Thrust to Weight Ratios

[nrshida]

Aha! And since the velocity vector need not align with the thrust vector this explains how a wing varies it's lift and also its lift induced drag. Bingo. 

[bozon]

...
Then would this be the situation in a steady 45 degree 1 G climb:-
...

A steady 45 degree climb must have G<1. It is actually about cos(45)=0.7.

Alternatively, pointing up at 45 degrees and holding 1G will not be steady. The nose elevation will continue to increase.

[2bighorn]

A steady 45 degree climb must have G<1. It is actually about cos(45)=0.7.

That's why climbers, when climbing those vertical walls, float? cos(90)=0.  Congrats, you've just invented anti-gravity.

When we talk about how many Gs are we pulling, we actually talk about acceleration, change of direction of travel and opposing forces (inertia) expressed  in equivalent of G. But G is always the same (same for all practical purposes but in reality it changes just slightly, depends on the position between pole and equator and the distance from body causing the G).

[bozon]

That's why climbers, when climbing those vertical walls, float? cos(90)=0.  Congrats, you've just invented anti-gravity.

Thanks. I have a patent pending on that.

When we talk about how many Gs are we pulling, we actually talk about acceleration, change of direction of travel and opposing forces (inertia) expressed  in equivalent of G. But G is always the same (same for all practical purposes but in reality it changes just slightly, depends on the position between pole and equator and the distance from body causing the G).

hmm... I am not as smart as I thought after all, because I have no idea what you are talking about here. G, poles, equator, distance from body? 

[hitech]

That's why climbers, when climbing those vertical walls, float? cos(90)=0.  Congrats, you've just invented anti-gravity.

When we talk about how many Gs are we pulling, we actually talk about acceleration, change of direction of travel and opposing forces (inertia) expressed  in equivalent of G. But G is always the same (same for all practical purposes but in reality it changes just slightly, depends on the position between pole and equator and the distance from body causing the G).

This is a little incorrect.

If acceleration is 0 in level flight then g's = +1. If g is +1 when upside down at the top of the loop the acceleration would be approximately 64 FPSS. Hence the general term g and acceleration are not really interchangeable.

I understand what you are speaking of when referring to gravitational constants, but what I am referring to , is just general aeronautical definitions , not general physics definitions. The confusion stems from a plane relative axis system vs a world axis system.

G's, when speaking about air planes, is normally referring to the total FORCE in the direction of the lift vector. Not acceleration.

And yes cos(90) = 0, this is why in a vertical climb with no motor and no drag you are experiencing 0 g's even though your total acceleration would be 32fps.

HiTech

[PuppetZ]

And yes cos(90) = 0, this is why in a vertical climb with no motor and no drag you are experiencing 0 g's even though your total acceleration would be 32fps.

HiTech

Interesting. I thought a zero G situation was that of a freefalling object. So if I'm in a plane climbing straight up, I'll be weightless?

Edit : I really dont get it. Do you define a G in a plane as a force acting straight down on the floor of the craft in level flight? If so it does make sense as depending on the planes attitude, gravity is going to act differently on your plane. Then by that definition, we could say a plane going straight up is experiencing 0g relative to that imaginary line coming perpendicular to the floor. Yet the pilot and airframe will still experience gravity but along a different axis. Does that even make sense?! I'm kinda comfused by this discussion.

[nrshida]

So if I'm in a plane climbing straight up, I'll be weightless?

Only at the top for a moment I think when the thrust runs out of steam.

[hitech]

Interesting. I thought a zero G situation was that of a freefalling object. So if I'm in a plane climbing straight up, I'll be weightless?

With the correct throttle setting you would be feeling completely weightless/falling, or more correctly decelerating

Then by that definition, we could say a plane going straight up is experiencing 0g relative to that imaginary line coming perpendicular to the floor. Yet the pilot and airframe will still experience gravity but along a different axis. confused by this discussion.

This is correct.

Remember we are not speaking what total physics are happening, but rather what the common term "g loading" refers to.

[Stoney]

Remember we are not speaking what total physics are happening, but rather what the common term "g loading" refers to.

Hmm...  Perhaps I got this confused at that beginning.

[2bighorn]

I understand what you are speaking of when referring to gravitational constants, but what I am referring to , is just general aeronautical definitions , not general physics definitions. The confusion stems from a plane relative axis system vs a world axis system.
HiTech

Yes, but in real world ie instrumentation combines the two, hence accelerometer (G-meter) is calibrated to +1. This is for good reason because forces acting on airframe and forces acting on (detached) bodies inside the airframe aren't the same and body inside the airframe, at constant speed no matter the direction, will always experience +1G.

 

[hitech]

Yes, but in real world ie instrumentation combines the two, hence accelerometer (G-meter) is calibrated to +1. This is for good reason because forces acting on airframe and forces acting on (detached) bodies inside the airframe aren't the same and body inside the airframe, at constant speed no matter the direction, will always experience +1G.

The accelerometer will show zero when traveling vertical.This I have done 100's of times in real life. Even though we call it an accelerometer, it really is a force gauge.  The accelerometer works identical to if the bottom of your seat was a bathroom scale. So in the vertical you are only exerting force on your back or the shoulder straps, not on your seat. Hence the bathroom scale will read 0 just like the accelerometer in the plane does.

HiTech

[2bighorn]

The accelerometer will show zero when traveling vertical.
HiTech

Single axis G-meter yes.

[hitech]

Yes, but in real world ie instrumentation combines the two, hence accelerometer (G-meter) is calibrated to +1. This is for good reason because forces acting on airframe and forces acting on (detached) bodies inside the airframe aren't the same and body inside the airframe, at constant speed no matter the direction, will always experience +1G.

 

You have confused me what you are defining as 1g. Is your definition of 1 g, that an object orbiting the earth is experiencing 1g? I'm not debating, just want to know your G definition.

Because is sounds to me you are just saying everything is accelerated by gravity the same?

(approx, I understand the distance difference)

[2bighorn]

I'm just saying that the forces acting on airframe aren't necessarily the same as forces acting on a body (let's say pilot) inside the airframe.

[Vinkman]

With the correct throttle setting you would be feeling completely weightless/falling, or more correctly decelerating

This is correct.

Remember we are not speaking what total physics are happening, but rather what the common term "g loading" refers to.

been listening. Now I get it.