Benefits of the forward sweep !

This has been researched thoroughly ! It says here a modest forward sweep is good and prevents stall. Swept wing - Wikipedia, the free encyclopedia Sweeping a wing forward has the same effect as rearward in terms of drag reduction, but has other advantages in terms of low-speed handling where tip stall problems simply go away. In this case the low-speed air flows towards the fuselage, which acts as a very large wing fence. Additionally, wings are generally larger at the root anyway, which allows them to have better low-speed lift. However, this arrangement also has serious stability problems. The rearmost section of the wing will stall first causing a pitch-up moment pushing the aircraft further into stall similar to a swept back wing design. Thus swept-forward wings are unstable in a fashion similar to the low-speed problems of a conventional swept wing. However unlike swept back wings, the tips on a forward swept design will stall last, maintaining roll control. Forward-swept wings can also experience dangerous flexing effects compared to aft-swept wings that can negate the tip stall advantage if the wing is not sufficiently stiff. In aft-swept designs, when the airplane maneuvers at high load factor the wing loading and geometry twists the wing in such a way as to create washout (tip twists leading edge down). This reduces the angle of attack at the tip, thus reducing the bending moment on the wing, as well as somewhat reducing the chance of tip stall.[9] However, the same effect on forward-swept wings produces a wash-in effect which increases the angle of attack promoting tip stall. Small amounts of sweep do not cause serious problems, and had been used on a variety of aircraft to move the spar into a convenient location, as on the Junkers Ju 287 or HFB-320 Hansa Jet. But larger sweep suitable for high-speed aircraft, like fighters, was generally impossible until the introduction of fly by wire systems that could react quickly enough to damp out these instabilities. The Grumman X-29 was an experimental technology demonstration project designed to test the forward swept wing for enhanced maneuverability in 1984. The Su-47 Berkut is another notable example using this technology. However no highly swept-forward design has entered production. My question is since I have no idea how to count the spanwise lift hitting the fuselage benefits in span efficiency number wise, that is a moderate forward sweep 10% better than an elleptical wing or more in efficiency ? Is the efficiency doubled in comparison when flaps are used or similar with straight wing ? Iliyshin Il-28 was slightly forward swept winged ac ( 4 used as target tugs in FAF ); http://www.youtube.com/watch?v=lwNdeRuAdqQ several source says it had straight wing ? Refined copy of this actually; http://www.youtube.com/watch?v=YvpbpIn9Zrc Junkers JU-287 http://en.wikipedia.org/wiki/Junkers_Ju_287 The swept-forward wing was suggested by the project's head designer, Dr. Hans Wocke as a way of providing extra lift at low airspeeds - necessary because of the poor responsiveness of early turbojets at the vulnerable times of take-off and landing. Anyone with an answer to my 2 questions ?

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