Zero Gs. Does this hurt the plane?

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
 
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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. :(
 
The video is just showing modest "pushovers" in a PA28, nothing outrageous at all. Biggest risk, in my opinion, is the vomit quotient.
 
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.
 
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?
 
Chairboy said:
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?
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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.
 
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.
 
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.
 
tonycondon said:
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.
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I get that nagging little cough too. :D So far, the engine has always started again. :yes: :fcross:
 
Is my memory correct--Standard/Utility design criterion is -1.52g? I do know that it is a value other than zero...
 
§ 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.
 
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