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No, that's not quite right. A stall means that the air has separated from the wing and the wing is no longer flying. The huge vortex created when a delta wing i

No, that's not quite right. A stall means that the air has separated from the wing and the wing is no longer flying. The huge vortex created when a delta wing is at high AoA actually causes the air to stick to the top of the wing, and this maintains control. I used to fly a 48" delta winged glider that had a catapult launch. The catapult would launch it at about 120mph. I could fly to about 300 feet in a nice vertical arc, but as soon as I yanked back on the elevons, the rather light plane would turn sharply and slow down significantly, due to the very effect discussed. A non delta wing would have been unable to maintain airflow over the wing because the high AoA (20-25 degrees) would have been far more than the 12-15 degrees that straight or swept wing can take. In other words, the Delta wing kind of acts as a giant vortex generator: https://en.wikipedia.org/wiki/Vortex_generator https://en.wikipedia.org/wiki/Vortex_generator

roelschroeven 4y ago
> A stall means that the air has separated from the wing and the wing is no longer flying. That's not quite right either. A wing doesn't stop flying when it stalls, i.e. when the angle of attack exceeds the critical angle of attack. What does happen is that the coefficient of lift starts to decrease instead of increase what increasing angle of attack, and with sufficient angle of attack the coefficient of lift can become too low indeed. A wing in stall can be flown, but it's tricky. Controls are inverted, natural stability of the plane doesn't really work anymore. It's not a situation you normally want to be in, but the plane does not suddenly fall from the sky.
- geocrasher 4y ago
  It's true. A stalled wing still has aerodynamic properties that can be used to keep it from falling out of the sky immediately, but in the sense of the OP's comment about a delta being stalled, my definition as used to explain the difference between the two holds up. The article referenced also talks about control inversion, interestingly. So yes, a stalled wing can be "flown" but not in the same way that the original question was referencing.
  - roelschroeven 4y ago
    Where does the article mention control inversion? I don't see any mention of it. We're not talking about adverse yaw thing, we're talking about the coefficient-of-lift-decreases-with-increasing-angle-of-attack thing.
    - geocrasher 4y ago
      Ha again you are correct. I was going on memory. You see, I've got a memory like a... Uh... Whatchamacallit

roelschroeven 4y ago

> A stall means that the air has separated from the wing and the wing is no longer flying. That's not quite right either. A wing doesn't stop flying when it stalls, i.e. when the angle of attack exceeds the critical angle of attack. What does happen is that the coefficient of lift starts to decrease instead of increase what increasing angle of attack, and with sufficient angle of attack the coefficient of lift can become too low indeed. A wing in stall can be flown, but it's tricky. Controls are inverted, natural stability of the plane doesn't really work anymore. It's not a situation you normally want to be in, but the plane does not suddenly fall from the sky.

geocrasher 4y ago
It's true. A stalled wing still has aerodynamic properties that can be used to keep it from falling out of the sky immediately, but in the sense of the OP's comment about a delta being stalled, my definition as used to explain the difference between the two holds up. The article referenced also talks about control inversion, interestingly. So yes, a stalled wing can be "flown" but not in the same way that the original question was referencing.
- roelschroeven 4y ago
  Where does the article mention control inversion? I don't see any mention of it. We're not talking about adverse yaw thing, we're talking about the coefficient-of-lift-decreases-with-increasing-angle-of-attack thing.
  - geocrasher 4y ago
    Ha again you are correct. I was going on memory. You see, I've got a memory like a... Uh... Whatchamacallit