Zero Gs. Does this hurt the plane?

Discussion in 'Flight Following' started by AdamZ, Dec 18, 2007.

  1. AdamZ

    AdamZ Administrator Management Council Member

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  2. EdFred

    EdFred Touchdown! Greaser!

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    If there is 0g on the frame, how much load are you putting on the frame? ;) Zero g is very easy to obtain, and can easily be done without even getting close to redline. Think power on stall, shove the nose over and pull the power just at about 1.2 Vs
     
    Last edited: Dec 18, 2007
  3. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser!

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    Even though an airplane is approved or certificated to do something, that something can cause wear, stress/strain, damage - so I think you are probably right, without seeing the video. Think 3 g landings!
    An examiner was telling me about people failing to unload the cj wing, before pushing over for an emergency descent demo - results in crinkled fuselage skin. :(
     
  4. SCCutler

    SCCutler Administrator Management Council Member

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    The video is just showing modest "pushovers" in a PA28, nothing outrageous at all. Biggest risk, in my opinion, is the vomit quotient.
     
  5. Teller1900

    Teller1900 En-Route

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    0 Gs, that's fine. -Gs, now that's where you can get into some trouble. But in a trainer like that or a Skyhawk, you have to go pretty far negative before you'll do any damage.
     
  6. Chairboy

    Chairboy Pre-takeoff checklist

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    I've done pushovers like this in my Warrior, but I've suspended it for now because I'd like to understand whether there's a chance I'm creating a lubrication-starvation situation in the engine. If I have zero or slightly negative G for a few seconds without an inverted oil sump, is that long enough for the sump to run dry and to create excess friction?
     
  7. Greg Bockelman

    Greg Bockelman Administrator Management Council Member

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    I would think an engine start, after not having flown in awhile, or on a cool to cold morning would cause more damage than negative G's for a few seconds.
     
  8. poadeleted20

    poadeleted20 Deleted

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    Zero-g is no big deal -- as noted above, no load is better than any load. The only issue would be how fast you enter/exit zero-g flight, as flexing can work-harden the wing spars, and that ain't good. So a smooth push/pull would be OK, but yanking and slamming could eventually cause problems. As noted above, the immediate issues would be nausea induction and all the grit and dirt coming up out of the carpet and getting in your eyes.
     
  9. tonycondon

    tonycondon Gastons CRO (Chief Dinner Reservation Officer)

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    its a lot more comfortable to do them in low wing airplanes because the engine driven fuel pump keeps fuel flowing, unlike a cessna were extended 0 g operations results in a little cough from the noisemaker up front.
     
  10. Diana

    Diana Final Approach

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    I get that nagging little cough too. :D So far, the engine has always started again. :yes: :fcross:
     
  11. RotaryWingBob

    RotaryWingBob En-Route Gone West

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    No biggie in an airplane. But you'll likely kill yourself in any helicopter with a semi-rigid rotor system :hairraise:
     
  12. jwriteclub

    jwriteclub Line Up and Wait

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    Obviously, don't exceed Vne. Also, a smooth entry and exit is a good plan.

    ~ Christopher
     
  13. jshawley

    jshawley Pre-takeoff checklist

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    Is my memory correct--Standard/Utility design criterion is -1.52g? I do know that it is a value other than zero...
     
  14. EdFred

    EdFred Touchdown! Greaser!

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    § 23.337 Limit maneuvering load factors.

    (a) The positive limit maneuvering load factor n may not be less than—
    (1) 2.1+(24,000÷(W+10,000)) for normal and commuter category airplanes, where W=design maximum takeoff weight, except that n need not be more than 3.8;
    (2) 4.4 for utility category airplanes; or
    (3) 6.0 for acrobatic category airplanes.
    (b) The negative limit maneuvering load factor may not be less than—
    (1) 0.4 times the positive load factor for the normal utility and commuter categories; or
    (2) 0.5 times the positive load factor for the acrobatic category.
    (c) Maneuvering load factors lower than those specified in this section may be used if the airplane has design features that make it impossible to exceed these values in flight.