A sailplane has lost 2,000 feet in 9 nautical miles. The best glide ratio for this sailplane is approximately which value?

• A. 23:1
• B. 27:1
• C. 30:1
• D. 32:1

Answer: (B)

Glide ratio tells you how far you can travel horizontally for each unit of altitude you lose. It’s the forward distance divided by the altitude drop, and it’s a key measure of a sailplane’s efficiency at its best glide condition.

Here you’ve got 9 nautical miles of forward travel and a descent of 2,000 feet. Convert the forward distance to feet: 9 NM × 6,076 ft/NM ≈ 54,684 ft. Divide by the altitude loss: 54,684 ft ÷ 2,000 ft ≈ 27.34. So the best glide ratio is about 27:1.

In still air, that means the sailplane can cover roughly 27 feet of horizontal distance for every 1 foot of altitude lost, and in this case it’s about 27:1, which matches the given scenario.