Won’t they be more manoeuvrable in dogfights?

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    $\begingroup$ Please give us an idea why you think that a symmetrical airfoil would be more maneuverable. (Decades of engineering, test, and real world trial by fire has gone into current designs.) $\endgroup$ Jan 7 at 4:05
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    $\begingroup$ It can produce lift when flown upside down. And are mostly used by stunt planes. $\endgroup$ Jan 7 at 4:40
  • $\begingroup$ Do you have any evidence that fighter aircraft do NOT use symmetrical airfoils? $\endgroup$
    – MD88Fan
    Jan 7 at 23:57

Fighters don't really need or want to fly at negative Gs for any sustained amount of time. There is no tactical reason to do so, and it is very uncomfortable on the human body.

A short duration negative G bunt may be employed effectively as a defensive maneuver, but overall a fighter will always keep positive Gs on the airplane. The body can tolerate many more positive Gs, which results in better turn performance, plus you can actually see in the direction you are turning!

Therefore it just makes sense to optimize the airfoil for best turn performance at positive G loading. Aerobatic aircraft spend a lot more time at negative Gs so it makes some sense to help them out with a more symmetrical shape.

  • $\begingroup$ Does it mean that there’s no tactical meaning in fly upside down constantly and with asymmetric airfoils will make jet have a smaller turn radius with just the movement of the tail foil? But this brings up a question for me, is there any more ice for symmetrical airfoils as wings? $\endgroup$ Jan 7 at 5:30
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    $\begingroup$ Correct, no tactical reason to fly upside down constantly. To the extent that turn radius is created by lift, then yes, an airfoil with a better coefficient of lift will have a smaller turn radius. (There are some caveats I am probably missing with this generalization, and maybe one of the aero engineering pros can explain better.) I can't see any connection between symmetry and susceptibility to ice accumulation. $\endgroup$ Jan 7 at 6:33
  • $\begingroup$ Sorry for the typo, I meant is there any more uses for symmetrical airfoils? $\endgroup$ Jan 7 at 6:52
  • $\begingroup$ Well, when you want the forces to be symmetrical, like on a vertical tail, wing strut fairing, etc. For wings? The only advantage I see is enhancing the ability to fly inverted. $\endgroup$ Jan 7 at 6:57
  • $\begingroup$ Also you can't fire missiles from underwing and ventral stores at negative Gs, and only few fighters even have wingtip rails and there can obviously be only two of those. $\endgroup$
    – Jan Hudec
    Jan 7 at 9:24

What makes you think they don't. As the old saying goes "with enough thrust pigs fly just fine" To be serious, fighters also have to land and a little asymmetry would help at lower speeds, although I don't expect they use much, and it may only be a portion of the wing. The F-16 lands around 155 kts, so the wings are probably pretty symmetrical. Keep in mind that modern fighters fly at supersonic speeds and high altitudes and there are always going to be trade-offs.

  • $\begingroup$ Pretty symmetrical yep, but not quite! $\endgroup$
    – Noddle
    Jan 7 at 7:30
  • $\begingroup$ I concur they are not. And any trend towards symmetry would be to optimize performance at the air speeds, altitudes, and positive G loading they are designed for, and NOT a compromise to squeak better inverted lift out of the wing… $\endgroup$ Jan 8 at 2:04

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