Originally Posted by obligatory
EF 311 kg/m^2
Rafale 326 kg/m^2
Gripen 336 kg/m^2
F-15 358 kg/m^2
Su-27 371 kg/m^2
F-22 375 kg/m^2
F-4 phantom 383 kg/m^2
F-16C Block30 430 kg/m^2
F-35 446 kg/m^2
MiG-31 665 kg/m^2
Boeing 747 727 kg/m^2
Originally Posted by Andraxxus
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.
http://forum.keypublishing.com/showthread.php?135460-test-pilot-quot-F-35-can-t-dogfight-quot/page11
Very good find, but i want to add that Gripen NG has much higher wingloading than Gripen C while using practically the same aerodynamic configuration
IMHO he probably estimated it from airfoil chracteristics or took information from soviet aerodynamic booklet
Sign In
