Angle of attack
Angle of attack turns up in 2 fields: railroad, aviation. Here is what it means to the people in each one.
Angle of attack in railroad
The angle at which a wheel flange strikes the rail head while navigating a curve.
The geometric angle between the plane of a rolling wheel and the longitudinal axis of the rail. In tight curves, a rigid truck cannot perfectly align its axles with the track radius, causing the leading outer wheel to steer into the rail at an angle. A high angle of attack increases friction, causes severe flange wear, and raises the risk of the wheel climbing the rail and derailing.
"The track inspector noted heavy gauge face wear on the curve, likely from the high angle of attack of the six-axle motors."
Angle of attack in aviation
The acute angle between the chord line of an airfoil and the oncoming relative wind.
This angle dictates how much lift a wing generates. As the pilot pitches the nose up, the angle increases, creating more lift but also more drag. If the angle exceeds a critical aerodynamic limit, the smooth airflow detaches from the upper wing surface, causing the aircraft to stall and rapidly lose altitude.
"Keep a close eye on your angle of attack through this turn, you're getting dangerously close to the stall warning."