Ah......the ole' egg. Know it quite well! I love scissors maneuvering!
You guys are way smarter than I am though!

USMCFLYR

I worked up the below explanation to explain turn rate and speed. It picks up where I left off answering Gestrich's questions. I only answered what is the relationship of speed to turning radius in my first post. It's really hard to explain this stuff using only words, so here is some math. I am not a whiz at this, I got all this out of an engineering textbook.

No you have not been out of the loop, immelmann, or Cuban 8 too long.

I made the statement earlier that for a given angle of attack, the radius is the same, regardless of airspeed. Think of a 3/4 inch drill bit...it cuts a 3/4 inch hole regardless of how fast you drill it. You can think of a particular wing as being a certain-shaped drill-bit...it makes certain-sized holes in the sky.

For this relationship to work, however, we are assuming all variables for that airplane have not changed. One that I cannot perfectly account for is tail-download. My best estimate is (for a fighter aircraft) the load is about 5% of the total lift in straight, unaccelerated flight, and as much as 10-15% when you are doing full-aft-stick, 9-g, "I've got to kill this SOB before he kills me!" ACM. I'm a mechanical engineer; Cubdriver is our resident aero, and could tell me if my ballparks estimates are about right.

Anyway, for me working backwards to calculate what speed equals the same AOA, I have to assume the tail-download into the equation, in order to figure the total lift the wing is generating.

Second, this 'constant radius for a given AOA' assumes I have the power to sustain said AOA regardless of speed or altitude. As USMCFlyer knows , this is not true (although a big-mouth Block 50 F-16 comes close). Generally, form-drag and parasitic-drag will become more significant at higher speeds, changing the radius slightly. At very high speeds, mach-wave will affect both drag AND Max Coefficient of lift...also changing it.

If you look at an EM diagram along lines of equal Ps, the radius is near-constant (which is what I am driving at).

Lastly, if I extrapolate these equations, I could (theoretically) pull 15 gs at 500 kts, and have the same radius of turn that I have at, say, 3 g and 300 kts. (I don't have a calculator in front of me, so don't hold me to those numbers....just for illustration).

But of course, my wings would have long departed the fuselage.

Point being, due to these minor variations caused by tail download and excess specific power, there is usually one point that is the best. But when I look at the airplanes I have flown, or fought against, as long as the configuration has not changed (ie, no flaps), the radius doesn't change much with changing speed.

Corner is where you can get:

1. Maximum allowable g

2. The slowest airspeed

If you are flying a utility category airplane with an allowable g of 4.4, you find the speed where it will be just about to stall at 4.4 g, and stalls if you try to pull 4.41. (Which means you didn't over-g your airplane).

Since you mention the egg (for those who don't know, it means a loop is not a perfect circle, but rather, shaped like an egg, with the pointy-part at the top), it illustrates that the top of the egg has a tight radius, even though you are slow and have little g to work with, because your g AND "God's g" (gravity) are both pointed in the same direction: DOWN. So, if this is what you mean by 'more positive turn performance,' I would say emphatically YES.

Conversely, the bottom of the egg is huge, even though you are typically pulling a lot of g and grunting like mad, because God's g is fighting some of what you are generating. And this is obviously 'negative' turn performance.

Incidentally, the horizontal/climbing turn/descending turn (pitchback/sliceback) could be described as also moving around the outside of the egg.

Ommlettes, anyone?

I'm glad I haven't be out of the O/DBFM that long - though my interests now lie more in trying to figure out how to do steep turns and smooth level offs in a King Air rather than nailing corner speed (which by the way does give us our max radius/max rate along with the other things that UAL mentions.

USMCFLYR

You answered my question...just trying to see if I semi-understand...

Over the top is more turn performance, then goes oblique turn, then horizontal.. except for the bottom of the egg where as it works in opposite order right?

Corner speed is akin to Va right?

So.. let me see if I have this right? ....

Max loading at corner speed will yield the best turn performance, where as going past corner speed increases the radius, decreases the rate (or structural failure at any higher G). Using oblique turns at the right time can allow you to keep cornering speed (if you lack the power)?

Possibly:

If you are above corner-velocity, and need to execute the quickest turn to something behind you (say, a bad-guy), you would start the turn climbing, to help reduce speed. Then, as you neared corner, you would over-bank and continue the turn while descending (assuming power was not sufficient to sustain your turn and speed).

Grade: A-minus. Move to the front of the class.

So who would have the advatage - the guy coming in with excess speed or the guy coming in right at corner velocity? An oblique turn would shorten the horizontal turn radius, but the guy who came in with at corner speed would have an angular advantage? Or is it the opposite?

Nose low turns at high G reduce speed deceleration right?

That is a good question. It would depend on the power available for those airplanes (assuming two of the same type, ie, equal).

If it was an airplane that could maintain or gain energy while max-performing at corner velocity (possibly a Block 50 F-16 or Raptor), then come in at corner.

If it was like most airplanes, ie, even full-power will not sustain the corner, then coming in fast and bleeding it down in a pitch-to-slice would be the fastest turn. (This means start with a climbing turn [pitchback] then transition to a sliceback [descending turn]).