In Flying - How Far are You from a Stall?

Speed - Load and a Stall

The lowest of the Angle of Attack means the same thing to many of us as "Speed." Slow flight, as covered before, means high Angle of Attack.

Another factor to consider about the Angle of Attack when you fly a plane depends on its load. If you load your plane up and need to maintain the same speed you need more Angle of Attack.

When you increase the Angle of Attack to compensate for the increased load to maintain the same speed you achieved at a lighter load you lose your reserve of lift. 

A stall occurs when your plane reaches the limit of its reserve of lift. Your load can increase only to that point where the maximum reserve lift limit is reached. At that point the plane will stall at the straight and level flight and speed.

Now, how does this apply to practical flying? The centrifugal force experienced in a turn or pulling up after a dive (g-forces) act like real weight or load that brings you and your plane closer to the maximum limit of your reserve of lift. 

Now you understand that, in a turn or pull out from a dive, the increase in weight does several things:

• Angle of Attack increases.
• Reserve Lift decreases.
• It approaches a stall even though the speed remains the same.

In straight flight speed and a sense of "lift" are the same thing. If a pilot can sense his speed he can also sense his lift. This is a definition of buoyancy. 

The tight turn centrifugal forces and g-forces in recovery from a dive can quickly turn into a stall. You must think ahead if you anticipate what can happen if you suddenly increase your load your plane carries.