What does the term "Vx" refer to in aviation?

The term "Vx" refers to the best angle of climb speed. This is the airspeed at which an aircraft will gain the greatest altitude over the shortest horizontal distance. Pilots use this speed in situations where it is necessary to clear obstacles during takeoff or immediately after takeoff.

When flying at Vx, the aircraft’s lift-to-drag ratio is optimized for climbing over an obstacle, making it particularly useful in scenarios where impaired visibility or terrain requires immediate elevation. It is critical for pilots to be familiar with Vx and how to achieve and maintain this speed to ensure safe and effective obstacle clearance during flight operations.