NACA Airfoils

Discussion in 'Engineering Retrospective' started by squirl, Aug 16, 2005.

  1. HoHun

    HoHun FH Beta Tester

    Joined:
    Sep 22, 2001
    Messages:
    2,643
    Hi Squirl,

    >It seems that there are two sections of reduced elevator control. The A6M3 encounters the first section when its speed drops below 200 km/h IAS at 5000 feet. This section stretches from 200 km/h down to 175 km/h indicated. In this airspeed range if one pulls all the way back on the joystick and uses elevator trim to assist, he still can not get enough elevator response to stall the airplane. Below 175 km/h, the elevator control is still reduced, but it is now possible to stall the A6M3, very easily I might add.

    Thanks for the accurate description, that's exactly what's needed to check whether the the next Freehost A6M implementation is an improvement!

    >Because of this, I believe that there is still a problem in the Clmax of the A6M3.

    I see. I'll try to do some testing of the in-game Clmax, though that's a bit difficult as it's hard to accurately determine the point where control is lost (and the exact weight is not known, either :-(

    >Did you experience this when flaps were deployed? I know that, in real life, flaps move the center of lift aft and therefore require some extra elevator back pressure to compensate.

    Yes, I first noticed it in the Ki-44 when it came out, and then in the Me 109 in a later version.

    The movement of the center of list depends on the specific design, and the A6M apparently had it moving forward when flaps were deployed so that elevator effectiveness was not an issue. (Additionally, deploying the flaps reversed the function of the aileron tabs, making ailerons less sensitive so that there was no danger of overcontrolling during the landing approach. That probably indicates that the flaps were not used much in dogfights.)

    Regards,

    Henning (HoHun)
     
  2. HoHun

    HoHun FH Beta Tester

    Joined:
    Sep 22, 2001
    Messages:
    2,643
    Hi Vadim,

    >Why the fuck Zeke pilot should trim in the same situation?!

    Did I say it should, my over-excited friend? :)

    Regards,

    Henning (HoHun)
     
  3. HoHun

    HoHun FH Beta Tester

    Joined:
    Sep 22, 2001
    Messages:
    2,643
    Hi Roland,

    >Different planes require different amounts of trim change

    You're quite right! The real-world A6M even required a different direction of trim change, which according to Robert Mikesh was a smart way of avoiding control problems in the landing approach :)

    Regards,

    Henning (HoHun)
     
  4. hugo baskervill

    hugo baskervill Well-Known Member

    Joined:
    Sep 15, 2004
    Messages:
    824
    Location:
    Březnice u Zlína, Czech Republic
    flaps get worse elevator response at lo speed, it cause nose heavy and it is bad, you can easy test it on 109 or esspeciality with loops in ki84, ki84 hasn't special advantage with flaps. Now i use flaps only when i want decrease speed.
     
  5. Vadim Maksimenko

    Vadim Maksimenko Well-Known Member

    Joined:
    Feb 12, 2000
    Messages:
    15,468
    Location:
    Vilnius, Lithuania
    I thought, you discuss the matter in any relation to the game. If not, sorry for misunderstanding.