What is a positive angle of attack when refering to planes?

Question

What is a positive angle of attack when refering to planes?

Answer 1

The angle of attack is related to the amount of lift. Lift will increase as the angle of attack is increased up to the point (usually around 17 degrees) where the aircraft stalls, the critical angle of attack

The angle of attack is the angle at which relative windmeets an airfoil. It is the angle that is formed by the chord of the airfoil and the direction of the relative wind or between the chord line and the flight path. The angle of attack changes during a flight as the pilot changes the direction of the aircraft. It is one of the factors that determines the aircraft's rate of speed through the air.

Answer 2

Angle of Attack is basically the airflow over the wings of an aircraft (lift):

http://en.wikipedia.org/wiki/Angle_of_At...

Answer 3

Angle of attack is the angle between the relative wind and the wing's chord line (not the airfoil).  A wing has many chord lines, often at different angles of incidence and having different angles of attack.  Where the chord line is angled above the relative wind, the AOA is positive.

Answer 4

Angle of attack is the angle between the wing itself and the air that is flowing around the wing. Lift is generally proportional to angle of attack.

During takeoff roll, the angle of attack is near zero. The wings are nearly level compared to the airflow passing them (note that I did not mention the ground - it is not important in this regard). When you reach takeoff speed, most pilots pull back on the stick to pull the nose up just a little. This changes the angle of the wings relative to the airflow. Suddenly, you are still moving straight forward, but the wings are angled slightly upward. The result is lift, and the takeoff is accomplished.

Again, the position of the ground has nothing to do with angle of attack. If you are flying inverted and have a positive angle of attack, you will "lift" downward toward the ground. You can also fly inverted and have a negative angle of attack, and therefore "lift" upward - relative to the ground. That's how aerobatic aircraft stay inverted for extended periods. If you maintain a steady positive angle of attack sufficient to result in the nose pitching upward, then you will perform a loop - with a positive angle of attack all the way over the top and down the back side.

Answer 5

Positive angle of attack is when your wing angle is rising relative to your flight path.  If your angle of attack is too high then your airplane will stall regardless of speed.  Usually, the faster you are going will increase your flight path vertically.  This is why some planes climb better than others.  

    When I was learning, I never understood how your angle of attack could make you stall regardless of speed until some one taught me that it is relative to your flight path.  So, if you are climbing almost straight up, your flight path is straight up.  If you exceed the critical angle of attack versus relative wind, then, stall..