The speed that yields the maximum lift-to-drag ratio in steady flight is associated with which performance?

The speed that yields the maximum lift-to-drag ratio in steady flight is associated with which performance?

• A. Best rate of climb
• B. Maximum maneuverability
• C. Minimum sink rate
• D. Best glide speed

Answer: (D)

The speed that yields the maximum lift-to-drag ratio is the one that gives the best glide performance. At this speed, the airplane achieves the most favorable balance of lift to drag in steady flight, so for a given altitude you can travel the farthest horizontally before you must descend further. Since lift equals weight in steady flight, maximizing L/D effectively minimizes drag at that lift, producing the smallest descent angle and thus the greatest glide distance. Induced drag is higher at slower speeds, while parasite drag grows with speed. Their combination creates a peak in L/D at an intermediate speed, which is why you get the maximum glide range there. Other options describe different objectives—best rate of climb is about excess power to gain altitude, minimum sink rate is about staying aloft the longest in a descent, and maneuverability relates to turning performance—not to glide distance.

The speed that yields the maximum lift-to-drag ratio is the one that gives the best glide performance. At this speed, the airplane achieves the most favorable balance of lift to drag in steady flight, so for a given altitude you can travel the farthest horizontally before you must descend further. Since lift equals weight in steady flight, maximizing L/D effectively minimizes drag at that lift, producing the smallest descent angle and thus the greatest glide distance.

Induced drag is higher at slower speeds, while parasite drag grows with speed. Their combination creates a peak in L/D at an intermediate speed, which is why you get the maximum glide range there. Other options describe different objectives—best rate of climb is about excess power to gain altitude, minimum sink rate is about staying aloft the longest in a descent, and maneuverability relates to turning performance—not to glide distance.