jmccaul, this diagramm shows the flight limits of a plane. On the X-axis you have speed, y-axis shows the max. turn rate (degrees per second) that are possible.
A plane has several limits. It begins at slow speeds (letīs follow the blue line), here at ~78 knots. This is the limit of maximum lift-coefficient. The plane MUST fly right of this line, flying left is NOT possible, it would stall.
78knots is the stall speed at 1G, level flight. If you become faster (move right on the x-axis), you can fly MORE than 1G, that means you can turn without altitude loss. The Limit is not 1G now, follow the blue line up, and you see max Degrees/second increases AND max G-load what is possible with this airspeed.
So where can you turn fastest (for a short time of course) ? Itīs the crossing of the line of max. Cl and max allowed stress.
At 6G the line hits another limit, the limit of maximum allowed stress!
And at 303 knots there is another limit, the limit of maximum engine power. You can see that you MUST fly less than 303knots to turn, or letīs say: Whenever you fly a endless sustained turn, you canīt fly with maximum level speed.
(Note, the line goes vertical down. That means if you START a turn from max level speed, for a short moment you can fly 6G-turn. Of course you will slow down very fast, but you canīt see this here, because itīs a static diagramm, it shows only one single moment of a flight, and not how speed etc. will change)
The engine limit for this sustained turn is the blue line between the limit of stress and 0G (level flight). It says to you for every airspeed how fast you can turn. At max. level airspeed, like i said already, you canīt turn logically. the point for max. level speed is also at 1G. The slower you fly, the more power of the engine is avaiable to fly turns- until you hit the point of maximum lift of the wing, at 3G.
Hope that helps
niklas
[This message has been edited by niklas (edited 09-07-2000).]
