Well, that is one very illogical interpretion of a *flight test* which have quite possibly has nothing to do with general maneverability of the aircraft. Did ever F-15/16 pitted aganist F-4/5 during their flight tests? No. Did ever F-4/5 *used* during 15/16’s flight tests? Yes, many times.
In more realistic version, F-35 has its requirements. These requirements are equal or above F-16’s performance. If they are not met, it won’t be accepted into service. So in order to be accepted into service F-35 will need to be better than F-16. LM guys don’t live in caves, they could have simply redesign F-35, just like from T-10 -> T-10S. On the contrary, X-35 to F-35 transition saw even less aerodynamic changes than YF-22 to F-22. They flew X-35 for 6 years, and F-35 is in tests for 9 years. If its really hopeless to meet requirements, why is it not redesigned? In fact, aerodynamics and engine people keep bragging are the ONLY things remained more or less same for 15 years. Even if somehow F-35 misses the requirements a little, and accepted as it is, this wont make F-35 unmaneuverable, or hardly at the F-4E levels.
2. What do you mean by F-35’s weight class? The type is actually heavier than an F-15C and weight-wise as far from a Rafale as it is from an Su-27. How can an F-18E-class fighter be sold as a lightweight type to make up numbers is beyond me (????).
I had gone over why comparing different generations aircraft on weight is illogical.
1st gen: Light MiG-17 = 3,6 tons, Heavy MiG-19 = 5,4 tons
2nd gen: Light MiG-21 = 5,3 tons, Heavy Su-11 = 9,5 tons.
3rd gen: Light MiG-23 = 9,5 tons, Heavy Su-15 = 10,9 tons.
4th gen: Light MiG-29 = 10,9 tons, Heavy Su-27 = 16,3 tons
See something odd here?
Back in Soviet times, the 11-ton MiG-29 has utterly failed in replacing the MiG-21 as the standard lightweight fighter for the WP. Nomatter if better or worse than the MiG-21 and fitting the Soviet doctrine, it was simply too complex and too expensive to make up numbers for air forces. The richer WP countries like CS, Hungary, Yugoslavia, Romania or GDR were able to acquire something like two dozens, others like Cuba just a few and many others like Monoglia, Laos or Mozambique didn’t even bother.. And while still visibly superior to the MiG-21 in 1-vs-1 or even 1-vs-4 scenarios, the overall capability of those Fulcrum air forces would have dropped down dramatically once the MiG-21s were phased out.
And F-15/16 did not replace F-4/5s all at once, even in USAF, and were several times more complex than those types. F-4E was more complex than F-105/106, which are more complex than F-86. Your point?
The same will happen to major NATO forces – either they will go on the very edge of combat readiness due to low numbers or they will be forced to bleed out financially by operating extremely costly fighters with capabilities not really needed..
If some countries are too poor that they cannot operate MiG-29 even if they wanted to, does that make MiG-29 a failure? If you cant buy a Bentley and stuck with an old Fiat is it Bentleys fault? Should they go down to the level of Fiat? No. If a country is too poor, and new aircraft capabilities are not needed, then they would not buy it, its that simple. F-16 is a good aircraft which will see service into 2040s.
And To be frank, I don’t see why countries like Netherlands even maintain an airforce let alone buy F-35. Whats the threat? Will Belgium come and conquer Amsterdam?
Again.. If I decide to go for an A-G type mission, then my kinematics is of secondary importance. What matters is payload and range, not acceleration or speed figures (until I have dropped the payload). But after the return, my aircraft need to go back to the usual business- which is QRA and air superiority over my own territory… that is how 90% of world’s air forces will operate their aircraft because they will not be able to afford to run multiple types…
an Igla vs F-16 with 2 Mk-84s, LANTIRN and 3 EFT is assured mission kill. an Igla vs F-15E with 2xMk-84s, LANTIRN and CFT is just evasion maneuvers. An F-16 with mentioned payload is stuck subsonic below 25000 feet. An F-15E with mentioned payload can go M1.45 at 25000 feet. You cannot deny such advantages even for carrying same payload to same range.
Same type irrelevant, a ground attack aircraft will not “switch” to air superiority. It will be fuelled just enough for A-G, and other aircraft (even if they are of the same type) will be fuelled correctly for air superiority. Others will be for Anti-radiation etc etc.
[QUOTE=MSphere;2239450]
And here we go back to the root of the problem. This scenario is a complete nonsense.. How many times in the history of the Ottoman Empire the Turkish F-16s were tasked with air superiority over Baghdad? Zero times? Right, glad you understand what I mean now… The F-35 is only better than an F-16 in scenarios which most air forces never require..
Well we have a saying roughly translates as “A country needs a strong army only once.” If an army is not required nor equipped to fight an enemy when its needed most, then what good is that army is for?
And it utterly fails exactly in those scenarios which are needed every day.. which is interception and maintaining air superiority over the own capital which is ~35 miles away from their landing strip..
Netherlands, Australia, Italy, Norway, UK, Japan, even Israel or US. Then in your “real world” assumption, I ask: when these countries EVER attacked so their F-16/18s are used for “maintaining air superiority over their own capital”? Zero times? Then they could easily used an F-5 or even a crop duster for CAP missions; it would have performed equally well (many missions, many flight hours, zero combat, zero kill) at much less cost.
And F-35 fails in what way? You want a real life scenario? Ok, Turkey has 911km border with Syria and we shoot down any Syrian aircraft passes border. On several occassions, Syrian SAMs locked and tracked our F-16s, so we keep ECM equipped aircraft in the air too. An F-35 can operate without such threat (esspecially from older SAMs), and with its fuel capacity less aircraft is needed to patrol the border. It has better avoinics to monitor enemy aircraft better. In real life, we shot down Syrian 4 aircraft (including 1 UAV) in 3 years, and while all were by AIM-9, none required maneuverability on F-16’s side. Somehow I don’t think any other F-35 operator (other than Israel maybe) will ever see actual combat for defending borders.
Well, the large internal space obviously has a huge impact on the performance of the F-35, because it sucks, plain and simple.. I would not go as far as to estimate which of the design features is responsible most, but the outcome is plain to see..
By the same analogy, Su-35’s internal space should be a huge impact on performance too.
And if the CFT have so little impact, then it’s another argument in favor of aircraft like Typhoon or Rafale – they can achieve the same/similar internal range without the penalty of being a constant lumbering track – the CFTs can be unbolted/removed whenever you need a light, nimble fighter.. And you’ll need it a lot..
Why unbolt something that already has negligable effect?
AndraxxusSpot on… by further tweaking the numbers you can come to a conclusion that the Tu-22M-3 is an even better fighter than the F-35 because it has a much better acceleration, max speed and range when hauling 15 tons of bombs plus 50 tons of fuel. For shooting down the target you simply pass it by and then shoot it down with the 23mm cannon facing backwards.
Technically, that is correct. and in essence, an aircraft designer doesn’t give a sh!t about aircraft being a bomber or a figther. Requirements (like payload, speed @ given altitude, G limit @ given conditions, range with payload etc etc) are what makes the aircraft. For carrying 15 tons of payload to 2000+ km range, Tu-22M will take-off and climb better, go faster and higher than F-35, even if you manage to make F-35 fly with that payload. So that tells us F-35 cannot replace a Tu-22M for that kind of mission. And that is the truth.
Which makes comparison “on equal basis” not less, but even more important. If you fuel F-35 for F-16’s missions, it will perform better for any mission one can think of. Its maneuverable enough for an F-16 replacement. As a side bonus, F-35 can carry sufficent internal fuel to reach F-15C’s range, but others in its weight class cannot. Its a good thing to have for any customer whos replacing F-16/18s with F-35.
If you fuel F-35 for the missions F-15 perform, it wouldn’t have the kinematics of F-15. This is not a problem for any F-35 customer excluding USAF. Even for USAF, they are getting VLO airframe and excellent avionics as a trade-off to kinematics of F-15. As USAF remains unchallenged in its power, I don’t think they would care. Otherwise they would have restarted F-22 production long ago to get *proper* F-15 replacements.
Speaking of F-35’s weight class rivals, if anyone thinks that Typhoon or Rafale will have better kinematics than F-15E when performing same mission (payload+range), or believe they can do everything an F-15E does, they are also pitifully mistaken (as demonstrated by a few envelope graphs I’ve uploaded to another topic some time ago).
I don’t give damn about what range can the F-35 do on internal fuel and even less I give damn about what you call fair.. What’s the use of internal fuel if it comes with the same drag penalty as in wet bags, but cannot be jettisoned? LM would have done better making it smaller and dependable on wet bags, instead..
For an airforce which replaces their F-16 with F-35, it would matter much more than arbitrary “50% fuel” performance comparison.
If Turkish F-16’s were wanted to gain air superiority above Baghdat, they would need 2 EFTs for 25 minute loiter and 10 minutes combat. For return, F-16 would need ~70% of its internal fuel capacity. For the very same mission F-35 could take off clean, and would need 35% fuel for return.
So for an airforce, its F-35 with ~%90 fuel, vs F-16 @ DI = 100, 34000 lbs when entering Iraqi airspace, F-35@ 60% fuel, with F-16 100% internal fuel and ~15% external fuel for mid mission, F-35@ 35% fuel for F-16@ 70% fuel for return. For all these points, I don’t see how an F-16 could even approach F-35’s potential kinematic performance in any of these conditions, even top speed. Only IF F-16 drops its tanks, and climb above 30k feet, then F-16 can make M1.67 and beat F-35 in dash speed (not that it could make it back with available fuel at full AB anyway).
“same drag penalty”: This is a very big and rather baseless assumption. CFT on F-15C has little effect on performance. Only degredation that would worth mentioning is that it limits aircraft to M2.0, and that is a structural limit, not aerodynamic. Same could be said for F-16C’s CFTs, which comes with near zero effect to maneuverability or top speed. F-35’s design is not even CFT, but fully integrated into its aerodynamics from start. So logically, it should work even better than CFTs. And from another POV is Su-35 worse than F-15C because of its 1.8x fuel capacity?
Andraxxusre. the upgrades, no not really. USAF -16s and -15s are by and by large vintage stuff. Antiquated RWR, ancient radar and zero “sensor fusion”. Any wonder the F-35 would make them look like a clapped out old Lada versus a Rolls Royce in comparison of avionics.
I strongly disagree with such way of thinking. If its old, so what? It does the job. An F-15C with its ancient radar can easily effectively track a Typhoon at BVR ranges, and share data between any other aircraft or radar. An F-15’s antiquated RWR can still detect a Typhoon’s radar, and show it on display.
According to SAAB ( fighter producer that isn’t related to USAF or LM at all) , F-22, F-35 are much better than Typhoon, Rafale
They are trying to emphasize their cost effectiveness of their own fighter, with quite nonsense. So Grippen NG have more operational capability than Typhoon and Su-35? Can anyone propose one single operational criteria that Grippen even matches Su-35 or Typhoon in capability?
As for which is better, I don’t think anyone denies F-22 is currently the best A-A fighter around, only to be challenged by T-50 a few years into future.
The discussion is not about whether F-22/35 is effective in general. Debating usefulnes of dogfighting is different than the discussing the ability of aircraft to dogfight.
As for that usefulness of dogfighting; an analogy; is a king’s ability to move in all directions usefull in chess? king may be useless in opening or midgame but in the late game its one of the most powerful pieces. If both players’ skills are evenly matched so they cannot “checkmate” their opponent in early stages of the game, one who uses the king in offensive roles at the endgame can easily gain advantage over an opponent who doesn’t use his king at all.
Andraxxus@Isengard, I simply don’t understand your obsession with top speed, nor why you turn it into pissing contest with F-22.
If T-50 has somehow M2.6 top speed, it is a failure in designers’ part. Its a multirole fighter not interceptor. So IF design is M2.6+ capable, why not simply enlarge wings by, say, 20%? You get much better maneuverability, payload, range (due to increased fuel capacity), and a top speed still around M2.2. All of these would make T-50 much better fighter than a M2.6 version.
Or instead of performance oriented one, they can also chose a more economical solution: why not just remove the inlet ramps, reduce empty weight, and gain more internal volume for fuel? Better maneuverability, and range in a simpler design, which still have top speed around M2.0+, is still a better solution than your M2.6 fighter.
AndraxxusBut are they similar? Wing loading is comparable beause the F-35 has a huge fuselage. F-35A area of wings only ie without fuselage is roughly 24.5 m2, compared to the F-16s 20.5 m2. That’s a mere 20 percent increase for a 55 percent or so weight increase. Fuselage lift probably is less effective than wing lift isn’t it?
Yes and no. It depends on the design of the fuselage. Your point is valid, but nearly 30 years in advancement in aerodynamics and CFD should also make F-35’s fuselage a lot more efficient than F-16. In fact, to gain most internal space, using small wings and large lifting body fuselage seems to be the general trend in many latest UCAVs and also T-50 (If you compare T-50 with Su-27, T-50 has tiny wings (MiG-35 sized) too, but entire fuselage is carefully shaped and acts as a low AR wing)
All in all, such difference is relatively small, for example a 10% difference will translate to ~2 deg/s at sea level, and ~0,5 deg/s at 15 k feet. Maybe not enough to conclude which is better, but more than enough to answer whether F-35 can dogfight or not.
Why does it have to be a 360 deg turn? In real combat a 180 deg turn will suffice..
So that we can measure it? A sustained turn will end where it starts. 180 degree turn is difficult, can be mistaken with instantenious turn performance. A neat trick for airshow would be to stop turning after each 90 degree turn, make some rolls etc to look cool and gain lost energy during the process.
A few gun camera videos will disagree about 180 deg being enough; usually both aircraft turn several times before it is concluded.
AndraxxusAndraxxus, I think you are oversimplifying the F-22’s inlet as a simple pitot inlet, when that really doesn’t seem to be the case based on my observation of its geometry.
No, I’ve said just fixed. It may have some shock geometry. But these shocks will only at desired angles at certain Mach number conditions. If this design point is M1.637, it will be outside inlet at M1.636 or move towards the inside of the inlet at M1.638. If it was even possible to make it work for a small Mach range, no one would bothered variable inlets in the first place.
On the other hand, the F-22 has a 3D inlet that seems to be two-shock, but between the two shocks it has a compression ramp. Maybe djcross can chime in and correct me, but I think the benefit of this is that a compression ramp can be isentropic, which makes it the most efficient system possible, but the downside is that since surface geometry fixed, the isentropic compression can only be achieved within a certain Mach range
No, There is no such thing as isentropy in real life. Even adiabatic process is a mere simplification for calculations and doesn’t exist in real life. Compression is compression, entropy and heat is both scalar and material properties, geometry itself has no effects on either of these. More you compress, more heat and entropy you will generate this is not avoidable.
Range = not range, a point.
which makes it the most efficient system possible,
Only efficiency you can speak of is frictional losses in flow. From rectengular cross section to circular, compared to paralelogram cross section to circular plus S-ducts. Other than the improved CFD analysis F-22 potentially use, I see no reason F-22’s inlets should be more efficinent in that area too.
this range may be increased by using bleed vents to control the back pressure down the inlet.
Not directly. For such thing to work, You need bigger than needed inlet area, recover what you can and bleed the excess mass flow away. Maybe it will work for +/- M0,2 range at best. Does it sound efficent to you?
Again, since the F-22 inlets are 3D it’s more difficult to analyze via geometry compared to the more traditional ones like on the F-15. That said, since the T-50’s inlets are 3D there may also be things I’m not counting for.
2D vs 3D analysis is not for making one better than the other. Ideal inlet is circular, and requires 2D analysis on cylindrical coordinates, as used by most early aircraft.
Rectangular inlets and analysis on cartesian coordinates born due to necessity, as it allowed multiple ramps to move independently to control multiple shocks, which was not possible with circular inlets.
Now 3D inlets came out of necessity as both circular and rectangular inlets are bad for stealth. Its not necessarily efficent, (and has great potential to be more inefficient, due to difficulties in design and implementation) its just another method. F-35’s inlets are also 3D design.
For instance, I don’t know if the T-50’s inlet also has compression ramps between its shocks, and I’m not entirely sure if the T-50’s inlets are external compression or mixed compression
According to my mk1 eyeball inspection, T-50’s inlets attempt to change geometry from trapezoid to 2D rectengular without disturbing airflow, then compress it 2 inlet ramps. Which brings the question, if F-22’s inlets are nearly as efficient as variable geometry ones (not even talking about “more efficient” claims), why Russians would go such lengths to put variable ramps on T-50?
AndraxxusArent you forgetting something Andraxx..
Better WBW gives more unstable jet meaning better AoA handeling
True, but sharper controls and better handling does not improve aerodynamics in the end. When both Su-27 and Su-35 pilot pull stick all the way back I am sure Su-35’s FBW will reach its max turn rate several miliseconds quicker, but in the end Su-27 will still make the tighter turn.
Or when you climb to 16000 meters with high fuel load, all that matters is if your wings can carry the aircrafts weight or not. If can’t, then FBW wont do any good (other than safety of course). With added 1-2 tons to fuselage, and another 1 ton to feed relatively stronger engines, thats a sufficent weight difference from base aircraft to lower service ceiling.
AndraxxusOk, either way. I havent seen reports about the F22 being garbage in dogfights vs the F15 or F16. I’ve only seen that in comparisons with the Eurofighter (and in a video against Rafale).
There was a video with F-16’s gun camera and a T-38 too. Though none of that would even indicate that F-22 is worse than those aircraft, it is a clear proof for two things: A) that its not several times better (in kinematics) than the legacy aircraft as some analysts, pilots and generals suggest; even around 20-25% performance difference between F-4E and F-16 is always decisive. B) as those people have no credibility, there is no source of information right now which provides something reliable
If it is as you say that there are no vents or no internal parts in the duct to manage airflow then the max speed is substantially lower and I believe performance will also suffer. I just havent looked it up.
F-22 does have bypass bleed doors located at top of the fuselage, but definetaly no ramps or shockwave mechanisms to control oblique shocks like F-15 does. On other aircraft such bypass doors are mostly used to protect the engine from overpressure not to improve performance.
AndraxxusI think this video from Paris 2015 show quite a bit more than 18-19 deg/s. Scroll to 01:36, IMHO that’s at least 22-23 deg/s
Are you sure you posted the correct video/time? Only 360 turn was in :26, and took 23,8 seconds; gives ~15 deg/s.
thanks for the numbers on thrust, here’s the other part: wing load
1- Based on what fuel? A EF at full fuel can be easily matched by F-35 at ~50% fuel. Without comparing them within a specified range/payload its apples to oragnes comparison.
2- And wing loading alone gives us what exactly? Its only a trade off between Drag coefficient (which increases with AOA) and Wing Area, due to Cl is linear but Cd is exponential.
a) higher the wingloading, more efficient is the aircraft at minimal AOAs = at cruising, level flight acceleration, low altitude sustained turns, high supersonic medium altitude maneuverability etc.
b) lower wing loading allows less drag in thinner air when AOA is sufficently high (because greater A means less Cl is required, so less AOA which leads to smaller Cd) = instantenious turns, medium altitude subsonic maneuverability, high altitude maneuverability.
So with high wing loading, F-16 Trades off slight high altitude performance for slighly better low altitude EM capability. F-15 trades off low altitude performance to be stay efficent at high altitude. Just like F-35 and F-22 relation, I see nothing wrong about that.
About rather detailed explaination of wingloading:
Aircraft G load * Gravitational acceleration * aircraft mass = 0,5 * density * wing area * Lift coefficient * V^2. If you move wing area to opposide side;
Aircraft G load * G * Wing loading = 0,5 * density * Cl * V^2 ; Assuming we are comparing aircraft on equal basis, G, density and V^2 is equal so can be negelected.
Ability to pull Gs is inversely proportional to wing loading and directly proportional to lift coefficent of the aircraft. In other words, wingloading alone is meaningless without talking about specifics of the aircraft. If aircraft are mostly similar (so their lift coefficients is similar) Wing loading is an effective method for comparing.
For example. F-16C vs F-35A? they are similar enough to be *roughly* compared on wing loading alone. They have similar layouts, (probably) ballpark similar Clmax and L/D curves, so any ratio between them will at least indicate the performance difference. With little difference between T/W, T/D, Wing loading and other criteria, difference will logically be small.
But comparing Typthoon vs F-35A with respect to wingloading? There are too much differences between lift performance for such comparison to be valid; IDK about F-35 or Typhoon’s exact data but lets talk about other extremes;
A delta like Mirage 2000 at 50% fuel has 221,4 kg/m2 at 50% fuel. A Su-27 has 315,9 kg/m2 at 35% fuel. 42% advantage. Mirage 2000 is known to have Clmax = 1.0; A Su-27 is known to have Clmax = 1.85;
Assuming both fly at 300 knots (154,3 m/s);
M2000 G load = (0,5 * 1,225 * 1 * 154,3^2) / (9,8184 * 221,4) = 6,68Gs, translates to 24,1 deg/s inst. turn rate.
Su-27 G load = (0,5 * 1,225 * 1,85 * 154,3^2) / (9,8184 * 315,9) = 8,66Gs, translates to 31,4 deg/s inst. turn rate.
For comparison however, we dont need such calculation; Ratio between Su-27 and M2k: 185% lift coefficent divided by 142% wing loading = 129,6% ITR performance. Considering wingloading alone in this case would have mislead us to think Su-27 had 70% ITR of Mirage 2k.
So for dissimilar aircraft, wingloading alone is meaningless. Its like measuring the length of a room, but not width, and then claim longer room is always bigger.
Getting tired of people using wing loading as some magical short hand to gauge performance. The Su-35 has greater wing loading than the Su-27. Are we suggesting that it’s a downgrade?
Oh. wingloading is directly related to both lift and drag and IS a valid method to gauge performance. One just needs to be careful not to neglect other criteria which are equally important.
And for Su-35.. Su-35 doesn’t improve upon Su-27S’s aerodynamics, so it definately is a downgrade for some parameters. Su-35 will never, ever match Su-27S in instantenious turns. It won’t match its service ceiling either. Due to significant thrust increase, Whether it may or may not match it sustained turns or climbs is very debatable, and scientifically, depends on “where” it stays on the Cd0 curve of the aircraft. Such would require rather long calculations. I for one cannot say which one is better. My guesstimate? Su-35 will be better at high payloads, but when light Su-27S will be better. Su-35 will also be better at low altitude but Su-27 will be better at high altitude. In each case, performance difference will be slight.
AndraxxusEventually meet the old KPP threshold if and when F-35 get a MLU with an entirely new engine some 20 years from now you mean ?
No, when it enters service in a few years. You are underestimating the power of the single F-135 engine as it is;
F-15C weigh 13380kg, has 211 kN of thrust. It still is a master of high altitude maneuverability. Now, F-35A weigh 13200kg, and has 191 kN of thrust. Only 10% difference. I don’t really expect F-35 to be in F-15/Su-27 levels, its simply out of its weigh class, but F-35 as it is, has more thrust than Typhoon or Rafale.
Claiming “it lacks thrust” is not sufficent. Compared to what? F-16 or MiG-29? No, numbers are there. Su-35 or F-15E? True F-35 will, one day, need to face them in the air, but they are still not its competitor. By same analogy, an F-16 block 50 also lacks thrust and sustained turn rates before Su-35 or F-15E, with fuel/range figures come into consideration, even vs Su-27 and F-15C.
beats me how prediction went so bad but i’m assuming the changes and weight increase were made after KPP threshold were defined
I don’t know about the weight increase, but how light are you expecting F-35 to be? Typhoon is around 11 tons, has less thrust, and lacks half a dozen features F-35 has.
I’m not buying F-35 has negative stability, firstly i have not seen the wobbling (read crash) F-22 & Gripen displayed before tuned,
F-16 or Su-27 didn’t crash due to such wobbling either. (Su-27 did crashed during an impulse test but still). T-50 didn’t crash yet, and I don’t recall any incidents about Rafale or Typhoon either
i have also not seen the hyperactive control surfaces at subsonic to keep it in controlled flight,
Negative stability has nothing to do with “hyperactive” control surfaces. Such motion happens due to rapidly changing pilot inputs; See an F-5E group flying in formation during an airshow, you will see such movement. See an F-16 or Su-27 sustaining a turn, you will notice elevators pretty solid.
By all accounts F-35 is relaxed stable, as is any fighter aircraft designed after Mirage 2000. Even MiG-29 and F-15 is later redesigned in their lives with negative stability. So why should F-35 revert back to something abandoned in 1978?
and lastly why would anyone even want negative stability on an a/c intended to lug around bombs at subsonic speed
Improve range?
the most offensive part is the claim Sears-Haack were made obsolete with the invention of F-35
I don’t know how idiot one can be to claim such things..
AndraxxusI understand that one reason the F-35 was chosen was its “commonality” with the F-22. First, is this even true? Second, assuming that it is, is it really such a big factor? Third, seems to me that the money that will ultimately be wasted on the program will far outweigh whatever “cost savings” “commonality” may realize.
Perhaps they meant not part commonality but commonality with aerodynamic and engineering solutions of F-22? In the lines of producing F-20 from F-5E? So that -in theory- they would not need to reinvent the wheel, just modify it. In *practice* however F-18E or Tu-22M proved such modifications are just as difficult as designing an aircraft from stracth.
However, that’s rather a lot of assumptions.
Of course. However crosschecking with known data, making such assumptions known aircraft (like comparing Su-27 vs F-15 etc) can explain (or at least indicate) the actual performance differences. This applies true for almost all aircraft, why not the modern ones?
AndraxxusYes, but its neither, 6+ was objective, 5.3 was the threshold, but F-35 didnt meet threshold, it is 4.6G 50% fuel 15k ft for A
Well eventually it will. Even if LM actually targeted 5.3G thresold (and risk aircraft not get accepted) and miscalculated, there wouldn’t be 14% difference. Literally hundreds of engineers work at there and there is such thing as CFD. Speaking of features like my F-15/F-22 post.
-Both F-35 and F-16 blk50 have same wing loading
-Both F-35 and F-16 blk50 have same T/D assuming Cd0 and inlet performance is the same.
-Both F-35 and F-16 blk50 have same T/W assuming inlet performance is same.
-F-35 has DSI F-16 has fixed pitot inlet. By all reports, there was slight performance increse when DSI is tested on F-16.
-GE-132 has lower bypass so it should work better than F-135 at high altitude.
-Both aircraft have negative stability.
-Both aircraft have LE flaps, but F-35’s TE flaperons are way larger and Flybywire algorithms improved.
-F-35 is 25+ years newer so cd diagram should improve.
-F-35 has VLO concerns, F-16 is pure aerodynamic.
All in all, there is nothing to indicate F-35 should perform any worse than F-16 but people are clearly convinced it is *significantly* worse. (while on the contrary F-22 has IMO clear indications that makes it worse than F-15E, people have no problem believing F-22 is much better).
I repeat myself: if a plane that made its first flight in 2006 has only marginal advantages over others that went operative in the seventies…
In this case it seems it is even inferior, it seems.
Well my 0.02; There is just too much propoganda and assumptions with all the new aircraft. I don’t believe there is significant kinematic difference between 4th 4.5th and 5th gen aircraft. The problem is in the internet, one writes a report from his rear end. Another copies it, and another, and as a result it becomes the truth. And whats worse, if something is repeated too much by too many people, any indication to contrary is also rejected. Only undeniable hard proof will convince most (and even then, not all).
The consensus about F-22 is that its very good. All the indications to contrary (that its repeatedly defeated in BFM, its airshow turn/climb rates suck, and numeric guestimates) is merely ignored, or “disproven” by another copy of a copied report.
The consensus about F-35 is that its very bad. All the indications to contrary (numeric guesses and aerodynamic feature list) and the lack of evidence (F-35 is not tested, not in service, and not seen maneuvering in airshows) is ignored or disproven by “hot air”.
And worse, F-22’s alleged performance is now used as a benchmark to trash talk F-35 further. All logic fails there.
You know not long ago (10 years), every USAF guy and their devoted forum people were claiming Su-27 can only maneuver in airshows, and its maneuverability was real bad when armed. Even 3-4 years ago people, including some in this forum, were claiming Su-27 can only make sharp turns not sustain them. Half were only to be convinced by airshow videos and flight manual data, other half just quietly disappeared. And now, all the talk about F-22 or F-35? They are all to be proven wrong like these.
Both F-15A and F-16A demonstrated 24 deg/s turn in airshows, MiG-29A demonstrated 23deg/s and Su-27S demonstrated 26deg/s; all sustained for full 360 degree circle and within a few years into service. Note that those are ABOVE their 50% fuel STR rates (as they carry minimal fuel). If they are SO good, where are Typhoon, F-22 or Rafale videos? 10-14 years into service, and not one exceeded 18-19 deg/s. Technically an F-4E with minimal airshow fuel loadout can do 18 deg/s too. My point? If we are questioning manufacturer claims, and looking proof of high maneuverability, there are WAY more questionable aircraft around than F-35.
AndraxxusAndraxxus – Rather than comparing wing area, compare how big the wings are.
Sorry I’ve missed that. Why? “Wing area” is a corrected value which directly affects the lift performance and drag of the aircraft. Otherwise on PAK-FA for example, actual wings are slightly smaller than MiG-29, but planform area is real huge. If I were to look at planform area however, I would have to include a multiplier to take the degraded lift performance of the body into consideration; for that I don’t have a clue; IMHO, wing area is already given so its both more valid and simple.
Andraxxusrather it was to press the limits of the high AoA control laws and then report out the flying qualities in that regime, using various specified maneuvers. The Viper was there to make things dynamic and unscripted. Also, please note “elevated AoAs and aggressive stick/pedal inputs” are also preludes to departing an aircraft, so the evaluation of the effectiveness was how does the anti-spin logic effect high AoA BFM.
Irrelevant of F-16’s qualities, the statment above explains WHY this cannot be a dogfight and all comments about F-35’s sustained performance is nonsense; in simplest terms high AOA maneuvers and energy maneuverability is mutually exclusive.
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