Help me understand wing loading

Discussion in 'Pilot Training' started by Ryanb, Jul 24, 2020.

  1. Ryanb

    Ryanb Touchdown! Greaser! PoA Supporter

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    I’m pretty rusty on this subject. Need some clarifying and education on it.

    part of the POH for the Archer II says :

    B64B2993-1F53-4E92-B5C9-0E488AF06C36.jpeg

    So what are these numbers actually saying?
    As for wing loading, what is 15.0lb/ft^2 meaning?

    if I’m flying straight and level at altitude, how much weight are my wings supporting? If I roll the airplane into a 45deg bank, how much weight are my wings supporting then?

    thanks all
     
  2. dmspilot

    dmspilot En-Route

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    Two different topics really.

    Wing loading = maximum gross weight divided by wing area.

    Load factor in a 45 degree bank turn is 1.41, meaning the wings are creating lift equal to 1.41 times aircraft weight.
     
    Last edited: Jul 24, 2020
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  3. Lindberg

    Lindberg En-Route

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  4. dmspilot

    dmspilot En-Route

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    The turn doesn't have to be level.
     
  5. eman1200

    eman1200 Touchdown! Greaser!

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    math math math numbers numbers math.
     
  6. red4golf

    red4golf Pre-takeoff checklist

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    does it not? If I bank to 45 degrees and don't maintain altitude, do I really have that wing loading?

    *edit* maybe I didn't understand what you were trying to say
     
  7. Larry in TN

    Larry in TN Pattern Altitude

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    Higher wing loading will ride better in turbulence but need faster takeoff and landing speed which produces long takeoff/landing rolls.

    Lower wing loading will ride worse in turbulence but TO/LND slower/shorter.
     
  8. Salty

    Salty Final Approach PoA Supporter

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    It does to have the 1.41 load factor. The load factor only occurs if you remain level. If you allow the nose to drop as much as it wants to naturally, then load factor is 1, but you’ll be in a pretty brisk decent. If you allow the nose to drop but not all the way, you still won’t get 1.41 load factor, but something between 1 and 1.41.
     
  9. flyingron

    flyingron Touchdown! Greaser!

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    It just needs to not be accelerating upward or downward. A constant rate of climb or descent has identical wing loading as level flight.
     
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  10. dmspilot

    dmspilot En-Route

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    Wrong. When the vertical component of lift is less than one, weight will exceed the vertical component of lift which will cause downward acceleration. Such a condition doesn't last long (either the forces balance or you create an impact crater).
     
  11. Salty

    Salty Final Approach PoA Supporter

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    I have no idea what that means, but banking doesn’t magically make your plane weigh more, nor does it cause more lift to be created.
     
  12. dmspilot

    dmspilot En-Route

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    It's a good thing that I said neither of those things.
     
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  13. Salty

    Salty Final Approach PoA Supporter

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    So, if you’re not remaining level (or ascending), where is the Increased load coming from?
     
  14. dmspilot

    dmspilot En-Route

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    Increased load compared to what?
     
  15. eman1200

    eman1200 Touchdown! Greaser!

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    maybe you need more of a colloquial explanation
     
  16. Salty

    Salty Final Approach PoA Supporter

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    Possibly.
     
  17. PaulS

    PaulS Final Approach

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    All of it.
     
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  18. Larry in TN

    Larry in TN Pattern Altitude

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    If you are at 1g, you're at 1g. Doesn't matter if you're climbing, level, or descending. Add a bank angle without accelerating vertically and you're at 1g plus the increased load factor due to the bank.
     
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  19. Salty

    Salty Final Approach PoA Supporter

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    A turn is acceleration.
     
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  20. PaulS

    PaulS Final Approach

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    When the plane is banked, the wing still produces lift perpendicular to itself. So for explanation sake, let's say you are at a 45 degree bank, you have 0.707 of 1 g pointed straight up and 0.707 of 1 g pointed in the direction of the turn. If you leave the plane in this situation, 0.707 g of lift will not balance out 1g of gravity, you will descend. So you need to increase the lift of your wing, in this case, (if I'm doing the math right, I'm sure I'll be corrected if not) you need about 1.4 g of lift from the wing which will give you 1g in the up component, counteracting gravity and maintaining level flight. You will feel the extra gs in your seat.
     
  21. Salty

    Salty Final Approach PoA Supporter

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    That’s correct. But that can’t happen if you allow the plane to descend. You’ll still be at 1 g if you allow it to descend naturally.
     
  22. red4golf

    red4golf Pre-takeoff checklist

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    please define
     
  23. Salty

    Salty Final Approach PoA Supporter

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    It’s a basic rule of physics.

    https://physics.info/acceleration/
     
  24. dmspilot

    dmspilot En-Route

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    He said "without accelerating vertically"

    A turn is not a vertical acceleration, at least not the kind of turn I thought pilots normally talk about.
     
  25. dmspilot

    dmspilot En-Route

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    Descending does not reduce load factor. What is the load factor during straight flight in a 10,000 fpm descent?
     
  26. Salty

    Salty Final Approach PoA Supporter

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    1. However, if you continue to hold bank without touching the elevator you will continue to accelerate your descent. The “death spiral” if you will. Your load factor will not go up unless you pull on the elevator.
     
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  27. dmspilot

    dmspilot En-Route

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    Maybe completely true in an airplane with no stability, but only partially true for most airplanes. Airspeed will increase which does what to lift?
     
  28. PaulS

    PaulS Final Approach

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    Yes sir, until the ground rises up and smites thee.
     
  29. Salty

    Salty Final Approach PoA Supporter

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    True, there will be some increase in load. Good point. But it won’t be 1.41.
     
  30. dmspilot

    dmspilot En-Route

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    Regardless, my intention was to discuss an airplane in controlled flight, not one that is out of control.
     
  31. Salty

    Salty Final Approach PoA Supporter

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    Your statement that the turn doesn’t have to be level is wrong. For the load to be 1.41, the turn has to be level.
     
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  32. MauleSkinner

    MauleSkinner Final Approach

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    Or constant climb or descent.
     
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  33. dmspilot

    dmspilot En-Route

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    My statement is not wrong. Your statement is wrong. The turn does not have to be level.
     
  34. Lindberg

    Lindberg En-Route

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    True of everything in flight
     
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  35. MauleSkinner

    MauleSkinner Final Approach

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    Except overwater operations. ;)
     
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  36. Salty

    Salty Final Approach PoA Supporter

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    We are both wrong and both right depending on the frame of reference. The only difference is that I’m willing to admit where you were correct.
     
  37. dmspilot

    dmspilot En-Route

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    That's doubletalk and you haven't admitted anything.
     
  38. Salty

    Salty Final Approach PoA Supporter

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  39. dmspilot

    dmspilot En-Route

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    The load factor is equal to 1.41 in a coordinated 45° bank without vertical acceleration. No caveats about frames of references, whatever that is supposed to mean.
     
  40. Larry in TN

    Larry in TN Pattern Altitude

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    I think you are misreading my post.