The Vertical Maneuvering Egg

[hawker111]

 

Here is a drawing of the vertical maneuvering egg:

My question is, even if a fighter did not loose a G going up, and gain a G going down, wouldn't the vertical turn still be egg shaped? Because the fighter will loose airspeed going up, reducing Gs, and gain airspeed going down, gaining Gs.

Thanks,

hawker111

 

[+streakeagle]

Imagine that air is a fluid like water. Now imagine that in water, your radius of turn is determined by the position of your rudder regardless of speed. If gravity didn't interfere, you held the stick back at a fixed angle, and you didn't stall before making it past the top of the loop, you would in theory make a perfect circle in spite of the speed changes. In reality, air is a little more "slippery" than water and a lot more than a car turning a circle with a fixed steering wheel position, but the principles is essentially the same. Somewhere online there must be a video of a stunt plane performing a perfect circular loop with both an outside view and a cockpit view so you can see how the pilot moves the controls to hold the circle. Before high thrust:weight ratio fighters, you simply dived to build up enough speed to hold the circle before stalling.

You will find that competition pilots use a combination of a visual reference and seat of the pants feeling to maintain a constant force/perfect circle. It does take practice to very the stick pressure at the right rate to hold the circle.

Edited January 24, 2018 by streakeagle

[+streakeagle]

These websites provide perspective on what it takes to avoid an "egg":

http://www.krepelka.com/fsweb/learningcenter/advancedflyingskills/aerobatics.htm

http://www.chegg.com/homework-help/questions-and-answers/illustration-shows-airplane-loop-fairly-low-speed-son-pilot-air-force-loops-500-mph-jet-pr-q10996085

http://www.planeandpilotmag.com/article/loop/#.WmgD6lUrJhE

http://www.hooked-on-rc-airplanes.com/aerobatic-maneuvers.html