What does drag do to an aircraft in flight?

Drag is a force that opposes an aircraft's forward motion through the air. When an aircraft is in flight, drag acts in the opposite direction to the flight path, creating resistance that tends to slow the aircraft down as it moves forward. Essentially, as an aircraft increases its speed, drag increases, which impacts the aircraft's ability to maintain its velocity.

Understanding drag is critical for pilots and engineers because it affects fuel efficiency, climb rates, and overall performance. By recognizing that drag slows down an aircraft, pilots can take necessary measures, such as adjusting power or attitude, to counteract this effect and optimize flight performance.