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By: - 12th February 2014 at 18:02 Permalink - Edited 1st January 1970 at 01:00
-Can do the Kessel run in less than 12 parsecs...
By: - 12th February 2014 at 20:11 Permalink - Edited 1st January 1970 at 01:00
Great.One more thread for another round of Russo bashing
By: - 12th February 2014 at 21:23 Permalink - Edited 1st January 1970 at 01:00
-Makes .5 past lightspeed...
By: - 12th February 2014 at 21:26 Permalink - Edited 1st January 1970 at 01:00
After flying every fighter type in existance, i have come to the conclusion that it just may be :)
By: - 12th February 2014 at 22:27 Permalink - Edited 1st January 1970 at 01:00
Other than the clearly superior instantenious turn performance, Su-27 is mostly comperable with other 4th gen fighters. In overall I would -subjectively- say "Su-27 is the most maneuverable 4th gen (due to numerical comparison), has some decent possibility of being more maneuverable than 4+ gens and 5th gens. (personal mk1 eyeball analysis)". It has great internal fuel capacity, and its heavy weight means less % drop in performance due to additional payload, i believe it will have edge when fuelled for same range and armed for same mission.
By: - 13th February 2014 at 01:40 Permalink - Edited 1st January 1970 at 01:00
Other than the clearly superior instantenious turn performance, Su-27 is mostly comperable with other 4th gen fighters. In overall I would -subjectively- say "Su-27 is the most maneuverable 4th gen (due to numerical comparison), has some decent possibility of being more maneuverable than 4+ gens and 5th gens. (personal mk1 eyeball analysis)". It has great internal fuel capacity, and its heavy weight means less % drop in performance due to additional payload, i believe it will have edge when fuelled for same range and armed for same mission.
According to you, to evaluate a high maneuverability aircraft, we need to focus on what parameters?
G-limit !
Turn radius !
Climb rate !
Roll rate !
Wing loading !
TWR ?
specs of engines (Max thrust & TWR of engines)
as far as I understand, TWR and wing loading are two parameters that need to be focused, TWR ratio is 0.9-1. And always low wing loading. From TWR (0.9-1 ratio) and low wing loading, we will have an aircraft maneuver
By: - 13th February 2014 at 02:03 Permalink - Edited 1st January 1970 at 01:00
According to that Red Flag video awhile back, the F-22 can sustain 28 degrees per second rate of turn, while the Su-30MKI sustains 22-23 degrees per second rate of turn.
There isn't going to be a large aerodynamic difference between an Su-30MKI and an Su-35.
Part of the problem he described was that the Su-30MKI's 3D thrust vectoring was set on a V-axis; it wasn't true asymmetrical thrust vectoring. This was great for instantaneous turning, but created a lot of drag which slowed the aircraft down.
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By: - 13th February 2014 at 03:26 Permalink - Edited 1st January 1970 at 01:00
Part of the problem he described was that the Su-30MKI's 3D thrust vectoring was set on a V-axis; it wasn't true asymmetrical thrust vectoring. This was great for instantaneous turning, but created a lot of drag which slowed the aircraft down.[ATTACH=CONFIG]225413[/ATTACH]
How do the thrust vectoring engines create a lot of drag? I'll probably accept certain level of loss of thrust through the vectoring nozzle, but drag? Really?
The primary factors for the sustained turning performance are wing-loading and thrust. Lower wing-loading means you need less alpha to execute the turn, less alpha means less drag squared, which means high thrust in excess. Almost all of the drag comes from the airframe where lift is generated, what little parasitic drag generated by the thrust vectoring nozzle is pretty negligible.
By: - 13th February 2014 at 04:49 Permalink - Edited 1st January 1970 at 01:00
According to you, to evaluate a high maneuverability aircraft, we need to focus on what parameters?G-limit !
Turn radius !
Climb rate !
Roll rate !
Wing loading !
TWR ?
specs of engines (Max thrust & TWR of engines)as far as I understand, TWR and wing loading are two parameters that need to be focused, TWR ratio is 0.9-1. And always low wing loading. From TWR (0.9-1 ratio) and low wing loading, we will have an aircraft maneuver
What you need to consider is Turn rates both instantenious and sustained to asses the horizontal maneuverability. Sustained climb rates or excess power is directly related to in line acceleration and vertical performance.
Other values are less of importance, without knowing specifics, they dont mean much. For example, Su-27 has higher wingloading than F-15, but it has an unbelievable 1.85 ClMax value while using ONLY automatic LE flaps. That will translate to much higher lift, and due to smaller wing area, also less drag. Same goes for F-16. It has even smaller wings, to minimize drag. Advantage is that F-16 have impressive sustained turn rates and in line accelerations at low altitude, but at high altitude it suffers from wing loading. Also we cant simply judge by TWR, because as long as we dont know how draggy aircraft is. AOA is also meaningless; Su-27 actually limited 24 deg AOA, while this looks inferior to MiG-29, for example, its ClMax is superior compared to 1.50 of MiG-29.
Considering all aircraft is fuelled with 50% fuel, Su-27 has an instantenious turn rate of 30,2deg/s which is superior to F-16 blk30's 26,2 deg/s, F-16 blk50s 24,8 deg/s, F-15C's 23,83 deg/s, MiG-29A 9.12's 27,2 deg/s, Mirage 2000's 29 deg/s and Grippen's claimed (but unconfirmed) 30deg/s. Its also superior to anything that can be observed from Rafale's Eurofighter's and F-22's instantenious pulls at airshows. Although they maybe flying on stricter g limits I dont know. (Before anyone say F-22 does some fast tricks, yes but rapidly changing AOA is not changing the flight vector. Time accordingly) To make the matters worse for the "opponents", Su-27 has much greater range with its 50% fuel. So to match the range of an Grippen with 50% internal fuel, it would only need around 28%. Difference in weight is directly proportional to G's aircraft pulling, which is directly proportional to the turn rate. In simpler words, under the same conditions a Grippen pulling 30 deg/s, Su-27 will have the capability to pull 32.9 deg/s. This, combined with relatively low wing loading and very high lift coefficient, will allow Su-27 to pull quicker turns that others simply can't without stalling.
Again with 50% fuel, Su-27 has sustained turn rate of 21,75 deg/s. This is inferior to F-16 blk30s unimaginable 23,0 deg/s, and MiG-29A 9.12s 21,9 deg/s, but superior to F-16 blk50's 21,5 deg/s, F-15C's 20,5 Mirage 2k's puny 18,9 deg/s and Grippens claimed 20 deg/s. Rafale have shown some comperable turn rates around 21-22 deg/s, but Eurofighter and F-22, never did complete a full 360 turn quicker than 20 seconds, translating to approx 18 deg/s. Again, they maybe going easy on the airframe I dont know. Same as above, 50% performance comparison is purely academic. For example to match F-16 blk30s combat radius, a Su-27 will require 38% fuel, and while doing so, it will also have pretty comperable 22,7 deg/s sustained turn rate.
with 50% fuel at sea level, Su-27 has 1G excess power of 305 m/s. This is inferior to F-16's ~320 m/s and MiG-29s unimaginable 345 m/s and F-15's ~315 m/s, but superior to Mirage 2000's 285 m/s. Once again above statment applies, if Su-27 were to match F-16's range, it would have 320 m/s or when matching MiG-29's it would have 330 m/s. This means in terms of non-maneuvering climb and in line acceleration performance, Su-27 is comperable to F-16, but inferior to MiG-29 and F-15, and superior to Mirage 2k.
That is talking about only sea level. With increasing altitude bigger winged aircraft like F-15 and Su-27 suffer less performance drop compared to smaller winged aircraft. I wont go into numbers there (as it would get too boring to read).
With ever incrasing mission demands, smaller types will be more effected by increased weight and drag. For example fuelled for extreme ranges (involving fuel tanks) and armed with 6 AAMs, an F-16 will be barely sustaining around 12 deg/s will have 19 deg/s max available turn rate, but Su-27 will still sustain 17,4 deg/s turn rate will have 25,8 deg/s ITR, and it will still be able to go M2.0+; imagine the maneuverability difference in a BVR combat. Sure F-16 can drop tanks, but that would be a mission kill for a long range CAP. Such advantage is always on Su-27's side when compared to specifically F-16, MiG-29 or Grippen, but also againist Rafale, Eurofighter and to a lesser extent F-15 and F-22 as well.
@Herp McDerp You are repeating exactly words of THE usaf colonel. However the fact that everything he said is BS; that does not change no matter how many times one repeat it.
-F-22 or any aircraft with present days tech cannot sustain 28 deg/s at 30k feet, not to mention carry 6 AAMs. A clean F-16 cannot even sustain 8 deg/s. With much superior wing loading, less drag and better T/W, PW220 engined F-15C can only sustain 8.4. I won't go into it futher.
-MKI may or may not sustain 22/23 but that is again at sea level. Su-27 can do 8.55 deg/s at 30k, MKI wont be much different than that.
Starting at 4:23, 28 deg/s sustained turn is something Su-27 barely does when extremely low on fuel, and on denser air (read: sea level) Even if F-22 can do this on sea level, waiting for your video response.
Part of the problem he described was that the Su-30MKI's 3D thrust vectoring was set on a V-axis; it wasn't true asymmetrical thrust vectoring. This was great for instantaneous turning, but created a lot of drag which slowed the aircraft down.
An utterly idiotic "problem" described by a colonel, with apperanly ZERO background of physics. On any *turn* which is done by using lift from wings, TVC nozzles will be locked at 0deg position to achieve the greatest thrust to overcome the drag, Even with Su-27 (or any variant) pulling its highest instantenious turns, or -non stall- minimal radius turns, this will be true by 100% certainity. As aircraft is relaxed stable, even elevators will have negative AOA relative to airflow (they MAY have positive deflection, but for example at 20 deg AOA, they will have 10 deg positive deflection and have 10deg negative AOA) and contibute to the lift and create little drag. What he is trying to say is post-stall maneuverability where TVC will be fully active. By defition, a stalled airfoil create incresingly more drag and less lift. This not instantenious turning as he claims, because aircraft is not turning, just nose pointing. This is very draggy, becouse millions of newtons of drag crated by the stalled wings, not the nozzles. It wont matter a bit if nozzles are II V X shaped or KLIVT-like omnidirectional. Even without TVC, as seen on Su-27 doing cobra, drag will be the same. Because drag comes from airframe not the nozzles, and applies exactly same to F-22, Su-30 or MiG-29OVT. The funny thing is, this as this is post stall maneuver. Extra drag is wanted. Ability is there, it can be used for a smart sharp turn or for an idiotic way to waste energy. Its up to the pilot.
Actually V nozzles are far more useful in dogfight than the 2d nozzles on F-22. All aircraft achive those numerically superior maneuvers very close to stall and departure limits. A 2d nozzle will stabilize a departure on pitch axis, simply cant to such stabilization: Start watching from 4:26 and look very carefully at 4:28 mark where TVC rapidly intervens to prevent counter-clockvise yaw departure by instantly turning to right.. Theoratically, rudders alone can prevent spin, but TVC does it much more sharply so that aircraft immedietaly start its horizontal maneuver. Such feature is absent on vertically mounted TVC.
By: - 13th February 2014 at 05:05 Permalink - Edited 1st January 1970 at 01:00
An excellent post @Andraxxus,
"That is talking about only sea level. With increasing altitude bigger winged aircraft like F-15 and Su-27 suffer less performance drop compared to smaller winged aircraft. I wont go into numbers there (as it would get too boring to read)."
Please do elaborate, i find it very interesting
By: - 13th February 2014 at 06:13 Permalink - Edited 1st January 1970 at 01:00
A few things regarding the F-22's acceleration. According to the 2010 SAR, the unclassified acceleration of the F-22 is 52.4 seconds from Mach 0.8 to 1.5 at 30,000 ft, apparently at full fuel.
By: - 13th February 2014 at 06:33 Permalink - Edited 1st January 1970 at 01:00
Why would it be at full fuel ?
normally it will consume fuel to get to 30k ft & M0.8
By: - 13th February 2014 at 08:14 Permalink - Edited 1st January 1970 at 01:00
A few things regarding the F-22's acceleration. According to the 2010 SAR, the unclassified acceleration of the F-22 is 52.4 seconds from Mach 0.8 to 1.5 at 30,000 ft, apparently at full fuel.
Very astonishing performance if it is true ~ Especially when you consider that it may take EF-2000 no less than 70 secs to achieve such kind of acceleration......
http://eurofighter.airpower.at/technik-daten.htm
Beschleunigung von Mach 0,9 (~951 km/h) auf Mach 1,2 (~1.267 km/h) in Tropopause: 40 Sek.
Beschleunigung von Mach 0,9 (~951 km/h) auf Mach 1,4 (~1.479 km/h) in Tropopause: 62 Sek.
By: - 13th February 2014 at 08:23 Permalink - Edited 1st January 1970 at 01:00
Very astonishing performance if it is true ~ Especially when it may take Eurofighter no less than 70 secs to achieve the similar acceleration......http://eurofighter.airpower.at/technik-daten.htm
Beschleunigung von Mach 0,9 (~951 km/h) auf Mach 1,2 (~1.267 km/h) in Tropopause: 40 Sek.
Beschleunigung von Mach 0,9 (~951 km/h) auf Mach 1,4 (~1.479 km/h) in Tropopause: 62 Sek.
I don't think it's really that impressive. A clean F-15E without CFTs (and maybe carrying 4 conformal AMRAAMs) will take 70 seconds from Mach 0.8 to 1.5 at 40,000 ft, so at 30,000 ft, it may be around 60 seconds.
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By: - 13th February 2014 at 16:14 Permalink - Edited 1st January 1970 at 01:00
How do the thrust vectoring engines create a lot of drag? I'll probably accept certain level of loss of thrust through the vectoring nozzle, but drag? Really?The primary factors for the sustained turning performance are wing-loading and thrust. Lower wing-loading means you need less alpha to execute the turn, less alpha means less drag squared, which means high thrust in excess. Almost all of the drag comes from the airframe where lift is generated, what little parasitic drag generated by the thrust vectoring nozzle is pretty negligible.
Thrust vectoring nozzles by themselves do not create drag. What creates added drag is the higher instantaneous turn rate, which TV allows for.
Wing loading alone is also misleading, since a lot of aircraft create additional lift via the fuselage. It isn't a 100% accurate figure either, since some aircraft with poor wing loading actually end up being more maneuverable than other aircraft with very good wing loading.
By: - 13th February 2014 at 16:48 Permalink - Edited 1st January 1970 at 01:00
I think altitude dictate ideal wing load, were the higher alt., the lower ideal wing load,
where everything else being equal, such as stability etc
By: - 13th February 2014 at 17:26 Permalink - Edited 1st January 1970 at 01:00
The comparison of wing-load and T/W ratio for anything other than a vague indication of potential turn performance can be highlighted by the controversy regarding the F-22's development. There were quite a few vocal critics proclaiming the F-22 to be a performance failure. The Riccioni paper being a famous example of how even a former USAF pilot can get it wrong.
The F–22 does not provide a Great Leap Forward in performance relative to the F–15C or MiG-29.www.dnipogo.org/fcs/doc/riccioni_paper.doc
At 65,000 lbs, with 18,500 – 18,750 lbs of fuel, with two nominal 35,000 lb thrust engines—it has the thrust to weight ratio of the F–15C, the fuel fraction of the F–15C, and a wing loading that is only slightly inferior to that of the F–15C, so it will accelerate, climb, and maneuver much like the F–15C for reasons of basic physics.There are two differences from the F–15—thrust vectoring and supersonic speeds in dry thrust. The thrust vectoring being in only one dimension, does not augment slow speed maneuvering; it serves another purpose.
The flight test program to validate maneuverability is utterly inadequate. Using a single number—the maximum steady-state G at 30,000 ft at 0.9 Mach, for an aircraft that operates from stall speed to beyond Mach 2, from sea level to above 60,000 ft, is a throwback to the Dark Ages of aircraft evaluation
The one point that is valid is using the single number of sustained g and 30,000 feet to validate the maneuver requirement. In reality, this is one metric where there is little difference between the F-15 and F-22 ( 3.7 g- although there is no indication of the fuel weight of the F-22 for this KPP. If it's 100% fuel and weapons, then that is impressive, if it's 50% fuel then there is little difference )
Riccioni went wrong for several reasons: 1. failed to take into account lift provided by fuselage, how massive size horizontal/ vertical stabs would improve agility 2. failed to take into account that the F-22 has lower drag 3. F-119 produced more power at altitude than the F-100 4. Underestimated the effect TVC would have on trim drag, supersonic envelope.
BTW, I don't think comparing aircraft turn rates at airshows is a valid method for comparing sustained turn rates. Most aircraft perform clean, there's no way to tell at fuel state, airspeed restrictions at different airshows, etc. Also, how can you tell it's a turn rate the aircraft can sustain? There is no way to eyeball if the aircraft is bleeding airspeed for higher rate of turn.
By: - 13th February 2014 at 18:46 Permalink - Edited 1st January 1970 at 01:00
BTW, I don't think comparing aircraft turn rates at airshows is a valid method for comparing sustained turn rates.
+10!
If you want to genuinely compare aircraft that are closely matched, you need access to the flight test data.
A few numbers can be indicative, but are unlikely to tell the whole story.
For instance, I round on the F-35 for its abysmal headline sustained turn rate - which raises the potential for disaster if air combat does not evolve as envisaged by the USAF - but I do recognise that it can get close to that with 4 AAMs and its instantaneous turn rate probably isn't too shabby at all.
[Albeit others like the Su-30MKI, Eurofighter and to a lesser extent the Rafale won't be drastically affected by carrying 4 AAMs due to carriage placement... and obviously the PAK-FA and J-20 are like the F-22 in that they don't really notice it.]
Posts: 194
By: blackadam - 12th February 2014 at 17:42
Su-27's family is the most maneuverable aircraft in the world?
-G-limits: 9G
-AoA: 33 degrees
-TWR: 1.23
-Speed: Mach 2.35
-Ceiling: 59,055ft (18,000m)
-Rate of climb : 300 m/sec
-Fly-by-Wire system
-Combat Radius: 1500km
-Low wing loading: 371 kg / m²
-Roll Rate: 270°/s
-Turn Radius: 28°/second
-2D/3D TVC engine for the version upgrade
Video: