What effect does the extension of trailing edge flaps have on an aircraft's glide angle?

The extension of trailing edge flaps increases the camber of the wing, which enhances lift at lower speeds. However, while this increase in lift can be beneficial during takeoff and landing phases, it also affects the overall aerodynamic performance of the aircraft in a glide.

When flaps are extended, the drag on the aircraft increases significantly due to the larger wing area and the changes in the airflow around the wing. This increased drag can lead to a steeper glide path, resulting in a degraded best glide angle. Essentially, although the aircraft is capable of generating more lift, the corresponding increase in drag reduces efficiency during a glide, making the landing approach steeper and potentially leading to a loss of altitude more quickly than when the flaps are retracted.

In summary, while extended flaps boost lift at slower speeds, they negatively impact the glide angle by increasing drag, thus degrading the best glide angle.